Household Battery Storage: A Comparison Of Product Price & Performance
Originally published on RenewEconomy.
Australia is already recognised as the principal global testing ground for battery storage technologies, which is why nearly all the major battery storage developers are releasing products here to take advantage of high network charges and the highest penetration of rooftop solar PV.
But which is the best product? That depends on what the consumer wants to do with the battery – go off-grid, provide back-up in case of a blackout, act as a hedge against time of use pricing, or simply to store their own solar energy for use at night.
The team led by Finn Peacock, from Solar Quotes, has developed what we think is the most comprehensive table that compares the numerous battery storage offerings in Australia – giving details on price, capacity, depth of discharge, dimensions, and purpose, and a list of pros and cons, and an overall assessment.
“As demand for solar battery storage starts to climb I’m getting more and more questions along the lines of: ‘I’m interested in batteries. What are my options – apart from a Powerwall’?,” Peacock says.
“A comprehensive answer to that question is hard, as new storage products are launched weekly. And trying to make an apples-for-apples comparison is even harder as many specifications are not online and even prices can be hard to get.”
Peacock says the aim of his Battery Storage Comparison Table is to eventually have every battery storage product available in Australia in the table, so their specifications and prices can be easily compared.
“When compiling this table we didn’t just get the required information from the manufacturer’s websites – because a lot of it is not there. My team had to call up and ask for much of the information you see presented in the table.
“Interestingly we found that when specifications are missing from a battery manufacturer’s website, it is usually because that particular number doesn’t compare favorably with the competition.”
And the initial findings? Peacock’s team votes in favour of the LG Chem Resu Product, a 6.4kWh lithium-ion product that retails for around $7,500, and has a 3.2kWh “expansion” product available.
“LG has put out, in our humble opinion, the best combination of price and performance currently available on the marketplace,” Peacock’s team notes.
Here is a taste of the table. Overall, there are 11 batteries storage products assesses, and 16 different criteria assessed. More can be found here.
“The table is our first effort,” says Peacock, and he says it will be updated monthly with new products as his team becomes aware of them. Presmably, this will include the new Australian offerings from Ecoult and Redflow. He’ll be updating those findings on this website.
Reprinted with permission.
Have a tip for CleanTechnica? Want to advertise? Want to suggest a guest for our CleanTech Talk podcast? Contact us here.
CleanTechnica Holiday Wish Book
Our Latest EVObsession Video
CleanTechnica uses affiliate links. See our policy here.
The table is an absolute godsend. There appear to be a few mistakes in it but I am sure that “crowd source” feed back…kind of like wikipedia, will continually improve the reliability and accuracy of the information. Of course, the prices are in the Australian market, which has some peculiar aberrations: notice the price of the 7 kwh powerwall is $8000 AUS. Which is about $5600 U.S. The retail price in the U.S. (not wholesale price, lets get that clear) is $3000. So, mysteriously, the price is almost double. That is fine, but calls for inquiry as to the reason.
But thanks for the effort, and thanks for sharing on Cleantechnica as well.
Also cheaper shipping in the US on the Powerwall.
Effectively making the ‘Peacock’, Poppycock, Locally.
Pretty sure Powerwall 2.0 is going to change the top pick even in Australia.
There are number of, what appear to be, mistakes. Maybe they can explain them. The cycle life of the powerwall at 3000: well, the warranty is 10 years which is at least 3650 cycles, and do they think it will conk out the day the warranty ends? Note, for instance the LG chem Resu, has 6000 cycles and also has a ten year warranty. That is 16.4 years at one cycle per day. So, does it not expire the moment the warranty is up?
The powerwall is also given as 80% depth of discharge. The Tesla battery site says “100% depth of discharge”. It is such items as this that will call for perhaps corrections to the comparison chart. I have only glanced at it so far.
Australia is the only country in the world where the Powerwall has been installed so far, and so these Australian figures are not likely to be mistakes. Of course, some of the figures can only be estimates and they will be refined over time. And perhaps some figures for the Powerwall will be different when it is installed in the United States.
The estimated cost of the Powerwall came from removing the normal cost of a rooftop solar installation from the cost of the Powerwall plus rooftop solar package and includes installation and tax.
The number of cycles presumably means number of cycles before the battery loses 20% of capacity. So this doesn’t mean the battery will stop working at that point. And in normal use they are unlikely to be put through a full cycle a day, so hopefully that will extend their lives.
If the LG Chem RESU and others perform well in the field I expect their warranty periods will be increased. But for batteries that can handle fewer cycles, there are obvious limits to how far their warranties can be extended.
Australia has a 10% Goods and Services Tax (GST) which applies to both the cost of the Powerwall and the cost of installation. Shipping costs are almost insignificant. At the moment it could cost less than $10 US a unit. Possibly even with paying a premium for faster shipping, as sea freight prices are extremely low at the moment.
Note: Currently $1 US = $1.31 Australian
By the way, though the Australians seem somewhat outraged by the price of these batteries and inverter, Americans do not realize just what you are paying for this whole package of PV, inverter, Tesla battery, fully installed. I almost fear to tell them lest they go ballistic…but I will. A 5 kw pv array plus Tesla 7 kwh battery and inverter fully installed $15,000. Now that is $3 watt. Just the PV installed in the U.S. is $3.50 watt. But wait…it gets worse…lets adjust for Aus dollar. In U.S. dollars you pay $10,500 fully installed…$2 watt U.S!! and they throw in the battery…as if for free!!! Ok, Americans, go ballistic.
Don’t forget to remove our 10% Goods and Services Tax. However, the Australian dollar is up, so it is still close to $10,500 at today’s exchange rate.
The $15,000 ($11,400 US) price includes a $3,450 ($2,620 US) subsidy for solar. Or rather a $3,140 ($2,390 US) subsidy, since we pay tax on the subsidy. Yes, the government gives us money and then we pay tax on the money they give us. Such is life.
The subsidy is part of our Renewable Energy Target. A target that the Abbott government cut by a third. It has been estimated to be equivalent to a carbon price of around $40 ($30 US) a tonne.
And as for feed-in tariffs, forget about it. You get roughly the wholesale price of electricity during the day for power exported to the grid.
Our PV installation prices are grossly elevated compared to the rest of the world.
I *do* have a theory about this. I think there’s a shortage of installers so they’re charging what the market will bear. They’re probably all making huge profits.
Are you telling me the Australian systems have about 2.5kw solar, inverter, and PowerWall for $10,500 US dollars equiv?
I got priced 11k to 15k for solar plus inverter alone installed. And thats not a premium SolarEdge inverter, but a crappy one with MPPT in the inverter.
Begin the outrage. LOL.
I think it is 5 kw pv, so increase outrage.
Here is a generous helping. I will shovel some onto a plate for you., 5kw solar plus inverter? I would be lucky to get that for 20k from SC in the US, But prices are dropping fast.
Got an email from a supplier today, 6kW system for $3,500 AUD, that’s 2,630 USD, or $0.438 USD per watt Installed. Outrage to ludicrous.
“The estimated cost of the Powerwall came from removing the
normal cost of a rooftop solar installation from the cost of the
Powerwall plus rooftop solar package and includes installation and tax.”
Early adopter penalty. You got charged extra to cover uncertainty by the installer. That’ll go down.
Since Tesla was in control of the process, it was extremely bad advertising on their part. Why skunge extra money from perhaps less than 10 installations and disappoint so many Australians who were looking forward to installing one or more Powerwalls? It has created a great opportunity for competitors to pick up disillusioned customers.
Is Tesla in control of what the installers charge? I don’t think they could do that without being charged with restraint of trade and monopoly abuse. Don’t know what its like in Australia, but in the US that can get you in big trouble unless you pay off a lot of politicians.
I guess we are just living in a libertarian paradise then. I don’t think there is any law against Tesla getting contractors to agree not to install their product for more than X dollars with the threat of going to someone else if they don’t. That sort of downward pressure on prices is generally considered okay. And Tesla is free to charge what they want for their product, whether $3,000 US, $30,000 US, or $2 US.
It’s a strange country. I’m free to sell adult rated videos, but as soon as I sell adulterated alcohol I get arrested.
I really don’t know. From your description of Aus utility regulation, I wonder it would be a bad idea to assume similarities to other countries.
If you have trouble sleeping, you can read US anti trust law.
http://www.theantitrustattorney.com/2014/10/02/classic-antitrust-cases-leegin-resale-price-maintenance-agreements/
If you guessed US law was pro corporation, you probably guessed right.
From a brief read, it looks like mfrs can do some dist price regulation if they tiptoe a bit. Not clear if they can control installation and added prices.
On the other hand, what interest does a manufacturer have in keeping installation costs and resale added costs high? Ought to be an advantage to lower installation prices. Seems mixed there. Idk.
One thing for sure. There is little competition with low volume and very few sources. Looks like that is changing fast. The manufacturers are pouring in now. Me 2.
They’re modern NMC which range from 5,000-10,000 cycles, Tesla has stated 5,000 within warranty, SonnenBatterie has a 10,000 cycles warranty on their NMC(though by then they are too costly and outdated).
I’m attempting to rectify this with the charts creator exchanging emails.
His source being Sunedison, which said 3,000 cycles under lease, another Solar distributor Solarcity says 3,285 under 9 year lease.
ALL non-lease are 5,000 cycles within 10 years.
Yes, Musk specifically on the record said 5000 cycles and also 15 year lifespan. Now I do not think those numbers appear in the warranty (which is available on line by the way). And they do get into specifics about what percentage remains in the battery at certain age etc. They do this with the car batteries as well. If they go below 70% in 5 years they will replace them etc. But of course the car batteries are a different chemistry.
The SonnenBatterie is a Sony product which claims 10,000 cycles and talk seriously about 25 year lifespan but warranty is ten years, if I recall. It used to be 15 years.
In the end lifespan is a slippery subject. Tesla has hired the top specialist in this area, Prof. Jeff Dahn. He has devised a machine which can accurately determine the true lifespan of these various chemistries but it is a very expensive build. Tesla will probably finance it. He is one of the judges for battery proposal that the U.S. Dept of energy will fund at such places as Argonne labs.
Tesla played it safe with 3,779 cycles within 10 years, the product life is estimated at >15 years.
When you’re selling a commodity cheap in bulk you have to lessen the warranty.
I trust the quality of their manufacturing enough to know the NMC owner aren’t getting boned.
Much like with Solar their output is grossely under estimated for manufacturer protection. Solar will produce for 50-60 years, Powerwall will throughput for 15-23 years.
Warranty is not how one calculates utility.
You share my optimism. But we live in a world of pessimists, don’t we?
Indeed, Pessimism often a byproduct of ignorance.
I’m not sure we’re optimists as we feel this cause/issue important due to our doubts of the future enviromentally.
I’d go so far to say our foundation’s rational and the world lacks confidence in where is needed and has an abundance where it isn’t.
Like a reckless teenage driver eating vegetables while at the wheel, lacking sight of the more statistically prominent risks.
We live n a world of alternate gullibility and over pessimism dominated by paranoid conspiracy fantasies. We seldom live in a world of carefully assimilated knowledge and facts. At least on the Internet, opinions are rampant and cheap, IMO. They can be had for 2c.
But some say the Tesla battery is 6.4kWh.
More important than tables is for some expert group to test the cycle life of Tesla batteries.
Yes, it could be called 6.4 since the round trip efficiency is 92% which is 8% less than 7 kwh. It is all just labelling. The standards are still being worked out. Lead acid batteries never had any of these sophisticated labels. They just said something like 6 volts 400 amps $200 and let the customer figure out that you could only use half of it and that round trip you lost 20% and that they would die quick if you didn’t fully recharge them almost every cycle and that they would only accept a trickle for the last 15% of charge etc etc. You had to be an amateur expert if you didn’t want to get skunked on the deal or end up murdering your batteries through ignorance.
But even so, Consumer Reports needs to do an independent study to determine the cycle life of Powerwalls.
I would pay for that report.
Not so certain I would. I would take a report from Jeff Dahn instead. CR has a habit of blowing it measuring things they have no expertise about, IMO.
I don’t get why people don’t understand that 7kwhr at 92 % efficiency is 6.4kwhr. Some people are turning this into a radical conspiracy.
If you lose 4% on the way in, then how are you storing that 4%? Hopes and dreams? If you ask me, it’s a 6.7kWh battery at 96% discharge efficiency.
If… you lose 4% on the way in. Losses are proportional to current squared. So if you operate at half the power, one quarter the losses. You only need to operate at one third to half one ninth the loss.
If you fold the efficiency into the energy capacity, you have to do a calculation to get the energy capacity. And energy capacity never changes just because efficiency does. Either way, all this discussion does is juggle numbers that have to be equivalent to be valid.
All this is just finding a way to spec the same thing.
No it’s not. How can it store it if it never makes it in? And why are we saying it does?
How can a 9V battery be a 9V battery when you draw 1ma and its only an 8.9V battery? Or maybe its an 8.99V battery when it draws 1ua. The internal voltage is always the same. Electrical engineers call it open circuit voltage.
Same with energy capacity. The energy capacity is determined by how many coulombs can be stored, not by how efficient it is to store them.
If you make the spec include efficiency assuming one current, the efficiency changes for a different load current. Tesla could have speced efficiency at another load current and stated the efficiency as higher or lower than what they did. And none of that would have changed the energy capacity or the main source of the losses, resistance.
Or Tesla could have produced a set of curves under all conditions of load, temperature, state of charge, etc. But that would not have helped matters for most users.
There is a learning curve.
I understand all that, but the glass can’t be 104% full, and that’s what they’re saying it is.
I have had a 12.5 gallon tank on several cars. I have never been able to fill it up 12.5 gallons or drive it down to 12.5 gallons. The gas pickup can’t grab the last drops. Does that mean it doesn’t hold 12.5 gallons?
if you put 13 gallons in every time and only pull out 12.5 gallons, is it a 13 gallon tank? Because you spill some on the way in.
Sure. Same with one quart milk cartons. They all say one quart, but you never get that last drop.
I don’t have any problem with that. Its my understanding that when an energy capacity is stated, its the maximum possible, not the useful amount after losses. Thats standard in engineering. A calculation always needs to be done to determine the actual losses for each situation. Assuming 92% efficiency could under or overestimate the losses.
Its not correct to assume the capacity is some flat value including losses. The specification has to state conditions to determine loss.
That last drop is the losses on the way out, we are not talking about them, we are talking about the losses on the way in.
Why do they call it round trip efficiency, it’s because there are losses on the way in. If the losses on the way in dont make it in then how are they being stored? Is there a magical ether that catches lost electrons and stores them. Wont these build up over time and add weight to the battery? Is the build up of magical stored electrons dangerous?
Congratulations on your upgraded 13 gallon tank by the way.
Yes. You lose some on the way in. This is physics. The amount of energy stored in a capacitor is proportional to the voltage and Capacitance.
Is a 1F Capacitor no longer a 1F capacitor because you have losses on the way in? No.
Same with a battery. The amount of charge is proportional to the active ions. The output voltage changes, however, due to ohmic losses. Same for the capacitor.
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capeng.html
What is the main selling point of these? Is it for those that don’t have a grid tied option or have one but only get a fraction in credit (e.g. .03/kwh credit vs .11/kwh for usage) for energy pushed back to the grid? Power outages?
I’m finding it difficult to make a case for a battery vs a propane generator for myself and only for the power outage angle. I’ve got an 8kw PV system which on its best days generates ~50kw. I can fill up even the best one of these in half a day. Luckily I have parity when storing on the grid which I assume is the Achilles heel in the main selling point of these things. I would only want back up power when the power goes out which it does on occasion in the mountains. The longest outage was maybe 5 hours and that was in the winter. Dec/Jan I use probably 50-60kw a day which is the only energy source for the house (no gas). 15kw would most likely get me through 6 hours on the worst of days. That’s 2+ Powerwalls. A generator seems like a far better deal. Not clean of course, but probably 1/4-1/3 the installed price. What am I missing? Maybe just waiting until the price of these plunges and the capacity of them increases as well, in a few more years.
agree, the price per kwh needs to drop drastically for these to make sense.
It is only in Australia that on-grid home energy storage is getting close to paying for itself. However, for off-grid porpoises, these new energy storage could be a god send. Or a satan send if you make lead-acid batteries for a living.
For power outages only? No, for that the battery does not make sense. These are for people who want to go off-grid, or who truly hate their utility company, or who want to get rid of fossil fuels completely, or who have sky-high grid power prices.
Actually, if used sparingly (say, backup use only, and outages are short and infrequent, which seems to be your case), a generator may well be cleaner than a large battery.
Going with the data about EV batteries, manufacturing and recycling a 6~10 kW⋅h system (incl electronics, etc) will cause the release of the equivalent of roughly 600 kg to 1 t of CO2 more than building a gas engine.
If we assume that this battery system will last 12 to 15 years, a generator would be a more environmentally-friendly option for anyone expecting to use on average less than 30 L or 8 gallons of gasoline per year.
Those figures could improve further if you manage to put the generator’s waste heat to good use as well…
Australia is the only country in the world where the Powerwall has been installed so far, besides Germany.