This article is all over the place, but the principle is pretty simple - rather than adding more generation for peak usage times, batteries store energy generated off peak and smooth out the macro usage trends.
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.
My utility doesn't have a program quite like this, but they do have a peak power rate that incentivizes similar behavior. I have our system configured to charge up to 90% at 12pm, and then consume no grid power until 7pm (peak rate is 1-7pm), or if the battery gets down to 35%.
I also have it configured to charge to 100% if there are any weather watches or warnings. That overrides the time-of-use configuration.
We do also have a generator that I can hook up if the batteries get too low. We have enough battery to get us through the night, but we don't have enough solar to keep up in an outage during the darker months, or if we want to run the A/C.
beaviskhan · · focus · HN ↗
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.
izend · · focus · HN ↗
organsnyder · · focus · HN ↗
I also have it configured to charge to 100% if there are any weather watches or warnings. That overrides the time-of-use configuration.
We do also have a generator that I can hook up if the batteries get too low. We have enough battery to get us through the night, but we don't have enough solar to keep up in an outage during the darker months, or if we want to run the A/C.