18 ms·

Tesla Virtual Power Plant

350 points by lawrenceyan 4y ago

jtchang 4y ago
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.
- kevinsundar 4y ago
  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-changes 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."
  - hedora 4y ago
    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.
    - beeboop 4y ago
      >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.
- flgb 4y ago
  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.
  - zbrozek 4y ago
    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.
    - jeffbee 4y ago
      Literally every building north of Ventura is connected to pg&e’s grid. It can’t be all that onerous if it’s universal.
      - zbrozek 4y ago
        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.
        jeffbee 4y ago
        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.
        zbrozek 4y ago
        Nope. I mean replacing a panel. It's precisely what I said, after all.
- fnordpiglet 4y ago
  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.
- fomine3 4y ago
  Off grid for everyone looks inefficient. We don't need huge battery on each house/office/factory thanks to big grid.
burlesona 4y ago
> 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?
- changoplatanero 4y ago
  I found some numbers for total PG&E generation in 2017 and based on that 675mWh would be about 10 minutes worth of power.
  - liketochill 4y ago
    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.
- flgb 4y ago
  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.
- seri4l 4y ago
  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%
jlv2 4y ago
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.
- fnordpiglet 4y ago
  Is that not optional? Seems a little intrusive if not
  - zaroth 4y ago
    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.
    - notpushkin 4y ago
      What happens if your battery is drained out at the time? What happens if you hack your battery to say it ran out?
      - ncallaway 4y ago
        > 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.
- thehappypm 4y ago
liketochill 4y ago
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.
- mulmen 4y ago
  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.
- xpe 4y ago
  > 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?
  - thrtythreeforty 4y ago
    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.
    - liketochill 4y ago
      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
      - 4y ago
whartung 4y ago
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.
- happyopossum 4y ago
  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.
  - rdtwo 4y ago
    Nah the grid hook up fee is likely the bulk of the cost. Simply being connected is the most expensive cost
    - liketochill 4y ago
      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
      - simfree 4y ago
happyopossum 4y ago
$2/KWh is a ton of money - it’s over 4x what the highest rate payers in CA pay for electricity!
- natch 4y ago
  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.
  - natch 4y ago
    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.
- recursive 4y ago
  I'm in CA. I pay 56 cents from 4pm to 9pm.
- beembeem 4y ago
  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.
digdugdirk 4y ago
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.
- fnordpiglet 4y ago
  I would be livid if I went out to go to work and my car was drained because my local utility sucks.
  - dymk 4y ago
    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.
  - FartyMcFarter 4y ago
    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).
- etimberg 4y ago
  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-transactive-energy-for-california-rooftop-solar-behind-the-meter-batteries https://www.greentechmedia.com/articles/read/opus-one-tests-...
black_13 4y ago
- smlacy 4y ago
zbrozek 4y ago
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.
- pottertheotter 4y ago
  Yeah. There should be some standard created for this.
- toomuchtodo 4y ago
  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/ https://nest.com/energy-solutions/
  - etimberg 4y ago
    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/ https://clean-coalition.org/distribution-system-operator-dso...
  - zbrozek 4y ago
    It feels like there could be a simple API and CAISO could easily deal with participants at any size. This isn't rocket science.
windows2020 4y ago
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.
- Daishiman 4y ago
  It’s a matter of not requiring to kick in more expensive and polluting energy sources.
  - windows2020 4y ago
    Is a large number of consumer batteries more environmentally friendly than say a nuclear power plant?
    - helf 4y ago
      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
      - etimberg 4y ago
        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 https://www.eia.gov/todayinenergy/detail.php?id=45956
    - dividedbyzero 4y ago
NotYourLawyer 4y ago
cptcobalt 4y ago
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.
tguvot 4y ago
PG&E running similar trial with SolarEdge and LG https://pge-battery-pilot.com/ 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."
etaioinshrdlu 4y ago
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!
- xpe 4y ago
  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-085600346.html https://www.engadget.com/tesla-powerwall-outage-ev-charging-...
  - etaioinshrdlu 4y ago
    But this is specific to Powerwall, no? Most owners don't have a powerwall.
    - xpe 4y ago
      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.)
Mandatum 4y ago
Couldn’t you run a diesel generator and turn a profit with this?
- peter422 4y ago
  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.
  - zxexz 4y ago
    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 https://powerequipment.honda.com/generators/models/eu2200i
    - peter422 4y ago
      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.
systemvoltage 4y ago
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.
astockwell 4y ago
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.
- iso1337 4y ago
  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.
  - strgcmc 4y ago
    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.
    - andreareina 4y ago
      Another model is phase change: there are critical points around which a small change in adoption can trigger a large change in aggregate behavior.
    - thehappypm 4y ago
      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.
traviswt 4y ago
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.
- jfim 4y ago
  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.
  - tsimionescu 4y ago
    And how exactly would you use your car if you discharge it overnight?
    - jillesvangurp 4y ago
      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.
    - 4y ago
bagels 4y ago
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?
- hcknwscommenter 4y ago
  most power emergencies are quite short, and are especially short if there is a sufficient demand response
- beckingz 4y ago
  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.
- ceejayoz 4y ago
  > 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.
- thehappypm 4y ago
  Hardly a pittance, $2/kwhr is a crazy high rate.
  - bagels 4y ago
    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.
    - bpodgursky 4y ago
      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.
dymk 4y ago
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?
- karmanyaahm 4y ago
  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.
- bergenty 4y ago
  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.
- newt_slowly 4y ago
  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.
  - dymk 4y ago
    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.
ackbar03 4y ago
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?
- hughes 4y ago
  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.
- newt_slowly 4y ago
  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.
- hedora 4y ago
  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.
- qqqwerty 4y ago
  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.
- Panzer04 4y ago
  I’d bet on ~95% round trip efficiency, if not more - lithium batteries are very efficient, as are modern power electronics.
sidcool 4y ago
I am amazed at what software can do. Kudos Tesla.
- Garlef 4y ago
  It's not a new thing. Sonnen is doing this for a few years already.
foota 4y ago
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 :-)
- snek_case 4y ago
  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.
  - kfarr 4y ago
    So generating electricity is not a lucrative career option at $2 per day
    - deleted 4y ago
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  - mrguyorama 4y ago
    Obligatory cyclist powering a toaster with their bonkers thighs: https://www.youtube.com/watch?v=S4O5voOCqAQ 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
    - foota 4y ago
      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.
hedora 4y ago
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.
- jeffbee 4y ago
  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 https://www.caiso.com/todaysoutlook/Pages/prices.html
  - hedora 4y ago
    All of those things are easily fixable via legislation.
- Garlef 4y ago
  > 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/ https://sonnenusa.com/en/virtual-power-plant/
coding123 4y ago
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.
- coolsunglasses 4y ago
  What batteries did you get?
- archi42 4y ago
  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.
zekrioca 4y ago
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?
deleted 4y ago
[deleted]
philjohn 4y ago
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/ https://octopus.energy/tesla/tariff/
RektBoy 4y ago
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.
- joelthelion 4y ago
  Wait for the winter... Things aren't looking good this year :-(
- bagels 4y ago
  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.
- kllrnohj 4y ago
  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.
- archi42 4y ago
  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 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 https://de.wikipedia.org/wiki/Virtuelles_Kraftwerk
Teafling 4y ago
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 https://leap.energy) and we have virtual power plants in CA, TX, and NY.

350 points by lawrenceyan 4y ago

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.

kevinsundar 4y ago
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-changes 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."
- hedora 4y ago
  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.
  - beeboop 4y ago
    >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.
flgb 4y ago
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.
- zbrozek 4y ago
  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.
  - jeffbee 4y ago
    Literally every building north of Ventura is connected to pg&e’s grid. It can’t be all that onerous if it’s universal.
    - zbrozek 4y ago
      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.
      - jeffbee 4y ago
        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.
        zbrozek 4y ago
        Nope. I mean replacing a panel. It's precisely what I said, after all.
fnordpiglet 4y ago
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.
fomine3 4y ago
Off grid for everyone looks inefficient. We don't need huge battery on each house/office/factory thanks to big grid.

burlesona 4y ago

> 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?

changoplatanero 4y ago
I found some numbers for total PG&E generation in 2017 and based on that 675mWh would be about 10 minutes worth of power.
- liketochill 4y ago
  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.
flgb 4y ago
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.
seri4l 4y ago
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%

jlv2 4y ago

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.

fnordpiglet 4y ago
Is that not optional? Seems a little intrusive if not
- zaroth 4y ago
  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.
  - notpushkin 4y ago
    What happens if your battery is drained out at the time? What happens if you hack your battery to say it ran out?
    - ncallaway 4y ago
      > 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.
thehappypm 4y ago

liketochill 4y ago

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.

mulmen 4y ago
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.
xpe 4y ago
> 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?
- thrtythreeforty 4y ago
  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.
  - liketochill 4y ago
    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
    - 4y ago

whartung 4y ago

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.

happyopossum 4y ago
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.
- rdtwo 4y ago
  Nah the grid hook up fee is likely the bulk of the cost. Simply being connected is the most expensive cost
  - liketochill 4y ago
    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
    - simfree 4y ago

happyopossum 4y ago

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

natch 4y ago
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.
- natch 4y ago
  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.
recursive 4y ago
I'm in CA. I pay 56 cents from 4pm to 9pm.
beembeem 4y ago
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.

digdugdirk 4y ago

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.

fnordpiglet 4y ago
I would be livid if I went out to go to work and my car was drained because my local utility sucks.
- dymk 4y ago
  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.
- FartyMcFarter 4y ago
  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).
etimberg 4y ago
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-transactive-energy-for-california-rooftop-solar-behind-the-meter-batteries https://www.greentechmedia.com/articles/read/opus-one-tests-...

black_13 4y ago

smlacy 4y ago

zbrozek 4y ago

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.

pottertheotter 4y ago
Yeah. There should be some standard created for this.
toomuchtodo 4y ago
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/ https://nest.com/energy-solutions/
- etimberg 4y ago
  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/ https://clean-coalition.org/distribution-system-operator-dso...
- zbrozek 4y ago
  It feels like there could be a simple API and CAISO could easily deal with participants at any size. This isn't rocket science.

windows2020 4y ago

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.

Daishiman 4y ago
It’s a matter of not requiring to kick in more expensive and polluting energy sources.
- windows2020 4y ago
  Is a large number of consumer batteries more environmentally friendly than say a nuclear power plant?
  - helf 4y ago
    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
    - etimberg 4y ago
      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 https://www.eia.gov/todayinenergy/detail.php?id=45956
  - dividedbyzero 4y ago

NotYourLawyer 4y ago

cptcobalt 4y ago

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.

tguvot 4y ago

PG&E running similar trial with SolarEdge and LG https://pge-battery-pilot.com/ 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."

etaioinshrdlu 4y ago

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!

xpe 4y ago
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-085600346.html https://www.engadget.com/tesla-powerwall-outage-ev-charging-...
- etaioinshrdlu 4y ago
  But this is specific to Powerwall, no? Most owners don't have a powerwall.
  - xpe 4y ago
    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.)

Mandatum 4y ago

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

peter422 4y ago
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.
- zxexz 4y ago
  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 https://powerequipment.honda.com/generators/models/eu2200i
  - peter422 4y ago
    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.

systemvoltage 4y ago

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.

astockwell 4y ago

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.

iso1337 4y ago
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.
- strgcmc 4y ago
  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.
  - andreareina 4y ago
    Another model is phase change: there are critical points around which a small change in adoption can trigger a large change in aggregate behavior.
  - thehappypm 4y ago
    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.

traviswt 4y ago

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.

jfim 4y ago
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.
- tsimionescu 4y ago
  And how exactly would you use your car if you discharge it overnight?
  - jillesvangurp 4y ago
    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.
  - 4y ago

bagels 4y ago

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?

hcknwscommenter 4y ago
most power emergencies are quite short, and are especially short if there is a sufficient demand response
beckingz 4y ago
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.
ceejayoz 4y ago
> 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.
thehappypm 4y ago
Hardly a pittance, $2/kwhr is a crazy high rate.
- bagels 4y ago
  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.
  - bpodgursky 4y ago
    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.

dymk 4y ago

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?

karmanyaahm 4y ago
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.
bergenty 4y ago
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.
newt_slowly 4y ago
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.
- dymk 4y ago
  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.

ackbar03 4y ago

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?

hughes 4y ago
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.
newt_slowly 4y ago
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.
hedora 4y ago
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.
qqqwerty 4y ago
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.
Panzer04 4y ago
I’d bet on ~95% round trip efficiency, if not more - lithium batteries are very efficient, as are modern power electronics.

sidcool 4y ago

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

Garlef 4y ago
It's not a new thing. Sonnen is doing this for a few years already.

foota 4y ago

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 :-)

snek_case 4y ago
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.
- kfarr 4y ago
  So generating electricity is not a lucrative career option at $2 per day
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- mrguyorama 4y ago
  Obligatory cyclist powering a toaster with their bonkers thighs: https://www.youtube.com/watch?v=S4O5voOCqAQ 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
  - foota 4y ago
    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.

hedora 4y ago

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.

jeffbee 4y ago
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 https://www.caiso.com/todaysoutlook/Pages/prices.html
- hedora 4y ago
  All of those things are easily fixable via legislation.
Garlef 4y ago
> 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/ https://sonnenusa.com/en/virtual-power-plant/

coding123 4y ago

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.

coolsunglasses 4y ago
What batteries did you get?
archi42 4y ago
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.

zekrioca 4y ago

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?

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philjohn 4y ago

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

RektBoy 4y ago

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.

joelthelion 4y ago
Wait for the winter... Things aren't looking good this year :-(
bagels 4y ago
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.
kllrnohj 4y ago
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.
archi42 4y ago
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 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 https://de.wikipedia.org/wiki/Virtuelles_Kraftwerk

Teafling 4y ago

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 https://leap.energy) and we have virtual power plants in CA, TX, and NY.