How I got a $33 power bill with solar – even with a crappy 8c buy back rate

Update: This post was written in 2015. It is still worth a read to understand how solar affects your bill – but if you want to browse all my recent bills you can do so here.

I got my quarterly electricity bill last week. It was $33. I was so happy that I tweeted AGL.

AGL’s reply is priceless:

I’m guessing AGL don’t get a lot of compliments on Twitter! I also posted a scan of my bill on SolarQuotes’ Facebook page:

We are getting heaps of posts on our FB page along the lines of: “solar is a rip off – you only get 8c per kWh for…

Posted by SolarQuotes on Monday, January 19, 2015


Lots of folks said in the comments that they have a similar sized system and still have a bill of a few hundred a quarter. They seemed to imply that – unless you can get an almost zero dollar bill – that solar panels are not worth it.

My response to that is “Imagine what your bill would be like without solar!”. If you have a 5kW+ system, you paid a fair price for it, and it is working properly then you should be getting an excellent return financially, whether your bill is $33 or $330 per quarter. (If your bill is $3,300 per quarter and you have a 5kW solar system then you really are doing something wrong – contact me and I’ll do what I can to help)

The problem with calculating solar savings, once installed, is that the most of the savings are hidden from the electricity bill. The average solar owner has no way of knowing how much they are saving!

In this blog post I’ll show you how to expose those hidden savings.

Two Mistakes Many Solar Owners Make When Calculating Their Savings

First let’s get a couple of common misunderstandings out of the way which were repeated many times in the 98 comments on the Facebook post:

1) Many people don’t realise that the miserly $0.08 Feed In Tariff is “Net”. It is not paid for every kWh generated by your solar panels. It is only paid for the solar energy you export. If you self-consume the solar energy in your house you are saving much more: around $0.31 per kWh at current electricity pricing. (If this makes no sense I explain how exports work here)

2) Your solar savings are a lot more that the part of your bill that shows a credit for solar electricity! Here’s that part of my bill highlighted in yellow:

my post-solar electricity bill

The red pen shows how much my bill was credited due to exported solar energy.

You can see that I got a credit of $196.5 for my 3 months worth of exports. Many people read this as:

“Hmmmm. $200 savings every 3 months. That’s only $800 savings per year. The bloody salesman said I’d save over $2,000 per year! What a crook! My $8,000 solar system is gonna take 10 years to pay off before I start seeing any return on my investment! Solar is a complete con!”

This common analysis is wrong on a number of levels. Firstly it is wrong because your savings with solar panels are a lot more than simply the value of your exports. Although it is invisible on AGL’s bill, most of my savings have come from all the kWh’s I haven’t had to buy from AGL at $0.31 per kWh.

So how do I work out how much I have saved through ‘self-consumed’ solar energy? Unfortunately it is not easy! The first thing you need is a good Energy Monitor. I use one called a Wattson which cost about $200. This allows me to measure the total electricity usage of my house before any solar energy is taken into account. When I plug it into my computer I can download my usage and generation in 5 minute intervals.

Here’s what that looks like on a typical Summer’s day (you can click the graph for a big interactive version).

Finn's House - Electricity Usage Vs Generation - Feb 3 2015

How to read this graph:

The blue line shows my power usage over 24 hours. Midnight to midnight.  The spikes just after midnight are the dishwasher heating the water and then drying the dishes at the end of the cycle. We put it on a timer because it is noisy!You can see the house start to wake up at 6am. Energy is used throughout the day. Mostly it is the clothes washer, dishwasher, oven (cakes!), computers and rainwater pumps.We put the kids to bed at 7:30pm and energy use falls off.

Calculating My Savings

Looking at the graph: if the orange line is above the blue line then we are generating more than we are using. Any electricity being used at these times is self-consumed solar energy. I’ve shown this energy as green below. Any excess solar electricity is exported. This is the yellow area below. The red areas are where I have to import from the grid.

graph of energy usage in a solar home

Imports, exports and self-consumption.

The total amount of energy used by my house in the 24 hours is the area under the blue line (red + blue areas). I can work this out in a spreadsheet and it comes to 13 kWh.My spreadsheet tells me that 10.33 kWh of that is the green area. This is my self-consumed solar energy. At $0.31 per kWh it means that I am saving $3.20 per day with self-consumption.My exports on this day (the yellow area) add up to $2.51 ( 31.4 kWh x $0.08 ).So most of my savings are coming from self consumption.The total savings for the day are $5.71.If I extrapolate this to the 93 billing days and take into account that some days were overcast, the savings come to about $500 for the billing period.

If I extrapolate this to the full year (taking into account that winter generation is lower) then the savings for a whole year come to about $1,900.

Is $1,900 per year a good return on a 6kW solar system?

A good 6kW system, at the time of writing (Feb 2015), will cost you about $10k installed.

So $1,900 of annual savings is a simple payback of just over 5 years.

And this is where we come to another misconception about the returns from an investment in solar power. Many folks believe that a payback of 5 years means that they see no financial benefit for 5 years.  This is wrong, wrong wrong! We need to take cash flow into account. When you work out the actual cash flows, many folks find that they are actually losing money not having solar panels! (Oh dear, I really am starting to sound like a sleazy salesman – sorry – but please bear with me because this is true!)

Working out the simple cash flow for a $1,900 per year return on a $10,000 spend.

Most people either pay for solar out of savings or add it to their mortgage.

If you have $10,000 in the bank right now it is probably earning about 4% interest. Let’s call it 5% to make the maths easy.

If you add $10,000 to your mortgage you are probably paying about 5% interest on it.

Either way you have an “opportunity cost” or “cost of finance” of 5%, ($500 per year) if you splash $10k on buying solar power.

But outweighing this is the $1,900 per year I am saving with solar panels.

Imagine a machine where you put $500 in and got $1,900 out. That’s what I’ve got on my roof. You gotta love solar energy.

Things that may reduce (or increase) your returns.

Please let me be clear – this is not financial advice. I am simply going through the savings of my solar power system, and looking at it in terms of both payback and cash flow.

If you buy solar panels, the returns will depend on how much energy you use and when you use it. They will also depend on the quality of the system. An el-cheapo system that seriously degrades or fails in the first few years is not going to give you good return!

If you are buying solar, ask the salesperson to show you the maximum and minimum savings. Any good salesperson or installer will be happy to do this. These savings are calculated using 0% and 100% exports respectively. Your return will be somewhere between these 2 numbers based on how much you export in the real world.

When I did the maths, before buying my solar panel system, my minimum savings were $700 and maximum $2,700 per year. I guessed that I would lie about halfway between those 2 extremes and it turns out I was right. But I spent my money with confidence because, even if I only saved $1,000 per year, I knew the system would be more than paying for itself based on current interest rates.

If you want to explore what return you could get from a solar power system on your roof, you can get 3 quotes (with estimated max and min returns) from my website.

About Finn Peacock

I'm a Chartered Electrical Engineer, Solar and Energy Efficiency nut, dad, and the founder and CEO of I started SolarQuotes in 2009 and the SolarQuotes blog in 2013 with the belief that it’s more important to be truthful and objective than popular. My last "real job" was working for the CSIRO in their renewable energy division. Since 2009, I’ve helped over 700,000 Aussies get quotes for solar from installers I trust. Read my full bio.


  1. Bill Mastrippolito says

    Another way to work out your self consumption is to read your inverters total power output every time your electricity meter is read. From there you can see how much you have produced and subtract how much you have fed into the grid.

    • Finn Peacock says

      Great point Bill – you don’t need to buy an Energy Monitor if you do that

      • Or, as I do, read your inverter every evening when production drops to below 100 watts (day’s production & total & hours).
        The read your meter (for total/daily total exported) which (compared to the inverter figures) will tell you how much you used and how much you exported.

        Also from your meter read the total/daily total for peak/off-peak imports, which will tell you how much you imported.

        It takes me about 2 minutes to enter all the values, and can be used to make any sort of calculations you want to make, including comparative periodic/yearly averages of power coming and going which can be used in all sorts of ways ~ including how much money you’ve made. (In 5 and a half years I’ve never had a debit ~ and average $1600 pa. cashback after costs (service gst etc.) ~ but NOT including the value of home-production I’ve used before it gets into the grid …which would also be easy to calculate.
        A bonus if daily is that any discrepancies show up immediately:- like the lights left on in a shed I might only get to weekly, or a curcuit-breaker flipped out isolating a whole string of panels.

        ….and the cheerful feeling you get every evening when you quickly, mentally figure out how much you’ve profited for the day is beyond a $-value!. In 5.5 years there have only been TWO days on which production hasn’t at least paid the costs.
        Disadvantages? Every so often my dogs eats my bloody pencil!

    • Those who have installed an Enphase PV System including Enphase Storage B
      atteries where installed get an On Line Browser Interface and/or an iPad Application downloaded from the Apps Store interface called MyEnlighten that reports [Australian implementation] in 15 minute time slices the kWh for PV Production, Export [FIT], Consumption and Import all supported with a range of appropriate daily and monthly reports.

      There is also a Free to Use web enabled application accessed via a browser interface called that performs all the analysis and cost calculations based on manual, downloaded file in *.csv format or Automatic Upload via in our case the Enphase API. This particular automated process has interfaces with a significant number of systems that support API connectivity.

      If you take the time to review at least the pvoutput system I think you will find that all you ever wanted to know about your systems performance is capable of being answered. Not only that but he application will display the performance of systems in close proximity for those users who have made there data available in the public domain. One of the magic numbers for gauging system health is the current kWh Production per kW of System compared with other systems in close proximity.

  2. Hi Finn,

    While you’re right that people often miscalculate their savings by not understanding the basics, which you’ve nicely laid out, I think comparing the $500 opportunity cost with your $1900 doesn’t work.

    Why? Because the $10K in the bank paying 5% is still there at the end of the term, while the solar power system at the end of its ‘term’ is valueless. This is a big difference!

    Because of this, payback time which includes opportunity cost is probably the ‘truest’ way to figure out the finances. And added level of complexity to what you’re trying to keep simple…

    • Finn Peacock says

      Hi Greg,

      I see where you are coming from – but I disagree. The non-solar owner will have to pay much higher electricity bills than the solar owner. This cash has to come from somewhere, and will more than eat up his interest payments, eating into his initial sum.

      But I agree the calculator should have show this better.


      • If you pay yourself $1000.00 per year from your profits , in 10 years you will have your capital back and you are still $400.00 per year in front after interest is paid .

      • Russell marsh says

        Hey finn,
        I have had a 5kw system installed 2 weeks after my last bill reading and have now almost double my usage ???? previous bill 24kwh per day, now with solar installed 45kwh per day ???any advice?

        • Finn Peacock says

          Who was the installation company?

          • Russell marsh says

            alpha regional, I have spoken to them and they think the electrician may have wired something wrong or configured the new meter wrong so getting it checked.Alpha have a great monitoring system of my install and all there info is saying opposite to my bill (daily average about 12kwh) they say they will talk to power company about a refund once we work out what has happened. I ask you as possibly you have come across this before and may have some helpfull input as to why this is happening? It seems the feed in and house usage of solar power is being added to my grid usage readings.

    • Minus inflation, which works very strongly in favour of Solar. As your rate of return will increase as your cost per KWh increase while your capital cost stays fixed at todays prices. Whereas your real return on fixed interest after inflation is only 1-2%. The rest you have to reinvest otherwise in 10 years your 10k wont buy you a big mac.

    • Quentin Bell says

      We installed a solar system 5 years ago and are nowhere near breaking even. The inverter has packed it in and would cost $1800 to replace putting us further behind and makes the installation of solar panels unviable if thisoccus every 5 years. Added to which the installer, Planet Power, told us that our system wasn’t big enough for any real benefit. A pity they didn’t tell us this when it was installed. So for would be solar energy users think about the cost of maintenance and if you decide in favour buy from a reputable installer

  3. Laurie Dobson says

    I have solar and received a power bill from Origin.
    The bill came to $158.73 for 07 nov 14 till 05feb 2015.
    Solar contribution was $21.66 for that period a total of 361 kWh .
    Why am I not receiving more payback for solar .

    • Finn Peacock says


      You are only getting $21.66 for solar exports for one of 2 reasons:

      1) Your solar system is not working correctly. This article will help you work out if this is the case.

      2) Your system is performing fine but you are self consuming a large proportion of the energy – as described in detail in the post above. if that is the case they you are saving heaps with solar – it is just not shown on your bill (as described in the post above).

      Hope That Helps,


  4. We found that by setting our dishwasher and washing machine to work during the day, it amounted to large savings. We rinse all our dishes or run the dishwasher on a quick 5min or so rinse cycle if required. (There isn’t much difference to leaving it until after midnight or till the next day, especially if they are clean).

    Anything you can do during the day, set it for then, you can save a lot by doing it on solar, try to stagger things also, don’t run the washing machine dryer dishwasher and other hungry appliances at once otherwise you may be drawing from the grid if you go over your solar production. Our bill dropped by around $100 a quarter by setting timers on appliances and using them during the day.

    • Finn Peacock says

      Great advice – thanks John. I agree, the “return-on-effort” for simply putting appliances on timers or changing your habits is huge when you have solar.



      • Peter Paynting says

        Since installing my solar system, my wife has altered the times she does the washing so that it is always done after 9am when the sun is actively generating power. For her, washing involves the washing machine, clothes dryer and the ironing at the same time. This is invariably powered by the solar system. I also record my inverter and meter readings morning and night so I know how much power I produce, how much power I consume and how much power I export (average 15kw per day).

    • Too true. But you might realise ever bigger savings if you run your dishwasher, washing machine, vacuum, etc. off a small demand/remote-start generator.

      I think it’s the overall totalisation of lotsa small savings that make the difference.

    • Peter Burns says

      This is the ideal , but in reality FALSE. The timer is good- wonderful if you are a dill that has a TOU Smartmeter. HOWEVER the touch switches used on todays washers, dryers, dishos for the past 4 yrs ARE NOT ( set timer) and push on for later use. The switch must always be powered. I read my Integral supply contract – I have Controlled load 2 ( OP2) on Domestic contract- This means I can apply to connect dishwasher, dryer, washer, poolpump at OP2 rates. The power comes back on at 10pm- I CANT set the disho or washer to come on at 10pm after Ive gone to bed as the power doesn’t power up the appliance switch circuit. If you had old rotary dial switches and flip switches Ok BUT NOT the modern ones. Caught OUT JOHN telling switch PORKIES.

      • Dont know about your appliances, but my ancient dishwasher (electrolux – cant tell what model because it;s worn off) and washing machine (Simson front loader, about 6 years old) both have a delay mode that lets you set a delay for when it will start – in 2 hour increments for my dishwasher, and in 30 min increments for the washing machine.
        Just use that function to delay the start by a few hours when you set the appliance on before you go to work.

  5. Hi Finn,
    I love my solar panels, I actually look forward to getting our bill as it’s been in credit ever since we had the solar panels installed. I’ve always thought I had a self consumption benifit but never thought of putting a figure on it. Out of interest I figured your self consuming ~24% of your total production which is probably a little low given the 8c buy back. From my last bill I calculated our self consumption at ~8% which is not bad considering my 55c feed in tarif. My supplier also gives me a 5% ‘pay on time’ discount for an account that is always in credit; their accounting system is clearly not designed to run backwards.

    I figure our 4.5kw system is worth $3,030 a year to use. Thats a pay back time of 2.4 years for an initial investment of $7250. Over ten years our initial outlay of $7250 will be worth a little over $33,000. Try beating that with bricks and morter or the share market!

    Another benifit that often goes un-noticed is the shading affect. Our system covers a fare portion of our roof and the temperatures in the bedrooms affected have been reduced by 2-3 degrees.

    Love my solar panels.

  6. Peter Burton says

    How long do solar panels last? You won’t save much if they die in 10 years, like the earlier ones did. Do they progressively generate less each year of service? I see where some companies are offering 25 year guarantees. Has the technology improved that much in the last few years, or don’t they expect to be around when you claim? What about Winter? Not much power being generated then. A friends early model 1kw system generated zero for months. If you averaged it out, it generated 2 kwh per day over 12 months, but all of that was in Summer. Up to 6 kwh on a good day. Didn’t get paid for exported power either, which did happen in the middle of a fine day and no one home, just the fridge. Was told he wasn’t a premium member, whatever that is.

    • Finn Admin says

      A good quality panel should last 25-40 years. Some manufacturers offer a 25 year manufacturers warranty on the panel, others 10 years with a 25 year performance warranty.

      A crap panel will last 2-10 years.

      • Peter Burton says

        Thanks Finn. Would you mind addressing the questions about how much do the panels generate in Winter, and do they progressively produce less each year of service? You say they last 25 -40 years. That’s a bit open ended for me. I presume they don’t die suddenly, so what happens when they’re getting towards the end of their life? Thanks, Peter B.

        • Finn Peacock says

          Hi Peter,

          A good solar panel should degrade at less than 0.5% per year. Most solar panels are guaranteed to generate at least 80% of their original power after 25 years.

          A good, Tier 1 solar panel should last 35+ years. But you will always have the odd premature failure.

          Generally they degrade slowly. Although if there is mechanical failure (water ingress or broken wires etc) they can stop completely. Although you can always bypass or replace any failed panels.

          Hope That Helps,


        • I put my first panels up ( 45-watt Unisys ~ second biggest ones you could buy) over 30 years ago, and they were second-hand when I got them and cost me $13.80 per watt. Used them for 20-odd years and gave them to a mate up in the mountains*, who is STILL getting 38/40 watts out of them on a good day.

          Despite the allegedly “cheap chinese crap”, I expect that today’s technology is hugely better than it was then (MOST certainly the case with inverters/regulators, etc.) so my guess would be that YOU’LL cark it long before your panels do.
          How’s that for a win/win proposition. 😆

          (the six smallest ones are the panels I gave her years ago.)

        • Sandra Lemming says

          I just have to share this. My first husband and I installed the top of the range solar hart hot water system 30 years ago on our roof. Back then it was only hot water systems and the tank went in the roof. We chose the best solar panels money could buy which were referred to as black chrome panels. We shaved 200 dollars of our quarterly electric bill which meant we were only paying between 20 and 30 bucks a quarter for the fridge, lights etc.

          My point being 30 years later the hot water system is still going strong and still saving the new home owners money. The other benefit was the actual resale value having the system had added to the home which we never even gave a thought to at the time. Back then that hot water system cost us just over $15,00 dollars but what we got back in terms of saving in our bills and investment in property value equated to a lot more.

          With fossil fuel usage looking to decrease dramatically in 10 years and carbon taxes hitting developed countries going up then from just an investment in the re-sale value of your property doesn’t going renewable energy sources make sense.

          • Hi Sandra, I found your story interesting as I too installed a “black chrome” Solahart hot water system in 2002, with tank and panels on the rooftop. It really did me well in sunny times but it boiled in 30 degreesC temps and we lacked hot water in winter so had to top up, but it was a very economical unit to run.
            That was until the ends blew out of the tank AND all the glycol drained down the roof and into our new rain water tank! Woe was I with it just out of warranty and insurance said it was a maintenance issue so wouldn’t pay a cent. My plumber somehow wangled another tank under the expired warranty, which was great.
            Well it happened again this year (2020) and we scored yet another rainwater tank full of glycol. This time I got rid of the system and I refuse to have glycol up there again! But, I can’t believe I have now returned to electric hot water storage and I’m shocked at the 5.8 to 7 units it uses at night. I feel like we have definitely moved backwards in a big way so I am now considering a bigger solar power system to my current 1.5kw set up.

            You did so well with your unit Sandra, but it just goes to show – life certainly has some lemons to throw at us at sometimes!

  7. Hi Finn,

    Love the in-depth analysis. However I think you should include depreciation if you want to calculate the money savings.

    For example, if I invest $5500 in government bonds, at the end of 20 years I have $5500 + the compounded interest.

    In contrast if I buy a $5500 solar system with a 20 year lifespan, at the end I have nothing of value left. So with a $5500 PV system that lasts for 20 years, then I need to include $250 depreciation in the calculations.

    It is also instructive to compare the savings made over the lifespan of the PV system with what would be accumulated with funds invested in a 20 year bond. In my case I save about $10-$15k with a PV system over 20 years. This is no more than I would get from investing the cost of the solar system in something yielding a conservative 3-5% growth per annum over 20 years.

    I really want to get solar – but if I do, it will be for environmental reasons, not financial. And for environmental I still have to go back and look at the environmental costs of making the cells and inverters.

    • Finn Peacock says

      Hi Alex,

      Thanks for the comment.

      Like most engineers I know, accounting is not my strong point. But I would argue that any interest earned on your $5,500 would be needed to pay your larger electricity bills. Or am I double dipping with that analysis?



    • Yeah……if the banks/governments/economies/etc. Haven’t crashed in the meantime, as happens periodically ~ and which the ‘experts’ are consensually tipping will happen beginning sometime this year.

      I had a photo of a relative in germany (between the wars? who was holding a bag of about a cubic-foot+ of BILLION Reichmark banknotes and couldn’t but a loaf of bread with them.
      The good thing about going alternative is that you remove your dependence on politicians, bureaucrats, economists and other paper-shufflers (who produce NO actual wealth) who think nothing of ruining YOUR net-worth for political short-term gratification.

      eg Remember when the Feds floated the $Aus ~ and everybody lost 12% of their real value overnight?
      Or when they gave us “The recession we had to have, and interest-rates/inflation soared to OVER 30% (in some cases) within a couple of months.
      Or when we had Fraser trying to topple the ALP and created an unemployment pool of something over a MILLION people out of work ~ from a total population of under 10 million (counting women, kids and dogs)?

      Rely on government bonds/promises?? By god!!

      In short, my grid-connect system cost me $4200 in early 2010. It repaid that in a tick over two years (I know how to be frugal/environmentally-conscious) and since then I’ve been getting $1600 PLUS back per year. Most of that goes to ‘good causes’ or into the stock-market for a minimum return of 10+% (and sometimes 20 times that)…….and can be dumped with the click of a computer-key.

      ps. False reasoning:- “So with a $5500 PV system that lasts for 20 years, then I need to include $250 depreciation in the calculations.”

      Depreciation doesn’t rate. If your panels are still supplying your needs after THIRTY years you’re still earning. Once the system has paid for itself (in dollar terms (realistically two or three years) the rest is pure profit, even if it were producing at half its rating. (and the value of the profit would be MUCH higher because of the increase ~ including inflation ~ of the normal power-bills.

      Speaking as an ex-greenie of intense proportions, the word is ‘Go for it kiddo’.

    • Your forgetting its 5,500 + compound interest MINUS inflation. So your returns in real value are only like 1-2% if you reinvest everything straight back in. If you don’t your 5,500 after 20 years will now buy you a Happy meal.

      On the flipside the returns on your solar panels grow overtime due to inflation. So say your yearly electrical expenses today are say 1900, in twenty years it would be closer to 5,500.Meaning your ROI would be close to 100%.

    • John Casburn says

      Alex – you seem to have forgotten to deduct how much tax you pay on your earnings from your government bonds in your calculations. It can be significant depending on what level of income you receive annually. John

  8. Peter Burton says

    It’s scrambling my brain. Too complicated. Peter B.

  9. Finn
    I am replying not about solar but about your bill. If your cost is $12 odd how can you pay GST of $20 odd. It should only be $1.27. I know AGL have charged you GST on the $200+ charge but that is not what it is costing you. You only pay the GST on the final figure because I bet that AGL are claiming a GST rebate on the cost to them of the $190 odd. End result – they will only be paying the $1.27 to the Govt and keeping the rest for themselves. Cheeky bastards, but have never had much time for AGL. I would request a refund of $19.65. Go for it!!! Would love to know the outcome.

  10. Rosie Thomas says

    Dear Finn
    I can’t thank you enough for explaining how a solar system works in such basic and easy to understand terms.

    I have struggled understanding this for many months. We purchased our new home and solar was already installed therefore we are only getting a very small buy back rate of about 5c.

    I have enquired many times with different solar companies about how it works and have just been given the usual sales speech. Understandably as I am not really a customer just a woman asking dumb questions they are a little reluctant to give me too much information.

    The few electricity bills we have had since we have been living in our new home have only shown small rebates eg. $15 for the quarter with our bills still being around $300.

    After reading your article I now realise that we have a lot of appliances that are set to come on after dark. Eg. Pool pump, dishwasher. I am now trying to remedy this by setting the timers for daylight hours and hope that this will start making a difference. If it doesn’t make any significant change to our electricity bills I now know I need to have the solar system checked.

    Thank you so much for making this clearer for me and also thanks to all your readers for adding comments that are just as helpful.

    Thanks again from a very grateful lady who does not have a degree in science or engineering and struggles to grasp the concept when described in technical terms.


  11. Finn
    So which Solar Company did you chose for your panels?

  12. Incidentally:- “An el-cheapo system that seriously degrades or fails in the first few years is not going to give you good return!”

    If it fails immediately it’s paid for itself (in dollars), then the return is STILL 100%
    ANYthing beyond that is sheer profit.
    …and TAX-FREE as well! (Until they start taxing sunlight…..and don’t think I’m joking! 😉 )

    • Greg Bell says

      “If it fails immediately it’s paid for itself (in dollars), then the return is STILL 100%”

      So if you give me $1000 and I give you $1000 back you think you’ve made a 100% return on your money? 🙂

      This is a common misconception with solar. It’s not like an investment in a debt instrument where you get your money back at the end, plus interest. Your money is SPENT on the system. Its value is $0 at the end of the term. How angry would you be if a bank term deposit did that?! When the system has generated the same amount you’ve paid, your return at that point is 0%. Beyond that is a positive return.

      I’m a big fan of solar – I just don’t want people thinking the wrong thing then being angry when it dawns on them how the money actually works out.

      • How is the Value $0 of the system at the end of the term? You could sell it easily. It isn’t suddenly worth $0

        Past the point where it pays back the initial investment, the money then saved is pure profit, and electricity prices are about to go up 20%. Not many investments will make a 20% return this year…

  13. Yes, I see your point.
    Unfortunately.though you sound like a pro., and are restricted to working ‘within’ the box. …and I should’ve chosen my words better.

    I see a difference between between ‘return’ and ‘profit’.
    And also between ‘using’ money and spending it.

  14. Thanks a lot for the info.
    I have ordered a 5kW solar kit and thought I should look into it while I still have a cooling off period.
    I think I have the jist of how it all works now.
    I was hoping as an example if I use 20 kWh in a day and produce 20 kWh in a day I would break even.
    Now I think I understand that what I feed into the grid is paid at a lower rate than what I draw from the grid so my example dosent work and I am better off doing what ever I can while the sun is shining and then relax and have a beer after dark.
    I would love if I could use the power I produced over a week and break even using the grid as a power bank for when I needed to make a withdrawal and since I sold the power while demand is high and used it while demand is low I don’t understand the fit rate.
    Still it will be a saving to myself, I just need to change how and when I do a few things.
    Thanks again for the info.

  15. Hi Finn

    I am on the NSW old 60c buy back rate and i still do not get savings like you. I am on a 2kw system. My energy bill is still around $200 per quarter, and there is only two of us in the house. I must be doing something wrong. Your article was good but you did not really explain what practical measures you take (on a daily basis) to really reduce your energy use. Have you written about those tips in a previous blog? I know the 60c rate will cease next year.

    • Finn Peacock says

      Hi John,

      1) Check your system is producing what it should. Here’s how:

      2) Here’s an old (but good) series I wrote on energy efficiency:

      3) And here’s an update about LED lights:

      Hope That Helps,


    • There is more to Solar that putting it on the roof. Consumption of PV Production has to be managed. For example we have a split Solar Hot Water Service which used to be on a Time of Use Tariff [TOU] that powered the HW Booster Element. We changed it over to General Tariff installed a timer in the meter box which allowed the HW Booster to have access to PV Production when it was available. The circulation pump uses little power and is always ON connected to the General Tariff. With this setup living in FNQ our hot water costs are negligible. We also run a pool pump and pool heater connected to the General tariff similarly managed with timers. The cost is negligible. We sequence other household consumption to when PV is being produced. Sequencing means you would not run the heavy energy consumers like a Washing Machine, Dryer, Oven, Cook Top and Dishwasher in any combination at the same time. In our case maximum PV production is usually produced between 11:00pm and 1:00pm and this is probably when we run any of the household services previously mentioned. Change light bulbs to 240V LED we do that when any of our CFL globes fail. LED cost more but they last longer and are cheaper to run. TV, Computers, Printers and similar devices left on standby all consume power which then becomes a question of cost over convenience. If you have not got a Desktop or Smart Device Solar Reporting system this is really a must to determine where you might need to modify your consumption behaviour or simply monitor system performance. There is a free application which allows you to map your own data and for some systems this process can be done automatically. What is probably more important is the ability to look at the production of systems in close proximity. An important value that can be used for comparison purposes is the kWh produced by each 1 kW of System Size in a 24hour Midnight to Midnight time period. It is comforting to know that you are producing the equivalent of similar systems at or near your location. We have an 7.99 kW System [Micro Inverter 30 Panels orientated to the N, NW and NE] in September our average daily performance in kWh’s was Consumption 27.61, PV Production 34.13, Imported 6.55, Exported 12.97. Daily cost without Solar $9.03 Cost with PV $1.72. Both include the fixed charge of $1.16 per day. General Tariff 0.28479c FIT 0.10102c. Given where you are at Solar wise I have a friend who lives in WA with a 1kW system that over the last 12 months has averaged PV Production of 5kWh per day. He currently enjoys FIT of 0.47c per kWh with the early adopter incentive of 0.40c due to expire early next year. On the basis of his performance to achieve the same cost per two months when his FIT falls to 0/07c per kWh he will have to upgrade to a 5 kW system to maximise the export to achieve a 4 to 1 export to import ratio in order to increase the billing credit to offset the new supply arrangement without the 0.40c added to FIT. Given the maximum system size allowable in WA is 5 kW [Inverter size] he is still going to end up with a bill at current rates of approximately $300 per annum. Of course you can get approval for a system greater than 5 kW but you forfeit the FIT which does not make any sense unless of course you was to subscribe to storage which requires quite a different financial analysis which unfortunately still does not defeat his fixed charge of 0.9491c per day $346.42 pa. He has the option to go to 3 phase power which would allow a 15kW system still enjoy FIT. We recently costed three phase power in our part of the world which included a new meter ($1,200) new trench cut lay a duct and cover from the distribution point [$1,000] Electrician [$1,000-$1,500] so all up as much as $3,700 plus the PV Upgrade $3,300 from 5kW to 7.99kW to what was then 5 kW per phase. On the 1st September 2017 those limits was increase to 10kW per phase to still enjoy the FIT applicable to export with the upgrade just costing the $3,300. I hope I have been helpful sharing this information because the better informed you are the better decisions you will make. In summary in the absence of upgrading your system you might well be in for a bit of bill shock.

  16. Hi.
    Just wondering if someone can help me with charging a hybrid car from a home that has a 44c feed in tariff. I charge the car at night once the benefit of the feed in tariff is extinguished. I also have the opportunity to recharge the car during the day after the battery is expired ( i use it to commute kids to school then it sits at home mostly). I’m trying to work out whether I’m better to re-charge the car again during the day (I end up doing one run back home mainly in hybrid mode ie petrol engine running), or only charging it at night. It currently costs me about 2.30 per charge, for 39km travel (I’m on standard tariff, but do have the opportunity to switch to time of use now). I also have a swimming pool incidentally, which I mostly run the pump at night also.

    • Finn Peacock says

      Hi Steve,

      It depends what tariff you are buying electricity for. If you are paying less that 44c for your grid-electricity, then use the grid to charge the car. i.e. at night.


  17. If I want to buy a system, which I can expand later on, either with more panels or with say with new battery options like Tesla, is there a way I can future proof my investment? What sorts of things should I consider?

  18. Hi, I have recently installed an 8 panel 2 kw system on my small unit. I also decided to switch power company’s at the same time, I went with RED as they said they were all Australian owned and operated etc. etc. This I thought would be seen as to be doing the right thing by the economy. I have also just installed LED Downlights everywhere throughout my home and surrounds. However my bills are still not what I expected, then on closer inspection of my last bill, I find they are charging me 27c/kwhr whist on solar, and 35c/kwhr when not on solar!! And paying me a measly 6 c/kwhr for the power I am putting back into the grid, I thought it was supposed to be let’s support the one’s with solar power not penalise them? any thoughts on a better deal? as in solar friendly companies?

    Cheers, Graham

    • Finn Peacock says

      Hi Graham,

      I’d shop around for someone with better rates. is a good start.

      Last time I looked Click Energy had the best feed in rates in many states. Powershop are also meant to be good.

      Hope That Helps,


  19. Six years ago we believed the solar company when the salesman said two of us would only require a 1.5 inverter. What a waste of money that was. I upgraded two years ago to a 3kw inverter and have not paid an electricity bill since. Then, the govt came along and said I broke my contract by upgrading my inverter and I’ve now lost my entire sell back govt subsidy of 44 cents /kW. Previously I had 44c + 6c supplier = 50 cents/kW buy back. Now I receive 6 cents. Recently widowed, and back to paying electricity bills again on single pension. I read both my inverter meter every day and outside electricity meter every day. In mid summer I can generate up to 12kW/day, at present with less sun I’m lucky to generate 2kW/day. No way is my household being run on the solar panels on 2kW/day.

  20. I also noticed Finn’s bill discrepancy re the GST. But what I don’t understand is the omission of the supply charge by the electricity supplier! In my case, the supply charge is about 2/3 of the electricity usage charge. It seems to be calculated per day, and as you buy electricity off the grid at night, how come no charge on your account! Am I right in assuming that savings are only to be made by savings in usage, not the supply charge? Thanks for clarifying

    • Finn Admin says

      Hi Irima,

      The picture of my bill shows the supply charge of 63c per day. Because I export so much I offset all of my usage and some of my service charge.

      Hence the low bill despite a daily service charge.

      Hope That Helps,


  21. When I tried to get a quote, there were these choices:
    Whats the difference between
    1. Solar Electricity for your Home
    2. Solar + Batteries for your Home
    3. Solar Hot Water for your Home
    4. Solar Electricity & Solar Hot Water for your Home

  22. Hi Finn

    What energy monitor did you use to get that graph of your usage and output?

  23. Hi Finn.
    Great website with some great information.
    My parents are looking at getting solar and were offered a $8000 install for a 4kw system.
    They are a bit unsure what to do.
    Does this quote sound ok? Not sure on the details of equipment but the company was Alliance Solar.
    Are there any companies you suggest for a good deal. Cheers

    • Finn Peacock says

      Seems expensive.

      I’m not sure where you are based but if you get 3 quotes thru the website – you’ll be put in touch with local installers that should be able to give you a competitive price.

  24. Hi Finn, thanks for your articles and responses to various questions asked, I have found them most informative and useful.
    I already have a 1.5kw system with a 2 kW inverter (on the only north facing part of my house roof) with a feed in Tarif of 50c. This was shortsighted on my part and I want to increase by installing a further 6kw system. I have a couple of questions.
    I have received one quote so far for $6000 for 6kw panels (tier 1 german made) with a 5kw SMA single phase string inverter.
    What does tier 1 mean?
    Shouldn’t I need a 6kw inverter to match the output of the panels?
    Can I still retain my 1.5kw in addition to the new 6kw giving me a total of 7.5kw?
    If I can retain the 1.5 kW system as well as add the new, should I get a larger inverter say 8 or 10kw?
    I live on the Gold Coast and the only available roof space with faces east or west. Which would be the better orientation for the new panels?

  25. Andrew Armstrong says

    We have a 5kW system on the Victorian Premium FiT. We export 81% of generation and have not had a bill since 10/2009. We now receive $3 300/year cash refund.
    The system cost $20K but with a tax free return of in excess of 18% p.a, although being installed primarily for environmental reasons, it well and truly stacked up financially too!!

  26. Hi Finn,

    Your article is of great help to everyone looking for solar.

    I have a question and a comment:

    Q: at present in May 2016, I got a quote of $8000 for a 5Kw system (that’s already after stc). And $5000 for a battery storage. Is this a fair price in the ACT?

    My comments to your article is hat you mention the money you use to buy solar is much better use that sitting int he back earning or saving you 5% interest you. I.e the $500 you say you put in and you get $1900 out from it. I see this as a negative argument to getting solar. Why, because you should really take the $500 of from the $1900 saving which gives you a real saving of only $1400, this means longer payback time. This is the real definition of opportunity cost.

    Thanks in advance for you advice on the price of my potential solar system.


  27. Chris Beasley says

    Hi all,
    I would like to determine if a solar system would even work where I live in the Dandenongs in Vic. Is there any way I can physically measure how much solar radiation I can receive on any given day notwithstanding that I am surrounded by trees. Is there a minimum requirement that would make a solar system viable.
    Thanks for the discussion it’s helped enormously


  28. Harvey Bishop says

    Your website has been a great help to me. I am pretty sure I am going to use one of the companies you recommended Technaus.
    i would like to get your opinion about my situation. My wife and i live in Melbourne, are in our late 60’s, One of us is usually at home during the day, sometimes watching TV and in winter using a gas wall heater from 5.30am – 11.00pm. We have Air conditioning so could use that to heat the room while sun is shining. Last year we used 2065 Kwhrs for the cost of $597 (and paid $416 in service charges). We are looking at getting a 1.8Kw system (generating 2295 Kw p.a.) for around $3.500. We would get 5 cents feed in tariff and pay 23c per Kw (less a 30% RACV discount).
    Do you really think that we will gain much from having this system installed? Will it be financially worthwhile?
    Thanks for your help

  29. Glynn Eyre says

    I have a 5Kw system on a 50c Kwh FiT. Can someone please explain to me why I am paying $80 – $100 GST when I am in credit every month? I have approached the energy ombudsman and Senator Nick Xenophon but no-one can explain why. If I buy a $100 item on special at $75, I pay $7.50 GST not $10. I thought the GST is levied on the final cost to the user. It certainly is on petrol as the excise on fuel is added first and then you pay GST on the fuel and the excise. There is no consistency here, they seem to add the GST at whichever point generates the highest return to the ATO. Without this tax on a zero bill my running credit would a little bit higher. I paid good money as an early adopter to reduce my electricity account but the Tax Office still gets it’s full wack.

  30. Andy Bodsworth says

    Hi Finn, firstly thanks for your excellent website which is invaluable as an independent source of reliable info for a pretty technical subject… We are a family of 4 in Canberra and about to fit a PV system prob around 5kW. We’re gradually double glazing and insulating our 1960s brick veneer house on brick piers as best we can (not much thermal mass) and about to do a small reno so a good time to re-assess appliances and energy use. My main dilemma is space heating. We have an old ducted gas system and small gas cooktop and I would like to get off gas. But without a battery for our PV I can’t really see how we’ll be able to run a suitable reverse cycle heater (and tiny bit of summer aircon) to give us reliable warmth on those many cold frosty mornings and cold winter days where our panels wont be too active. Electric hydronic seems to suffer from a similar constraint? I’m doing a lot of reading on all of this but this seems to be an issue! modern efficient ducted gas unit used sparingly seems a pretty good option but would love to go all electric. Hope you can offer some advice! cheers Andy

    • Finn Peacock says

      Hi Andy,

      Heat pumps (aircon) are the most efficient way to heat a house.

      Yes – you’ll use them on cold/dark mornings and you will import a bit of electricity from the grid (unless you get batteries – which will be economically sensible in 3-5 years). But don’t get hung up on not pulling any electricity from the grid (to top up PV). The grid is a good backup. Perfect for cold mornings until batteries come down in price.

      Getting off gas is a good move – for environmental and economic reasons.

      And investing in glazing, gaps and insulation before you by batteries is a very good idea.

      Hope That Helps,


  31. Good Morning All,
    I have a problem which I need some help in explaining.
    I installed a 2Kw system 5 years ago and found the cost benefits paid for the panels.
    In checking the Inverter Meter readings against the Solar output meter they are exactly the same ( well more or less). From this I interpret that for every kwhr I generate,and return to the Grid I will receive 5c. For every Kwhr I use I will be charged 30c.( These are the rates currently advised to start in Jan 2017
    If this is the case why would you bother with Solar

  32. G’day Finn

    Have an existing 1kW string-inverter (6 panels) system with gross meter, from Aussie Solar, on 60c/kWhr rebate. Did your “3-quotes” system, so far only had 1 reply, another I had already gotten a quote from a couple of days before, with silence from the 3rd (What was it that Meatloaf sang?)

    Both companies spruiked the microinverter concept, which does sound good to me. But a couple of things I have been told:

    1. Is it true that, for a string system, if one panel is outputting 50% (e.g. tree shade) and the other 5 are at 100% (say), then the string system can only produce 50% from all six panels? (no, I don’t have a circuit diagram for my system).
    2. Is it true that a shortage of net meters is anticipated next year?
    3. Is it true that Ausgrid will only accept a net meter to be installed that has been received by the installer within the previous two weeks?
    4. Based on last summer’s huge bill (avg 32kWhr/day), one company recommended additional 3kW system, the other 2kW. My existing 1kW system outputs up to 4kWhr/day.

    • Finn Peacock says

      Q1. Is it true that, for a string system, if one panel is outputting 50% (e.g. tree shade) and the other 5 are at 100% (say), then the string system can only produce 50% from all six panels? (no, I don’t have a circuit diagram for my system).

      A1. In this situation, a string system will either: a) produce 50% from all the panels, or b) use bypass diodes to bypass the shaded panel altogether, so you lose the output of 1 panel but keep the other panels high. It depends on how the bypass diodes are configured and where exactly the shading is. But the micro inverter system will cope with partial shade much better.

      Q2. Is it true that a shortage of net meters is anticipated next year?
      A2. There will certainly be a huge spike in demand. I have no idea whether the meter supply has been stepped up in anticipation. My guess is that there will be a shortage as people realise they are losing money after 31 Dec 2016 by having a gross meter.

      Q3. Is it true that Ausgrid will only accept a net meter to be installed that has been received by the installer within the previous two weeks?
      A3. I haven’t heard this. But Ausgrid are pretty painful to deal with at the best of times, so it would not surprise me if they had such a silly rule. But I just don’t know.

      Q4. Based on last summer’s huge bill (avg 32kWhr/day), one company recommended additional 3kW system, the other 2kW. My existing 1kW system outputs up to 4kWhr/day.
      A4. This explains how to size a system for net metering: But with that kind of bill and low panel prices combined with a generous rebate I’d go at least 5kW so you gave plenty of power during the morning, late arvo and winter.

  33. Eric van de Weyer says

    Hi Fin,

    nice article which explains things nicely.

    I installed a 5.25kW system just over 2 years ago (I’m in Sydney) not long after we moved into our new house. In it’s first 2 years it has generated about 14.5MWh overall and my savings are great.

    As I am now retired, I do most of the big consumption things during the day when I am consuming my own power such as dishwasher, washing machine, vacuuming etc. I also tend to turn the aircon on early if I am going to use it so that the warming or cooling of the house takes place whilst i am generating power and then it only has to maintain once it gets to the set temp.

    I have a feed-in meter (installed when the system was installed) and initially was taking readings once a week of the amount consumed from the grid, the amount I had fed in and the total amount generated by the system from the inverter. From these figures I have a spreadsheet which shows me my average daily savings over time. even if I only spasmodically take readings, it still can work out the averages as the date of the reading is also recorded.

    I calculated originally that I would probably pay for the system over about 8 years (I bought outright – no interest to pay) and am very happy with the results.

    During summer I can generate over 30kWh per day and in winter is seems to be about 18-20kWh on average. This is for sunny days, of course. Cloudy days reduce those figures.

  34. Lets just put the cards properly on the table here, with utmost respect of course.

    The most significant heading should read –
    “It’s when you use the power that counts”

    and then maybe a sub heading,
    “Just how much power are you really using during the day?”

    People just need to forget the feed-in as it’s only adds a small bonus on the new Tariff scheme.

    All you need to do is figure out how many kilowatts you’re truly using during daylight hours as an average (when the system is generating) and if that number is low – FORGET SOLAR.
    If your day usage is high – Then CONSIDER Solar, but only match it to a system that will offset your day usage and ONLY if it pays for itself in less that 6 years.

    I used to sell PV systems and I’ll tell you right now, once the feed-in dropped so did the eligibility of most of my clients (an honest salesman you ask?- rare, but they do exist)

    Once I ran the numbers (generally speaking) it would only ever be worth it for
    1) Pensioners
    2) Big family households – WITH PEOPLE HOME IN THE DAY
    3) Or those with many, many power hungry appliances, pools etc.

    And those systems would normally equate to a 1.5kW/2kW system and that would normally settle it before becoming excessive and relying on Feed-in. There’s a reason the market now targets industrial solar and solar for businesses… because that’s when buildings are staffed and are using power.

    If you want to know if it works for you – you need to really do the maths and don’t trust sales people to do it for you.

    Hope this helps. Feel free to dispute my statements.
    Cheers – N

  35. Orpheus Perera says

    Finn Is Lucky. I installed 3KWh system 4 years ago which cost me over $7000 through Origin. My bills went down from over 800 to about $450. Then one day a guy from Endeavor Energy(They had something to do with the installation) came and said he came to check the efficiency of the system. Bill after 3 months became about $650. I was angry and complained to all 4 involved in installation. Endearuor said they will send a man to check it. I asked them to send a man and show me how the system work. I never show the man. The receptionist said they did send a man and nothing wrong with the system. Then next bill was correct. Again last quarter bill is higher than the highest bill 5 years ago. All four companies keeps on passing the buck without helping. I complained to Energy Ombadsman and they said AGL will contact me this week(When 2 bills were high I changed from Origin to AGL).Can they secretly come and control the usage of Solar output?

  36. Glynn Eyre says

    They cannot control the solar output. It puts out what it puts out. Your power bill should include the amount generated in KW/h during the periojn of that account. Just multiply that number by the feed-in tarriff to give you the dollar value of your solar generation. please bear in mind that what you have produced will not be taken off your account in it’s entirety as you will have used some of your own electricity. It will tell you how much value you are getting though.

    • Orpheus Perera says

      Bill shows Solar KWH as 100 and they have credited e with $ 8.00 for that. Bill for the winter quarter says I have use 34.25kWh of their energy per day. My refrigerator rating is 750 KWh per year and we used heating for few hours per day for few days(this is in Sydney). We have gas for hot water system and cooking.

  37. Hi Finn,

    I installed a 3.12 solar system in Feb2016 and so far it’s working really well. I’ve been monitoring it’s production thru the Fronius’ web-site at

    I’ve been looking at the next step which is monitoring usage and was wondering if you can give me your opinion on the following:

    1. Rainforest Eagle Smart Meter App and Gateway (

    2. Smappee Energy Monitor (

    3. Smappee Solar energy monitor (

    The prices are Rainforest at $155.00, the Efergy at $230.00 and the Smappee energy monitor is $299.00, while the Smappee Solar Energy Monitor is $449.00.

    Just wondering whether it would be worthwhile to pay the extra for the Smappee as it appears to have some additional features which could be useful such as “Smappee detects all of the important electric appliances in your home, as each one has a unique electrical signature. Via the app you’ll get real-time readings of their use and cost, on your tablet or smartphone” –

    And if the Smappee is the best, should I get the Smappee Solar Energy Monitor at $449.00, rather than just the plain energy monitor.

    Thanks for your help

    Cheers Peter

    • Finn Peacock says

      Hi Peter,

      Great Question – I’m planning on writing a roundup of energy monitors soon.

      I am not familiar with the energy monitors you list – but here’s what I can tell from the websites:

      1. Rainforest – may good solution if you have a smart meter. Most of Victoria now have smart meters. Most of the rest of the country do not. If you don’t have a smart meter then you can’t use it.

      2. Smappee looks good from the website. I’ve just ordered one to have play with it so I can see if it lives up to the marketing! But you’ll definitely want the solar version so all the consumption and generation data is on the same portal.

      Also – if you have 3 phase, you’ll need the 3 phase kit.


      Other options:

      1) I really like this monitor as a low cost solution:
      You will need an electrician to install for solar, as you need to re route a couple of wires. Should take about 20 mins for a good sparky.

      The best thing about it is you can monitor individual appliances for $20 per appliance with these:

      THis is really useful for spotting energy efficiency opportunities.

      2) Expensive – but best solution:

      This is hardwired in and is really excellent. I have one. See the website for the features.

      Do not pay full price – tell them I sent you and ask for a discount – expect to get a few hundred dollars off.

      Hope That Helps,


      • Hello again Finn,

        just noticed that Choice magazine has done an article on home energy management systems and has analysed Solar Analytics Monitoring (which you recommended above) and CarbonTrack which is about twice as expensive (

        cheers Peter

  38. i don’t get your bill.
    I consume between 1,300KW to 1700KW per 90 days and i have 3 adults and that is average for 3 people so i can’t see how you only consume what you consume.You must live in the dark with no air and the hot water disconnected .My figures hardly have varied for 10 years. Hot water service alone consumes over 634 watts. and then my byback from AGL on 2213.781KW was $135.04
    I was lucky because I am a pensioner so i got a rebate of $58.00 on top of the $135.04 by back and $38.70 pay on time discount.

  39. John Leonard says

    I have now turned my solar system off I am not Willing to accept a fraction of what the power I generate is worth.
    I have a 3kw system it generates 4500kw per year I will get paid [email protected] pkw this is $274.50 rebate per year. The life expectancy of the system over years to come is 25 years (if I am lucky) of which there is 20 years left 20x $274.50 equals $5490 is this enough to replace it in 20 years (assuming it lasts another 20 years) maybe, maybe not, in any case where does the money come from to reduce my electricity bills?

    • Ronald Brakels says

      John, electricity produced by your solar system goes towards meeting your household electricity use first before it is sent into the grid for 6.1 cents. So if you are paying 25 cents a kilowatt-hour for grid electricity, each kilowatt-hour of solar electricity you use saves you 25 cents. If you use half the electricity produced by your rooftop solar system and export the other half for 6.1 cents a kilowatt hour then over a year you will save around $700. I suggest you turn your solar system back on.

  40. John Leonard says

    Ronald, thanks for your response the problem is I currently have a gross meter so your scenario will not work.
    Energy Australia will install a net meter and to do that the want to charge me $120 PA ($10 per month) for ever! And if my system breaks down tomorrow and given the current figures with the rebate shortfall repair is not justified, and then I am left with no solar power at all and an additional charge of $120 PA on my electricity bill that I am required for ever.

    I also asked Energy Australia if I go to a net meter can the give me in writing a guarantee they will not put me on Time Of Use tariff and they would not could not guarantee this in writing but assured me verbally they would not very suspicious!

    If someone can tell me how to apply commercial principals ( because we are all trying to reduce our electricity bills) and not on emotions and justify Solar energy under the current arrangements I would love to be able to turn my solar panels back on.

    I would suggest if every one turned their solar systems off then maybe we would see some equity come back into rebate amounts.

    • Ronald Brakels says

      If you have a gross meter, then I assume you must be in NSW. This means from 3 days ago you will be getting nothing for the electricity you send into the grid until you get a new meter. I suggest you contact different retailers and see if you can get a better deal from them. Maybe you could try Powershop.

      I wasn’t aware of a $10 a month fee for new meters. If there is a link you can give me to information on it, that would be great.

      I also suggest you consider switching your solar system back on. It is good for the environment. While it probably doesn’t make any real difference to Energy Australia’s retail side of things whether it is turned on or not, switching it on will hurt their electricity generation side of things. The more people who have functioning rooftop solar systems, the less coal and gas generated electricity their power stations will sell.

  41. John Leonard says

    Ronald re “This means from 3 days ago you will be getting nothing for the electricity you send into the grid” This is not my understanding my understanding is the gross will send every kw generated back too the grid (I am in NSW ) at 6.1cpkw if you are correct then it re-enforces my decision to turn it off.

    In relation to the $10 fee I was advised this by phone on two separate occasions, nothing about it on the web site that I can see.

    “Solar power is good for the environment” I agree totally. The best way to grow solar generation is sustainability! and to achieve this it has to be financially viable. If industry/customers do not do something to bring pressure to bear then nothing will change and solar will stagnate. Me turning my solar panels off will achieve nothing other than personal satisfaction that I made a token effort, however if panels were turned off on mass I have no doubt fairness/ equity then sustainability and growth would be achieved.

    • Ronald Brakels says

      I’m sorry, when I read you had a gross meter I assumed you were on NSW’s Solar Bonus scheme which ended at midnight on the 31st of December 3 days ago and so would be getting nothing for electricity sent into the grid. But if you are getting 6.1 cents for every kilowatt-hour you generate, that is better than nothing. I’ll have to look into this.

  42. Orpheus Perera says

    Until 2012 I had bill to $650. After installing 3KWH(Origin) bills went down to 450 and again increased to about $630. The lowest daily usage recorded was 10KWH, highest is 34kwh(Invert er reading 6-8kwh per day)). I spent $6500 to install Solar panels. I changed to AGL, but bills are still big. Normally day time we have a fridge that takes only 750kwh per year. How come you get bills so law. I talked to everybody including Energy Ombudsmen. Everybody kept on passing the buck to other(Origin, AGL,, Installer and the manufacturer) A guy call Rushi gave a call saying they clean Solar panels to increase the efficiency(From Energy Control). I paid his worker $225(discounted from $250). After one month no improvement and the phone numbers he gave are wrong.How can you escape with $33 bill? Please some one help me to solve this wastage. I just got retired and soon I will not be able to pay such big bills.

    • Ronald Brakels says

      Hello Orpheus. Ronald here. The good news about being retired is, it will now be easier to use electricity during the day when is the sun is shining. This should increase the amount of solar electricity you use and decrease the amount of grid electricity you have to pay for and lower your electricity bills.

      Finn has a very well insulated and energy efficient home, so it is easy for him to keep his electricity bills low. But people who live in normal Australian homes can still do things such as use energy efficient LED lights and people who use a significant amount of electricity for heating and/or cooling can save money with insulation and weather sealing.

      You may want to consider replacing your fridge as a modern 400-500 liter refrigerator should use under 500 kilowatt-hours a year. But if you are in a very hot location that could explain why it is using a lot of electricity.

      I’m afraid for most rooftop solar systems, cleaning doesn’t cause a large improvement in performance, as the rain usually keeps them fairly clean.

    • Leigh Phillips says

      6 – 8 kWh from a 3kw system is very low output, you need a solar tech to diagnose what is wrong, I suspect that it has been installed with 2 strings and tone of the roof top isolators has failed (very common)

  43. John Leonard says

    Ronald, yes I am in NSW and yes I was on the 60cent scheme for 5 years which finished 31-12-16 and as of the 1-1-17 i would receive 6.1 cents per kw hour (if I had not turned it off) for all the power generated and put back into the grid through my gross meter

    Without paying more money to my current supplier for a net meter and exposing myself to additional costs of potentially a TOU tarrif and possible load shedding by my supplier I am being forced to sell my kw I generate to Energy Australia for 6.1 cents and then buy it back for 25cents plus per kw surely by any measure is unfair and for me unacceptable.

    • My study of Retailers’ tariffs have warned me against going with any of the Big Three (sorry EA ….). I’m in NSW too but my own retailer pumps hydro energy into into southern Victoria, which I like immensely and certainly adds to consumer agency.
      Anyway, my retailer decided to delay their forays into ‘deals’ where they supply a new Net Export meter to customers before the start of 2017. With the 60c Solar Bonus ending there was no choice but for me to organise a Level 2 Sparky to provide a new bi-directional basic (Ausgrid Type5) Net Export Meter. Cost $600. Since I did well out of the Solar Bonus I was happy to get it done and try to shift loads to allow consumption of my own energy.
      I even though my Retailer doesn’t do meter installs I would be very wary of retailers (like the big three) offering new meters. Like you I suspect they are going to claw back All their expenses, one billing cycle at a time, forever. They could also string you along, delaying your install (claiming they are ‘busy’) and getting a significant advantage out of your current situation. Be a free agent and investigate what you could do yourself. It will allow you to look around and ditch your retailer anytime they piss you off.

  44. Ronald,
    Your analysis may be great for those living in places other than the Northern Territory, but the situation in Darwin is very different.

    We get a 1:1 feed-in tariff. For whatever reason my quarterly power bill shows a saving of about $300 per quarter thanks to the solar inputs.

    That being said, my power bill is only about $400 cheaper than it used to be, so all the parts of the bill you mentioned that I don’t get to see (such as power I didn’t need to buy) doesn’t really make a huge difference to me.

  45. my power goes into the grid at 8c and is charged to me at 25c/peak (supply charge about 76c/day). I actually send more than I consume at times and still end up with quite a bill (for my 1-2 person household). There are 6 panels on my roof. It was as much as I could afford to put up there at the time and it took me a while to save up for them. NSW customer of AGL electricity. Bill late 2015 used to supply figures above.

    My daughter helped tidy up and now I cannot find current account or those for 2016! – will wait for the next. I had no idea that we were going to get nothing for what we generate – as note of your correspondents above said – is that true? I primarily bought the system to do my bit for the environment (ie it was after the generous schemes were stopped) but I cannot – as a pensioner – afford to be penalised (eg if there is a meter charge etc) I will contact them on Monday)

    • Ronald Brakels says

      Hello Elaine. If you were receiving 8 cents a kilowatt-hour last year then nothing should change for you this year. New South Wales high gross feed-in tariff ended on the 31st of December, but that was only for people who were getting a 60 or 20 cent feed-in tariff.

      You will be on a different net feed-in tariff and most of the advantage of your solar system comes from it reducing your grid electricity use during the day and a much smaller part will come from the feed-in tariff.

      Hope this helps – Ronald

  46. Orpheus Perera says

    Lucky to get $33 bill. I installed 3kw system 3 years ago, cost me 6500. My end of September bill was $830 and this time $320. No improvement than before it was installed except the 200kwh I have sold them for 8c per kwh.

    • $850 to $320 looks like a very good improvement to me!

      I’ve had my 5.25kW system for just over 2 years now (Sept 1st) and it has so far generated over 17MWh of which about 10MWh has gone back to the grid. I try to use major appliances such as dishwasher, washing machine vacuum cleaner etc during the day when I am using my own generated power. I also turn on the aircon during the day to cool or heat the house whilst the sun is out so I only have to maintain the temperature later in the evening. My bills are about half what they were prior to installing the solar. I calculated that the system would pay for itself in about 8 1/2 years.

      How anyone could expect the a feedin tarif of around 60c/kWh was sustainable was fooling themselves. It was a short term incentive to get people to take up solar and I am surprised that it lasted as long as it did. It is not economically viable to pay more than double what you are selling for.

  47. Orpheus Perera says

    Actually before installing the Solar Panels Those two periods bills were *860(June-Sep) and 420(Sept December). Both were reduced only by small amounts. I think I did not explain properly. The two figures for 2 consecutive periods. Not for the same period before and after installing. I expected the bills to drop to from 850 to $500(for June-Sept) and one for Sept-dec to drop from 420 to 250.

  48. Great article.

    Myself, I’ve been happy with our install & payback even though it’s only 2kw on and small 7c FiT in Perth.

    In 2013 we paid ~$750 per year for electricity. On installing the system for around $2500 early 2014, our yearly bill is now ~$430. In summer we’re seeing approx 75% drop in our bills, mostly what’s left is paying for our electricity connection. At worst in winter, normally around August, about 25% drop in our bills. For our suburb the average daily kWh consumed is ~16, we do 3.6.

    Overall about a 8yr pay back (ignoring any electricity rises since 2013 which would mean even faster pay back realistically). I’m fine with that as we are a net exporter even on this small system, the environmental benefit to me is as morally important if not more so than the savings. But by the by I get benefit of both even on 7c FiT.

    I guess the point I’d like to make, investing in big systems or even small systems like I did, like this article says, it’s quite possible to get a comfortable return on a small FiT.

    Just for fun this summer, as we’re already an energy efficient household in moving our use to during the day when the sun shines & turning TVs etc off at the wall, I’ve been working with a power meter to identify vampire power use around the house to see how low we can really go. Signs are good we’ve dropped maybe another 15-20%. Our next bill will tell I guess. Overall it’s been a fairly painless exercise.

  49. Hi all, In December I decided not to wait for Red energy to upgrade my smart meter as they could not guarantee to do it before January. Went ahead & got a level 2 sparky to come & do it for me, cost $250.00
    well worth it.

  50. David Knox, J.P. says

    Date: 22-Jan-2017

    We had a 4 kVa Suntwins 17 x 260 w panel solar system installed in Nov. 2012 on a 5 year warranty. Solar export rebate = 44¢ / kWh.
    We have kept statistics weekly since.
    Total install cost = $ 7,150 net
    Tariff 11 (day rate) = 18,590 kWh === $ 7,144 +
    Tariff 33 (night rate) = 16,950 kWh === $ 2,186 +
    Service Fee + Meter Services Charge === $1,360 = $10,690
    QLD Gov’t Rebates (Aged Pension) === $1,430 +
    Solar Rebates: 14,613 kWh === $6,430 = $ 7,860
    Net cost to date = $ 2,830 = approx. $1.47 / day (over 1,920 days)
    Final analysis: By the end of the 5 yr warranty, the rebates will have covered the install cost. So from now on we are in front … till the time comes when the panels may have to be replaced, but they have a 25 yr life expectncy, & I’ll be pushing up daisies by then!
    So going off-grid is not an option for us as yes.
    During pwr outages and esp. After Cyclone Larry, we ran a 5kVa generator for 3 months, till ERGON reinstalled pwr.
    As a side note, service fees have gone from $26.20 per bill (90 dys) to $107.60! Up here ERGON has no competition, unfortunately.

    Hope this helps anyone make an informed decision

  51. This is a really interesting article – thanks for posting it. It seems to me that the question of value comes down to how long the solar system lasts and what the maintenance costs. Can you tell me in general terms how long a good solar system will last, and what is required to keep it working each year?

    • Ronald Brakels says

      Hi Duncan. Rooftop solar systems are pretty reliable. You can expect them to last longer than any other electronic item. Tier one panels are trusted by large financial institutions to last for 25 years when used in large solar farms. They don’t expect every panel to last that long, but they do expect the large majority to. If you are willing to pay for premium panels such as SunPower or Solarwatt, which respectively come with 25 and 30 year product warranties and I would expect them to be operating after 40 years.

      Inverters don’t last as long. Fronius inverters now come with a 10 year warranty. Enphase microinverters also have a 10 year product warranty, but in the US they come with a 25 year warranty, so they appear to be extremely reliable.

      Most solar panels don’t need to be cleaned as the elements will do the job:

      But if you are in an area where grime does build up on them they will need an occasional clean.

      So while the inverter will probably need to be eventually replaced, with a good quality inverter that may not be required for 15 years or more. The solar panels are likely to last for decades.

      • Ron, We have a 5kW array with Enphase Micro Inverters and after a not inconsiderable amount of aggravation and a charge of about A$750 and trying about 6 installers we now have the Enlighten manager software installed and operational.

        Not sure if you have had access to this or if it is of interest to you but I could provide screen shots of the data. I am reluctant to post a link as I suspect a smart person viewing the system may be able to make changes.

        The collected information is interesting and comprehensive with quite a bit to learn especially about panel installation. Over the summer we can clearly see the panels which get hottest reducing their yield. Based on this observation it would seem smarter for the panel installers to provide a 75-100mm gap between the panel edges to allow hot air to escape rather than to move upwards heating the panels up slope more .

        Anyway my next project I think will be an AC Powerwall 2 later in the year if Enphase do not get realistic with their battery pricing. I plan to gather a years worth of data which will make battery selection easier.


        • Ronald Brakels says

          Hello Ian.

          Thanks very much for the offer of information on the Enphase Enlighten monitoring system. I think people may be interested in how well it performs and the struggles you had installing it.

          If you want to send me information and any observations you have, you can email it to me at:

          [email protected]

          No promises that I’ll write an article, but I may be able to get around to it.

  52. Richard Eckersley says

    Hi, Finn

    Looking at your bill, you don’t appear to buy green power for what you take off the grid.

    I looked at installing solar panels in 2014 and decided it wasn’t worth it for us because of the low feed-in tariff. Unlike you, we use very little power during peak generation times. Living in the NSW southern highlands in an all-electric home (plus a wood heater) and good thermal efficiency, we rarely need to heat the house during the day in winter, and don’t have air-conditioning. I estimated we were using in winter about 3-4 kWh between 8am and 4pm, so the remainder would go into the grid, for which we’d be paid 6c/kWh.

    So I decided to continue buying 100% green power (for which, incidentally, the power company charges over four times what they’d pay us if we had solar panels feeding into the grid). Asking friends, I was surprised that some of those with panels were not buying green power for what they took off the grid. So they were feeding clean power into the grid and taking dirty power off it.

    I think it should be mandatory for those with solar panels (especially those who were getting high feed-in tariffs), to buy green. Power companies source green power on the basis of the demand for it.

    Any comments?

  53. John Leonard says

    With respect to feed in tariffs, I am so annoyed that I feed in my generated solar power into the grid and get paid 6c/kwh and then buy the same kw back at 26c/kwh hence as of the 30/12/16 I have now turned my solar panels off. From my point of view it is inconceivable how the 6c/kwh was arrived at.

  54. Eric van de Weyer says

    Well, John, anyone with an ounce of brain should have realised that 40+ cents per kWh was totally unsustainable in the long term.

    I have only had the solar on since moving to my new home and I expect it to pay for itself in about eight and a half years. I have boon on the 6c from the start andnut is still about half on my quartly bills so itnis definitely worthwhile. Even at that rate, it is better than nothing at all, which is what you’ll get by switcjing it off!

  55. John Leonard says

    Well Eric, If you think state governments gave 40+ cents per KWH out of the goodness of their hart I would suggest you think again! and to buy back something at 26cents + that you sold 6cents if you think that is a good deal well!
    What do you think would happen to the 6 cent rebate if every one turned solar panels off!

  56. I’m with Eric. With 7c FiT in Perth I’m happily looking to pay my panels off as described in the comments above, and I’m doing my bit for the environment too. I came to the market too late for the larger FiTs, but I’m fine with that.

    John, I do think turning the panels off seems like a pointless protest given you can still get a return on investment and it is a reasonable one. And its not just about the FiT, you also offset your daily use which is a much greater amount, there’s plenty of money to save there (and there’s where my panel payback period is really reduced, we offset a large amount of daily consumption).

    Ultimately with your panels off you’re now saying you’re happy to pay the larger state chargers for electricity, and you’re also happy to continue to pay those charges as they increase too. It seems to be you’re capitulating to the very organizations you’re protesting against?

  57. To One and All
    It is irrelevant what the feed-in rebate is. The main point is to be energy conscious in your home. Use efficient lighting e.g..
    We installed solar 4 years ago and were lucky to lock in the 44¢ rebate. So the by the end of this year, the cost of installation will be covered.
    Even at 6¢ rebate, on our current usage, we would have benefited:
    6¢ x 14,610 kWh = $875. For this then would have taken 7½ years to recover the cost of installation. Then we would be in front as we are now.
    Our home is in FNQ where monsoon rains can last 3 months or more. This is compounded by the inevitable cyclones which can wipe out the power infrastructure.
    Our main gripe is that when ERGON stops providing power, we cannot use our own solar power in the house. We then have to use the generator. Our only alternative is to go completely off the grid with back-up batteries, which at present we are not likely to do … not worth the extra expense.
    Hope this info helps in anyone’s decision making.

    Yours for a bright light
    15-Feb 2017

  58. John Leonard says

    Chris, it does not matter how solar is justified the rebate is too low. In my case with the $10,000 initial outlay I should have left my money in super the return would have been far greater even at today’s low super returns.
    As I have said on this forum before if renewable energy is to continue to grow and it is to everyone’s benefit that it does, then it must be viable when commercial principals are applied.

    • John Leonard says


      As I have posted here before the 6cpk being paid for electricity back into the grid falls way short of the actual value its refreshing to see I am not the only one identifying the scam.

      • John, you’re concentrating on the feed-in tariff when you should be concentrating on the consumption charges you DON’T get charged by generating your own power.

        Forget about the 6c or 7c you get on excess power given back to the grid. It’s the power you self generate during the day and use (fridge, tv, air con, washing machine, dish washer etc) that you’re running for free during the day. Now that’s where the savings are!

        You said earlier that you turned off your solar panels because the feed in tariff you are getting is too low. But what about the benefit you are now missing out on?

        You’re concentrating on the cream on top, not the substance of the main meal below it!

  59. Richard Eckersley says

    Apart from the issue of the low feed-in tariff, I’d be interested in others’ views on buying green power for what you buy off the grid. As I said, those with solar panels are contributing less than they could ( and should) towards the switch to renewables if they don’t buy green power. They are effectively contributing green power to the grid for those who buy it, but taking off ‘dirty’ power themselves.

  60. Hi Finn,
    I have a 3.8Kw inverter, with 22 panels. we have 2 adults and 2 children in our household. Our bill every 3 months is still over $1000 with a 60c feed in tariff. It says we use up to 5000Kw per quarter. I just don’t get it. Our house is not large, 3 bedrooms but we do have an inground pool and a fridge in the shed as well as in the house. Our hot water is electric, as we have LPG bottled gas where we live, which we use for heating and cooking (don’t even get me started on how much that costs) I know these things add to energy consumption, but this much????

    • Ronald Brakels says

      Hello Stacey, Ronald here. I don’t know where you are, but the average family of 4 in Sydney with a pool and gas apparently uses an average of around 8,000 kilowatt-hours a year or around 2,000 a quarter. If you have 5 kilowatts of north facing panels connected to your inverter then you can expect to be generating around 1,800 kilowatt-hours. If you consume half that electricity yourself and send the rest into the grid for a feed-in tariff then that means you are using up to 5,900 kilowatt-hours a quarter in your home. That is nearly three times as much as the Sydney average.

      Usually when people have huge electricity bills it turns out they are using a huge amount of electricity they didn’t realize. More rarely they have a defective item is driving up their electricity bills.

      If you heat your pool, that could easily explain your high electricity bills. Just running the filter can also consume a lot. The old fridge can use a significant amount of electricity, and if the shed is hot it can use a lot more. Almost constantly running air conditioning or space heaters in a poorly insulated home, which is most of them in Australia, can also do it.

      Things such as dripping hot water taps can consume a lot of electricity and if the hot water system itself is leaking that can explain a high electricity bill.

      To find out where your power is going you can install an energy monitoring system. These can vary significantly in quality and price, but can make things very clear.

      But you can start checking yourself right now with a paper and pencil by checking your electricity meter and recording your electricity use. Once you have an idea of how much you use a day you can start switching things off to see how much of a difference it makes. You can switch off the pool and see how much of a difference that makes. Same for the refrigerator in the shed. If you are pretty sure they aren’t the main culprits you can move onto other devices and see if switching them off helps. But the likely big sinks or energy are the pool, heating/cooling, the old shed fridge, and excessive hot water use or a defective hot water system.

  61. Hi Finn,

    My husband and I are both retired pensioners and are home most days and nights. I have been trying to research a solar system for us in Hamilton Victoria and wanted good quality panels and inverter. I find it very confusing and will apologise now if I don’t say “things” correctly.
    We just moved into our current house at end of January this year and as we only have electricity for heating and cooling – a Daikin 14.5 kw ducted super inverter appliance, I have discovered we are using on average 40kwh per day and on one day left aircon all day and used 99.93 kwh! I think in winter it will average around 60 kwh per day.
    Is it possible in Victoria to get an inverter above 5kw for a single phase property? From what I can gather, we can’t get above this, but can with panels and have around 6.0kw in total, but this isn’t big enough for us I don’t think. If this is the case and we can’t get bigger, I’m not sure if we’ll be better off in the future with a solar system as we would lose our current 40% discount off our current usage with Simply Energy, and therefore be paying more for what we acutally use say at night time or in the winter when panels don’t have too much output.
    We would greatly appreciate any advise you can give us.

    • Ronald Brakels says

      Hello Lorayne, Ronald here. Hamilton is in the Powercor Network Operator area and looking at their website I see they say single phase homes are limited to “Generation up to 5kW”. That phrasing suggests homes with single phase power are limited to 5 kilowatts of solar panels. However, it may be possible to install more than 5 kilowatts of solar if it is export limited. This involves setting up your solar system so no matter how much electricity it generates it never sends more than 5 kilowatts into the grid. This may be an option, but I can’t see any clear information on the Powercor site. You could try contacting Powercor, but since it is often very difficult to get information from electricity network operators, you may have better luck finding out what your options are by talking to a a solar installer.

      I’m not sure why you would lose your 40% discount with Simply Energy if you get rooftop solar. Electricity retailers are not supposed to discriminate against people with rooftop solar, so if you did get it you shouldn’t have to pay more for grid electricity.

      Sorry I couldn’t be of more help.

  62. Be careful about installing more inverter capacity than the specified 5kW as here in WA the providers look at inverter capacity and are not interested in export control systems and will cut off export credits if you go over the limit. The best advice I can give is install about 15-20% more panel capacity than the inverter/s rating/s as in the real world you almost never see 100% from an inverter and also they degrade over time. In addition inverters have an overload capacity and can be run over nameplate capacity for a while to a point where they will shutdown which is not a big deal. At least talk to your installer about this as I found out about it after installing a system and missed out on this opportunity to maximise the systems capacity under real world conditions.

  63. Hi One & All,

    I am in SE Melbourne and have a 2.5kw PV system with 3kw Inverter. Currently the system generates 540kw per quarter and with the rebate we get $26 back, and it doesn’t seem like we draw any electricity from the PV System. Is this because we have a Gross Feed In system??

    Usage is twice as much as the PV system generates and with discounts we pay approx $330 per bill.

    To me the better option would be to go to a Net Feed In system where by we consume as much electricity we can from the PV system and buy any we need from the retailer?

    If I have got this correct IE: changing to Net Feed In System, can you advise how much it would cost us to change? Will I need to change inverters or buy additional hardware….??

    • Ronald Brakels says

      Hello Craig. Victoria doesn’t have a gross feed-in tariff so you should already have a net feed-in tariff. The current minimum feed-in tariff is not much in Victoria. It’s only around 5 cents a kilowatt-hour. So if you sent 540 kilowatt-hours into the grid last quarter then you would only get about $26 in feed-in tariff. The good news is from the 1st of July the feed-in tariff will increase to 11.3 cents a kilowatt-hour, so the amount you receive for sending electricity into the grid will more than double.

  64. HI Ronald,

    Thanks for the info. From what you say I should be using any power generated by my PV then draw on the grid. When checking my bill from Energy Australia it seems like we are only getting 0.05c feed in tariff and not using any PV generated electricity.
    I plan to contact Energy Australia tomorrow to see how my system is configured.
    So I don’t seem like a complete dunce, can you advise what questions I need ask and what instructions (if any) I need to give them we can use all PV power then draw from the grid when needed?

    • Ronald Brakels says

      Hello Craig. Your home should definitely be using power generated by your solar system, but it won’t show up on your electricity bill. It will just reduce the amount of grid electricity you use and so reduce your electricity bill that way. It is possible for a 2.5 kilowatt solar system to produce 1,000 kilowatt-hours or more over the summer quarter in Melbourne. If you exported 540 kilowatt-hours that you received a feed-in tariff for last quarter, then you are probably using hundreds of kilowatt-hours of solar electricity yourselves. If you self-consumed 300 kilowatt-hours of solar electricity and you pay 20 cents for grid electricity then that would have saved $60 but it won’t show up on your bill.

      Generally, the amount of solar electricity people self-consume depends on whether they are at home or not during the day.

      To see that you are self consuming electricity by checking your electricity meter on a sunny day at a time when your home is using some electricity but not a huge amount. If the meter shows your are not using grid electricity then your home is self consuming solar electricity and will be entirely solar powered at that time.

      I’m afraid your electricity retailer won’t be able to help you with any questions about your solar system. All they will know is how many kilowatt-hours your system has exported to the grid and only up to the last meter reading. They are only interested in people paying their bills.

  65. Ok…thanks Ronald!

  66. If I have a solar panel can I share with my neighbour

    • Ronald Brakels says

      You normally can’t legally share electricity with a neighbor in Australia, Shirl. But any surplus electricity you panels produce will be sent into the grid for other people to use.

    • Lawrence coomber says

      Shirl there is a much more elegant PV plus battery storage design solution to consider and discuss with your neighbours that is quite simple to design and install cost effectively, and able to easily satisfy the total demand reliably and without any fuss 24/7.

      Importantly these installations have absolutely nothing to do with the Grid or any other entity whatsoever for that matter.

      Go Off Grid, or more precisely create an “Off Grid Micro Grid” with your neighbours on either side, or better still with 2 neighbours on either side for a total of 5 properties.

      Five typical domestic properties (either side by side or back to back) is the perfect scenario for a small scale, high performance, fully featured domestic micro grid solution.

      There are several different business models (and variants within these models) that cover domestic micro grids such as, equal joint ownership; ownership in common; one or two owners only with PPA agreements in place with the remaining micro grid members, etc etc.

      The legal matters are simply and cost effectively managed by a (renewable energy law specialist) and generally involve a Micro Grid Generation commercial contract between the members plus a land title registered easement across the rear property line of each property to allow for trenching for cable works and risers.

      High efficiency performance is guaranteed in this type of system design due to the high load diversity inherent in having five separate users being serviced from a single PV and battery storage system.

      Overall these system designs can be very efficient, reliable, scalable, and robust solutions for a group of like-minded domestic users to take control of their future energy requirements cost effectively.

      I expect you will see many domestic and rural small scale Off Grid Micro Grids installed throughout the country from this year on.

      Lawrence Coomber

  67. Di Ardrey says

    I have a 2kw solar panel system and have recently been given a net meter time of use from AGL.
    My husband and I are now retired and it’s just the two of us and we use the washing machine in daylight hours etc.
    My question is.. should we change of hot water system from the Off Peak time to peak so it heats up in the daylight hours?

    • Ronald Brakels says

      Hello Di. If you aren’t getting a high feed-in tariff then it is possible you will be better off putting your hot water system on a timer and having it heat water during the day, but it is difficult to say if you would come out ahead. Because you only have a small solar system your hot water system would probably often draw power from the grid, particularly on cloudy days and in winter, which is when you are likely to use the most hot water. My suggestion would be to not worry about it and leave it as it is, since there is a good chance changing won’t save you money.

  68. Hi Finn,

    I am a little confused. In the above case study, you self consume 10.33 kWh and export 31.4 kWh = total 41.73 kWh per day. You have a 6kW Solar Systems which should generate 25.2 kWh of electricity per day (according to the sales consultant). Are I missing something?

    Thanks for the clarification.

    • Ronald Brakels says

      Hi Lisy, Ronald here. The day that Finn used in the example was quite sunny, so on that day his 6 kilowatt system generated 41.73 kilowatt-hours, but the average over the year would be around 25 kilowatt-hours a day. (Finn took this into account when he estimated his savings over a year.)

  69. Thanks to my solar power diverter , I fed only 3 ! kwh into the grid during June 2017 . @6.5 cents it amounts to 20 cents credit on the bill !!! Now the FIT has been doubled here in Vic. to 11.3 cents. I will be credited 34 cents….. whoopy. I will be rich.

  70. Liz Hall says

    I have been reading your comments above today with great interest, especially the explanation as to how solar works. I live in Adelaide, South Australia. Can you tell me if tariffs rebates and solar self consumption works the same in our state. I am hoping it does, but as most of your other comments are referring to other states I am not sure. Would just like clarification.

    • Ronald Brakels says

      Hello Liz, Ronald here.

      The “solar rebate” that lowers the cost of rooftop solar is the same scheme throughout Australia. People in Adelaide will receive the same reduction in price as people in Sydney, Brisbane, Canberra, and Perth.

      Feed-in tariffs for new solar solar are higher in South Australia than in any other state. Using our comparison tool:

      I see that feed-in tariffs are as high as 18 cents a kilowatt-hour in SA. (Ignore Origin’s 20 cent feed-in tariff. That only applies for 12 months if you buy a solar system from them.)

      As both electricity prices and feed-in tariffs increased at the start of this month, I would say installing as large a rooftop solar system as you reasonably can is the way to go.

  71. colin murphy says

    Hi Finn,

    Had a 5kW system installed last Dec (18 * 260w panels) and would like to know how many extra panels I can install without overloading the inverter?
    I have already installed 2 extra panels(same type and size), so am now up to 20 panels. Can I get away with installing another 2 or 4 even?

    • Ronald Brakels says

      Hi Colin, Ronald here.

      With a 5 kilowatt inverter you can have a maximum panel capacity of 6.66 kilowatts. As you currently have 20 panels of 260 watts each totaling 5.2 kilowatts, you can install 5 more 260 watt panels and remain within the limit. That will give you a total of 6.5 kilowatts of panels.

  72. Hi,

    Love the website. Just wondering if you have done a review of the evergen system that has a grid/pv usage optimisation computer? Any thoughts or experience with it?


    • Ronald Brakels says

      Hi Max, Ronald here.

      Haven’t covered energen yet. From the little I know it is a lithium iron phosphate battery system that emphasizes its smart battery management system. Banging on about intelligent battery management is common among companies that use this battery chemistry, as they can tolerate being cycled more than other lithium battery chemistries and they want to make the most of it.

  73. John Drew says

    Hi Finn,
    Your article is a great read. When the solar incentives ( NSW) were available several years ago we installed an Apricus hot water system and 12 panels for about 1.6kW output. The system has paid for itself with the 60c feed in tariff. I am currently shifting our thinking to the opposite of what we used to do, ie. use less during the day to max out the feed in, and now we find ourselves trying to do everything during the daytime. I thank everyone on this site for your belief in solar…it is pure magic turning sunlight into electricity and I look forward to the day ( but I doubt I will be around) when we enjoy solar vehicles and affordable energy in our homes.

  74. John Leonard says

    I have just changed from Energy Australia to AGL and am trying to reconcile changeover meter readings and with any metered product take an closing meter reading take away the opening meter reading and that is what I used .

    However I am being told this information is not available and all I can get is usage in KW every 15 minutes this does not allow me to reconcile my account.

    This at best will allow covering up mistakes by energy suppliers and at worst allow manipulation of usage.

    Has anyone experienced this situation

  75. Will Ferrett says

    Why are you showing and talking about an Electricity bill dated 2015. totally irrelevant with the present costs of power with AGL

  76. Jose manchola says

    I am gettig repoff getting 2 bills one powr co and solar co.(vivit) 50d ea, 2 people not electri heat. What can i do each co blame the other

    • Ronald Brakels says

      If this the American company Vivint? If so, I’m afraid I can’t help you as I am only familiar with Australia.

  77. Jonathan says

    Our family of 4 uses just under 13kwh per day and at that rate my sums in ~2013 indicated it was not that worthwhile, even though three of us are at home during the day. We pay about $0.22/kwh inclusive and I believe this wold go up a lot if we switched (variable rate). Of course on top of that there is an access charge of about $33 per month. 13kwh gross seems very low for a family of 6 – well done!

    As a 2kwh system produces the same energy as a 6kwh system after the sun goes down, isn’t the object to produce no more energy than is necessary due to the low FiT which may not repay the additional investment for a larger system for many, many years.

    Based on the graph, wouldn’t a 2-3kwh system that just met daytime consumption make more sense than a 6kwh system, going by the relatively small amount of energy being used during peak solar generating hours and the considerable amount being exported to the grid? I assume it costs around another $5,000 to go from a 2.5kwh to 6kwh system.

    Please enlighten me, I am not averse to solar but 50% higher energy rates would offset some of the gains.

    • Ronald Brakels says

      Hello Jonathan, Ronald here.

      Given today’s high cost of grid electricity, increased feed-in tariffs, and low costs of solar, for a typical household it often makes as much sense to install as much solar as will reasonably fit on the roof. I go into the details of why here:

      In a nutshell, feed-in tariffs can make a larger system worthwhile even if only slightly decreases the amount of grid electricity a home uses compared to a smaller system.

      • Jonathan says

        That is interesting, Roland, but your comment:

        “Even if you only owned your solar system for 5 years before you sold your house, provided it added only $1,500 to the value of your home, then with an IRR of 8.2% it will still beast the the IRR of 7.1% for money invested at 5% over 5 years.”

        That is not, with respect, valid.

        Solar might offer a better return but with the cash investment one expects to receive all of one’s capital back in addition to the forecast dividend, coupon payment or capital gain.

        With the solar investment, all one has done in the first 6 – 7 years is recoup one’s capital investment, meaning no return whatsoever beyond the investment. Or, gained an annual return by way of net energy savings but been forced to surrender all but $1500 of the $7000 capital invested when selling the house.

        So no returns inside 7 years, just capital returned, no?

  78. I need help. I have a 4.5Kw solar panel and last year (with the solar panel), I have been paying approx. $500 per quarter electricity bills. The record was showing we were using 30kwh per day .
    From March 2018, I haven’t been using as much electricity compared before (due to personal circumstances) and I switched from AGL to Energy Australia and my bill this time is $1300 (usage of 52kwh per day.
    I spoke to Energy Australia and Ive been told that their reading is accurate as we have smart meter. I checked my solar system and it is working generating 3kw.
    Can you please advise if there’s someone who can check WHY my kwh is higher. As Ive said, from March 2018, I have less appliances that I used compared before.

    • Ronald Brakels says

      Hello Lanie

      It is possible you have a defective appliance that is increasing your electricity consumption. For example, I had a friend whose electric hot water system was leaking and she had huge electricity bills as a result. I had a higher than normal electricity bill at the end of last year because of a defective refrigerator. But often high electricity bills occur because someone in the house is using a lot of energy, often without realizing it. For example, I had another friend whose daughter left a bar heater on in her room 24 hours a day all winter and she had a very large bill as a result. So it can pay to look for both appliances that are using too much electricity and people who are using too much electricity. Some things that often catch people out because they don’t realize how much electricity they use are:

      * electric space heater or bar heater: 1.5 to 2.4 kilowatt-hours per hour of use. (Using a room air conditioner as a heater generally uses less than one third this amount.)
      * Hot water: 0.5 kilowatt-hours to heat 10 liters to 60 degrees.
      * Clothes dryer: Around 2 kilowatt-hours per hour of use.

      Things that use little electricity these days are LED lights, modern TVs (despite how big they usually are), laptops and most computers.

  79. Lanie Cato says

    Hi Ronald,
    Thank you for your reply. This morning, the solar people checked my solar to ensure that my solar is working and there’s nothing wrong with them.

    He checked my bills and he said to ask the Energy Australia if the ‘net feed solar meter is working properly?’

    Here’s the number he wrote for me
    Jan 17 bill – daily usage is 31.58kWh – Feed in tariff is 8.15kWh per day
    AGL = Oct 17 – Jan 18 – my daily usage is 40.45kWh
    I transferred to Energy and my first bill is for one month only
    Apr 18 – my daily usage is 33.93 kWh – Feed in tariff of 5.57kWh per day
    May-Jul 18 – may daily usage is 51.2kWh – Feed in tariff is 2.04 per day.

    Last year my feed n tariff is averaging to 8-9kWh per day.

    He said that I don’t have an appliance that will increase my electricity. My hot system has his on block of usage and has a consistent ave usage of 900kWh per 3 months.

    I have airconditioning but as I previously mentioned my usage changed dramatically from March because my husband passed away. When he was alive, the aircon (with heating) of the whole house was ON 24/7 plus I have a bar heater if it was still cold for him even in a summer day. I also worked from home, our lights were On all night, etc.

    From then on, it is different, I don’t use the aircon, I get rid of the bar heater, and we are not home in day time. I am expecting that my bills will go down.

    I have a pool that the pump was set up to run 5 hours per day( 10AM-3PM) which I changed to 3 hours per day – 10AM-1PM, which should be using the energy from my solar system.

    The graph of the smart meter from my Energy Australia website is showing that even in day time (where I have my solar working), I am using up to 5kWh in an hour.

    I rang again the Energy Australia and I asked about this “net feed” and I have been told that it will cost me $670 to check the smart meter.

    I ve been informed it was very unlikely that the smart meter is faulty.
    So I really don’t know what to do.
    Please help.

    • Ronald Brakels says

      Hi Lanie

      I’ll have someone from SolarQuotes get in touch with you directly by email.

      • Lanie Cato says

        Thank you Ronald for your assistance. By the way, coincidently, my husband name is Ronald too. He is not here to help me but at least there’s another Ronald assisting me. Again thank you.

  80. Hi Finn

    We are a couple in our late sixties still working trying to stay alive so rarely home during the day. Our energy use would be mainly late PM (after 6pm) and early morning before leave for work around 7:30/8am.

    Currently we are using around 10,000 KWH peak and 2500 KWH Ct1 per year.

    We are based in Western Sydney with a south facing house so rear roof faces North.

    We have 3 phase electricity supply to the house

    We have just changed retailer to a new mob based in QLD who have provided us with a real-time discount of 20% off the mandated NSW tariff with no fancy discounts linked to term contracts etc.

    Major users we suspect will be the washing machine and drier used 3 times a week in the evenings and Split system aircon downstairs in the evenings and small room heaters (each 2400 W) upstairs in the mornings. Summer time cooling is with fans mainly.

    We are looking to reduce our heavy electricity cost (currently $3,400 pa) and were considering Solar as an option but are concerned that our usage mainly being at night and early mornings would not provide us with the best solution as the FIT would not allow us to maximise the use of the power that we would be generating for our own use due to our absence from the premises during the day-light hours.

    Also, we would welcome your advice on the right size of system to seek quotes for to cover our needs and make it a viable venture

    • Ronald Brakels says

      Hi Quaggie, Ronald here.

      Using our retail electricity plan comparison tool:

      I see in Western Sydney you can get a solar feed-in tariff of 16 cents with a per kilowatt-hour charge for grid electricity of 24.2 cents including GST. So if your current retailer won’t give a good feed-in tariff there’s always the option of changing.

      Because you can get a good feed-in tariff you don’t really need to worry about getting a system that is too big. Provided your roof doesn’t have significant shading it will still provide a good return even if most of the electricity it produces is sent into the grid for the feed-in tariff.

      Because you have three phase power you can get as large a system as will reasonably fit on your roof. If you don’t have the budget or the desire to get a large system, then I’d suggest getting close to 6.6 kilowatts as you can as this provides a good combination of low cost per kilowatt installed and good electricity production.

  81. Hi:
    Can I keep running and old system 1.5kw and add a second kit larger to complement the power requested at day time?

    • Ronald Brakels says

      Hello Louis

      You can get a second solar system, but if you have an old high feed-in tariff you will generally lose that. If that’s not a problem then you’re choices are to either keep your old system and install a second system or remove the old system and install one new large one. While it is a bit of a waste to remove a working system it often makes sense to use the space for a single large new system.

  82. pieterr tenuile says

    i have had a 10kw solar sytem installed on our roof it cost us $10.000 for 30 panels the first bill i got from my energy provider ( ergon energy ) was $1100 for the quarter after 16 months it has come down a bit but we are still paying $700 per quarter i dont know what is wrong with our system but pardon the expression i get pissed of when i hear people spout of when they have a 4 or 5 kw sytem installed and only get a quarterly bill of $150 what is wrong with our system?

  83. Hi,

    Happy with my system and spreadsheet, happy to pass it on or explain it.

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