If you live in Massachusetts in NationalGrid or Unitil territory and have considered going solar, or went solar anytime since roughly 2016, you likely were told about the 10 kW AC Limit. And if you live in Eversource territory, you will soon know all about it too.

What is the 10 kW AC limit? Basically, it’s a rule about net metering for Massachusetts solar. If your system is under 10 kW AC any power you push back to the grid gets you a full kW hour credit on your bill to use for another billing cycle (currently that’s about $0.25 per kilowatt-hour). But if your system is over that limit, any power you are sending back to the grid each billing cycle is worth about a nickel. Imagine that. Based on the size of your solar generation system, the value of the electricity you produce is reduced by 80%!

Why does this matter? Maybe your solar system isn’t meeting your usage and you’d like to make it bigger. Maybe you’re thinking about adding electric heating or cooling (by adding mini splits or other type of heat pump). Perhaps you’re going to get an electric car. But if you make your system bigger (or want to buy a bigger one right now), this could put a real damper in your plan to live exclusively on clean energy.

So what can you do about it? If you are looking into Massachusetts Solar, call your senator and house representative because right now there is a bill in the senate that will largely fix this problem for the vast majority of residential (and even small commercial) customers. The bill is “Senate-2819” or (S2819 for short). In a nutshell, it will increase the 10 kW AC limit to 25 kW AC.

If you want your solar system to be as big as it can (and needs to be) it is a major game changer.

So again, if you are a Massachusetts resident, please call or write a letter (don’t email) your state Senator and your state Representative now with a firm “ask” to support S2819. You will be glad you did.