7 ms·

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 a

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 https://twitter.com/AlexGuichet/status/1559748677626777600 A VPP tracker in the Tesla community: https://www.lastbulb.com/virtual-power-plant 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 https://www.youtube.com/watch?v=ggdYts4muu0 CAISO Grid Outlook: https://www.caiso.com/TodaysOutlook/Pages/default.aspx https://www.caiso.com/TodaysOutlook/Pages/default.aspx

jeffbee 4y ago
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.
- conorcleary 4y ago
  We've come so far in so little time and people like to keep puting progress down.
  - jeffbee 4y ago
    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.
- epistasis 4y ago
  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.)
  - jeffbee 4y ago
    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.
    - epistasis 4y ago
      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.
      - jeffbee 4y ago
        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.
- ajross 4y ago
  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.
  - ac29 4y ago
    > 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.
    - akira2501 4y ago
      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.
    - ZeroGravitas 4y ago
      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)
    - archi42 4y ago
      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.
- hedora 4y ago
  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.
  - ZeroGravitas 4y ago
    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)
- ZeroGravitas 4y ago
  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 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.
xattt 4y ago
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)”.
- drewnick 4y ago
  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.
  - bdamm 4y ago
    $2/kWh is insane though. My power rate is $0.12/kWh. $2/kWh is still 6x California’s most expensive power.
    - mschuster91 4y ago
      > $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.
    - jpalomaki 4y ago
      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-to-peak-at-record-4-000-per-mwh-on-wednesday https://news.err.ee/1608686533/estonia-s-electricity-price-t...
      - ragebol 4y ago
        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...

jeffbee 4y ago

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.

conorcleary 4y ago
We've come so far in so little time and people like to keep puting progress down.
- jeffbee 4y ago
  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.
epistasis 4y ago
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.)
- jeffbee 4y ago
  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.
  - epistasis 4y ago
    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.
    - jeffbee 4y ago
      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.
ajross 4y ago
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.
- ac29 4y ago
  > 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.
  - akira2501 4y ago
    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.
  - ZeroGravitas 4y ago
    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)
  - archi42 4y ago
    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.
hedora 4y ago
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.
- ZeroGravitas 4y ago
  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)
ZeroGravitas 4y ago
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 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.

xattt 4y ago

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)”.

drewnick 4y ago
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.
- bdamm 4y ago
  $2/kWh is insane though. My power rate is $0.12/kWh. $2/kWh is still 6x California’s most expensive power.
  - mschuster91 4y ago
    > $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.
  - jpalomaki 4y ago
    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-to-peak-at-record-4-000-per-mwh-on-wednesday https://news.err.ee/1608686533/estonia-s-electricity-price-t...
    - ragebol 4y ago
      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...