Tesla expands Powerwall-to-grid program to cover most of California More Tesla Powerwall owners in California are getting the option to help fight blackouts – and get paid for it – as thecompany expands its virtual power plant (VPP) program to new areas of the Golden State. Trialed last year with multiple California electricity companies and rolled out in Pacific Gas and Electric's (PG&E) …
Using batteries for this purpose is not great.
Lithium batteries are hugely damaging to make and eventually recycle. The only benefit is short term storage or excess from solar or wind.
Gas turbine can ramp up in a couple of minutes and keep running. That people are being paid to install them is similar to the daft incentives in the UK where the reason for doing something is not to be green or benefit the grid but to make money.
It's only going to be paid during "load management events", which I think is PG&E for "getting close to a partial blackout or brownout". During these times, $2/kWh is probably at or below the marginal cost of getting more generation online.
Over here in the UK, National Grid recently paid over $11/kWh for a couple of MW of additional power from Belgium to stop demand disconnection in the south east.
They did indeed. And the reason why that was necessary is pretty simple : a fire to the North of London was burning close to a double-circuit overhead line. The fire brigade correctly contacted control to both circuits to be switched out. Tackling the fire or risk and risk of flashover through the smoke were risks to life. Obviously, a flashover type event would have disrupted the system in any case so choosing to do switch it off deliberately to nature deciding when it fails for you.
Losing a major double circuit like that in unplanned manner tends to mean that you have to reconfigure the network quickly; and pay whatever-it-takes to procure an alternative. When it was switched out, a number of assets went up to a 100% or greater loading condition; which they can do for limited periods of time but you MUST take action to reconfigure the system at that point.
The alternative is deliberately disconnecting demand.
So, at what £/kWh is deliberate disconnection preferable to paying whatever-it-will-take?
The electricity pricing problem is academically interesting. At what point is willingness-to-pay outstripped by the price? If Don't Pay UK's claims are true (questionable), then about 100k people are already beyond breaking. Others may be broken but haven't seen the damage on their direct debit yet.
There are other problems out there. Elexon, the operator of the platform used to implement system balancing services (and therefore generator capacity auctions) has a character limit on the bid/offer price field... It's limited to 99,999.99. Inevitably, when there is a whiff of a problem; those with generating capacity to spare, IF they are awake can type a bigger number in that field... up to the limit of 99,999.99. There is nothing stopping anyone, just like happened with student fees, to type in the limit value.
In fact, there have been change requests sent to Elexon to increase the character limit on the field to permit bigger numbers to be used. So far, those requests have been denied; but it is only a matter of time.
The design of the energy market is fundamentally broken as has been amply pointed out by Prof. Dieter Helm and many, many others. Tory govt' isn't prepared to do what's necessary to shift it.
A good place to start would be bulldozering through planning permission for half a dozen nuke plants at Hinkley C scale; and associated transmission lines. That kind of action would lose a lot of traditional Tory voter votes, because "NOT IN MY BACK YARD".
As my late friend and author David MacKay pointed out "Make sure your policies include a plan that adds up!"
We haven't had one that adds up for about 40 years (when the CEGB and BG went on the chopping block at the hands of Thatcher). The chickens are now coming home to roost.
I remember Professor Ian Fells telling us of the perils of the "dash for gas" back in the early '90s, with particular reference to the unstable parts of the world we would be dependent on for our fossil fuels. Only surprised it's taken this long for the wildfowl to return.
Would I want the clusterfsck that is Dounreay or Windscale in my backyard? Not especially. But I'd be quite happy to have a reactor complex of proven design, with multiple levels of resilience rather than risk global catastrophe.
"reactor complex of proven design"
That's a problem in itself. We've not had many improvements due to nothing being approved. The same thing has hampered transportation. A city council will only go with a "proven design" which often means sticking with diesel busses instead of putting a toe in the water with PRT system or testing out a couple of bus routes with an electric bus.
We haven't had one that adds up for about 40 years (when the CEGB and BG went on the chopping block at the hands of Thatcher). The chickens are now coming home to roost.
Indeed. Privatising natural monopolies was & is a very dumb idea, especially given lack of any effective regulation and regulatory capture. But this is much the same story as the 'renewables' lobby pushing for grid-scale battery 'storage'. They're massively expensive, ineffective as actual storage solutions, but do allow for huge profit potential if you've rigged balancing payments in your favour. If not, then you could still play the arbitrage game.
At least with this idea, or EV-as-storage, it socialises some of the profits, but only if you can afford the buy-in. So the people being pushed ever deeper into energy poverty and debt won't be able to benefit.
And as I’ve said elsewhere, storage does not have to be a battery. There are other ways to achieve that effect without mounds of short lived Li-Ion batteries.
Mid scale pumped or mass storage systems in the 500kW to 5MW generating capacity range; times 400 substations would offer a massive boost to the strategic and tactical planning of the system.
Wind has a place but when 50% base load is coming from gas, we clearly can’t rely on wind alone and it would be dumb to do so. Wind plus storage will work - but you have to build the damn thing. Current rules don’t allow the TO or DNO to do it!!
Offshore wind is popular with Tories because planning permission doesn’t lose you elections. Bills of 5k, on the other hand. That will lose elections. And not before time.
Mid scale pumped or mass storage systems in the 500kW to 5MW generating capacity range; times 400 substations would offer a massive boost to the strategic and tactical planning of the system.
Alternatively, you finally realise that trying to build a reliable energy grid based on fundamentally unreliable generating sources is never going to work. It doesn't matter if it's batteries, winching mass blocks up and down with cranes, or pumped storage... It only adds cost. Plus in an island like the UK, where would you put it that isn't already covered, or proposed to be covered in windmills or solar panels? Hydro's great, but only if you've got suitable locations to build it.
Offshore wind is popular with Tories because planning permission doesn’t lose you elections. Bills of 5k, on the other hand. That will lose elections. And not before time.
I think you'll find it was dear'ol Ed Milliband and his main squeeze, Baroness Worthless who gave the UK the Climate Change Act and got us into this mess. Sure, not many MPs voted against the CCA and it's 'legally binding' committments, but any future government could unbind that thanks to legislation Blair gave government.
Problem for the UK is both parties still think 'renewables' are a good idea, and we should be investing even more of our money into scum sucking subsidy scammers. It's not their money after all, and while both parties agree to hand over our money to the Green Blob, nothing will likely change.
Then again, there have been hints that some realise it's not working, will never work, and investing in nuclear is probably a really good idea.. But that'll take time to come online.
The point really is that a mix is needed. Ploughing just into nuclear is a bad idea. Ploughing into just Wind and Storage is bad.
At the minute we have ONLY wind and gas, which is just plain fricking dumb; and the consequence of 40 years of bad decisions made on both sides of parliament.
A logical level for Nuclear base load is to consider minimum demand at any time. Accounting for Heat+Transport+Electric baseload; 6 to 10 Hinkley C equivalents is easily justified for Nuke.
Looking back at the CEGB's plans of the late 70's and early 80s, low and behold, they intended to do just that. Sizewell B was meant to be the prototype of a bunch of new reactors. How many did we get? 1. Privatisation lead to Dash for Gas; and subsequently to Wind.
The incumbent government have had 12 years to do something about the mounting situation; we see mostly token gestures and MORE windmills going up; not nearly enough nuke and zero storage. (In fact, storage is negative if you allow consider the Closure of e.g. Rough).
Ministers might point to the benefits of interconnection, but as amply displayed by the Germany situation, Interconnection is a profiteering tool if you're not a net exporter. Which the UK isn't.
"Ministers might point to the benefits of interconnection, but as amply displayed by the Germany situation"
Yes, politics can come into play and a megalomaniac like Putin crops up from time to time. If your country can be gripped in the nether regions by an outside entity so easily, you have a big problem. The US has lost so much manufacturing capability to China, that it doesn't dare take too firm a stance on anything or there won't be uniforms for the military and many large retail chains will have nothing to sell on their shelves but the shelves themselves.
" but only if you can afford the buy-in. So the people being pushed ever deeper into energy poverty and debt won't be able to benefit."
That's an argument that drives me nuts. Poor people (invariably a minority when in news articles) can't afford to participate so it's racist or a bad idea. There is a world of things I can afford and them's the brakes. I can't take advantage of the rule that would allow me to put enough money in a bank account earning interest and designate it as financial liability so I wouldn't have to pay for auto insurance. I also can't afford (or justify) a top notch accountant that can make sure I legally pay the least amount of taxes every year. Should they be banned?
"The reason professors like you have a place to teach is because people like me donate buildings" ~Thorton Melon
In 10 years when there are more and more used EV's for sale, more people will be able to afford them and will also be able to participate in these programs. If the programs never get off of the ground, they won't be there later.
"I also can't afford (or justify) a top notch accountant that can make sure I legally pay the least amount of taxes every year."
You can't afford not to. Unless you are using the EZ form, even H&R Block will be better than doing it yourself ... they actually take classes to make sure they are up to date on whatever changes have been made year-on-year. Under $200 for most people, and typically they save you over five times that.
"In 10 years when there are more and more used EV's for sale with ten year old batteries and motors, the junk yards will be full of them."
FTFY
"So, at what £/kWh is deliberate disconnection preferable to paying whatever-it-will-take?"
At some point the problem is some sort of bottleneck on the network and not price. A power company may be forced to disconnect load to prevent a substation from going off bang that will take days to rebuild or bypass.
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Residential peak rate is about $0.25/kWh and rising. This offer is good for SolarEdge and maybe some other batteries too. As I understand it, it's used for testing and emergencies only.
I didn't sign up because the invitation is indistinguishable from a phishing email. There's literally nothing official about it, no references from official sites, and nobody at PG&E or SolarEdge replied when I asked if it was real.
They probably need to offer an incentive.
Based on a recent solar panel installation with batteries in the UK, it is obvious the house owner will need to install additional batteries over and above what is necessary for their needs, or risk running out of stored electricity themselves during the "load management events".
Aside: The batteries make a huge difference to solar panels; correctly sized and you draw very little from the grid. Given the change in energy prices, my friend expects to recover the installation costs within 3 years, with batteries having a circa 10 years life and the panels circa 25 years...
'Correctly sized' is the issue, you'll need to know your normal hour by hour power draw over a year (8,000+ data points) then install the solar+battery to fit.
The problem comes when a family on a tight budget looks at their numbers and finds they'll need double the installation that the single bloke across the road has to get the bill down to the same level.
If the power company decides that batteries are the way forward for load balancing, they can either buy their own battery packs and slap them next to the distribution substations or pay outright for a set to hang off my solar, I'll be happy to let them and I know which one will be cheaper by the mw.
If I decide to install batteries to compliment my solar I'll make sure that come an 'event' my money is keeping my lights on and not subsidising a power companies fubar. As it stands at the moment my solar is useless during a power cut because the system disconnects at mains failure to avoid putting power into the grid that may have engineers working on the cables. this can be remedied but so far outage frequency isn't worth the cost.
> As it stands at the moment my solar is useless during a power cut because the system disconnects at mains failure to avoid putting power into the grid
With a straight solar install, no mains also means no solar...
Battery systems have an "emergency power supply function" (aka UPS) that switches in when there is a power outage.
>'Correctly sized' is the issue
Being 'techies' and comfortable with maths, we spent far too much time analysing data... Because the batteries are largely used overnight, it is this usage data you need, as that is what your batteries will be called upon to deliver. However, daytime draw is also a consideration, as you really want your panels to recharge the batteries and at the same time supply your home.
But then perhaps being the US its a one size fits all approach to home batteries, so whilst we in the UK debate whether to have a 2.4 or 4.8kWh battery (£500 more), there 24kWh is the smallest battery unit.
This is the gotcha I don’t really get.
If there is an extended power outage, that’s one reason kinda why house bought a power wall, and will be keeping it for themselves, so they can keep their Nespresso machine fired up whilst they wait it out.
Feels like another ‘Tragedy of the Commons’.
Aside: if you can afford the capital cost without having to fund it via a loan you are quid’s in. If not, the numbers on solar don’t have a great ROI and are a long term gamble.
"Aside: if you can afford the capital cost without having to fund it via a loan you are quid’s in. If not, the numbers on solar don’t have a great ROI and are a long term gamble."
Solar can have a good ROI if the system is sized correctly. Most aren't since the big solar companies are massive thieves and will talk people into what they want to sell rather than what the customer really needs. They'll hand them misinformation like sizing the system a bit larger so there's room to grow (rather than finding ways to be more energy efficient). They'll show "calculations" on how a larger system can pay itself back faster through feed-in rebates (which can go away in seconds). Surveys/audits only look at the monthly bill and not the time of day power is being used. If the house is mostly empty during daylight hours, most power usage will be at night when there is no solar generation.
Battery backups get really tricky. If you live in a city with rare outages, a battery might not be a good investment. The sizing will be critical as well. When my dad was alive he had a home that was second to the last property on the end of a power line way out in the country. A big snow storm could lead to the power being out for days until they could gets the trucks in to make repairs. The pot belly stove was fine for heat and cooking (my dad loved to "camp out" at home), but it meant the well pump wasn't going to work.
As I type this, my power went out. Good grief. Ok, back on in around a minute but it will be a couple before the internet is connected again.
To continue: For my dad, a battery system would have made sense (good grief some more, the frequency is going mad. I expect the power will go out again). Still not Tesla. BYD, LG, Bosch, Siemens and many other companies have been in the market longer, sell a wider selection of systems and there are ala carte systems now that can be tailored to a specific need.
> the numbers on solar don’t have a great ROI and are a long term gamble.
A couple of years back (probably a lockdown activity) I did the maths on a set of solar panels. Over the 25-year life, ignoring feed-in tariffs and assuming a fixed energy price, I would be around £500/6 months energy better off.
However, just as with cavity wall insulation back in the 1980s and 1990's, the only way for utility-delivered energy prices to go is up; so not really much of a gamble, with recent events simply accelerating the trend.
To me the addition of batteries massively enhances the value of solar panels and from the initial data have a much shorter time before they break even. Only issue my friend now has, is the battery pack in the cupboard under the stairs and the fire hazard it presents...
I'm not sure I understand how your payback can be so slow..
I've just had a solar array installed. With a 9.2kWh lithium ferrite battery and a 4.2kW peak capacity solar array, I'm expecting break even to be somewhere between 9 and 9.5 years, although the coming price hike in october will probably reduce the payback time.
Without the extra expense of the battery, which doubles the cost, the payback period was going to be between 11 and 12 years. Without a battery, the payback takes longer despite the fact you've spent less because instead of using all the electiricty generated, you end up selling electricity to the grid, and then at night paying between 4 and 7 times as much as you were paid tper kWh o buy electricity when you need it.
>I'm not sure I understand how your payback can be so slow..
Firstly, this was for a pure solar panel installation, no batteries. So the only saving was on my then current daytime electricity usage. As the feed in tariffs were being removed, I assumed all surplus electricity would effectively earn me nothing. Finally, as you note the utilities 'love' solar panels as they enable them to put such customers on special low user tariffs ie. significantly higher cost per unit.
Secondly, the installation price I was using was a raw quote obtained without all the usual sales b*llocks(*).
Thirdly, I was wanting the then newly available higher efficiency panels, which would have raised the price..
(*) It is surprisingly difficult to get a reasonable quote for anything major like solar panels, double glazing in the UK, without the provider insisting that all people with an interest in the property are present so that they can comply with the law and send a salesperson along. Meaning the initial price can be x2 the actual price, giving the salesperson room to negotiate their commission and offer "sign now" discounts...
"Aside: The batteries make a huge difference to solar panels; correctly sized and you draw very little from the grid. Given the change in energy prices, my friend expects to recover the installation costs within 3 years, with batteries having a circa 10 years life and the panels circa 25 years..."
Does your friend have Tesla batteries? They are about the most expensive on the market.
Usage is going to be key to whether solar and a battery backup system is going to have much of an ROI. Batteries are a very expensive way to store mains power. Local regulations can play a big part too. In California, the power companies were required to pay retail prices for feed-in from residential (under 10kW nameplate) installations. I knew that couldn't last and the power companies were going to keep lobbying until they could get it down to only having to pay wholesale rates. What was a bit unexpected was some draft bills that would also have residential solar owners also having to pay a monthly fee to the power company based on the nameplate power for their solar system (not just what they generate). That has the potential of a negative ROI for a grid-connected solar system. It could make more sense to have a grid connected home and a solar system with a zero export configuration. The grid is used to make up power needs beyond what a solar or solar+battery system can supply.
>Does your friend have Tesla batteries?
Get real !!! :)))
>Batteries are a very expensive way to store mains power.
Mitigated slightly by charging them via the solar panels rather than the mains. But as noted elsewhere in discussions about UPS's the big energy drain are the investors needed to convert battery output back into 240V etc.
Following the logic of UPS's it would seem the next step will be to increase the intelligence and to have the local control hub block the usage of high-draw appliances.
It'll cost SCE $30,000 if they take the full 5kwh from each of the 3000 owners they expect to sign up ($10 each), but still it's only 15mwh total and apparently that's enough to power 11,250 homes @ 1.3kwh each on a Californian summer evening - No A/C units running I take it?
15mw is less than half the output from a single MT30 gas turbine generator which costs far less than $30k/hour to run but does cost a few million to pick up in the first place so it would take the powerwalls perhaps 200 one-hour events to catch up.
This provides such a marginal benefit (less than half a watt per Californian!) that it seems to me they're just putting a marker down for using other peoples hardware to avoid investing their own money in generator capacity. Their future blackout excuse being 'If only we had all the home batteries connected, this wouldn't have happened'.
This provides such a marginal benefit (less than half a watt per Californian!) that it seems to me they're just putting a marker down for using other peoples hardware to avoid investing their own money in generator capacity.
I think it's more snouts than markers. Very recently, this happened-
https://www.bbc.co.uk/news/world-us-canada-62568772
US President Joe Biden has signed a $700bn (£579bn) bill that aims to fight climate change and healthcare costs while raising taxes mainly on the rich.
In typical Bbc fashion, it gets just about everything wrong. Previously the bill was 'inflation reduction', but hard to keep calling it that when you're printing money. It also retains tax breaks for the rich, ie carried interest loopholes used by the hedge fund & PE crowd who push 'climate change' and make massive profits from 'renewables' scams. So then-
The bill does not require companies to reduce their emissions, but includes tax incentives for firms to invest in renewable energy and rebates for people who buy electric cars or invest in energy-efficient home improvements.
So there you have it. Subsidies to flog more 'renewables' crap, personal and corporate tax reduction so the Green Blob can keep more of the profits. It'll increase inflation, increase energy poverty and 'raising taxes' really means hiring 80,000 more tax inspectors to go after America's middle class. If you're wealthy and well connected, you'll still be able to carry on paying for hookers, drugs and personal expenses for you and your family out of your 'investment' company(s).
Here in Cali-Forn-You expect to pay $.50 / kwh during peak hours. Or more, depending...
I shall not get into why, but when we had more nuclear and oil and natural gas plants, it was WAY less than HALF this much. But that was 18 years ago when Ahnold was Governor. Ahnold became governor due to a recall election of "Gray out" Gray Davis, whose policies had kept power plants from being constructed (as I recall). Ahnold reversed these policies and encouraged power plant renovation (etc.) such as the Moss Landing power plant (an oil burner), and new construction also (as I recall). THEN Cali-forn-you had PLENTY of electrictiy. And it was WAY cheaper, adjusted to inflation even. (I should know, I was here)
Cali-Forn-You STILL has some of the most expensive electricity, though. Even back then. Home solar systems with battery systems (like Tesla's power wall) in some ways help distribute the cost around a bit among individuals, but aren't a 100% solution. It is often VERY hot after the sun goes down (in August), and peak hours are from 4PM to 9PM (when electricity costs the most). Batteries only store so much.
Paying individuals $2/kwh for "peak power" is not unreasonable, actually, when the costis already so high, since it is an average of power generated by many sources, and that extra small percentage for brief periods of time will likely prevent the grid from collapsing. It becomes a drop in the bucket for electrical providers, and a cash boon for those willing to put their surplus power on the grid during the peaks.
It really does NOT have to be this way. We have the technology. But I think *SOMEONE* or *SOMETHING* doesn't WANT us to live like we;re in a 1st world country... so here we are,.
My electric rate is about $0.10/kwh, so that's 20x the market rate.
And just where are you?
PG&E's rate is about $0.34.
SDG&E's Tier 1 rate was 34.5 cents/kWh as of Jan 2022.
SCE's rate is around $0.30/kwh.
So just where are you getting electricity in California for 1/3rd the going rate?
$2/kwh is NOT much money for energy storage. Each charge/discharge cycle shortens the life of your very expensive battery pack... That's why the vast majority of folks with solar panels remain connected to the grid. Pulling power from a remote power plan is vastly cheaper than batteries.
The term for this is: Levelized Cost of Storage (LCOS).
According to the first source I found, the Tesla Powerwall comes in at about $0.30/kwh LCOS.
If they were offering $0.30/kwh, which is 3X what you say you're paying for electricity, absolutely NOBODY in their right mind would sign-up... you'd be losing money.
Sources:
https://climatebiz.com/tesla-powerwall-cost/
https://ertpw-ratemailer-updater.s3.us-west-2.amazonaws.com/OutPutFiles/07-07-2022%2020:45:59.141/Peninsula%20Clean%20Energy%20(PCE)%20PG&E_ResidentialE1_07052022.pdf
https://www.cpuc.ca.gov/-/media/cpuc-website/divisions/energy-division/documents/electric-costs/sb-695-reports/electric-and-gas-cost-utility-reports-from-ious/sdge--2022-recommendations.pdf
https://ertpw-ratemailer-updater.s3.us-west-2.amazonaws.com/OutPutFiles/08-18-2022%2015:28:16.665/Clean%20Power%20%20Alliance%20(CPA)SCE_Residential_08152022.pdf
V2G (Vehicle 2 Grid, bidirectional charging actually) would be way more useful; cars typically have 5x to 10x the capacity of a Powerwall.
The fly in the ointment is that Tesla's aren't currently wired to feed power out - so no software update is going to "fix" this.
Still, it's a good start and perhaps the non-Tesla-plug versions, CCS, might have the tweaked hardware to allow this?
As I understand it, the CCS standard doesn't currently allow for V2G, and all the trials I have heard of use the Nissan LEAF with its CHAdeMO connector.
Over here in Europe, by the way, Teslas have been using CCS since the advent of the Models 3 & Y, and the older Models S & X can be retro-fitted to support CCS with a small(ish) adapter.
GJC
The real flies in the V2G problem are:
1) When my car has been plugged into its charger for a couple days, I expect it to be fully charged, not half charged (or less), when I jump into it to go somewhere.
2) Who pays for the additional wear and tear on my battery and charging infrastructure? Because it sure as hell won't be me! I'm altruistic enough to give away my extra veggies to anyone who needs them, but I draw the line at loaning out the power tools used to grow them.
1, you charge your car for cheap overnight on cheap overnight baseload electricity. When there is peak demand from 6-8pm you stop charging or sell power back to them. You get reduced price electricity and get paid for any sent back.
2, except for totally discharging, the most damage is to do with charging rate and temperature. Slowly charging and discharging at home with the rate set by the battery computer is the best thing for you battery - compared to driving.
There is definitely a price I would agree to this for - and I only pay $0.10/kwh
Car batteries are huge compared to home hookups. The same limitation that prevents fast charging at home means you're not loosing much if the flow is reversed for a bit. If they drain your 100 kWh battery to 80% you'd get $35 to $40 out of it, depending on your cost to recharge it.
At least for the home battery systems, you choose how much PG&E may take.
I personally don't feel like doing any favors for PG&E. I'd only participate if it was really easy and made real money. Give me a monthly participation payment. I only export power from Spring to Fall but I'm being charged a customer hookup fee like a consumer.
It would work if you could set it up to stop feeding the grid when the battery reaches a certain level, which can be set by the user, eg at 60% for day-to-day or switch off completely if a big trip is planned. As long as it's user-controlled and cannot be overridden externally.
With regards to cost, you're typically charging at an off-peak tariff much less than $2/kWh, and then selling it back at $2/kWh. It's up to each user to calculate for themselves whether that is enough compensation for the power company using their battery. If it doesn't work for you don't do it.
Well, by paying your electricity bill you are paying for the charging infrastructure: at least both the transmission and distribution networks elements of it. Transmission is a tiny fraction of the bill, but distribution is quite expensive (because many personnel and huge inventory)
The charging point on the end is an extra cost; if you pay for one at home that's your's to maintain. Those on garages and "petrol stations" will be factored into the price of using the charger.
That both distro networks and charging network are hopelessly inadequately sized to accomodate demand has been recently reported on El Reg and represents a BIG increase in distro network funding that must happen.
Petrol and Diesel are all rather convenient by comparison. But, climate change or not, are also quite expensive as well as haemorrage your hard earned cash offshore.
It's well known that the batteries in Electric Vehicles degrade as more charging / discharge cycles are put on them, resulting in sometimes significantly lower capacity after a couple thousand cycles.
The Tesla Power Walls aren't any different and quite possibly may have even less available use cycles.
The cost of replacing vehicle batteries is very substantial (if even possible) so vehicle to grid would not seem to be a good idea for the owners of the vehicles.
Even with your power wall, signing up for such a scheme might mean the lifespan is cut in half or even more, and those are not cheap either.
I could see some governments trying to mandate it, so then the question is, will they be paying the owners for the replacement costs since they could easily have cut the useful working lifespan in half?
The marginal rates on offer (as per the $2/kWh quoted in the article) make the slightly shortened battery life very much financially worthwhile. And it is only a slight shortening - most V2G trials I have seen only use something like 10% of the total battery capacity, rather than a full discharge/charge cycle, so degradation is minimal.
GJC
"Whats the lifetime of the powerwall given a typical california summer. Has anyone crunched the numbers?"
I'm in California, and recently converted to a fully off-grid solution. Note that each homeowner's situation is different, claims vary wildly, and nobody really has all the answers.
Tesla::spit:: claims 5,000 cycles @ 96% for the Powerwall2's LiNMC battery. Somehow, I doubt this. The Lion Energy "Sanctuary" units that I use claim 6,000 @ 90% for their LiFePO4 battery. We'll see ... But I have seen claims of 10,000 cycles @ 90% for competing LiFePO4 batteries.
Your guess is as good as mine as to what this translates to in the RealWorld.
The LiFePO4 technology is what made me tell PG&E to fuck off ... a complete home solar+battery system should pay for itself in about ten years[0], have a total lifetime of thirty+ years, with only one battery change in that time ... and possibly a second battery change, with a projected pushing-the-envelope lifetime of somewhere around 45-50 years, depending on solar panel degradation[1].
[0] Extrapolating PG&E rate increases.
[1] Don't buy your panels off the back of a truck. Pay for name brand.
What the greens fail to understand is the life the developed world lives today is not primarily focused on finding something to eat and how to stay warm. This luxury is provided by reliable, economical and dependable energy. Even if the world is cooking in a greenhouse there is no feasible way to remove the fossil fuel we consume today. Anyone who tells you this is a fool or benefactor of tax money pouring into green energy. The technology does not yet exist.
All energy should be used and keep looking for technology that will be green and reliable and cheap.
Humans have used solar power since time immemorial. Same for wind.
The Greeks and Chinese had hydro power around 3,000 years ago. It may go back much further, but given that most of the infrastructure rotted out because it was wooden and located in a wet by nature environment, nobody really knows.
Not hydro-electric, mind ...
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