Want $0 Electricity Bills? On-Grid Solar Beats Batteries.

zero dollar bills?

Want Free Future Electricity Without Blowing The Bank?  Get On-Grid Solar Without Batteries.

When it comes to buying rooftop solar and batteries, people have a wide range of motivations.  Some want to save money, most are environmentally concerned, there are tech-heads interested in the technology, while others just want to be trendy.  Then there are confused people who ordered a battery thinking they were buying artillery or possibly a chicken.

But one motivation that pervades our society is love.  Love for free stuff.  In this case, free electricity.  Most people I know would love to have $0 electricity bills or better yet, be paid for providing clean solar electricity to the grid.

If $0 bills are what you want, it’s okay to admit it.  You’re among friends here.

But people sometimes make mistakes in their pursuit of free electricity.  For some reason the idea of free stuff seems to short circuit our brains.  It can have such a hold on people’s minds they don’t care how much money they have to spend to get it.  To help you avoid making mistakes and short circuiting your bank account, I am going to lay out your options for getting your electricity bills down to $0.

Three Options For $0 Electricity Bills

There are several ways to set things up so you’ll never have to pay for electricity again.  One of the ways makes excellent sense both financially and environmentally and simply involves installing a large solar power system.  It can not only pay for itself, but is the best investment most Australian households can make.  While it’s often not practical to install a system large enough to achieve $0 bills, it still pays to get as close to that goal as reasonably possible.

And then there are a couple of other ways that don’t make financial sense at the moment and they involve buying home batteries.  They may make sense in the future.  In fact, they bloody well should.  But if your goal is to save money then you won’t be doing that if you buy batteries now.

The three main ways for getting your electricity bills down to an average of $0 over a year that don’t involve sitting in the dark are:

  1. Install enough rooftop solar so the feed-in tariffs received from exporting surplus electricity will reduce your bills to nothing.
  2. Install rooftop solar and a battery on-grid.
  3. Install rooftop solar, multimode inverters1, a generator, and enough battery power to let you kiss the grid goodbye.

The first option is the easiest and unlike the other two will make you money.  But to get your electricity bills all the way down to zero you’ll either need to be a modest user of electricity, or failing that, have a really big roof and preferably 3 phase power.

The second option of installing a battery while staying on the grid can give you $0 bills, but no battery system available now will pay for itself for any remotely normal household.  Once the cost of capital is accounted for you won’t come out ahead.  It can help you reduce the number of solar panels you need reduce your electricity bills to zero, but it’s not going to help your wallet.

Finally, there is going off-grid for good.  Unfortunately this will cost a small fortune if you want the kind of convenience being on-grid provides.  But even if your home is fully capable of going off-grid without a problem — maybe you won a free off-grid system in a pub raffle — it can still make financial sense to stay because the value of feed-in tariffs received from exporting surplus solar electricity can easily exceed the cost of grid supply charges.

Using Solar Power Alone To Gain $0 Electricity Bills

Using rooftop solar to get your electricity bills down to zero is pretty straight forward.  Put plenty of solar panels on your roof and make enough money in feed-in tariffs so you don’t have to pay a cent on your electricity bills, or better yet, get paid for the electricity you provide.  Unfortunately, there there is a pretty big problem in most people’s way.  The majority of Australian homes have single phase power which limits them to installing a maximum of 6.66 kilowatts of solar panels.

Bad Omen

Young Damien was livid he could only install 6.66 kilowatts. “I require 100 times that amount!” he insisted.

This limit makes it very difficult for for typical households with average electricity consumption to get their bills down to nothing.  A typical household only has 2 people in it, as that’s the most common household size2.  This graph shows the average annual electricity consumption of two person households by state and territory:

Annual Electricity Consumption

As you can see there is a considerable amount of variation, with Tasmanians consuming more than twice as much as Victorians.  The difference is due to most Victorians using gas for hot water and home heating while Tasmanians generally use electricity for everything, including heating, and it gets bloody cold in Australia’s full stop3.  Victoria’s mild climate also means they use little electricity for air conditioning in summer.

$0 Bills With Single Phase Power In South Australia

South Australia is a state with low electricity consumption and the highest average feed-in tariffs, so if a typical household can get $0 bills with single phase power then this should be the place.  According to PVWatts, a household that installs 6.5 kilowatts of north facing solar panels at a 20 degree angle in Adelaide will generate 9,800 kilowatt-hours of solar electricity a year.

If this home uses the typical two person annual average of 5,000 kilowatt-hours and it is evenly split between grid electricity and rooftop solar power, then it will produce a surplus of 7,300 kilowatt-hours of solar electricity that will be sent into the grid for a feed-in tariff.

Using our price comparison tool the most effective retail electricity plan I can see has a 17 cent feed-in tariff.   After taking into account the kilowatt-hour charge for grid electricity, supply charges, discounts, GST, and the total amount of feed-in tariff earned, the household’s annual electricity bill comes to negative $50.  This means they’ll be earning almost a whole dollar a week from selling electricity.  While that’s not a lot, it’s infinitely better than nothing.

This is for a new system with almost ideal output, so this result won’t be easy to replicate under real life conditions, but it is possible for a typical South Australian household with single phase power to at least break even and have $0 electricity bills.  Adelaide is the only capital where this can happen apart from Darwin, which is a special case, as they still have a very high feed in tariff that is equal to what they are charged per kilowatt-hour for grid electricity.

Of course, not everyone’s electricity consumption is typical and for efficient or frugal households, 6.5 kilowatts of solar panels may be more than enough for them to make money from their electricity bills.

Export Limiting May Allow Larger Systems With Single Phase Power

Households with single phase power may be able to get permission to install systems with an inverter larger than 5 kilowatts and solar panel capacity greater than 6.66 kilowatts, if the system is export limited so it can never send more than 5 kilowatts of surplus solar power into the grid.  This has the disadvantage that the export limiting equipment has to be paid for and some clean solar electricity may go to waste, but it can still be a cheaper way of getting $0 electricity bills than buying a battery.

Three Phase Power Will Often Be Required

Because households are generally permitted to install 5 kilowatts of inverter capacity per phase and three phase power has — surprise, surprise — three phases, this means homes with it can have up to 15 kilowatts of solar inverter capacity.  Solar panel capacity can be up to one-third larger than inverter capacity, so three phase homes generally can have up to 20 kilowatts of solar panels.

But even with high efficiency panels, most roofs are going to have difficulty fitting 10 kilowatts worth.  That much requires a big house.  Or possibly a small house wearing a giant hat.

Upgrading from single phase to three phase power is expense.  I’ve heard of it costing only $2,000 to $3,000 but it can easily cost over $5,000.  That’s in a town or city.  If you live in a rural area it can cost more than paying for hairdressers during a shearer’s strike.  So you’d want to be certain it’s worthwhile for your situation before shelling out that much.

Minimum Solar Power System Size For $0 Bills By Capital

If, as in the Adelaide example above, a household uses 5,000 kilowatt-hours a year, evenly split between grid and solar electricity, then the minimum amount of solar panel capacity required for a home to have $0 electricity bills in the state and territory capitals when using the best retail electricity plan available would be:

Minimum kW for $0

In this comparison Canberra does well because it has the lowest electricity prices in Australia while Perth performs poorly, despite high levels of sunshine, thanks to its low feed-in tariff of only 7.1 cents per kilowatt-hour.  While Tasmania’s 9 cent feed-in tariff isn’t quite as bad, it is still low and Australia’s shoe heel is a shady place by our standards.

Update 9th December:  Unfortunately, for households in Western Australia that want large solar energy systems, they are normally not permitted to install more than 5 kilowatts of inverter capacity even if they have three phase power and they’re not allowed to work around this limit through export limiting either. 

If you consume more than 5,000 kilowatt-hours a year then you’ll either need a larger solar power system or work on getting your electricity consumption down through energy efficiency measures such as improved insulation, LED lighting, efficient appliances, and for winter: cross breeding a kangaroo with a sheep to make a woolly jumper.

Batteries Can Allow $0 Bills With Smaller Solar Power Systems

If I use one kilowatt-hour of grid electricity that costs 34 cents and my feed-in tariff is 17 cents, then I’ll need to export 2 kilowatt-hours of solar electricity just to break even.  But, after allowing for charge and discharge losses, I might only have to store 1.2 kilowatt-hours of solar electricity in a battery to avoid using one kilowatt-hour of grid electricity.  Because of this, home batteries can reduce the amount of solar panel capacity required to get $0 bills.  But at their current cost this is only a good idea if you are determined to get $0 bills and don’t care about saving money.  This is because batteries do not pay for themselves yet.

One year ago I wrote about how the Powerwall 2 won’t save households money and this is still the case.  It’s actually worse now than what I calculated then, as the total price appears to be higher and its efficiency lower than the figures I used.  What has improved is they are now actually being installed, which is infinitely better than what was happening last December.

Because the Powerwall 2 leads on cost per kilowatt-hour of storage, if it can’t pay for itself then neither can other battery systems.  While electricity prices increased over the past year, for most Australians higher feed-in tariffs either resulted in either no change in the economics of batteries or made them worse.

So if you want $0 bills a battery can help you achieve that, but it’s not a smart moves as far as your wallet is concerned.  You’d be better off using the money to make a house payment or investing it in a term deposit.  You also won’t be helping the environment because, at this time, energy losses from battery storage results in less reduction in fossil fuel emissions than simply exporting electricity to the grid.  In the future this may not be the case, but it is the case now.

Going Off-Grid Won’t Save Money

Supply charges are fees we are hit with for the glory of being connected to the grid, regardless of how much or how little of its electricity we actually use.  The average is approaching $1 a day with a typical annual total being around $330.  Going off-grid means never paying this again, but it also means never receiving a feed-in tariff.

In order to get through winter and periods of bad weather, off-grid homes normally produce much more solar electricity than they consume over a year.  So even if it cost nothing to go off-grid, it would still make financial sense for many homes to remain so they could continue to receive feed-in tariffs.

But rather than being free, the cost of going off-grid is extremely high.  To provide even modest users of electricity with convenience approaching that of being on-grid can cost $30,000 or more.  This is not a once off cost but represents batteries and inverters that will eventually need to be replaced.  While their cost should fall in the future, they are unlikely to be free any time soon.

Backup Power Provides Only A Small Benefit

One advantage of many, but not all, battery systems is the ability to provide backup power during a blackout.  This varies from only being able to provide energy currently stored in the battery and then becoming useless until grid power is restored, to being able to charge off solar during the day and provide power at night independently of the grid for years.

This feature is definitely useful but its value is not very high for most Australians.  This is because in most regions blackouts are rare and so it can be cheaper to simply tolerate them when they occur than go to the expense of installing batteries.  And where people decide it is worthwhile to have a backup source of electricity, a generator can be a cheaper option.

Personally I tend to look forward to blackouts as they are the perfect excuse to eat everything in the fridge.  Sometimes, if I move fast, 5 minutes worth of blackout is all I need.

 

Do What You Wanna Do, Be What You Wanna Be…

The more things change, the more things don’t stay the same.  I can’t be certain what will happen in the future with electricity prices, feed-in tariffs, battery prices or even how much solar households will be allowed to install.  What I can be sure of is things won’t stay the same and maybe next December this article telling people batteries don’t pay for themselves will seem quaint.

I also can’t account for individuals’ taste, so by all means buy batteries if that is what you want to do.

What I do know is solar can definitely pay for itself.  So if you want to get your electricity bills down to zero, filling your roof with solar panels and skipping batteries for now is the way to go.  A few years down the track, you’ll happily end up with more money than you started with, rather than less.

 

Footnotes

  1. Multimode inverters are also known as hybrid inverters.  If you want the sort of reliability the grid provides in populated regions of Australia, then you’ll probably want to have two of them.
  2. I know this seems to suggest Australians aren’t terribly gregarious people, but shrinking household size is a trend in every country as it grows richer.  I used to wonder if, once the old social structures had finished unraveling, this process would reverse itself, but I now realize it won’t due to recent advances in artificial intelligence that will stop anyone from ever being lonely.
  3. Tasmanians using twice as much electricity has nothing at all to do with them having two heads.
About Ronald Brakels

Many years ago now, Ronald Brakels was born in Toowoomba. He first rose to international prominence when his township took up a collection to send him to Japan, which was the furthest they could manage with the money they raised. He became passionately interested in environmental matters upon his return to Australia when the local Mayor met him at the airport and explained it was far too dangerous for him to return to Toowoomba on account of climate change and mutant attack goats. Ronald then moved to a property in the Adelaide Hills where he now lives with his horse, Tonto 23.

Comments

  1. “But rather than being free, the cost of going off-grid is extremely high. To provide even modest users of electricity with convenience approaching that of being on-grid can cost $30,000 or more. This is not a once off cost but represents batteries and inverters that will eventually need to be replaced.”

    let me point out that a large PV array can cost $30,000 or more and if so that only means that ones yearly kWh consumption is high. One could easily thke that same $30K and reduce ones consumption and at the same time

    You can buy an off grid system for $30K and that system can last up to 40 years. PV modules will last 40 years, Off grid inverters can and usually do last up to 40 years. The missing link is the battery. Nickel iron fits that bill. Lithium may be able to replace a nickel iron for longevity, but the jury is still out, but the life cycles of lithium ion are definitely getting longer rand longer. And the nickel iron battery is the only battery technology you can replace the electrolyte that can make the cells last up to 40 years, or even longer.

    Service fees in the USA are getting higher and higher. If my son where hooked up to the grid he would be paying $53 a month for service fee. That is $636 a year. That fee is if he where to use 201-400 kWh a month. If he went over 400 kWH a month his month fee would be $68. $816 a year. As utilities keep raising basic service charges it will make more and more sense to completely disconnect. Service fees have only gone OEN direction and that is UP, not down.

    With proper planning and energy efficiency measurers one can easily get their monthly kWh usage down to 400 kWh a month. That would be 13 kWh a day. Easily achieved with a modest sized battery bank.

    As I remind my best friend and I will remind you as well. If we all lived our lives according to “payback” then no one would buy computers, cars, cell phones, exotic cars, fancy boats, etc. After all we are creatures of habit and the habit has been you just hook up to the grid. But being off grid is really “priceless”.

    And one more thing.Option one is the best option, but only if you have low kWh usage and or a big enough roof space for a large array, using the grid as your storage bank, not doubt about it, but is it the best thing in the long run? In the long run you are truly such better off going being off grid. The item is coming when tariffs will go away , battery banks rookies will be so inexpensive and have such long lives there will silly be no need for the “utility”.

  2. Patrick Comerford says

    If as you say Ronald a solar plus battery is not financially smart at the moment, what price do you put on getting a zero electricity bill then?
    As the MasterCard add says it’s Priceless. Trust me my Powerwall 2 and 3.8kw PV is delivering zero power bills and I’m loving it.

    • Erik Christiansen says

      Patrick, how does that 3.8 kW PV fare in winter? (Its winter output would be less than half nominal down here in Victoria, from what I read.) Admittedly, there’s no need for aircon in winter, and room and water heating can be from the wood heater, but there’s still microwave, breadmaker, rice cooker, fridge, …

      • Patrick Comerford says

        I live on the Gold Coast which provides great PV output year round. Also use micro inverters with LG 315w neon 2 panels which give added production. My PW2 was installed in August so experienced the last of winter. My average daily PV production was about 14 kWh peaking at 17kwh, also done a bit of home demand management and replaced some ten year old items such as the ducted ac unit, fridge and pool pump ( fitted an ECO pump). Previously my ave daily consumption in winter was 18kwh excluding off peak HWS. This is now around 14/15kwh with the added bonus of now using my PW2 capacity and grunt to cover my HWS consumption of 3/4kwh by simply using a timer. Current PV production is around 23/24 peaking at 26kwh. So I am achieving 100% self consumption and what I export to the grid at 12c /kWh gives a zero electricity bill. Even enough spare to charge the EV which I plan to get next year.

        • Katrina Hunt says

          You can export to the grid and have battery storage? What I’ve read so far seems to infer that it’s not the case.

    • Hey Patrick, I think if you look solely at the financial costs vs savings, the benefits of the battery is rather suspect. As an example, a solar PV system could bring down your electricity costs from $2,000 to $200 p.a. (just guessing the figures to demonstrate the logic).

      That will mean the maximum financial benefit of the battery is $200 p.a. If you had to outlay $10,000 to save $200 p.a., it doesn’t really make sense. Financially, you would be better off putting that $10,000 in your home loan offset account or managed fund etc etc. That would give a better net effect.

      BUT, personally I do like the idea of the backup capability of batteries. Being able to withstand sweltering summer blackouts is something I value. Not having to worry about stuff melting in the freezer or being able to get a restful sleep at night.

  3. TJ Roberts says

    In 2013, I started building a grid-connected solar PV system for my home with (3) strings of Enphase microinverters. By 2017, I had 6 strings with 85 microinverters. In the States now, with the Winter Solstice approaching, I am producing ~70,000-Watts of power per day. In the summers, I am hitting near ~100,000-Watts. I do have some shading, and I use South, West, and East roofs. My home uses about 30-40kW per day. I am grandfathered in at an NEM rate of $0.12/kilowatt. Now the utility is only paying $0.05/kilowatt for new solar PV customers. Still, solar is worth it. Approximate cost of all the hardware was $20K. My labor was free. My system has produced 80.2-Megawatts over its lifetime now according to the Enlighten monitoring software, so I am about halfway to breaking even. Using a mix of M215 and M250 microinverters, I have not had one fail yet. I like your comment [ For some reason the idea of free stuff seems to short circuit our brains. It can have such a hold on people’s minds they don’t care how much money they have to spend to get it.] Ronald, it is really that — it’s the idea of not having control over my utility costs, sort of like a maximum hedge against inflationary costs from the utility that made me do it. Here in Florida, the Sunshine State, the people just beat down a major Amendment in the voting polls that would have given the utilities the power to add on a fee to solar customers utility bills. Right now, the most they can charge is $5 called a “Solar Administration b.s. Fee” … you can decide what the “b.s.” stands for yourself. It’s a classic fight, Ronald. Power to the People!

    • “labor was free” in your case maybe but 99% of people who install solar system pay some one to install their PV system. So you have to include those costs.

      I am looking forward to the enphase inverters that will allow them to be operated WITHOUT grid interface. That will be a major milestone because then you can do modules level monitoring with an off grid system which is not yet available. I am assuming that those units will simply allow a battery system to be used with their inverters, but maybe it will only be their battery. If that would be the case then that battery better be “affordable”.

      and yes “power to the people”

  4. Couldn’t agree more with your article.
    I consider the “grid” as my battery since installing another 6500 watts of panels on top of my preexisting 2660 watts I am receiving approximately $100 in credit a month and thats after my electricity bill is paid. And thats on 12.8 cents a kW from my energy retailer.
    Interesting to note that it has taken almost 6 years to pay off my first pvc grid connected system on a 60 cents per kW pay back
    But I estimate paying off this newer 6500 watt system in approx 3 years.
    Of course with the help of my old system to help.
    That is an SMA inverter and Suntech Panels and still works like new.
    The newer system is a Fronius inverter with Jinko panels.
    Happy Days

  5. I have now had 7 “load shedding” events (i.e. blackouts) in the last 7 months. I have started monitoring the grid when I feel it is under voltage (more or less all the time now). For those that do not know, under voltage means I am also being over metered for the delivered power according to some “electricity grid experts”. I live in WA – i.e. a paltry 7.1cents per Kwh exported. Over here our supply charge just doubled on 1/7/17 as well as the import charge increasing (again – at least once a year). Our daily usage is 15.6Kwh, only 4 Kwh at night.

    On a badly shaded site I have 3Kw of panels and 6 mini inverters (two panels per inverter). Despite sending over 3 Mwh of power to the grid we are still getting “sub $100 bills”. Luckily I have 3 phase so I could put 10Kw of panels (Ronald’s break even point) on the roofs – three of them. Most people are not so lucky (3 phase / 3 roofs). Given an electric vehicle and an upgrade to the solar are both imminent, I doubt the battery maths above will be relevant anyway – the upgrade will have to include a new inverter big enough to charge said vehicle in a few hours. In that situation putting a few Kwh of storage (6?) or using the vehicle battery overnight would almost be worthwhile – especially given the fuel saving (furthest round trip is about 180Km apart from the rare road trip) should be added to the mix.

    Thoughts?

  6. Living in Tasmania, we are used to bring left out of national news and polls etc, so it was good to see you include our little slice of heaven. You also mentioned tbat due to a push by our power generator Aurora, the majority of heating, hot water and cooking is done using electricity, hence we lead the pack re household power consumption. Fair point, however these aspects of living are not free in most other parts of Australia, so if you are going to put Tassies cost of living in the equation, then to be able to compare apples to apples should not those charges also be included for mainland comparisons ?

  7. Whilst I believe that battery storage (configured to act as a transparent UPS and, to provide usable capacity of about two days electricity consumption) would be good to have as part of a domestic rooftop photovoltaic system, and, it appears, from Ronald’s confidence in the grid electricity supply, that he has not lived in WA, the criticisms above, of his article, appear to be on the basis of what exists in the USA (and, it should be remembered that that is the country that put the president Chump in power, giving the USA, the world’s most powerful sex offender), and, it should be remembered, and, emphasised, that, whilst the articles published in the blog, may be of interest to people outside Australia, I believe that the blog is written (for the most part) about conditions in Australia, and, for application to Australia.

    I stand to be corrected, if I am wrong in this.

  8. At this point in time (and here Im only speaking from the point of view of main land Australia.
    That I rather invest in a good sinewave inverter generator than any battery availabile at the current prices ie 2017 for power backup.
    I withdrew my deposit on Tesla Powerwall 2 because I was required to fork out another $700 on top of the 12 Grand to have just one battery charge available.
    As I was informed by Tesla Co. So my existing pvc would not charge the battery until the grid was back on line. Go figure no doubt there might be a safety reason from the grid companies line workers but it doesn’t cut the mustard to pay 12,700 dollars for one day backup. I can buy a top Honda or Yamaha sinewave inverter generator for a lot less.

  9. What if you had a battery on an interest free or green loan, such as what the friends of solar quotes offer?

    I have a green loan on my solar system and so far, in the spring and summer months (only had it that long), I am in credit. It will save me $3000 per year and that’s being conservative! So the savings far outweigh the repayments.

    If you already own your solar panels and you add a battery on a green loan, would the credit you earn from all the extra exporting and zero importing, end up paying for itself in 4-5 years. I haven’t crunched the numbers.

  10. Ronald
    Can I ask a blonde question (please forgo the usual comments boys I’ve heard them all before) Am I correct in my understanding that it is better, at present, to feed excess power into the grid during the day and then use the grid to charge the EV at night rather than store the excess in a battery during the day and then use the battery at night to charge said EV ????

  11. Ironically, Western Power just sent a letter advising me of another day (19th) without power due to “scheduled maintenance” – hopefully to fix the under voltage & reliability problems in this area. I really wish I had battery backup now – I will have to drag out my 6.9 KVA generator and put up with the noise for at least half a day.

    I am at the point of saying “to hell with the economics, just go offline and get reliable power”.

  12. As a number of applicable aspects have changed, since the datestamp of the article published at
    https://www.solarquotes.com.au/blog/powerwall-2-payback/
    including the Powerwall 2 things apparently likely becoming available some time in the next couple of years, (in the states where they are not banned, with WA single phase grid electricity customers being prohibited from having the electricity supply stability that a Tesla Powerwall 2 system could provide), and, pricing both of the Powerwall 2 things, and, of grid electricity, having likely changed, in each state/territory, and, possibly, the costs of finance, perhaps, a review/update of the article published at
    https://www.solarquotes.com.au/blog/powerwall-2-payback/
    (now being almost a year old), could be appropriate?

    Also, the value of a battery storage system functioning as a UPS, to provide some sort of electricity stability and security, where the electricity supply is erratic, like in the WA SWIS grid, and, providing usable electricity when the grid can not, and, allowing the use of domestic rooftop photovoltaic systems when the grid fails (I think that, when the grid fails, whilst domestic rooftop photovoltaic systems are not allowed to export to the grid, they should be allowed to charge backup storage batteries) is something that should perhaps, be taken into account, when assessing the value of battery storage systems being connected to domestic rooftop photovoltaic systems.

  13. I have just found a report linked from the Renew Economy web site, which is interesting, in the context of the above article.

    The report/article to which I refer, is published at
    https://onestepoffthegrid.com.au/solar-unlimited-use-inverters-get-past-export-limits/
    and indicates how domestic rooftop photovoltaic systems generating capacity may be limited, not by the “inverter capacity” limit, but, instead, by other considerations, such as generating capacity potential (roof faces orientation and available roof faces areas) and available funds.

    It is, I think, an interesting report/article, with the point that it makes.

  14. I believe that South Australia has a new limit of 5kW for single phase domestic solar installations as of 01/12/2017. So once again we are being screwed by SAPN. Maybe the $0 bill is not quite as achievable in Adelaide anymore!

    • Ronald Brakels says

      Hello Lee. I’ve just been writing on this and should have an article up about it very soon.

      If I were not a little mad and generally silly I would give you my advice upon the topic willy nilly,
      I’d show you in a minute how to tackle with the question and you’d really be astonished at the force of my suggestion,
      On the subject I shall write a most valuable letter full of excellent suggestions when I feel a little better,
      But I’m afraid that at the moment I’m as mad as any hatter, so you’ll have wait a little while I pull myself together.

      – Paraphrased from Gilbert and Sullivan

      • If I Had Matter I’d respond in kind, as I resemble that remark… . In short, WA initiated a similar 5kW limit, right after I’d installed 7.2kW on our local school roof. [email protected]@rd$.

  15. Dennis Kavanagh says

    My 9.8 kW system is on single phase in the United Energy area of Victoria. My maximum half hour export so far has been 4.125 kWh which equates to a maximum exported power of 8.25 kW for that half hour (or 34 amp). So Ron, how does your limit of a 6.66kW system come about?

    I also have a small house but I have also used the rear patio, garage and small bungalow for panels. So even some small houses can accomodate a large pv system.

    • Ronald Brakels says

      You were lucky. United Energy allowed 10 kilowatts per phase, including for single phase power. If they still do it may the only place in the country. South Australia used to, but that’s no longer the case. I should have an article about that up very soon. The Australian/New Zealand standard 4777 allows for only 5 kilowatts of inverter capacity for single phase homes. Distributed Network Service Providers can make exceptions to this, but they generally don’t. Solar panel capacity can be up to one-third larger than inverter capacity so a 5 kilowatt inverter allows for a maximum of 6.66 kilowatts of solar panels.

  16. Dennis Kavanagh says

    And after I have been with my current electricity retailer (GloBird) for a full year, I estimate they will have paid me just over $1,000 for my small, all electric house. And that does not include the savings from self-consumption.

  17. This has been aired before…..more than once. And again I say that stand-alone systems are the ONLY way to go (even though I used to make a profit $1600 pa from Origin due to my no-waste nature.)
    The components are dirt cheap these days, and if one sticks to the practical issues the whole concept is an exercise in simplicity.
    I’ve demonstrated that the price of good BASIC LEAD-ACID BATTERIES is recuperated in about five years (or much less if you use your head in acquisition) , and with a bit of luck you can get a few years more. In my situation (before I sold the house) the saving of about $600 pa. in ‘service-to-property-fees paid for the batteries in five years, and the rest was gravy.
    Arithmetic can be as complicated as you want to make it, but the bottom line is that the power companies/distributors/governments/etc. will always make sure that they DON’T operate at a loss. ie. they’re in it to get your money off you. End of story.
    ….and the ‘what they’ll allow’ question becomes irrelevant is you don’t tell ’em what you’re doing. I never could understand why people tell the taxman ~ for example ~ how much they’re making…..and then bitch about having to hand a big whack of it over.
    I have this well-founded theory that it isn’t just women who have a built-in masochistic streak.

  18. ps…..and if I couldn’t set up a solar-system for. say. a frugal 3-person family for under $10k I’d bare my arse in Bourke St, as they used to say.
    Want a break-down?

  19. ” I never could understand why people tell the taxman ~ for example ~ how much they’re making…..and then bitch about having to hand a big whack of it over.”

    Well, I figure that honesty remains the best policy… . In fact, I’d argue it’s the _only_ policy. Yeah, I agree that we Aussies are screwed over by governments… and pollies who bleed us with their own excesses, but we do get regular opportunities to end their careers.*

    Where _do_ you draw-the-line, once you decide to cross it?

  20. * Not that these excesses cease, once they retire… .

  21. yoo-hoo…….. Haven’t we been here, done that?

    The best ~ if not only ~ and absolute ~ way to “reduce bills to $0” and “Avoid blackouts” is to get off the bloody grid! Is it possible to overstate the obviousness of that??

    I’ve lived for years ~decades! ~ without grid-connection ~ and also without deprivation….though that may be because I lived alone. (more people simply means more panels/batteries, etc; ALL DIRT CHEAP THESE DAYS. ) But make NO mistake: living off-grid is not only possible, but also financially a PLUS.

    A small adjustment or two in usage/time-of-usage provides all the power you need; and storage batteries can easily cope with ‘normal’ use if the adjustments’ are made.

    And battery-storage is MORE than ‘financially viable’ if one were to cease the massively-overpriced ‘lithium’/etc bullshit and stuck to the tried and tested ~ and still too-pricey but getting cheaper ~ LEAD-ACID batteries.

    I’ve demonstrated the arithmetic (and adjustments) on these pages more than once, and lived accordingly for probably longer than some of you have been alive. Simply out:- LA batteries store a kw of electricity for about $150 (yep ONE HUNDRED AN FIFTY)
    Double that to $300 to allow for a battery-friendly 50% DOD.
    Halfway decent LA batteries should last for (at least) 5+ years if well-treated. I used to get well-worn bulldozer batteries from the tip, which usually lasted about two years ~ though one lasted for a mere 12 months and another for eight years.
    And a LOT of experience in all sorts of situations tells me that anyone who can’t live comfortably on a maximum of 10KWH per day shouldn’t be allowed near a power-switch in any case. As a fairly-frugal single ‘household’ I used about TWO kwh per day for years…..and only got on the grid once because I couldn’t resist the cash Origin was sending ME every month (up to $1600 pa)…….. Rather better than a $0 bill anytime.: particularly when the price of ‘connection’ was about $600 pa. back then.

    Lead-acid has many advantages, especially PRICE, over the latest hi-tech gee-whiz must-have ya-ya offerings. Such things ~ in ANY commercial context are NOT, EVER, invented and produced because they’re superior. The sole purpose for their creation is BECAUSE MUCH MORE CAN BE CHARGED for lookatme!! gizmos which suck in the Jones’ neighbours.

    ie. the new-generation batteries are built for no reason other than profit: not your’s, the manufacturer’s.
    So were hula-hoops and yo-yos.

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