National Grid vs. Eversource: Which Is Better for Solar in Massachusetts?

Eversource customers save approximately $120/year more than National Grid customers because of higher retail rates ($0.2836/kWh vs $0.2718/kWh). Over 25 years, that difference is about $3,000. Both utilities offer 100% retail-rate net metering, SMART eligibility, and ConnectedSolutions, so the difference is purely in the rate — not the policy.

Yes. Both Eversource and National Grid credit solar exports at 100% of the retail rate for residential systems up to 25kW AC. This means every kWh you send to the grid offsets a kWh on your bill dollar-for-dollar. This is one of the strongest net metering policies in the country.

The residential net metering cap was expanded from 10kW to 25kW AC in February 2025. This applies to all three investor-owned utilities: Eversource, National Grid, and Unitil. Many websites still incorrectly list the old 10kW limit.

No. Your electric utility is determined by your location, not by personal choice. Eversource and National Grid serve different geographic areas of Massachusetts. You cannot switch between them. However, both utilities offer excellent solar economics, and the difference in annual savings is relatively small ($120/year).

ConnectedSolutions is a demand response program that pays battery owners $225–$1,500/year to discharge during peak demand events. Both Eversource and National Grid participate. Unitil does not offer ConnectedSolutions. The program runs primarily during summer afternoons (June–September).

Both utilities offer optional TOU rates. Eversource peak rate is $0.3284/kWh (Mon–Fri 12pm–8pm), with off-peak at $0.2201/kWh. National Grid peak is $0.3155/kWh. If your solar exports align with peak hours (which they often do midday), TOU rates can increase your net metering credits by 10–15%.

Eversource performs its annual true-up in April, while National Grid does theirs in March. At true-up, any excess credits are zeroed out with no cash payout. Size your system to match your annual consumption to avoid losing credits.

The SMART program structure is the same for both utilities — both offer the same base rates, battery adders, low-income adders, and location-based adders. However, each utility has separate capacity blocks that fill at different rates. The rate you lock in depends on which block is open in your utility territory when you enroll.

Unitil serves a small area around Fitchburg with approximately 28,000 customers. Unitil rates are lower ($0.2412/kWh), so annual savings are less ($2,326.56/year). Unitil does not participate in ConnectedSolutions. However, Unitil customers are eligible for SMART, net metering, and all state incentives.

Eversource serves Eastern MA, Greater Boston, Cape Cod, South Shore, North Shore — approximately 1.4 million electric customers. National Grid serves Western MA, Worcester, South Coast, parts of Greater Boston — approximately 1.3 million customers. There is no overlap; your utility is determined by your address.