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Tesla Virtual Power Plant

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350 pointslawrenceyan255 comments

I'm not OP, but the timing context of this post is important:

Today, California has issued a FlexAlert, and Powerwalls in PG&E and SCE will start discharging at 6pm to help reduce load on the grid. It's not a daily action, but it's emergency support when the grid needs it the most.

And the time window when it happens is important: Powerwalls are contributing to to reduce load when the grid needs it the most. It's not meant to support the entire grid, just directly attack the problem at the time where every Watt and Watt-hour counts.

You don't need to own Powerwall to benefit from this, just like how you don't own the peaker plants that typically spark up at these times. You benefit because there's a big chance that there won't be rolling blackouts in California this afternoon—distributed assets like this can be dispatched.

Dispatch Info: https://twitter.com/AlexGuichet/status/1559748677626777600

A VPP tracker in the Tesla community: https://www.lastbulb.com/virtual-power-plant

Some technical details of how Tesla VPPs work, as organized distributed systems: https://www.youtube.com/watch?v=ggdYts4muu0

CAISO Grid Outlook: https://www.caiso.com/TodaysOutlook/Pages/default.aspx

Important to have some perspective on scale, though. All powerwalls acting together can source 125MW, max. Yesterday, grid-scale batteries in California discharged a peak 2751MW. The powerwall tricks are cool, but I’m not sure it solves a problem the ISO actually faces.

We've come so far in so little time and people like to keep puting progress down.

Regulated market participants are adding the equivalent capacity every month. That's where the progress is coming from, and where you should expect most future progress to occur. Long-tail stuff just isn't efficient enough to really make a dent.

But the number of power walls is not fixed, and going from 125MW to 12,500MW is only going to happen there are proper incentives from the grid.

And as it is, utilities in the CAISO are generally too fossilized and change averse to view behind the meter aggregation as something that they can benefit from, and they will likely instead fight it. Smarter utilities would see the opportunity and approach regulators with rules changes that profit everybody. Instead, we will need legislators to impost such schemes on regulators and utilities, as there is zero innovation among leadership of utilities, and regulators have zero capability for this too.

(Perhaps I exaggerate, SMUD is tiny but they may have the vision for at least part of this. Vermont's Green Mountain Power has the leadership that we need in California, though.)

Regulated market participants went from zero to 3000MW/12000MWh of capacity in only 2 years. That's 100x faster than powerwall installations. I don't see how you can conclude from these facts that CAISO or the CPUC are stuck in the mud.

Central installations are perfect for the current incentives: they use the same amount of T&D, for which utilities can always charge their profit margin, as long as they can convince regulators that the expenditure is justified.

Behind the meter storage is a fundamentally different beast, because it has the potential to drastically reduce T&D costs, which are the vast majority of bills (at least mine under PG&E).

Christopher Clack has some great economic modeling of the grid at a very fine level, showing that deploying a bunch of storage and solar at the grid edge right now will greatly reduce costs and enable far more utility scale installs in the future, because the local storage and solar reduces the need for T&D peaks.

This sort of cost optimization is not incentivized but anyone in the current setup, and is impossible to achieve without direct regulation to change incentives for utilities.

I don't disagree with any particulars of your analysis except one omission: powerwalls compete with electric cars for relatively scarce high-tech batteries. It is globally optimal for the time being for those batteries to all be used to electrify transportation, while utility power can be enhanced with large, fixed installations using whatever kind of battery they can get. Lead-acid or anything else, it doesn't really matter. But nobody is selling turn-key residential power packs using anything but lithium-ion batteries.

I thought a lot of these were recycled from vehicles when their energy density doesn’t meet the needs of a vehicle anymore but make sense in a house since the house doesn’t move?

Note this same argument is used against EVs. Saying the batteries should be used for hybrids instead.

In both cases, the fundamental mistake is to think of these as costs, when they are investments with rapid paybacks and so the obvious answer (and the reality) is massive expansion of battery manufacturing capacity.

The hybrid thing is true though. With the same number of batteries you can cut carbon emissions from cars by either 50% with hybrids or 2% with electrics. It makes perfect sense as the thing to do now with the capacity we actually have.

No it doesn't.

The thing to do now, is increase our battery capacity.

Not all parts of the energy grid are as “clean” as a gas cars’ ICE unfortunately. You’re better off driving an ICE in those regions than charging an EV. Globally we’re better off creating a sustainable carbon-free grid in regions with poor grid generation first.

In California, where this applies, the grid is very clean, so yes the dirties/most polluting part of the system is probably the cars.

Seems like having an available 5% bonus on peak (!) usage is a huge deal, actually. Buffering shortfalls have an exponential frequency curve. I wouldn't be surprised if 5% extra generation would have been enough to cover, what, 60-90% of all brownout/failure conditions on the grid over the past few decades.

Also, too, it's a brand new technology just being rolled out, and building more capacity at the limits of factory bandwidth. You're acting like the number of powerwall users are all we're ever going have, which seems silly.

> Seems like having an available 5% bonus on peak (!) usage is a huge deal, actually.

CalISO showed a peak demand today of ~42GW. 125MW is more than nothing but nowhere close to 5% of peak usage.

And solar was providing about 3GW less than it was about a month ago. Lower solar output but spiking fall temperatures. It's sort of a "coffin corner" for the state, currently.

I think they meant that if grid batteries are a good thing (which they are), then distributed batteries equal to 5% of their peak contribution, isn't nothing. (125MW/2751MW)

The baseline is not zero GW. If the grid planned for 35 to 40GW of demand for today and then sees 42GW load, the 0.125GW are over 5% of the excess load.

Serving baseline from batteries is unrealistic and will be for quite some time. Smoothing peaks or helping with unexpected high (or low!) load however is slowly becoming viable.

I'm surprised it is so low. Our pack discharges at at least 10kw (max averaged by hour over the last two weeks; didn't look up specs). That means we're over 1/12,500th of the state wide pilot's footprint.

Apparently, (as of 2021) Tesla has only sold about 200,000 powerwalls globally, so I guess that sort of checks out.

Annoyingly, our batteries are set to minimize our bill, but didn't get the memo about the special rates today (they are not powerwalls). They stopped selling back to the grid just before 6pm, and are almost half full as I write this.

More annoyingly, every morning they aggressively charge themselves during the precommute CO2-intensive demand spike, since power is cheap then (due to a policy setting, they normally only charge from solar)

I wish I could forbid them from charging before 10am or that PG&E would fix their rates.

Many of these devices do let you set 'fake' time of use details if you want to further restrict them. Not ideal, but a quick way to make your energy use greener if you consult one of the APIs that tells you when your local grid is greenest (which probably roughly, but not quite matches their time of use rate structure since they have to simplify, possibly averaging over a year when it various seasonally)

The Tesla stuff is just a name-brand subset of a larger demand response program in California though:

https://www.caiso.com/participate/Pages/Load/Default.aspx

I think the demand response stuff adds up to about 2GW, so the same as the grid batteries at the moment, and both are set to grow at rapid rates.

Has anyone done the math to determine whether the added wear-and-tear on the battery is negated by the payout?

I wouldn’t want to go from a 7-10 year battery replacement cycle to a 3-5 year battery replacement cycle out of pocket just because “I’m Doin’ My Part for the Grid(TM)”.

At $2/kWh you’re making as much as $16-$20 per cycle so it is almost certainly worth it to the battery owner to use your battery for this vs. load shifting, etc.

$2/kWh is insane though. My power rate is $0.12/kWh.

$2/kWh is still 6x California’s most expensive power.

> $2/kWh is still 6x California’s most expensive power.

You only need that power ("operating reserve") for extremely short times in a day, the rest of the time the power plant stays idle. Mostly these are hydro pump dams or gas peakers (as they can start in well under 60 seconds), batteries are a relatively new thing - and all three of them are pretty expensive to build, so it is obvious that their power generation comes at a high enough price that the plants still stay profitable.

Yesterday the peak price for electricity in Europe was 4€/kWh (that was in Estonia, was one hour period, due to some production issues at multiple power plants).[1]

[1] https://news.err.ee/1608686533/estonia-s-electricity-price-t...

And FWIW: I pay 0.42029€/kWh to my provider in the Netherlands while getting back 0.115€/kWh back for every kWh delivered back to the grid (after I generated and used most of it in my home)

Used to be 0.23ct or something.

I don't want to talk about or look at the prices for a cubic meter of gas...

Here in Estonia the spot market pricing works the same both ways. So I set my system to feed at 7kW during the hour and made about 28EUR for helping the grid. That is twice the $2/kWh this Tesla peak power provides but it's literally the only time price has gone this high.

You're confusing peak pricing with average pricing. Peak price is about 50-250x as much as average price.

During the trial its $2/kwh. A powerwall costs ~$10.5k for a single unit with a capacity of 13.5KWh. You'd need to do 5MWh to pay for the powerwall, and that would be ~370 cycles.

The pack should be good for over 1k cycles. This is definitely a beneficial thing for the owner at these prices.

For reference:

https://www.tesla.com/sites/default/files/pdfs/powerwall/pow...

If it's being used for solar-piped home backup it's covered for unlimited cycles, and for any other usage they rate it for 37.8 MWh of lifetime AC output.

Now, I don't see anything talking about the Powerwall's warranty within this article explaining Tesla VPP, so whether or not this might be considered when they determine warranty eligibility is anyone's guess.

I would think that just charging $2/kWh during peak time would be enough to bring down peak load without using any batteries.

Well, yeah, probably. You'll also make a lot of people unhappy

$2/kWh is very expensive. I guess by paying the powerwall users you can limit how much you spend with them. Not sure with how much local granularity can you turn them on, but it definitely helps

How can they pay powerwall users $2 if they're not actually charging $2?

Presumably most of the time they are charging end users more than they are paying energy providers.

By amortizing that across off-peak pricing?

By not having to build more power plants or not putting the battery equivalent of all the power walls.

Also, I imagine this is to get the power wall users 'hooked'. Then over next few years that $2 will turn into 20 cents.

This isn’t actually unique to powerwall users - this is a program for energy providers to supply emergency power. There’s a minimum amount of power needed to be eligible and a powerwall is too small. Tesla realized that they have the unique ability to manage a fleet of small batteries to act as a single large one to qualify.

Will the price go down in the future? Maybe. Is this a gimmick to get people hooked? Probably not, assuming Tesla isn’t paying end users more than they make to join in.

And hope that won't realize they're destroying their battery without enough compensation?

You're buying the bare minimum to stabilize the grid and you're buying it "delivered" already

Only if people reacted to it reliably and predictably, which generally at the moment they can't.

So they're being paid not just for not using this power at that moment, but being part of a system of "demand response" that lets the grid plan ahead and modulate demand.

They also do this with people's AC and various large industrial energy users.

But, time-of-use rates are a currently underutilized idea, and with greater computerisation, you can get more and more value from this on short-timescales.

You want to start with the low hanging fruit first, and EV chargers are that easy win as they are being installed now.

> But, time-of-use rates are a currently underutilized idea

Is it not normal in the US to pay less for electricity at night and on weekends?

That's very common in the places (Netherlands and Switzerland) where I've lived, for as long as I can remember, and seems much more low-tech than using consumer batteries to supply back to the grid and paying them a custom rate.

It's still 'controversial' and little used in the US:

https://www.utilitydive.com/news/an-emerging-push-for-time-o...

> A new idea is to vary the price of kWhs, making the price higher for residential customers during peak demand, and lower at other times, allowing for more precisely pricing kWhs at what they cost.

> With today's flat per-kWh rates, "customers who use the grid more during peak demand are underpaying for the costs of meeting that demand," Brattle Group Principal Ahmad Faruqui told Utility Dive. "Customers who use the same kWhs during off-peak times pay the same bill and are subsidizing the others. TOU rates can redress that inequity."

The quotes drive home why it is "controversial"; because generation and transmission companies see it as a potential way to improve revenue, not as a way to improve the grid.

I will assent to these powerful features when there is a strong legal guarantee that it will be used to improve the world, not to juice up someone's q2 numbers by charging me more.

Remember that these are the same companies that by and large lobby against being able to sell solar power back to the grid.

> lobby against being able to sell solar power back to the grid.

Worse, they lobby against residential solar as a whole. I could install enough solar panels & batteries to cover 100% of my needs through the year, but unless I disconnect from the grid completely, I'd still pay about half of my current electric bill, without using any electricity from the grid. The utility company with local monopoly is specifically making sure as little residential electric is installed as possible.

In San Diego, we get to choose whether we want to opt into the time-of-use pricing, or whether you want to pay based on the traditional flat-rate tiered pricing (where your monthly consumption is compared with your neighbors to determine your price per kilowatt).

It sounds fancy and pro-consumer, but in reality, we have some of the worst rates in the nation. Jon Oliver even did a recent bit about how ridiculous it is. (Search for "Jon Oliver SDG&E".)

How long will the trial prices last? $2/kwh is insanely high; usually the wholesale electricity prices hover closer to $0.02-$0.04/kwh, although the recent gas price increases have disrupted that for now. The war in the Ukraine is not going to last forever though, and if gas prices remain this high we might see an accelerated transition to non-fossil based electricity generation.

At $0.20/kwh, so prices 10x above "normal", you'd need 3.7k cycles to pay for the powerwall. That would be well above the lifespan of the pack, so at lower prices the profitability of the scheme (to the owner of the pack) falls off rapidly. I suppose it all depends on how long you estimate the trial pricing will last. TFA mentions in the fine print that this project "shall continue until at least December 31, 2023, unless expressly extended by PG&E or terminated sooner." Take from that what you will.

Peak pricing is much, much higher than the prices you quoted and in the ballpark of the trial. E.g. before the 2021 Texas outage the offer price for additional power was the legal cap, $9 / KwH at the time.

Peak pricing is indeed higher, but also much rarer. Prices of $2/kWh are reached extremely rarely, so the VPP in this scheme might only be operating once or twice a year. The calculation in the GPP about payback time for the powerwall assumed you could get a lot of cycles in, but at these elevated prices that seems unlikely to happen. Note btw that the $2 is flat, so even if prices reach $9/kWh you'd still only get $2/kWh back.

I notice that the article does not include any expectations about how often the "events" would happen btw, even though the utilities would surely have enough data to at least make an estimate.

The payback calculation was a direct reply to the concern that VPP use will wear out the battery too fast. The only reason it was done was to show that if VPP would trigger often enough to meaningfully harm the pack, it would also pay you more than enough to replace it.

In practice, VPP will be rare, and thus the payouts will be low. But so will the harm caused to you by participating, assuming you already own a suitable system.

Also the 1k cycles is until the pack capacity goes down to 80% of the original. You could still use the pack well past that unless tesla somehow limits it or complete short of some of the elements in which case you should be able to replace the element.

TBH, I think it goes well past 1k even for the warranty. Someone else pointed out that its closer to 2,800. I wasn't sure, so I picked a conservative number.

Although it was a much more extreme event, no fewer than 246 people died because of the Texas outage in 2021. It’s not just the economy that can suffer if there is a grid outage.

https://en.wikipedia.org/wiki/2021_Texas_power_crisis

That 246 includes all deaths directly or indirectly attributed to the storm. Not specifically the power outages.

"In addition to hypothermia, DSHS attributed the storm-related deaths to "exacerbation of pre-existing illness" (10%), motor vehicle accidents (9%), carbon monoxide poisoning (8%), fires (4%) and falls (4%)."

Seeing as the storm does not produce carbon monoxide itself, I think "storm related" here includes "people dying because the storm knocked out their power"

not having power also doesn't produce carbon monoxide

Portable combustion heaters do. People were using those because they didn't have gas or power for heat, and that's usually how people end up dead from CO. I don't think there's an honest way to spin that into not being the storm and grid failure's fault.

The flip side is that in an event like that, the power is worth far more than $20 to the owner of the PowerWall.

I lived through that outage, and I lost more than $20 in food that spoiled in the fridge/freezer (didn't have a good storage container to put it outside where the raccoons/cats couldn't get it). Some people lost dramatically more than that when their pipes froze and burst.

Central heating also doesn't work without power. They draw less than 600 watts. In that situation, would you rather have $20 or enough power to have your heating run for 24 hours? And that's actual runtime, you could probably keep your house warm-ish for 2 or 3 days by turning it on and off.

Personally, I'd only be interested if joining something like VPP came with a substantial subsidy on the price of the PowerWall or a monthly payment that could offset a significant portion of the cost. Or it had enough storage that I actually had extra power after running essentials (it does not currently).

These stationary battery should not require anywhere close to a 7-10 year cycle. The chemitry should be above 80% for much longer and te battery should stay usable for decades.

> out of pocket just because “I’m Doin’ My Part for the Grid(TM)”.

Exact mentality why we'll never ever fix our ways of life

The grid in California is run by a problematic for-profit company that has a history of starting deadly wildfires.

People should generally be willing to make sacrifices to help the greater good, I’m sympathetic to people who don’t feel obligated to do their part.

For Australia, it was not worth it, except to get a few thousand off the purchase price (then quit VPP as soon as humanly possible).

My experience was their algorithm is terrible and it gets into a charge+discharge cycle for no reason for hours at a time, costing $0.40 to charge and earning $0.10 to discharge, plus wear, for no benefit to the grid.

I used to turn off my battery a lot.

I'm contemplating enrolling in this.

Right now I'm a net generator, even with our 100 deg days, but I am not 100% off grid. The Panels charge the Powerwall during the day, the Powerwall is drained overnight.

The batteries currently do not survive the night. Even though the house cools down, it retains enough heat that the AC still kicks on, thus draining the battery. Note my AC is 78 all day/night. We got a thing from the power company "do these things on this day and get power credits by lowering your usage", and, of course, we already do all that...no credits for us!

So typically during transition at dawn, I pull in grid power.

But I'm still a net generator, they get more than I take.

The concern was simply if I enroll in this, then the batteries kick in and drain even before the evening, and I go to grid power sooner.

But, thinking about it, "I don't care". It's an offset. They're draining because they need the load NOW, and I can provide it. Later, when things settle down, I'll pull it back.

I think this works out, simply as a "be a good citizen", use my battery to prevent someone in Fresno's AC browning out late in the heat of the afternoon.

Maybe I'm just being whimsical, but I'm still thinking about it.

Also thinking about bolting on another battery, I already have two.

If you consume that little electricity, the $2 they’d pay to pull from your power wall is probably 8-10x what you’d pay to refill it from the grid.

Nah the grid hook up fee is likely the bulk of the cost. Simply being connected is the most expensive cost

Where I live the connection fee is $20/mo and bi monthly bills are anywhere from $100 to $1900, we have electric heat in and older house

Electric baseboard heat with minimal insulation?

A heat pump is much more efficient than electric baseboard heat, you might as well run your computer to generate heat since it is equally as efficient as electric baseboard heat or space heaters.

Idea: sell space heaters that secretly are bitcoin mining rigs.

Funnily enough it's been done:

https://heatbit.com

https://bitcoinminingheater.com

If only we could have the heater PCs do something actually useful.

Imagine showing this real product to yourself 15 years ago.

And imagine actually using one of these. Space heaters are one of the leading causes of fires, these ones seem like they have much greater fire risk since the Bitcoin stuff adds complexity that regular space heaters dont have.

Lots of insulation but probably crappy tenants leaving windows open. Also it is -20 outside.

If you live in one of the 26 states that have time-of-use rates (mine is 21¢ peak and 1¢ overnight), you can enroll in that, import your schedule in the powerwall app, and it will automatically deliver the bonus power to your house during the peak, allowing you to export even more solar to the grid during high demand.

Enphase batteries support this too. (I suspect all brands do.)

Do you have any documentation on that? I have a hard time finding the relevant details on this.

Not saying you should but can’t you stack the power walls to bring you to off grid?

I wonder if a whole house fan would help avoid using the AC through the night. Of course, the next obvious question about is it worth the installation cost...

I have a whole house fan, and it's awesome. Cools the house down really quickly at night. I mostly did fine in the Pacific Northwest without any A/C until a couple years ago. A whole house fan is worse than useless, though, when you have wildfire smoke and it isn't getting below 75 outside at night. I finally had to cave and buy an air conditioner.

They also aren't that great in humid climates. They will cool the house, but the air is still damp, leading to mold and other damage.

We have a whole house window fan that was probably manufactured in the 50’s (“Homart Cooler”). It is excellent for upper Midwest summer nights. Our house is old enough to make ducted AC a nonstarter, so the ability to cool the interior of the house over night is very helpful.

try high velocity ducted ac, via heat pump. the ducts are 1.5 inch diameter flexible insulated pipes. Alternatively, ductless AC (minisplit) via heat pump. That said, whole house fan is nice.

Agree with ductless A/C, we are in a 100 year old house with radiator heating and the ductless A/C cools two floors admirably.

Air King makes one (9166F) that can be put in a window and will cool the air pretty quickly. I've barely ran the AC this year since I've started pulling in cold air at night and closing the windows in the morning.

As another comment points out, with wildfires it's kind of useless when the air quality outside is bad.

They live in Fresno where it is quite hot even at night during this time of year. It isnt going to be below 80F for more than a couple hours during the night (early tomorrow morning).

If you have excess generation during the day, why don't you cool your house to 72 in the late afternoon and then back to 78 when the sun starts setting? It would probably delay you batteries having to power your AC for about 4 hours.

This. Energy can take many forms. You don't have to store all in a battery.

Another idea: assuming you have an electric water heater, when your battery has been fully charged and you still have excess generation, use the excess to heat your water heater up to a very high temperature like 80 degrees C. You'll then be using very little hot water in the evening for showers and dishwashers, etc, and the water heater basically won't need to turn on at all.

> use the excess to heat your water heater up to a very high temperature like 80 degrees C

Wouldn't that be quite dangerous? That's basically instant scalding temperature if anyone accidentally turns on just the hot.

You can get a mixing valve that's installed at the heater. Very easy, then turn the heater up really high, they are only like $15-20 and will effectively double or triple your hot water capacity.

e.g. https://www.watts.com/resources/references-tools/thermostati...

Interesting, I didn't know those existed. Seems like it makes a lot of sense.

It also seems like if you simply leave it on a higher temperature 24/7 it will use more power due to thermal losses overall. This is a great hack for households with several people who like to take long showers (and thus run out of hot water), though, or if you can do some sort of variable temperature setpoint to store energy as described in the thread, though I think at least in the US electric tank-based hot water heaters are relatively uncommon.

Do not install these if you have hard water, they will clog up extremely fast - and the hotter your hot water is, the faster it will clog up.

Which is especially amusing considering this is PG&E territory. The bay area water was so hard you could make limestone castles by rinsing a glass.

There are new 120v heat pump hot water heaters that operate in this way:

https://cleantechnica.com/2021/11/29/120-volt-heat-pump-wate...

"120 volt heat pump water heaters come with a mixing valve integrated into the water heater itself. This mixing valve allows owners to keep their water at a higher temperature and as the water leaves the tank, the valve will mix “in the exact amount of cold water needed to ensure the water comes out of the water heater at the correct temperature.”

Make sure you adjust your faucets so they won’t go full hot. Don’t want to scald someone.

I've been thinking about this. Do you/anyone happen to know if it's a decently efficient use of the stored energy?

I love the idea of our hot-water boiler acting as battery (potentially along with another actual electric battery).

I have a handle on the hardware, but not on the efficiency of it.

Thanks,

Technology Connections does a similar thing, over-cooling his house at night as a thermal battery.

Video: https://www.youtube.com/watch?v=0f9GpMWdvWI

Reddit discussion: https://reddit.com/r/technologyconnections/comments/oo2b3i/b...

He estimates it at 16 KWh of storage. Same ballpark as a Powerwall, right?

And/or add more thermal mass to the house.

We do this here in Sonora, CA. Our PV array supplies more than our A/C uses. We turn the A/C on around 10am, cool to 70°, turn off at 3pm. House insulation has limited indoor temperature to 76° on recent 101° days.

You get paid for the power your battery provides to the grid. Power is generally cheaper at night as there is less demand (at least the spot price is cheaper, not sure how your utility passes that savings on to you). It seems like it's totally possible that it's better for you economically to allow your battery to power the grid during the day. You'll have less charge in your battery for the night, but hopefully you can get power at a cheaper price.

What does your attic insulation look like? Blown in cellulose to roughly R-60 made an instant difference and was the best ROI home improvement I've ever done.

This x1000.

Blow in, not spray on, insulation is the easiest, cheapest, bang for your buck home improvement I ever made. It took 3 hours and ~$1000 of insulation from Home Depot.

The house maintains its temperature so much better. Outside noise is reduced. My bills are smaller. And I can keep my AC at 72 now - or whatever temperature I feel like really.

Another one of the pitfalls of houses not being affordable.

I life in Maine. We get freezing winter every damn year. My apartment was built in like the 80s, there is no insulation (three of my walls are 3 inches of concrete and then the outside), windows and doors are the utter cheapest shit that doesn't even seal, heat is electric resistive hot water, electricity has always been expensive in Maine, but that's okay they make me pay my own.

Result, building owner got to cheap out in a hundred ways, pass the externalities on to me, I have no way to fix it, and my electric bill in the winter for one person in 600 sq ft kept to 70 degrees costs $250.

Where's Greta when you need her. I feel like I should have standing to sue the property owner on the planet's behalf.

Did you ask about the bill in winter before signing the lease? It’s a standard question before signing a lease in Chicago. Are you otherwise ‘getting a deal’ on rent and now you know why it was a deal?

No, I am not getting a deal, I am paying quite a bit. I had some warning, when I signed up with the power company they required a deposit "based on location usage" which they sized at $350, so I knew ahead of time that was going to suck.

The only thing that really concerns me about all of this is if I’m bearing the capital expense of the batteries and equipment that is being worn out by cooperative use. Can we socialize those costs?

But they are paying $2/kwhr aren’t they? They are socializing those costs.

Am I misunderstanding something?

No it’s probably me who is misunderstanding it. If that’s the case then yeah, problem solved!

$2/kwhr is also extremely generous—much more than normal

We are in a similar situation!

To help with this, we had a second Tesla battery installed!

Although, sadly, in South Australia, Electricity is charge at a flat rate, day or night!

One thing to keep in mind, is that during periods of high demand they run the most inefficient, most polluting power sources, like diesel generators or natural gas peaker plants which are generally less efficient. So by dumping power on the grid when it's most needed you're reducing CO2 output more than if you just kept it for yourself. You then use it back when demand is low (early morning/late night) and efficient power sources are running.

This. There's an entire industry around getting companies to use their industrial generators at peak energy consumption times (and also do things like turn down their thermostats). The power bill for a huge electric user is absolutely massive if they're hitting hard at peak peak times. Like several percent of their annual energy cost can come from a few hours of use.

It looks like it’s cooler outside at night these days (below 70ºF between 9pm and 7am). I’d recommend that you air out your whole house with a big draft when that’s the case: fresh air, less CO2 indoors, but also a big saving on cooling. That’s what my grandmother did all summer in Provence, and she never needed AC. If you power-cool in the afternoon to use your house as a thermal battery, you might only need to do it in the morning, but it’s always very enjoyable.

People have mentioned roof insulation. It’s a good idea, although if you have solar panels, you might want to cool the outside of the roof under the panels to improve their efficiency. I’ve seen technology using water evaporation; maybe that one is less popular these days. There should be a way to do it by heating the water for your shower.

The most effective idea is a lot low-tech though: outside blinds. Covering your glass windows from the outside is what prevents most of the heat from getting in. Even better if you can have slated blinds that block the sun but let the air through. Anywhere traditionally warm in summer (i.e. built before AC), I’ve seen houses with wooden blinds that you can shut all day, while you keep the windows open.

Quick math shows a long range Model 3 has about six times as much battery capacity as a Powerwall. I’m willing to bet more people have Model 3’s than Powerwalls. And I’m willing to bet 16% of your car’s battery capacity will impact you far less than 100% of your Powerwall.

F-150 Lightning called it right: EV’s should ship with grid-tie inverting.

It's pretty interesting if you do the math too.

The CAISO shows that their current power generation capacity is about 53000 MW.

A Tesla model 3 has 60kWh of capacity. A million of those would allow generating 60000 MW for an hour if they would be discharged from full to empty during the span of that hour.

In practice, they wouldn't be able to be discharged that quickly and there would be losses due to going from DC to AC, but it's interesting to think that the total deployed battery capacity of EVs could have a significant impact on the need for peaker plants in the upcoming years.

And how exactly would you use your car if you discharge it overnight?

You wouldn't fully discharge it. The car has way more power than your house needs in a single night. You could probably run your house for a few days, even if your house has the AC on full, is huge, and poorly insulated. In which case you'd have a huge incentive to do something about your grid electricity cost. Installing solar panels and batteries is a way to do that. Driving an EV makes total sense if you have those. And adding that battery capacity to the mix makes even more sense.

You'd use an app to control how much power you allow to be taken and when. Mainly grids have peaks in the early evening and excess wind power during the night and excess solar power during the day. It's as much as being able to absorb that excess power than it is about providing power during peak hours.

As I understand it, this program starts discharging at 6pm. Off-hours power is almost always cheaper, so I imagine you could discharge in the evening/night and buy back whatever you needed from the grid in the cheaper hours of the night/morning for a profit.

The idea is not to fully discharge it overnight, but to smooth out demand.

During the daytime, solar power is plentiful, but not during the evening. However, during the evening, there is demand from residential customers so that they can cook, watch TV, use their computers, and whatever else people do in the evening that uses electricity.

Because there needs to be as much energy supply as there is demand, peaker plants (coal or gas typically) run during the evening to compensate for the fact that solar generation isn't available in the evening. There is less demand for power overnight though, since most people are sleeping.

As such, what would make sense would be that people would recharge their cars during daytime, drive back home, connect their cars to the grid and have them contribute some percentage of their battery to lower the need for peaker plants in the evening, then charge to full overnight.

People don't seem to understand that the battery chemistries optimized for cars is not the same battery chemistries optimized for grid storage though. You'll reduce the lifetime of your car substantially by cycling it every night.

You are downvoted but you are right. A Tesla model 3 battery is not designed to balance the electricity grid. Maybe it can be done in the future by using different chemistry, with some downsides, but the current cars would get destroyed by the many cycles.

Any usage will reduce a battery’s lifespan, but this isn’t a donation. The point of enrolling in a sharing program is you get compensated for letting the utility company use your resources. It should much more than offset the extra degradation.

Degradation of lithium batteries is also not constant. It depends on several factors such as C rate, heat, and voltage. All of these factors would be far less during load sharing than just driving your car.

And keep in mind most people wouldn’t want to share their entire batteries. They would want to save most for themselves. If they only offered 10% of their capacity for load sharing, then the shared usage would be far less than a full cycle.

The back of the envelope math is beautiful here. EV production is really ramping up now. Tesla expects to put out around 2 million cars per year by the end of the year. If we round the kwh of their batteries down a little to 50kwh, we get some nice round number to work with. 2 million cars is 2 x1000 x 1000 times 50 kwh is 100 gwh. So Tesla alone is adding 100gwh of battery per year (well a bit more but you get my point). Other manufacturers are also producing cars. and we'll soon hit 20 million EVS per year. Or about 1 twh / year of battery production.

Those batteries have long lives in the car and then typically a second life in storage solutions. Some cars now come with vehicle to grid technology and when they are plugged in, they could be used to provide power to the home, or the grid.

So we have a fleet of car batteries that is currently growing by the hundreds of gwh per year and soon twh per year that can be plugged into the grid. Even just using a tiny amount of that represents an enormous amount of power.

That's a huge buffer to dump excess power in during the day (from e.g. solar panels) and withdraw from during peak hours. The current Tesla virtual power plant is tiny in comparison. If you then consider that batteries have a fixed number of cycle times (around 1500 or so), you basically get to pwh scale in terms of amounts of energy that flow through that buffer every year. A lot of that power is cheap renewable power. Just with car batteries. Other storage solutions are available. The world currently produces a bit over 25 pwh per year currently.

I've been wondering why Tesla doesn't just do this. IIRC from the public Model 3 and Y teardowns, the cars already have the hardware to do this, so it's just a question of a software update and policy. Would love to know why it isn't in production yet; it seems like a no-brainer so there must be something impeding it.

If Tesla rolls this out, it's probably a program that they want to spearhead and manage, and my guess is that this is an absolute monolith of a problem to tackle and requires participation from notoriously super shitty power companies.

I don't think they have the hardware to do it. And I think the house themselves would also need extra hardware and integration, and its also different from state to state and country to country as far as I understand. But I don't know the details.

I’m not sure that you can rely on cars being plugged in as much as Power Walls. If things go bad, it’s very tempting to disconnect your car.

Interesting how in California you get to set your reserve.

Here in Massachusetts, when VPP has an event, it drains my Powerwalls down to 20% no matter what my reserve is set to. And Tesla's "Storm Watch" feature isn't triggered by the typical summer thunderstorm that causes power outages here in the north east. The result is that during the heat waves 2 weeks ago (8 out of 14 days were over 90 degrees F), we had several severe t-storms that caused power outages right after VPP had drained our Powerwalls to 20%. Thankfully all of them were short duration for us (an hour tops), although half our town was out of power for 12 hours after one storm.

Is that not optional? Seems a little intrusive if not

It’s not only optional, you get paid good money for providing the service. But once you opt-in you are under contract to provide the power when they come knocking.

What happens if your battery is drained out at the time?

What happens if you hack your battery to say it ran out?

> What happens if your battery is drained out at the time?

My guess is nothing.

> What happens if you hack your battery to say it ran out?

My guess is nothing, unless they catch you in which case they probably sue for breach of contract.

In that case you're probably financially on the hook for whatever their costs are for you not fulfilling your contract, or whatever damages are specified in the contract.

What town? I also live in MA (just outside of 95) and have never once lost power

Would it be worth it to have several power walls? Have a couple connected to Storm Watch and one for yourself in case things get hairier? Are there scaling efficiencies?

They pay $2/kWh. A powerwall can export 7 kW with a capacity it 12.5 kWh so you can make $25 in a little under 2 hours if you let them drain your power wall.

Prices infrequently get to $2000/MWh so I expect most years the powerwalls would not be called upon at this price level.

It is weak that they only pay for energy delivered instead of being available to deliver as reserve, but I am sure that will come once the technical details are ironed out.

The downside of this type of tech is that it adds a dependency on the internet for reserve power.

Seems fine for reserve power but not for emergency power. And in an emergency you don’t want back-feeding anyway.

But I’m not an expert on any of this.

> The downside of this type of tech is that it adds a dependency on the internet for reserve power.

I haven't researched this yet, but wouldn't a true "smart" grid have wiring for communications as well as power?

I want to say there's a lot of powerline communication on the grid, but a lot of that infrastructure can't talk through transformers.

There is power line carrier signal used between substations and generators on a line but expensive high voltage wave traps are required and you get about 14bits of bandwidth. The applications I’ve done if your bit drops out and health is still good then you have to disconnect.

Transmission lines often run fiber too, but used to still use a whole fiber to transmit 8 bits, or serial at 9600 baud

Ha, that's hilarious. How do you send serial over fiber? Simple on-off keying?

Fiber makes a ton of sense. Non conductive and long range. Surely cheap at utility quantities.

Not usually, no.

I mean, my home is already served by cable for the telephone company, cable for the TV company, and a choice of several cellular connections.

Most 'smart grid' stuff doesn't try to reinvent the wheel.

> It is weak that they only pay for energy delivered instead of being available to deliver as reserve, but I am sure that will come once the technical details are ironed out.

I think the bigger problem is that residential users can't really guarantee supply, so it doesn't work for the utility to contact for that.

PG&E running similar trial with SolarEdge and LG https://pge-battery-pilot.com/ . They sent me a bunch of emails starting at March inviting to join the trial.

"California needs energy now more than ever, and as a SolarEdge system owner with a battery, you can help.

By participating in PG&E’s Battery Storage Pilot, you can receive between $462 and $1848 and help keep the grid clean and reliable."

I would like such a thing to be open access and not involve Tesla at all. I should be able to profitably sell to the grid as a random person if there's need.

Yeah. There should be some standard created for this.

This attempts to obtain the benefits without the costs and ongoing effort that commands value. California grid operators aren’t going to deal with system sizes this small (5-25kw) individually, hence the orchestrator (Tesla). You could build an orchestrator (I highly encourage such an endeavor for competitive reasons), but a standard alone is insufficient and of minimal value. Same reason you don’t get paid much to shed load (token amounts), Google via Nest does.

With that said, you can operate autonomously on the grid with solar and batteries (and the inverters will sync and follow grid voltage and frequency), and can even use export restrictions so you never send power back to the grid (curtailing) if desired; but energy marketplace participation is much more than that. Enphase and SolarEdge (inverter and energy system manufacturers) are positioned as competitors to Tesla for VPPs, but haven’t made the effort (that I’m aware of).

https://nest.com/energy-solutions/

There are some pilot projects that have individual prosumers but they all operate at the distribution grid level. There's a concept coming called "DSO" or "Distribution System Operator" where the distribution grid is run more like a typical transmission network. The distribution grid operator could then procure services from DERs, microgrids, etc. [1] has a good overview

1. https://clean-coalition.org/distribution-system-operator-dso...

It feels like there could be a simple API and CAISO could easily deal with participants at any size. This isn't rocket science.

You can sell negative demand to the grid and get compensated for it with Ohmconnect:

https://www.ohmconnect.com/

It absolutely can be, in Australia we have several players involved and from what I understand, integration is dictated by the network operator. Eg, provided the battery used supports VPP, you can join under a number of different providers offering different contracts. See here [1] for a comparison table.

[1] https://www.solarquotes.com.au/battery-storage/vpp-compariso...

You want an unregulated market like Texas?

Agree but we need to start somewhere and the government is setting these prices and making the policy so unless there’s regulatory capture I see no reason it wouldn’t be expanded once the model has been proved out.

Wow, $2 per KWh? I'm willing to lug some water up a hill and let it drop for those rates!

Edit: turns out 1 KWh is 2.6 million foot pounds, so that's either a very tall hill or a lot of water :-)

From Google: "a beginner cyclist may average around 75–100 watts in a 1-hour workout. A fit participant will average more than 100 watts, and pro cyclists can reach 400 watts per hour."

So 1KWh would be the output of a pro cyclist going hard for 2.5 hours, or a decently fit person biking for maybe 8 hours.

So generating electricity is not a lucrative career option at $2 per day

Obligatory cyclist powering a toaster with their bonkers thighs:

https://www.youtube.com/watch?v=S4O5voOCqAQ

IMO people often don't take the time to think about energy enough. By some quick math, I've found that the energy taken out of one 0 degree celsius ice cube to make it freeze (latent heat of fusion) is roughly equal to the energy in a ubiquitous AA battery. About 4 watt hours

In fairness latent heat of fusion is surprisingly high.

Actually, I don't think this is quite right. A cube of water 10cm in size is 10 grams. The heat of fusion for water is 333.55 J/gram, and a AA is 14400 Joules. So the energy for the ice cube (which is 4 inches across, in imperial units) is 10 grams * 333.55 J/gram = 3335.5 Joules, which is ~1/4th of the very large ice cube.

>10cm in size

What about the other two dimensions? I used an ice cube containing 50ml of water, ie 50 grams. That specific number came from a quora answer where someone measured their own ice cube tray, but they seem to have giant ice cubes. Other sources mention numbers from 20ish ml to that 50ml upper bound, so I'd say the number I calculated is actually double a more reasonable answer.

So a middle sized ice cube required the same energy available in an off brand, cheap-o non-alkaline chemistry AA battery. Damn, that's way less of a convenient number.

I was curious, so I checked: If you get your own energy from e.g. vegetable oil (very high energy/$) you'd pay only $0.2 per kWh of food intake.

(Apply conversion efficiency of the human body before embarking on this business opportunity...)

Tesla have been doing this with Octopus Energy in the UK.

Essentially you get a big discount on the Per KWh price of electricity, but give up control of your powerwall to Tesla to operate their "virtual power station"

https://octopus.energy/tesla/tariff/

$2/KWh is a ton of money - it’s over 4x what the highest rate payers in CA pay for electricity!

And around 16x for the lowest rate payers I know of (11-13 cents/kwh variable off peak/peak) who don’t have solar. Even better for those who do have solar.

Replying to myself.. there are some caveats obviously that getting days when this payment happens is presumably not guaranteed, although with temperatures tending to rise one could expect it to happen. And maybe the price is not guaranteed either beyond a certain point. In other words, maybe don't buy a PowerWall unless you need one for other reasons.. it's probably not a reliable money making idea. Just in case, on the off chance, anyone was thinking of this as a small side income, lol.

I'm in CA. I pay 56 cents from 4pm to 9pm.

Agreed it's a hefty amount. The second part of your statement is not entirely true.

SDGE charges over $1.50 from 4-6PM on FlexAlert days (like yesterday). They charge 4x normal rates from 2-6PM. From 2-4PM which is off-peak it will be over $1, and between 4-6PM it will be $1.60+ which is 4x the on-peak rate.

Is this the first example of an "extra" distributed grid system?

By "extra", I mean the long advertised-not yet achieved dream where electric cars and battery backups are seamlessly integrated into the current grid, giving and taking energy in a "smart" way depending on grid conditions.

I would be livid if I went out to go to work and my car was drained because my local utility sucks.

Luckily, this is an opt-in system. If you wake up and your car/wall is drained, that's on you for saying you're okay with that possibly happening.

Presumably there would be an option to set a minimum amount of battery that wouldn't be used.

Or even better, a target amount for a specific time of day (which would allow the battery to get low when needed and then ramp up on time).

No, this is certainly not the first such system. I helped build one at a previous job where we could even value each battery individually in response to near real-time distribution grid conditions. For example, if a transformer is nearing capacity than a battery discharge downstream has extra value because it prevents the expensive transformer from being overloaded reducing it's life.

https://www.greentechmedia.com/articles/read/opus-one-tests-...

Isn't a power emergency exactly the time you want your battery to be full? Why would someone with batteries want to drain them for a pittance and just be another person without power?

most power emergencies are quite short, and are especially short if there is a sufficient demand response

Putting ~1-5% of your stored energy towards keeping the grid running and affordable means that you rarely have to use the other 95% and pay less overall.

> Isn't a power emergency exactly the time you want your battery to be full?

The point is to prevent the sort of power emergency that'd make you (and everyone else in your area) need said batteries.

Hardly a pittance, $2/kwhr is a crazy high rate.

It's $20 for a 10kWh battery and you then don't have sufficient energy left when they shut it down anyways. Hardly seems worth it.

If you read the release there's a Backup Reserve setting:

> • If you prefer to reserve more energy for use during a grid outage, or if your area is more prone to outages, you can set a higher reserve percentage.

So you could easily reserve 50% for yourself to run the fridge/lights or whatever and sell up to half.

Demand based outages are likely to be transient.

We sized our batteries and solar (and fireplace) to get us through multi-week outages in winter (PG&E really sucks around here...)

The AC drains the batteries overnight, so we wouldn't really need the charge between now and dawn anyway.

Since we sized the batteries for winter emergencies, after selling all but reserve capacity, we'd still have enough left over to power the electronics and plumbing all night.

This program is mostly (entirely?) aimed at using your battery storage during peak demand times - not power outages. That's why they can pay so high, because they bill hundreds or thousands of times more than the normal rate to really high electric consumers during these peak peak times

This is the first example I’ve seen of truly what distributed automation can do. Once the “network” reaches a critical mass of participation (think of early Facebook), it becomes exponentially more valuable.

This is the true promise of things like autonomous vehicles too. They’re not just to free up your driving time; once there are enough of them, it unlocks the whole next tier of promise: emergency vehicle access gets way better, whole categories of deaths get reduced, parking lots reclaimed, etc.

There’s no network effect though?

On FB, more people on the social network means the draw to the n+1st user is immense.

Whereas for home batteries, it could be the inverse. As more people have batteries, the payout is lower.

I’m all for home batteries, but I think we also need to restructure utility incentives in america. Currently they get to pass down all sorts of charges/fees to the customer.

I think that poster probably meant feedback loops or virtuous cycles (ones that create beneficial second and third order effects, with outsized impact vs what you might assume based solely on the first order change), more so than network effects.

Another model is phase change: there are critical points around which a small change in adoption can trigger a large change in aggregate behavior.

The network effect here is cost and word of mouth. As more and more people buy these batteries, they get cheaper. And as more people get them, more people get to brag about keeping their lights and TVs on during a blackout.

Unless you live in an apartment.

And so many tout increased density living as being the solution to homelessness and house pricing, the walkable city etc etc. But who wants to actually live there?

I live in an apartment. I'd rather live in a standalone house thanks. Then I might get to jump on these opportunities too.

An apartment would be a great use case for a big battery backup, the cost would be amortized over everyone and you’d get better economies of scale

Start with basic physics. The battery works well in conjunction with a solar array. But the whole point of an apartment building is "lots under one roof". And so as a ratio with energy use there, the amount of solar deployed is smaller, often much smaller in the bigger buildings.

Then, the obvious limits of social contract. Good ideas rarely get past the body of apartment owners. Getting them to agree on fundamental "the building is broken" bits is already like herding cats. Trying to get a "good idea" into play? Nah.

1. Hip pocket concerns, how do we pay for it? Cue shrill: "I'm not paying for it, I already pay too much for management anyway..."

2. Where is that big battery going to go? Cue shrill: "Not next to my apartment, I don't want to die in a lithium fire.."

3. How it is going to be wired in? Cue shrill: "That will make xyz part of the building ugly and reduce value of my apartment."

Some of the apartment owners don't live there, it is an investment, they won't pay for anything that makes living there nice. Some of the apartment owners live there but then care about stupid things far too much.("You can't chop that out of the garden!" "State regulations say it is a weed and literally should be removed on sight...")

This is why I want my own place. So that I can implement "good ideas"(obviously subjective) without others getting in the way AND take advantage of all the middle class standalone homeowner subsidies.

Very cool. But...

Tesla warranties the Powerwall for 10 years at 1 discharge cycle per day (according to the internet), or "37.8 MWh of aggregate throughput". At that point they claim 70% capacity after 10 years.

Would participating in this, and potentially discharging your battery more than once per day (let's say the event happens mid-day), void the warranty?

The page says they're paying $2/kWh, the average electricity cost in (as an example) San Jose is $0.24/kWh. That means they're probably reserving this for emergencies, not for daily or weekly use.

If you get paid for discharge everyday for two hours you can buy a new power wall in under a year with how much you get paid. Not really a point for concern.

If you only used your Powerwall for this program, and kept a 100% reserve otherwise, you would make $75,600 burning through the 37.8 MWh of throughput ($2 per kWh). That's a good deal more than the system cost, so to the extent that your system may wear out quicker, you are definitely being compensated more than enough to replace it when the time comes.

I recognize that doesn't address the situation where Tesla refuses to maintain the battery under warranty if you use more than 1 discharge cycle per day, but if the discharge is due to participation in a Tesla-involved program, that would be pretty poor optics for Tesla.

One almost certainly won't have the opportunity to get $2/kWh for a full 37.8 MWh though, and my question is more about the warranty being voided if the battery is used outside of Tesla's original designation. Let's say you do a full discharge 100 times over the course of the battery outside of normal day to day use - would they still cover you if your battery broke?

I agree it would be poor optics, but it's still a question to ask for those thinking of participating in the program.

Can anyone provide some intuition on how efficient it is to actually send power back and forth? Some of the power has to be lost along the way moving around the wires or something right?

Especially if you're sending it from your house or whatever which is presume is mainly designed as a power consuming end-point rather than generating?

Efficiency will always drop any time energy is converted between forms or transmitted.

The point is not to be efficient, it's to ensure the power is available when needed.

The implementation of such a system doesn't even need to send energy back to the grid at all - simply by having your batteries kick in to power your own load when they would otherwise maintain a reserve you are in effect providing power to the grid (that you would otherwise be drawing). The power is coming from literally inside your house, reducing the amount of energy that must be transmitted to your house from the grid.

You more-or-less can't charge your battery from the grid (except in emergencies, subject to local regulations, etc.), so it's not sending the energy back and forth.

Our system seems to discharge 20% fewer watt hours than it spends charging the batteries.

As for transmission losses, you are likely powering houses on the same block as you, so they're hopefully mostly negligible compared to the battery charge/discharge loss.

In an event like this, you are effectively helping to power the other houses in your neighborhood. So it is likely to be fairly efficient.

I’d bet on ~95% round trip efficiency, if not more - lithium batteries are very efficient, as are modern power electronics.

It actually mostly just stays in your local area. You are effectively providing power to your neighbors. Some neighborhoods providing too much excess power back to the grid with solar panels is actually a challenge for grid operators currently. They simply don't have enough cable capacity. So, having a lot of batteries in the area helps them on that front because the power can be dumped there and then extracted when they actually need it.

I'm surprised that this doesn't include also the ability to just automatically pause your Tesla vehicle from charging during these moments.

This would be relevant to far more customers!

Are you sure it doesn't?

Tesla has paid attention to grid outages w.r.t. Tesla charging before. See https://www.engadget.com/tesla-powerwall-outage-ev-charging-...

But this is specific to Powerwall, no? Most owners don't have a powerwall.

I would expect the Tesla Gen 3 Wall Charger to pay attention to grid conditions. (Many utilities already partner with Tesla or a third party to offer discounted EV charging, so this kind of capability must exist.)

> 50,000 Powerwalls

At 13.5kWh per powerwall that’s 675mWh, right? Anyone know how many minutes of electricity consumption that represents for the State of California?

I found some numbers for total PG&E generation in 2017 and based on that 675mWh would be about 10 minutes worth of power.

The peak demand in the WECC is about 170,000 MW, so 675/17000060min/hr60s/min=14 seconds with of power.

While the time is interesting for context, it is more about reducing the magnitude of the peak when there are no other generators to bring online or transmission capacity is saturated than powering the entire load.

MWh

.. appreciate your are trying to get a sense of scale, but it’s important to note that short-duration batteries are not there as a generator to serve load, they are good for providing peak demand support to the system and the local LV distribution network, and to help regulate frequency.

I’m not familiar with the US market environment, but in Australia where we have a number of VPP operators, including Tesla, it the latter service that is the most used.

Frequency regulation services are associated with absorbing and injecting energy into the power grid over milliseconds.

Since it takes at minimum 4 hours to drain each battery (3.3KW discharge rate), a better question would be what percentage of peak demand power they can provide.

Max power: 3.3 * 50000 = 165MW. Peak demand for 2020: 47121MW (18th August 15:57). Percentage of power: 165 / 47121 = 0.35%

Using the yearly average instead (31713KW): 165 / 31713 = 0.52%

There was a paper I read about a decade back about the existential crisis of power companies. After everyone has the ability to generate and store power locally in their home why do you need power companies anymore? Or will they even be able to charge as much. How will they keep up with the maintenance of the grid? Some interesting questions but I guess we will see the answers in the coming years.

Power companies will just switch to charging a high monthly grid interconnect fee. And people will pay because no one wants to "run out of power".

This is already proposed to happen in California: https://www.solarreviews.com/blog/california-net-metering-ch...

"It also adds a monthly Grid Participation Charge of $8 per kilowatt (kW) of solar to the bills of all people who go solar after implementation of the new rules, costing the average homeowner almost $600 per year, or $15,000 over 25 years."

If they increase the interconnect fee enough, homeowners will simply stop paying the bill and disconnect from the grid.

The PG&E proposal would cost the homeowner approximately 100% the price of their solar panels over 25 years. If it were not for net metering, that would already be enough to make a rational consumer oversize solar and batteries by another 50% and close their PG&E account.

The price of solar and batteries is dropping so fast that the threshold for a "too high" bill will soon be below the cost of line maintenance.

Unless something changes, at that point, the power grid will collapse in the same way the landline phone grid is collapsing.

That will drive up bills for remaining subscribers, driving more loss of business, creating a death spiral.

I think they should jack up the cost of electricity to cover grid maintenance, and allow community net metering, so that people without a roof can buy into solar collectives that count toward net metering. This would rapidly phase out nonrenewable generation by severely penalizing people that rely on power plants.

Once that became untenable, the aging zoomers can sit outside on their non-ruined planet and fret about supporting their carbon neutral power grid with taxpayer dollars.

>and disconnect from the grid.

Pretty simple for the awful, awful power companies to do some lobbying to not allow this - just make it so that if you have solar, you're required to have active electric service to your house, even if you're not an active account holder to any power company. I have heard there's parts of Mexico that do this - you're not allowed to run your house on only solar, you're required to be hooked up to the grid and you can only sell your solar back to the grid, it can't be used directly to power your home. So you're forced to sell at a certain rate and then buy it back at a certain rate.

VPPs are actually a treatment for this issue. By recognizing the value of these new customer-owned systems can provide back to the electricity system, we can give people a reason to stay connected and to contribute back to the common resource.

PG&E makes it so onerous to be connected to the grid that it'll absolutely take something like this for me to stay connected. But I don't belong to the Tesla ecosystem, so this is clearly not the answer for me.

Literally every building north of Ventura is connected to pg&e’s grid. It can’t be all that onerous if it’s universal.

Try replacing a panel. They make what ought to be routine work, hard. Only in the last couple years has it become cheaper to say screw it and not take their BS and go off grid instead. One of my neighbors already did that instead of spending hundreds of thousands of dollars with PG&E.

You mean upgrading your service, not upgrading your panel. Anyway I don't see how being charged for capacity becomes "onerous". Taking a home that needed a main service upgrade off-grid instead would also cost a huge amount of money.

Nope. I mean replacing a panel. It's precisely what I said, after all.

Hire a licensed electrician, most seasoned pros will know how to fight this misapplication of regulation, especially if your just doing a like for like swap.

There is no recourse. So have said all three electricians who I have consulted. The PG&E project coordinator makes a decision and that's it.

Different private utilities and PUDs act differently.

There is one PUD here in the Puget Sound region that all the electricians groan about, as their lineman often attempt to go well beyond what their authority permits, claiming everything needs to be brought up to code in like for like swaps, which is truly a beyond the pail demand.

That's exactly how replacing a fire hazard panel would cost me $80k. Random PG&E person decides it's not a like-for-like replacement (despite both being ordinary 200 amp panels) and therefore the underground feeder needs to be replaced (PG&E Green Book has changed guidance in the last fifty years, after all). And since that's on the utility side of the meter, only the utility can do that work, and at ridiculously inflated rates.

No thanks. For now I'm leaving the fire hazard panel. And sometime next year I'm just cutting the cord entirely.

It’s a non trivial capital investment to outfit your home like this. I also wonder if the aggregate cost of decentralizing production far exceeds centralized production and distribution. Regardless I struggle to imagine a world where a family living paycheck to paycheck as is lays out tens of thousands of dollars to produce their own off grid power.

Now, once Mr Fusion is available it’s a different ball game.

Off grid for everyone looks inefficient. We don't need huge battery on each house/office/factory thanks to big grid.

If you are a business and want to contribute to stabilising the grid (but don't have a Tesla power wall specifically, any device works!): I work at Leap (https://leap.energy) and we have virtual power plants in CA, TX, and NY.

It seems odd that only Tesla would be allowed to participate. What about me with my 66kwh of batteries that I purchased for about the same as a single power wall. I have an inverter than can interact with the grid. Is a special signal sent out to just Tesla? Other people have non-tesla batteries.

What batteries did you get?

You could try to integrate into another VPP. If there is none (or no suitable) you have to either wait until someone starts one, or take the initiative ;)

//Edit: I suppose only allowing Tesla is for two reasons: 1. They can do the necessary software adjustments very easily (homogenous system) and 2. this adds an incentive for consumers to buy Tesla over other solutions.

How do these batteries know when to charge? Are their input signal purely $/kWh or some other signal like how much emissions would that kW emit?

I am amazed at what software can do. Kudos Tesla.

It's not a new thing.

Sonnen is doing this for a few years already.

What are the downsides? I am not sure if its a valid concern, but first thing comes to mind is PG&E becomes too dependent on a system like this and instead of having centralized control, you've exposed the entire grid during peak hours to things like activism and collectivist strikes, etc.

Couldn’t you run a diesel generator and turn a profit with this?

No because this works through Tesla software.

And even if you could I doubt with fuel costs, the cost of the generator and cost of operating the generator you are not making much profit off $2/kw.

But the real reason of course is that from CA’s perspective they don’t want to incentivize cheap generators to burn diesel fuel in residential areas and try to feed that garbage power into the grid.

IDK. A Honda EU2200i (their second smallest portable generator) generates 2.2kw for a little over 3 hours with 0.95 gal tank [0]. Which sounds pretty close to break-even with fuel cost at this price. The efficiency generally increases with size. I'd imagine running a diesel generator (usually more fuel efficient) with red diesel could easily push you into profitability. Assuming you could somehow get this to work with the system - maybe trick the Tesla software somehow.

[0] https://powerequipment.honda.com/generators/models/eu2200i

But you have to buy and maintain the generator. In addition to the huge upfront cost a gas/diesel generator is going to require yearly maintenance (at minimum oil, oil filter, cycling the fuel). You’ll either need to do it yourself or pay somebody to do it, eating into your margins.

How often do you get blackout in California? Here in Central Europe I didn't get even 1min. blackout for a year, lol.

Guys, you should upgrade your power grid and build more powerplants, not this dumb BS.

Wait for the winter... Things aren't looking good this year :-(

Some years a dozen times. PGE is punishing us for suing them over wildfires. They shut the power off for multiple days , multiple times because it was breezy.

More powerplants isn't the answer to ever increasing spikes. Powerplants can't ramp up & down very quickly, so addressing spikes with more powerplants just leads to more waste. And since we're talking reliable power at dusk, that means large co2 emissions & non-renewable, dirty fuel sources.

Grid energy storage is increasingly critical. Distributing it to all the houses isn't really a bad idea for a battery-based solution. Pumped water is a great option for grid storage and is used throughout the world for that, but we are talking California here. Water is a precious & limited resource there.

At least UK and Germany also have virtual power plants for various purposes. It's a smart way to handle peak demand and it's great that Tesla allows regular people to participate (and profit) from this [edit]so easily[/edit].

Wikipedia: https://en.wikipedia.org/wiki/Virtual_power_plant

The German Wikipedia has some more details on the various kinds of VPP in Germany. For those interested in the topic I recommend using a translator like deepl or Google translate: https://de.wikipedia.org/wiki/Virtuelles_Kraftwerk

This is such a gimmick.

PG&E should publish price forecasts 24 hours in advance, and then push real time prices to the battery controllers every 60 seconds.

(Insert undergrad reinforcement learning homework assignment here.)

And then the battery manufacturers could advertise by publishing their average regret (the machine learning metric) over the last year in terms of dollars saved vs. some baseline.

PG&E doesn't set prices. Retail prices don't fluctuate, they're regulated. You can say with absolute certainty what the retail price of electricity will be tomorrow at any given time and place in California.

PG&E also doesn't set wholesale prices. The grid operator publishes day-ahead, hour-ahead, and real-time market price for every interchange point on the grid, at https://www.caiso.com/todaysoutlook/Pages/prices.html

All of those things are easily fixable via legislation.

> This is such a gimmick.

It's not.

This is not a new solution and already exists for a few years from other providers and it's making money.

https://sonnenusa.com/en/virtual-power-plant/

It's concerning when a power company can't produce adequate power and needs to rely on consumer batteries. It's cool from a tech perspective but isn't such an event exactly when you'd want power? At that point, your battery no longer provides you resiliency but provides the power company a margin they can rely on without investing in additional infrastructure.

It’s a matter of not requiring to kick in more expensive and polluting energy sources.

Is a large number of consumer batteries more environmentally friendly than say a nuclear power plant?

That’s not the point (disclaimer: I love nuclear power), the point is this let’s them Supplement rapid energy demand /spikes/ over the span of literally seconds vs ramping up generation from other sources which are all slower as well as generally being further from where it needs to be at that moment. This allows them to readily absorb spikes happening randomly around the grid in an easier manner

Agreed! Inverter based resources have the ability to respond within a few milliseconds whereas the next fastest response would be from hydro power and that could take as little as 10s. More conventional generation takes a lot longer. [1] has some nice charts showing cold-start times for different types of generation.

1. https://www.eia.gov/todayinenergy/detail.php?id=45956

Wouldn't currently available nukes take way too long to ramp up and down for this use case?

In general, after a nuclear plant is shut down, it has to be kept off for a few days to let Xe-135 completely decay. Quoting from Wikipedia [1] " After about 3 days of shutdown, the core can be assumed to be free of 135Xe, without it introducing errors into the reactivity calculations"

1. https://en.wikipedia.org/wiki/Iodine_pit#Fission_products_de...

What nuclear power plant?

Consumers have not necessarily purchased batteries to be part of this program; while a potential outcome, it would be much more wasteful for the batteries to decay over time without being utilized significantly.

It's an optional opt-in and the rewards are pretty good. Some places don't even allow you to install solar because planning a national grid power demand is not easy and solar generation needs to be taken into account and it depends on a lot of factors, it's a solvable problem for sure but these companies aren't known for their technological innovations..

You also don't want your power provider to build expensive peaker plants for the occasional peak demands. Programs like these and other DER programs help flatten out the curve and lower yours and everyone else's bill.

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