It’s possible that your system will have produced more electricity by the end of the billing cycle than what you used. You won’t lose this energy; in fact, both PSEG LI and Con Edison will continue counting your kilowatt-hour credits in your favor against your usage in the next billing cycle.
For example, let’s say in one month, your solar system produced 1,000 kWh. Your household consumption was 800 kWh. Your net consumption was -200 kWh; in other words, your solar system produced an extra 200 kWh more than what you needed that month. Your utility will credit your electricity account those extra kilowatt-hour credits for the next month, if you need them. It will be indicated on your bill as your “energy bank”.
Let’s say the next month your solar system produces another 1,000 kWh. However, your home uses 1,200 kWh. In this case, the utility will include the 200 kWh credit from the previous month. In this case, everything evens out, and they wouldn’t charge you for electricity, because your net consumption was zero.
If you happen to have additional excess electricity produced in the second month as well, you won’t lose the first month’s excess. Both PSEG LI and Con Edison will continue accumulating your kilowatt-hour credits until the end of the year. That’s where they differ — more on that later.
Net metering is especially useful for regions like the northeast, which have four distinct seasons. Solar systems in New York State produce more energy in the spring and summer, on average, than they do in the fall and winter. Net metering allows you to carry your excess power from the “bright” seasons into the “dark” seasons so your year-round average bill remains low.
It’s quite common that people don’t have excess power at all. You’re still being credited for your kilowatt-hour production either way. For example, if your solar system produces 800 kWh, and you use 1,200 kWh, the utilities will bill you for the difference — 400 kWh.
Your electric utility bill will be reduced by your solar system. How much you are paying for your solar system — which might vary depending on whether you’re financing or leasing your system — would depend on your arrangement with your solar contractor. If you’re currently reviewing your options, you might want to review how solar ownership works compared to solar leasing.