Net metering is a beautiful thing for homeowners with solar arrays on their property. But what is it, exactly, and why is it so beneficial for you? We get asked these questions quite frequently. Another question we get asked is “Do I need a battery system with solar?”
Virtually every home in Virginia is connected to the power grid. When you install a grid-tied solar photovoltaic (PV) system on your roof, the system hooks into your house’s main electrical panel and feeds electricity directly to your appliances, HVAC, lighting, etc. But your home remains connected to the power grid, just as before. When the sun is shining, your home pulls power from the solar panels. At night, and on rainy days, your home pulls power from the grid.
What happens when your solar PV system produces more electricity than your house uses, which is the case on most sunny days? Wouldn’t it be nice to keep that electricity stored up somewhere, so that you can use it later when your solar panels are not producing power? Enter net metering.
Net metering is an accounting system that allows you to push excess electricity out to the power grid and in a sense, retrieve it later when you need power again. The power grid itself becomes your battery system. When you push excess power out to the grid, your electric meter literally runs backwards. When the sun goes down and your house starts pulling power from the grid, your meter runs forward again. (When you install a solar PV system on your property, your utility will come to your house and swap your old meter for a bi-directional meter to properly account for the electrons flowing in and out.)
If, at the end of the monthly billing period, it so happens that your solar PV system pushed out more electricity than your house consumed, then you retain a credit for the excess kWh. The credit is used toward the next billing month. This happens all the time during sunny days, especially in cooler months when your home is not running the AC. Depending on your cooling and heating needs, you will be amassing monthly kWh credits during winter and spring, and then drawing down your credits in the summer and autumn months.
As of July 1st, 2020, Dominion Power’s net-metering rules allow up to 150% solar offset of your typical annual electric usage. This means that you can size your system a bit larger in preparation for future EV car(s) purchase or home additions/improvements. The maximum system size will also increase from 20kW to 25kW for residential customers. Other co-op utilities (i.e. NOVEC), will continue to allow 100% energy offset and 20kW maximum system size.
In sum, net metering allows you to get full credit for every kWh exported back to the grid and therefore makes solar power an even more affordable and attractive way to power your home. If you have more questions about net metering, one of our solar experts can help.