Spread across thousands of ordinary homes, Vermont's virtual power plant has become its largest power source. It's protecting owners from outages and providing cheaper, cleaner energy.
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Our local utility in NC has a program where they'll pay you ~$50/battery/month to enroll in their virtual power plant program. In exchange, they can take control of your battery up to 36 times per year for a period of a couple hours. Summer events are typically early evening during peak air conditioning times. Winter events are typically early morning during peak heating times.
In practice this means one of two things:
* They make your battery charge to full capacity in advance of the event, and then you run your home off the battery and don't take any power from the grid during that time * Sometimes you'll also return power to the grid beyond that used by your house - they pay you the contracted rate for the power you deliver
We've paired our batteries with solar panels, so generally we have a full charge going into the summer VPP events. We have gas heat, but I expect we'll pay for at least some grid energy to charge batteries during the winter events. Regardless, it's been a good program for us - even without solar, we would not pay for any more power than we used, and the monthly rebate from the utility makes the economics of the system a lot more favorable, especially here in the land of relatively cheap coal power.
> We've paired our batteries with solar panels..
Does this imply that the scheme will charge your battery from the grid, and that you don't technically even need solar?
I've never considered that one might get a battery without solar, but I guess you might have some power needs that would make it worthwhile to draw on during cheap periods and drain at peak?
Our battery is under automatic VPP control, but it’s not like it randomly starts exporting when we don’t want it to. When regional demand is high (hot days) or supply is low (no wind or cloudy), our battery might start exporting. But that’s a good thing for us, because our electricity is priced wholesale and changes every 5 minutes, and export rates are high in this situation. A couple of times there have been price spikes and we’ve made a few hundred dollars in under a hour. It’s a win-win for us (making money) and the grid (providing stability). To be fair, those spikes are rarer now than they were a year ago.
You can always control the battery if you want. Sometimes I’ll manually export even if prices aren’t high if I know I don’t need the power in my battery. Sometimes I’ll prevent export if I know I want to charge the car overnight from the battery. But mostly I let it do its thing.
From an investment perspective, the battery has been a no-brainer. Even without the windfalls from price spikes, being able to defer grid consumption to daylight hours (when wholesale prices are very cheap or even negative, i.e. we get paid to charge the car) puts the ROI in the 3-5 year range.
If clean energy is being curtailed increasing usage is a better response which negative prices also incentivize but in many jurisdictions they refuse to pass those price signals onto users because they'd rather waste clean energy so they can sell them dirty energy later.
Our battery/inverter system automatically curtails solar generation when our battery is full and export prices are negative, so this isn’t anything we need to think about. (Exception: I’ll charge the car to drain the battery overnight if I expect curtailment the next day. No point letting all that free sunshine go to waste!)
Many plans offer a 3 hour period where electricity is free to encourage shifting your load to that time. Which is amazing if you're able to charge an electric vehicle in that time, a standard single phase charger could provide 21kw/h in that 3 window all for free.
Do you get the full 5 minute spot price, or do they then charge you re-injection costs per kWh?
And are the grid-costs fixed yearly, or do they also charge you per kWh re-injected?
Most of the time, distribution charges are higher than the spot wholesale prices for import and export.
Which, we should remember, is a good thing for society.
https://electrek.co/2026/07/28/vermonts-largest-energy-sourc...
Seems like they supply each person with 2 Tesla powerwalls for the $55/month and get a reduction in their bills that depends on how much power they choose to share to the grid during power outages.
They've already closed down 2 peaker power plants because of this, so it doesn't seem to just be about handling power outages, but also handling fluctuating power usage instead of firing up extra power plants.
Yes, that was a significant early argument I remember around the public benefits. The daily power spikes have always been a major challenge particularly when you don't have much commercial/industrial base. And even in the earliest period of the original 2000 home pilot they were surprised and pretty happy about how much load could be spread and the resulting savings. Note though that regulators were cautious and there was controversy around how well it'd actually work, you can find articles like this 2019 VT Digger one [0] from the era. Fortunately it did indeed work out, but easy to forget it was all pretty new at one point.
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0: https://vtdigger.org/2019/09/05/state-calls-for-investigatio...
Those tesla wall packs will be a massive headache when they give up the ghost. Read the contract carefully. Who is responsable for end-of-life disposal? Where/how are they to be disposed of? Lead acids can be taken to any number of recycling centers, some will even pay you for them.
I would also suggest that size and weight are bigger concerns than you're giving credit to. They aren't assembling packs on-site from individual batteries. They're rolling in whole-ass packs in one swell foop. Getting them into basements isn't a small job[0]. Getting them back out will be even less fun for the crews.
Their total on-site install time was maybe 6 hours, and that included tying everything in to the existing system. Putting the hardware in place took maybe an hour of that time. If you want to go with heavier packs or more/larger packs, you're going to add to that a bit. And their doing this in people's finished homes. This isn't new build where they can have a couple of big dudes wrangling packs around without a care in the world for furniture and finished surfaces. The ergonomics of smaller packs matter.
[0] They used a two-wheel dolly with a hydraulic disc brake (bicycle hardware) to get them down our basement stairs.
https://www.whalebattery.com/blog-detail/lead-acid-vs-lithiu...
Cost per kWh per year:
lead-acid batteries: $100 per kWh per year
LFP batteries: $50 per kWh per year
https://www.justplugsolar.com/blog/lithium-vs-lead-acid-batt...
US is outsourcing recycling of Lead acids to Africa.
https://www.nytimes.com/interactive/2025/11/18/world/africa/...
I think a bigger question is if sodium batteries starts to take over (seems better for homes, heavier but seemingly safer but also for cheaper cars) and lithium/rare-earth metals prices goes down.
Source? Last time I checked a few years ago the prices were similar and lithium has dropped significantly since then.
It's not as if the batteries people are paying for become their property, or are only for the homeowner's benefit. The utility company has the right to use that power however they want at any time including the "right to use all the energy in the battery". The homeowner also has to allow contractors, subcontractors, or third-parties onto their property. Physical access aside, they also have to allow the utility free access to their network and free use of their internet connection/bandwidth. The utility will not compensate homeowners for any of that.
Homeowners must also agree to install the utility company's cell phone apps/software. I'd bet those apps are collecting data and probably pushing ads too. They have to agree to the “Customer Privacy” terms, which will only be shown to them "upon installation of the Equipment".
The utility company advertises this as a means to prevent power outages (which, if they were doing their job in the first place, should be extremely rare occurrences), but the fine print makes it clear that homeowners should not assume that they will have any access to the power that battery holds in the event of a power outage or at any other time.
The utility also requires homeowners to agree to terms that state the utility will not be liable for any damage to persons or property caused by use of/replacement of/repair of/or the utility's failure to repair the utility's equipment and software. The homeowner also "bears the entire risk of loss, theft or damage" to the utility's equipment.
This would be a bad deal even if the utility were paying a monthly fee to homeowners. The fact that they've conned customers into paying the utility for using them, their internet, and assuming all liability/responsibility for the utility company's hardware is insane.
I participated in this program early on (currently on year 8 or 9) and I don't think you're giving a fair characterization. First, the batteries took the place of a generator, and have reliable protected my buildings from power outages since. Part of the program is that in case of storm warnings or other risk it actually switches out from the VPP for the duration to protect you instead. So there's direct value to having them, particularly in a rural area of a rural state, regardless of any other money. Having a sizable generator isn't free, not just in terms of purchase but in terms of
Second, the utility did in fact pay with a pretty massive discount (around $5-6k per battery at the time IIRC). The amount they were willing to pay wasn't enough to completely cancel out the battery cost back then, but it was like 70-80% of the cost. And in general looking at all the various VPP programs in the region utilities remain very much willing to pay you per kWh, whether it's a lease or BYOB.
There are multiple ways to make a battery work for you in terms of ROI, and the math has changed over the years as various component costs have changed as well as being individual to each person's situation in terms of their own usage patterns and generation. But I don't think this was a scam at all, it was a genuine win/win even before getting into softer factors like reducing usage of fossil fuel peaker plants that a lot of us do really care about. In an ideal world neutralizing that carbon pollution would all just be built into pricing so the market could better sort it out, but as it stands I don't feel bad about supporting a shift to some extent too. And even though I'm probably going to just buy my own batteries next time around due to other changes, I'd certainly consider contributing to a VPP again depending. It's been a positive experience.
>The utility company advertises this as a means to prevent power outages (which if they were doing their job in the first place should be extremely rare occurrences)
This is just really hard in some parts of New England given the history of grid development (we have a lot of really weird legacy layouts), weather, trees, population density, and lack of resources. If you're at the end of a quarter to a half mile driveway in the forest up a steep mountain dirt road and aren't able to bury the lines then it can be tough in storms. Plus other weirdness, last year a pole came down and it turns out bears had been using it as a scratching post and just ripped through the entire thing. Was actually pretty cool but also a power outage.
>but the fine print makes it clear that homeowners should not assume that they will have any access to the power that battery holds in the event of a power outage or at any other time.*
In all these years it's never once been an issue though. And I don't consider that "fine print" but obvious: if you're participating in a VPP at all, then obviously there will be times when your battery has been drawn down. That's the deal duh. And with the best will in the world they can't predict things like some drunk driver taking out a pole and causing an outage (this happened again not that long ago). It's not impossible that there could be the bad luck of that happening right when the battery happened to be down to a low level. That's the risk. But they do pay you for it. And almost any way you'd make batteries pay beyond power protection entails some risk or else some cost too, like if you want to rate-shift so that you only pay the lowest night time energy rate by charging then and then running off your batteries during the day, then you'll of course be at risk of lower remaining storage if there's then a grid failure too when you were expecting to charge back up again. You can spend money on that risk in turn, but there's no free lunch here.
We should be doing this as a society (or as a state or as a utility company) instead of relying on individual do-gooders to pay for it. 70-80% of the cost sounds very good, but if you're not getting any latitude on how the things are used, that 20-30% is still unfair. If they belong to the utility, the utility makes all decisions regarding it, and you are giving up your space for it, if anything you should be getting paid, not paying.
They could at least let you actively decide if you want to allow it to be drawn down and to what extent; some sort of latitude. As it is, for them it's money for nothing.
That being said, the article says that they're starting to install them for free. Thanks for sharing your experience.
The generator would have been yours, and only used for your needs. It wouldn't have involved any data collection, the uncompensated use of your bandwidth, or exposed you to so much liability.
> Part of the program is that in case of storm warnings or other risk it actually switches out from the VPP for the duration to protect you instead.
They may do this, but by their own terms they aren't obligated to. The good news is that in the event where a cable is cut/down and they lose the ability to siphon power from your battery you will be sure to get the benefit of whatever power it has stored. It's also nice that they compensate you for the power that they draw, but again, all of that energy is already theirs by right.
The state contracts them to provide the people with reliable power and you pay them for that service. They should be expected to reasonably deliver that in exchange. Installing their equipment inside people's homes can be part of how they manage that responsibility, but it's still their responsibility and they should compensate you for that and not expect you to pay them even more for the privilege of paying their costs and accepting liability.
> it was a genuine win/win even before getting into softer factors like reducing usage of fossil fuel peaker plants that a lot of us do really care about.
It's honestly not a bad idea conceptually. It seems like it can have real benefits, but the terms are exploitative. At a minimum they should be obligated to prioritize your power needs above others when it comes to energy stored in the battery on your premises, and they should be obligated to compensate you for power taken, as well as for providing them storage, access, security and bandwidth for their equipment, and they should also assume responsibility for any damage/harm their equipment causes to your property and anyone one on your property as long as it wasn't caused by tampering or improper use. Ideally, you'd also be able to opt out of all personal data collection (not related directly to the use/monitoring of their hardware), and any loss/theft/damage would be covered by their insurance (provided their equipment was reasonably secured), otherwise they'd have to pay you enough to get additional insurance coverage of your own.
I'm glad it worked out for you when you had it, but unless the terms were very different from what they are today you were absolutely cheated and being taken advantage of, even if you didn't feel that way.
With consumer units, you can reasonably expect that they’ll operate with zero maintenance and zero direct supervision for a decade plus. If the cost of those units is low enough, that reduced operational burden starts looking very attractive, especially if you want to scale up your battery capacity across your network very quickly.
It is as if. The article says it's a lease agreement, and provides this link.
https://greenmountainpower.com/rebates-programs/home-energy-...
>the homeowner "bears the entire risk of loss, theft or damage" to the utility's equipment.
What are you quoting?
It's like leasing a car, except with a car lease you have the option to pay extra to buy it out at the end and take ownership; with this lease agreement you don't.
The way an article is written doesn't explore the fact that at its core batteries are a 'consumer of energy' and not a producer like a power plant. You are losing electrons through heat losses and degradation in a bid to match demand with lowest cost supply.
Replacing generators with a battery make sense when the peak capacity is overbuilt, but it shouldn't be left unchecked.
The other challenge is that the customer's savings usually come not from the battery itself (the energy arbitrage) but from avoiding the usage charges from their distribution and transmission networks. Deploying batteries on grid without a plan pushes forward the grid death spiral where some users of the network feel like they no longer need to be connected as they can be self sufficient. That means that those that cannot be self sufficient have to share the same cost of infrastructure with less users on it. That is assuming that being self sufficient is economically viable and sufficiently reliable.
Those who think that home batteries and solar are 'cheap' should look into the true underlying costs. The per MWh cost of a home system is MUCH more expensive than a utility scale system. The savings are often just an arbitrage on a relatively high level usage-based pricing allocation of the transmission and distribution systems.
The network costs are mostly fixed by their nature - it's recovery of equipment cost and ongoing cost of maintenance activities. Cost per KWh can be different at different times because you need higher cost equipment that works during the time of high load. If there is no high load - the equipment is not needed and cost can be reduced. But this cannot happen overnight because the equipment is already there! Without forcing the networks into taking heavy losses - you have to allocate the costs to users,and unfortunately those that cannot afford to have these expensive home systems will end up paying the higher price. In effect your battery 'savings' are coming from people who cannot afford to have one.
Unless this is very carefully managed (and I do not think governments are generally capable enough), this will result in a lot of new problems. One will be major difficulties in developing new housing (or intensification) due to lack of electricity supply. Another will be insufficient supply during 99th percentile events in which home batteries alone will be insufficient to close the gap. Another will be distribution. Some neighbourhoods will have higher battery penetration than others, and this happens organically and without the permission of the grid companies. That's very difficult to plan around. Some areas are going to be secure, and others will not, unless the grid purposefully oversupplies, negating the potential cost savings.
Batteries are good at marginal demand smoothing, but I am very dubious about shutting down energy generation. Especially at this time. All analysis points to the reality that due to technology demands, we're facing an imminent power generation crunch. Prices are going to rise everywhere and demand will only increase.