A happy family with their 4.8 kWh of Enphase AC batteries. These 4 batteries will cost about $10,000 installed and store about $1.44 of solar electricity.
Guess what! You can now read another tax-payer funded document that does more harm than good.
The NSW Government has published the NSW Home Solar Battery Guide 2020. It’s supposed to help the people of NSW and Australia decide if getting batteries is right for them.
I have read the report and have concluded that it is insane.
By insane, I mean it appears to support two mutually contradictory ideas:
- Home batteries can pay for themselves if they are bought at the same time as solar power.
- Home batteries are the last thing households should consider.
I can only guess it was written by committee. A committee who decided not to work out which advice was correct for NewSouthWelshpeople. It seems they, instead, decided to simply lump the two mutually contradictory views into the one report.
If you don’t like me describing it as insane — if you think that’s an insult to insane people — then I’ll say it is totally Star Wars. There is a light side to the advice and a dark side to the advice.
On the side of giving bad advice to people:
- The NSW Minister for Energy and the Environment states, “While batteries may not be suitable for everyone, people with rooftop solar should consider whether storage works for them.” This is despite the fact that, at the moment, it’s completely unrealistic to expect a home solar battery to pay for itself in NSW.
- The report claims a payback time under 10 years for solar and batteries when bought together. But the report fails to disclose how they use solar’s excellent payback time to hide the truth of the matter: that home batteries in NSW are unlikely to ever pay for themselves at their current installed costs.
- It has a number of amusing little blunders such as failing to define power correctly.
On the good side it…
- Contains a lot of information that isn’t wrong or misleading.
- Gives advice on a range of alternatives that make a lot more sense than getting a solar battery.
- Wasn’t printed on paper, so no trees died for a report that needs to be rewritten.
I’ll start off by describing the bad advice in the report before moving onto the good. The section on bad advice will be a lot longer because it’s a comedy gold mine, but this doesn’t mean there isn’t a lot of good advice in the guide. The problem is, when people are relying on the guide to help them make big financial decisions, it doesn’t take much bad stuff to make the whole thing worse than useless.1
Yes Minister
The report begins with a foreword from the NSW Minister for Energy and Environment, the Honorable Matt Kean, who seems awfully keen on home batteries for some reason. He wrote…
“While batteries may not be suitable for everyone, people with rooftop solar should consider whether storage works for them.”
That’s a shitty thing for the Minister to say. This is because it’s his job to serve the people of NSW, not to help them get served by being sold a solar battery system that only ends up costing them money. As home batteries right now will cause the typical family in NSW to lose money, he should use his taxpayer-funded position to be clear about this fact. Let me fix his statement for him…
“Currently batteries will lose normal households money. People interested in buying batteries to save money should not consider storage unless their situation is exceptional.”
There, that’s a better use of state resources! After all, he’s a Minister, not a battery salesman. I don’t expect Ministers to understand stuff like solar battery payback, but I do expect them to make an effort to protect the people they serve from making financial blunders. It’s not as if NSW is suffering from some sort of critical lack of battery optimism he has to make up for.
A Poor Start
The third and fourth sentences of the guide state:
“Home solar battery systems can store solar energy generated during the day and make it available when the sun isn’t shining—potentially saving the household money. They deliver a clean, secure and reliable energy supply.”
We’re just on the second paragraph of the first page and we’ve already run into problems. These are:
- The suggestion that normal households saving money by getting a battery is a realistic possibility.
- Saying energy from solar batteries is clean when — at the moment — their use generally results in increased pollution and greenhouse gas emissions.
Not A Money Saver In NSW
Unlike South Australia, NSW doesn’t have a big battery subsidy of up to $4,000. What they do have are interest-free loans for batteries provided you live in the right postcode. This is not nearly as good as thousands of dollars off the cost of a solar battery like in SA. On top of that, electricity prices are lower in NSW. So while a subsidised battery may pay for itself in the Festival State, it’s not a realistic possibility for any NSW home that is remotely close to normal. This is true even for the cheapest batteries I’ve seen advertised and buying the cheapest solar batteries on the market may not be a great idea.2
Joining a Virtual Power Plant (VPP) should improve the return from batteries, but they haven’t proved themselves yet and joining one isn’t without problems. It involves giving up some control over your battery and VPPs have a financial incentive to make as much money from a home solar battery as possible while paying you as little as they can. Current VPPs are likely to deliver lower profits this year – due to lower wholesale electricity prices – thanks to COVID. We will have to wait and see how much benefit VPPs can provide in the future.
Use Our Solar & Battery Calculator
If you don’t believe me that batteries can’t pay for themselves yet in NSW, go to the SolarQuotes Solar & Battery Calculator and see what it gives as the simple payback time for batteries for a typical household and a household with 3 times the typical electricity consumption, on a flat-rate tariff. While it varies depending on the solar battery system chosen, it’s often over 30 years.
The simple payback time from our solar and battery calculator using defaults for blue and 3 times typical household electricity consumption in orange.
As the maximum warranty length for lithium batteries is normally 10 years and they degrade with both use and time, it is not at all realistic to expect one to last 20+ years. If you don’t like the default prices our calculator uses, you can enter your own, letting you use any advertised installed price you think is fair dinkum.
Note from Finn: What about Time of Use Tariffs?
The SolarQuotes calculator makes its calculations based on a flat tariff3. A common argument for money-saving batteries in NSW goes along the lines of:
“The peak rate on the nastiest time of use tariff is 52c per kWh with a feed-in tariff of 7c. So if I drain my 13.5 kWh battery in the peak period, I’ll save 52c – 7c = 45c per kWh = $6 per day = $2,190 per year = 7 year payback on a $16,000 battery!”
A few issues here:
- If you settle for a 7c FiT in NSW you are a sucker as 11c or more is easily available.
- If you want a ToU tariff and you choose one with a 52c peak tariff you are a sucker as other retailers offer a much better peak rate.
- On many ToU plans, the peak rate is not available in Spring or Autumn, that’s half the year.
- In summer the peak rate is typically from 2pm – 8pm. Sunset is about 8pm in Sydney in January
- Why are you choosing the most expensive tariff possible to compare with? – Battery savings should be compared with the cheapest electricity plan for solar owners. For most solar owners this is a flat-rate tariff.
So no: cherry-picking expensive time of use tariffs for your calculations does not make your solar battery magically pay for itself.
The Guide Should Be Honest With The NSW Public
By not making it clear that there is no real hope of home batteries paying for themselves at this time, the guide has done the people of NSW a disservice.
Not Very Green
As this article explains, energy is wasted every time a battery is charged or discharged. Storing solar energy in one during the day and using it at night increases emissions compared to sending that solar electricity directly into the grid during the day. I wrote that article four years ago and said the environmental benefit of solar batteries would improve in the future. Since it’s the future now, or at least it will be soon, I can say the environmental credibility of batteries is getting better, as a larger portion of our electricity is coming from solar and wind and joining a Virtual Power Plant can greatly increase the ability of home batteries to support the integration of renewables into the grid. This integration includes helping avoid further restrictions on the ability of rooftop solar panels to export energy to the grid, so batteries can be a big help to solar power.
But, generally speaking, home solar batteries are still likely to be environmentally worse than greener options such as more solar panels, home insulation, a heat pump hot water system, or replacing your V8 interceptor with an electric car or — better yet — a bicycle.
It’s Full Of Blunders
If you want to make an engineer cry all you have to do is show them the following passage on measuring energy from the guide:
Nooooooooooooo! Power doesn’t measure energy! Power measures power! I may as well go to the Apple shop right now and buy a new laptop, because when Finn reads this his laptop won’t just short out from his tears, it will probably get washed out to sea.
It’s like saying there are two units to measure distance: distance (km) and speed (kph). It is nonsensical.
But I should probably relax because this could just be a typo. I’m going to keep telling myself it was probably just a typo until the pain starts to go away.
Unfortunately, my mental equilibrium isn’t helped by them immediately giving a poor example of appliance energy consumption :
It’s not that they’ve written anything wrong. If something uses 1.5 kW for 13 hours it does indeed use 19.5 kWh of energy. But it’s a lousy example. An air conditioner changes its power draw all the time as it regulates the indoor temperature. It is very unlikely to draw a constant amount of power for 13 hours. Not unless it’s operating flat out through a heatwave. But I’m probably overreacting here. I should be glad they didn’t get power and energy confused.
But here’s something that really steams my clams. At the bottom of the same page they have this graphic:
Five kilowatts of solar panels exposed to the sun for 4 hours is not going to produce 20 kilowatt-hours of electrical energy.
Image: The Good Solar Guide
Not on this planet. Sure, maybe they could produce 5 kilowatts of power at noon, but you may have noticed noon doesn’t normally last 4 hours.4
Nobody likes a cheat, Joshuah.
Maybe what they meant was the equivalent of four hours of sunshine under Standard Test Conditions (STC). But that’s not the sort of conclusion you should expect a casual reader to leap to. Then they say “If the solar energy was stored in a battery” it could power a 1.5 kilowatt appliance for 13.3 hours. This is not correct because energy is always lost when charging and discharging batteries. If the round trip efficiency was 90% — which is high for a home battery system — then it could supply 1.5 kilowatts for 12 hours.
A 10% difference may not seem like much, but when you have a 71-page guide that’s enough bloody space to include a clear description of battery losses, rather than a single vague bullet point mentioning “efficiency losses between solar, the battery and your appliances” two dozen pages further in.
This information is not provided on page 64 or anywhere else, but they do include a link to the SolarQuotes Battery Comparison Table, which was nice of them.
Biggest Blunder = Blended Payback
By far the biggest blunder, and the one that makes this guide royally bin-worthy, is where they mislead the people of NSW into thinking a battery can pay for itself within 10 years by blending the good payback time of solar panels with the bad payback time of a home battery:
This is an idiotic mistake with plenty of potential to cause financial hardship for families. It is also against the long term interests of the solar battery industry.5 Even worse, this mistake was completely unnecessary, as there was at least one person involved in writing the guide who grasped the problem of blended payback – on page 41 the guide says people should try to understand…
“…what part of the savings are due to the battery itself and what parts are due to installing solar panels.”
But this advice is completely ignored in the section on battery payback.
There is a small particle of truth in what the guide says about the payback of getting solar and batteries at the same time, so I’ll get that out of the way before dealing with a huge dollop of stupidity.
A Battery Can Be Cheaper When Bought With Solar
The cost of getting solar panels and a battery at the same time as an integrated system can be cheaper than getting a solar system and then adding a separate battery system. But this difference is nowhere near enough to allow a battery system to have a payback time of under 10 years. If you use our Solar & Battery Calculator and look at the payback time for just the battery, you’ll see there aren’t any that have a simple payback period of under 20 years for a typical household. This is more than twice the maximum 10-year warranty of lithium battery systems and, because solar batteries wear out with use, there is no chance of them lasting that long, unless perhaps they are hardly being used, but that means it’s not going to pay for itself anyway.
To sum up: Yes, batteries can be cheaper when bought with solar power. No, the difference is nowhere near enough to make them pay for themselves.
Blending Payback Doesn’t Magically Make Batteries Pay
If you buy a chicken that lays 20 eggs a month and at the same time buy another chicken that lays zero eggs, just because you bought them at the same time doesn’t mean you have two chickens that lay 10 eggs a month each. It means you have one hen that’s a good layer and one that’s only good for the pot.
It’s the same with batteries and solar. If you buy a battery system that loses money, it is going to lose you money no matter if you buy it with solar power or without. Getting both at the same time doesn’t magically make the solar battery pay. It just means you have one thing that saves you money and another thing that doesn’t.
Obviously, if your main motivation is to save money and you have the opportunity to buy something that doesn’t save you money, you shouldn’t. When the guide gets rewritten to correct its mistakes, it should make this 100% clear for the good of society6.
What The Guide Gets Right
The guide isn’t all bad. There’s a lot of good advice in there. The trouble is, the people it’s aimed at aren’t going to know what is good advice and what stinks worse than an Appalachian skunk kicking contest, which makes the whole thing useless.
This is a pity because they’ve screwed up a good opportunity to help people. There’s a whole list of things they recommend doing before people even think about getting a solar battery:
- Make sure you have the best retail electricity plan for your circumstances.
- Insulate your home.
- Cut energy use by using LED lights and washing clothes in cold water.
- Buy energy-efficient appliances.
- If you have solar power, set appliances and hot water systems to run during the day.
- Get an energy-efficient heat pump hot water system
- Finally — install more solar panels.
A Battery Calculator
In addition to the guide, there is a companion Solar Battery Calculator. I intend to check it out sometime in the next few days and write about how it stacks up. It will be interesting to see which of the committee members who put this guide together worked on the calculator. It may have been someone who understands battery payback and presents the results without bullshit.
Redo From Start
The NSW Home Solar Battery Guide has the potential for economic harm. It encourages people to incorrectly believe that a battery system can save NSW families money provided they cast the magic spell of buying it at the same time as solar power. This version should be thrown out. They can replace it with version 1.1 with all the errors removed.
If they don’t do this, then if I was the NSW Minister for Energy and Environment, I’d want to take my name off it. I’d sign it the Honorable Alan Smithee, Minister for Pigs, Lipstick and Self Preservation.
Footnotes
- It’s kind of like how it only takes three or four dead cockroaches to put me off my entire meal. ↩
- I think the possibility a battery will turn into a brick after the companies providing warranty support disappear from the country should be considered before buying and the chance of this may be higher for batteries that seem to be real bargains. ↩
- watch this space – ToU compatible calculator coming soon ↩
- Yes, solar panels on a tracker could have a pretty constant output over 4 hours. No, most people aren’t going to put a tracker that follows the sun on their roof. ↩
- “A happy customer tells a friend; an unhappy customer tells the world.” Note: This is a business proverb, not an opportunity for a revolutionary new world-spanning communication system. ↩
- That was a literal statement and not comedic exaggeration. If it appears to be an exaggeration it’s because our standards are too low. ↩
About Ronald Brakels
RSS - Posts
Sounds to me like it’ll be best to wait until I buy my 1st electric car. With the new VTG technology, cheaper price and longevity, the battery will become much more useful to the average home.
Provided we get it right, there is massive potential for electric vehicles to support the grid and home generation/consumption.
Hi Ronald,
I just tried NSW Solar Battery calculators. At least it is honest. I put in my existing 9.5kw system and quarterly bill. It told me that I would not benefit from installing a battery.
….errr… It WOULD if you weren’t getting a quarterly bill. ie ~ went stand-alone.
Why would anyone elect to stay connected, particularly in this day-and-age when solar components are so very cheap? eg panels down to 20 CENTS/Watt and (PROVEN) suitable batteries for well under $2 per ah. (ie under $150 per kWh. (start by omitting the ‘service charge’; say about $600 pa whether it’s working or not.)
Hi Jackson, what brand and type of batteries do you recommend?
Dave it depends entirely on what your load requirements are, including loads duty cycle and load diversity.
If you are a battery system integrator you would already be an accredited and qualified battery stack designer/assembler and installer familiar with the range of battery chemistries and technologies, and how this knowledge is applied to various types of systems and their required functionality.
This is an important point, because battery storage can play many roles in a system. A case that illustrates this point and termed a “single circuit battery solution” involved a suburban doctor with a standard 1 phase supply to his surgery (a domestic residence) and he wanted to install an MRI machine as a new in-surgery service. This 3 phase machine demand exceeded his mains supply limits, but after understanding the expected daily duty cycle of the machine, it was obvious immediately to the battery solution designer that a standalone battery was the most cost efficient and enduring quality solution to manage this scenario.
No further consideration was necessary for an expensive mains upgrade, and the battery was control charged as required at the lowest tariff available to the customer automatically.
Mission accomplished promptly and efficiently and importantly it was a self managing remote monitored solution requiring no customer intervention whatsoever. Single circuit battery solutions can be applied to any commercial premises; factories etc where a high current machine that normally sets the customers maximum demand penalty tariff, can be removed from the grid supply circuits and managed entirely by a custom battery solution. Understanding load duty cycle and load diversity as it applies to multiple circuits is the key metric for efficient and costs saving battery solutions designs.
Custom high voltage (nominal 480+ VDC) solutions are increasingly in high demand throughout Australian commercial operations and this strategy also applies to domestic battery solutions. It is important to note that these standalone (controlled) custom battery solutions are not the same as the typical “battery backup” solutions being installed in domestic residences.
Good luck with your battery sourcing Dave.
The most important point I can leave you with Dave after many years now as an active power systems engineer working with all battery chemistries, and stack designs up to 900+ VDC including EV stacks in Detroit US, is to understand that batteries age near ratio-metrically by the upper range magnitude of both the charge and discharge current over time. In short, the lower the current for both charge and discharge, the longer the battery life.
This should not to be confused with battery voltage. A 480 VDC battery discharging at 2 Amps = 960 W; whilst a 48 VDC battery supporting a similar load (960 W) will need a current of 20 Amps. The 480 VDC battery will outlive the 48 VDC battery by a long margin all other parameters being equal.
Discuss this point with your local power systems engineer.
If you are exploring a typical ELV Lead Acid battery solution, a long life battery spec like this (managed properly by a custom BMS) and remote monitoring and control functionality, could be expected to last many years.
https://aquilapower.solutions/battery-storage
This battery is characterised by a very low equivalent internal resistance IR and is the preferred choice for many high reliability UPS mission critical designs such as those for hospital operating theatres.
Lawrence Coomber
Thanks Lawrence. Very helpful.
Solar quotes shows that Lithium batteries don’t pay for themselves on a home setting. I was wondering how other chemistries such as Lead Acid compare. I looked at Redflow a while back but very expensive and not reliable according to reporting of Canberra battery testing by Solar Quotes.
Just a note regarding the “Five kilowatts of solar panels exposed to the sun for 4 hours” issue …
The authors of the guide are probably blurring this idea with the established solar design idea of “peak sun-hours”. (I’m guessing this is in Finn’s book somewhere too)
In order to estimate the total solar energy available across a day in a given location, meteorologists created the measure of Peak Sun Hours (PSH). It’s determined by summing the total energy under the bell curve and then expressing it as total hours of exposure at 1000W/m2.
Most major cities in Australia get between 4 and 6 PSH daily (averaged across the whole year), so 4 is a very rough conservative estimate for PV yield calculations.
Hence if you have a PV system rated at 1kW, in a location that receives 4PSH, it will generate 4kWh across the whole day (excluding any losses from conversion efficiencies).
Of course I agree with you that they should have done a better job of explaining this in a 72 page booklet!
https://www.yourhome.gov.au/energy/photovoltaic-systems
Yes, the peculiarly despised paper appears to assume an array of 5kW average _yield_ over 4 hours, and does explicitly state “solar power generation” in the challenged example. Generation is output.That is a perfectly sound modelling assumption for a simple example. For the purpose of the message bing communicated, it would be superfluous to add that computation of that average mathematically involves the first integral over time, of the peaks and troughs in irradiation, due to passing clouds, birds, aircraft, and UFOs. There is certainly no requirement for a constant array output for average x time to equal the integral over time.
Omission of the second order effect, battery efficiency, is perhaps also helpful to the obviously simplified example, intended for an audience not entirely composed of engineers. In any event, new Li-Ion batteries claim to be quite efficient, so even an engineer might omit that factor for a quick mental first order approximation if using very high efficiency batteries. Granted, a note under the graphic, to be read _after_ the main message is digested, could usefully point out that real battery technologies have various degrees of cycle loss.
Obsessing about the assumed pollution impact of battery loss ought also wear some caveats. It exists only for as long as polluting energy generators remain, and even then only to the extent that export is permitted. When you have 18 kW of array and a 5 kW export cap, then much imagined pollution impact is quite illusory. And when export is further throttled back due to line overvoltage, as increasingly happens now, then self consumption or storage are the only alternatives for utilising excess system capacity.
In fact, where line voltage falls again after sunset, i.e. everywhere there’s high penetration of rooftop solar, that stored energy can REPLACE polluting generation, just as Snowy Hydro 2.0 is intended to do. (Queue fanfare of angel’s trumpets.) If it is good for EV batteries to support the network, then it makes no difference if the batteries are in the chookhouse when they support the network. In both cases, batteries _reduce_ pollution where they replace polluting generation, using energy not accepted by the network when generated.
One day there’ll be no fossil generators, and batteries will always be good.
But they can also be good now, on the path to perfection.
If the article were mine, I’d claim indigestion or too much blood in the caffeine stream, and moderate a bit of the ctiticism of the alternative viewpoint. Maybe. (Water & bridges)
And you can do even better if you install a solar-tracker. (Or track manually as a friend of mine does. Beyond that there are several other factors one rarely hears mentioned, such as the TYPE of panel in re. the variable climatic conditions on several levels, size of cabling, etc. etc.
Having used and been involved with solar systems since 1980, the only ‘reality’ that there are NO hard and fast rules in the production/use of solar-systems. Consequently the smartest way to get the available benefits is to oversize EVERYTHING ~ and be prepared to increase the size of the system incrementally until you reach the optimum system for YOU.
There are a couple of other relevancies to consider:- 1. Components are so cheap these days that almost any degree of oversizing comes out of petty cash, and 2. Oversizing will reduce your DOD to a degree that your system (particularly the battery-bank) will last much longer than might otherwise be the case.
Moreover, in terms of ‘payback time’, a CHEAP lead-acid battery-bank will more than pay for itself much sooner than one of the gee-whiz hi-tech umpteen-thousand-dollar ‘power-wall’-type options. eg. a battery costing under $150 per kw and with an unconditional 3-year warranty (and designed for a 10-year life). AND you can install/maintain it yourself! Do the bloody arithmetic!
Don’t despair Ron your analysis is accurate.
Battery and Solar PV Technologies are both still on an ascending (but slowing) curve. They both lack the degree of scaling potential; cost competitiveness and commercial viability necessary [LCOE] to be considered as main players by financiers, as the global power generation future topic moves forward.
Many people however (end users, electrical retailers, industry practitioners, Government advisers, community commentators, the media in general, etc) bring different motivations; drivers and individual perspectives to their discussions about renewable energy technologies, than maybe those that you or me might find compelling Ron.
Personal drivers, ideologies, discretionary spending habits, seperate us all Ron, and this applies to every subject there is of course; including batteries.
From a technology only focus though: there will always be a place for Batteries and Solar PV (in improved forms) as practical technologies at small scale and in boutique applications everywhere; for example in mini-grid applications where the cost to reticulate low (LCOE) cost generated grid power would be prohibitive.
Regarding the closely related concepts of Power and Energy:
Energy is an amount of Power used in performing work, for a given period of time; (1 Watt of POWER used in performing work for 1 hour equates to 1 Watt/Hour of ENERGY expended doing that work).
Lawrence Coomber
Good article again Ronald. Since domestic batteries are neither good financially nor good for the environment, why are state governments encouraging them?
However batteries controlled intelligently could be useful for FCAS (frequency control ancillary services). If that’s the case, the financial incentive should be to pay people for FCAS rather than encourage mindless energy cycling to try to recoup their cost through arbitrage.
Hi Ronald. You stated that peak rates are not available in Spring and Autumn on TOU plans. This is what distributors like Ausgrid announced in order to encourage customers to use more when the distributors have a surplus at those times. However, if you check the government’s energy website you will find most of the retailers haven’t passed this on to customers. As the only info on time of use is on the distributors website most customers think they are safe from peak charges in these milder seasons and probably increase their usage as there is no way to check this in power bills unless you download your usage data in 30 minute intervals and manipulate it in a 4,000 row spreadsheet. After I did just that and pointed it out to AGL they gave me a large credit to stop annoying them. So it’s a win for distributors increasing their throughput and a win for retailers still charging eye-watering rates on the increase. The only “good” news is it makes batteries look slightly less bad.
I wouldn’t even waste my time reading a document from a coal owned government as the intention of coalition government are TO BUILD MORE COAL FIRED POWER STATIONS. All the rest is noise, lies, deceit and BS meant to confuse the mentally challenged.
I think Finn has it right when he writes that batteries cannot pay for themselves. The rest is as you said a waste of taxpayer money. This is pretty well true of every government department because our coalition governments are not transparent and are masters of deceit. Likely the document which upset you Ronald is just one of many designed to do the same thing: convince voters this lot is doing something when it has no intention of doing anything other than building fossil fuel dinosaurs for its donors.
Sorry about the political perspective but this is what your story is really about, the failure to do what is in the public interest.
ummmmm…. doesn’t the same argument apply to people who push particular products (like hugely-expensive batteries), without offering the alternatives, for their own commercial reasons?
Hi there,
I am a retired diesel mechanic, I started with solar and a set of batteries about 6 years ago now with the simple realisation that I like most people was getting too old to work and not yet rich enough to retire comfortably, I worked out that it was simply a better and cheaper option to spend some money to get rid of bills rather than needing truckloads of money invested to pay bills. since then I have upgraded my solar panels twice. I really cant say that batteries pay for themselves or not by themselves, as a system they do for me.
I now have a big solar system for a domestic system and rainwater tanks, I first thought that the tanks were a bit of a waste of money when water was less than $1 / KL now at $2.50 / KL they are saving us money and paying for themselves. My power bill has gone from $800+ / quarter to $800+ / quarter credit, this now pays my council rates for me!!!!!!!!
I did the solar with the idea that I would own an electric car to help pay for the solar and tanks but haven’t yet bought a car but spent the money on more solar instead, the petrol bill is now affordable with no power or water bills but we will buy one in the next few years.
Solar is a long term project and has to be viewed more on what the power will be in 10 years time when your solar is paid for and power is worth a lot more than it is worth now, we are also knocking down our power stations and not building as many new ones, our population is increasing as well as it is looking like we will be bringing back a lot of manufacturing back from China and our grid may well go down because it is just overloaded or some other major problem?????
My batteries are now getting old and will need to be replaced in a few years for some newer better batteries, not having to worry about the grid going down, being able to heat my house in winter, air condition it in summer, keep my food in the fridge and freezer, have a cold beer, a Spa, lights and cooking all off my roof is a great way to be to me, my biggest concern of the grid going down would be a loss of revenue to pay my council rates.
Go batteries if you can afford them, they have worked well for me so far!!!!!
Here here Martin – well said. “Peace of Mind” has an unquantifiable value that Bean Counting Ron often overlooks !!!
You are dead right about that Adam Ant, peace of mind is worth a lot of $$$, being able to turn one bill into a credit makes life so much better, looking forward to your power bill coming in because you know it is a credit is something that more people should get to experience, it is priceless!!!!!!!!
Hi Martin,
What batteries did you buy?
I won a set of 1250 ah Gel cell batteries on eBay that finished on Christmas day 7 years ago this coming Christmas, no one is really thinking batteries on Christmas day so I got them for a song, I knew nothing about batteries or solar when I bought these batteries, now I know quite a lot about them I will buy some Lithium batteries next if I can afford it or a bigger set of Gels if money is tight on the day.
Well said, Martin. Thinking outside the square should always be an automatic approach. Herewith another suggestion you might want to consider, re (bloody expensive) water tanks, which worked for me for years –> Instead of very pricey steel/plastic tanks which needed solid footings and which would’ve required great effort/cost to get to my property in the bush, I bought a total of three above-ground swimming-pools (second-hand) from the Trading Post. They were sized at 15ft diameters x 4ft height, and cost cost me $25 each.
Transport was via a 6×4 trailer, and (by myself) were rolled out/set up on a fairly flat bit of cleared ground and left to find their own levels of ‘settlement’. A rockery around them and a recycled colourbond cover completed the job. Sited on a slope uphill from the house I didn’t even need a pump to run the hot-water system,etc.
They were kept filled with a (aforementioned) home built hydraulic-ram pump and the overflow directed to my gardens and from there back to the creek. The whole thing cost (from vague memory) less than a couple of hundred dollars, lasted near two decades and largely credited with saving my house from the Black Saturday bushfire of 2009.
Well Ron I bought an LG Chem at the same time as my solar (18 panels as that was all the room I had on my apartment roof). I borrowed $10K through the TEELS scheme here in Tassie and put $5K something in myself for the 6.5 kwh battery. I am about to make the last payment on the $10K as I worked out how much to pay off per month to ensure I didn’t pay interest after the three years interest free under TEELS.
Whilst I am sure you are right about my battery not paying for itself (yet) the nice warm and fuzzy feeling I get from using my own power at night instead of buying from the power company’s at their rate almost has a value in itself.
I appreciate you are trying to keep the bastards honest but remember it’s not economic own a dog or cat either by a lot bigger margin than a battery – doesn’t stop people buying them though does it because they provide something other than a pure statistical return !
Well done Martin.
A $1600.00 swing per quarter (due to feed in tariff) is significant.
But how did you swing that high tariff after two Solar PV upgrades, which would normally bring you back to a nominal lower tariff? Or did you “go big” with your upgrades to 25+ kW total, to make the maths a bit more understandable.
Whatever you have accomplished, well done. At an accumulating $800 per quarter effectively in your pocket and zero electricity bill to boot – that equates to $3200.00 per year to go towards recovering your Solar PV upgrades so far. After 3 years ROI its all cream for you going forward.
Yours is a compelling positive story Martin, and thank you for sharing.
Lawrence Coomber
I really dont know how I swung such a high input tariff, I just shopped around for the best deal I could find, if it drops back to like $0.05 I will just disconnect from the grid and go stand alone.
I now have about 21 kw of panels, 9 Kw of these is a grid connected DC coupled stand alone system with a 4 Kw inverter which I started off with, I then added another 12.6 kw of panels via an 8.2 Kw Fronius grid tied inverter to feed the grid and my big appliances, Spa, air conditioner, big kitchen ovens cook tops etc. I also have a diverter that I got custom programmed to sell 5 Kw to grid and then put whatever else is left into my HWS which already has 218 evacuated tubes in winter and 98 in summer, with this amount of hot water I can heat my Spa on most days as well as central heat my house in winter, air condition it in summer, the extra comfort of this is just about priceless when it comes off your own roof!!!!!!
I am going to need to upgrade my batteries and 4 Kw inverter in the next few years as the batteries are now ageing, I will look into what is best when the time comes, it became obvious to me that trying to find the money to invest to pay my ever increasing power bills was just impossible for me, so, I decided to spend a bit of money and get rid of my power bill, best investment decision of my life by far!!!!!!!
My best tip for anyone with solar, go as big as you can possibly afford to go, dont worry too much about hot water buy a diverter that will feed the grid first then put what is left into your HWS far cheaper than evacuated tubes, my other tip is, once you get power off your roof you will use it, all those things you dont use now because of cost become affordable again and you will use them now it is affordable to do so, the bigger the better and ENJOY the luxuries that come with it!!!!!!!!
Again with the biased, dictatorial, twaddle! -> “As home batteries right now will cause the typical family in NSW to lose money, “. To make valid assertions the first requirement is that terms used are defined and alternatives examined from an unbiased perspective.
‘Home batteries’ can mean anything to anybody, depending on requirements and usage.
There’s no such thing as “the typical family”.
The ‘value’ of the chickens depends upon the REASON you bought them and how much you paid for them. (ONE eg of many:- If you paid less than 50% of the going rate for the chickens and only half of them laid eggs you’d be well in front… assuming egg-getting was your purpose, which wasn’t stipulated in your childish ‘example’.
Your ‘Chicken’ analogy is a nonesense on any level (details available if required). And it’s the first time I’ve ever seen a chicken morph into a red herring! It is, in fact, unsustainable in the sense that your power company ‘averages out’ your power use in compiling their account.. eg. Your bill for, say, 300kWh usage in a month may well include some ‘hours’ where NO kW were used. (ie no ‘eggs’ produced). I’d love to see you refusing to pay for those ‘potworthy-only’ kWh!
And yet again you fail to stipulate the parameters. eg. The price of the batteries you reference. And, among other issues, the unjustified and unjustifiable, insistence that a battery-bank MUST stay connected to the grid. As elsewhere asserted only a fool would buy the hugely expensive and complicated sort of batteries/systems you advocate (without offering options!). You know, the same sort of idiot who’d buy eggless chickens if his sole purpose was to get eggs.
As has been repeatedly pointed out (and figures provided*), a stand-alone solar-system supported by a suitable (and relatively very cheap) lead-acid battery-bank will NOT ‘lose you money’, but WILL save you money… and also maintain your independence..to the point that you can adjust your usage/etc. at will ~ without being locked in to some (environmentally-destructive!) power company.
And on that basis, the savings made by NOT paying a variable-at-will ‘service charge’ (AS WELL AS as power-use) will just about make up the cost of said battery-bank over time.
* figures & references STILL available.
ps:- Thanks, Ronald for drawing my attention to this “tax-payer funded document that does more harm than good”
I’ve asked around, and nobody I know would’ve seen it otherwise.
(Incidentally, do you vote for politicians and pay taxes to support a system so riddled with fallacies and outright errors!)
Yes AdamAnt.
I know that Ron is just as aware as you that personal drivers, ideologies, emotions and discretionary spending habits, seperate us all, just as you have alluded, and this applies to every subject there is of course; including batteries.
But Ron’s main mission is to inform us all about technical issues firstly and foremostly, and we need to encourage that above all the other stuff I have mentioned above.
Let the practitioners practice unchallenged and the consumers consume unchallenged.
Knowledge is power, and what separates us all is how we might individually apply knowledge in practice. And all of those variations are perfectly OK.
Lawrence Coomber
I totally agree Lawrence we could not do without the Ron Brakels’ of this World because we need science before emotion – providing that after getting the facts an emotional decision can be made without fear, favour or ridicule. I wanted to add into the mix that there are other factors that drive purchasing decisions beyond pure economics and, as a result, help drive new technology forward.
If there weren’t us early battery adopters who are prepared to pay over the top for an emerging technology that is not yet economically viable it is unlikely that manufacturers would risk going further into production. If people hadn’t originally bought in to comparatively expensive early solar panels of dubious quality years ago they may not be as cheap and economically viable today.
I’m not persuaded by the ‘not very green’ argument. I’ve worked out from detailed analysis of personal consumption data that I could install a Powerwall 2 and satisfy my entire electricity demand from generation of my rooftop PV system – after allowing for the 90% roundtrip efficiency. 35-40% of my daily demand falls outside the period when I am generating. This peak and shoulder load appears on the grid in the absence of a battery and that additional demand will most likely be met by gas or coal-fired generation.
My goal is to make my off-peak and shoulder demand disappear from the grid so that it does not require firming generation from FF sources.
I reckon the battery option is green. It may not pay for itself because we currently don’t pay for the carbon pollution, but it should reduce the carbon pollution compared to no battery. With no battery, your shoulder and peak load will have to be met by FF more often than not.
Yes correct AdamAnt.
Driving new technology development is my companies key focus since 1985 through R&D and innovation, then manufacture, commercialisation and sales if everything comes together as planned.
R&D thru to manufacture of prototypes, is expensive beyond belief and there are always more failures than successes moving concepts forward.
We have fortunately managed to stay on the positive side of the ledger for 35 years so far and it is very rewarding and quite a buzz to bring new technology products and solutions into service.
Lawrence Coomber
I love SolarQuotes, I’ve learnt so much from Finn & Ronald, however I am probably in the camp of simple “calculations”.
Currently with a PowerWall 2 & 3 x String Inverters with 15.5kw of Panels (58 panels – Orientations East, North & West):
– I no longer have on average $750 energy bills per quarter (Household of 5).
– With the 20 cent FIT tariff from AGL we average $250 credit per quarter back in our pocket (which helps pay down the PowerWall2 – 50 Months Interest Free on ZIPPAY-Bradford Solar).
I’ve run our power usage and solar exports against other plans and the AGL Plan is the best for us by far. I do occasionally charge the PowerWall off-peak if the weather is average and we do use a heat pump dryer and dish washer during off peak. Point being our off peak usage is offset by the higher FIT during the day. And we have changed our home energy usage behaviours based on TOU and the weather!
We are looking at getting an EV at the end of the year and plan on dipping into the solar credits a bit obviously for home charging, however I should save $3k a year on Fuel which is a great start (not including maintenance cost savings). I will charge the car from the sun on the weekend or when I’m home. Through the working week it will be with off-peak.
I honestly think if you can get the right finance a battery can work for you. Be an early adopter if your circumstances allow. And of course do your research and don’t get ripped off (particularly with Solar). We managed to get our Powerwall for $12,500 fully installed 2 years ago. Very glad we did as early adopters of sorts and the fact that the price went up some months after we got it made the timing perfect.
Dave:
Ron is correct, the business case for batteries in traditional on grid scenarios is very weak, and is guaranteed (by the principles of energy generation and conversion plus the business relationship with the grid) to be incapable of much change moving forward.
You don’t need to be Einstein to figure this out. The energy equation teaches us everything related to power conversions and efficiency and these principles are what drives the business model of a national grid generators also. The grid business must be profitable. It does not exist to run at a loss in favour of some customers who think they can recreate or manipulate the fundamental energy equation in their favour. So that’s it in a nutshell. The end user in an on grid scenario will always be the customer of the grid; and the customer therefore must always be the payer not the payee going forward.
This principle is locked in except an FIT if available can skew this rule a bit in favour the customer, and it is this component that the grid are looking at very aggressively and closely to claw back from customers, through new tariffs and service charges particular to types of equipment fitted (solar PV; battery etc) to get them back on the right side of the traditional supplier customer relationship moving forward.
This will become more and more evident over the next couple of years to the point that only moving entirely off the grid will provide any net benefit for consumers.
Moving off the grid is a realistic option for customers already (not all customers though) but many individually, and also collectively in mini-grid solutions. It’s horses for courses on this subject.
Talk with your energy engineer more about this subject Dave, your situation might prove to be a good one for a solo off grid solution, or in a collective off grid solution.
Lawrence Coomber
Lawrence,
Thanks for the advice. I will follow it.
Dave