New Hampshire became the seventh US state to legalize plug-in solar on May 28, 2026, when Governor Kelly Ayotte signed SB 540 as Chapter 89. The law takes effect July 27, 2026.
New Hampshire has the second-highest electricity rate of any enacted state at 28.1¢/kWh, behind only Maine. That rate is driven by the state’s heavy reliance on natural gas for generation, deregulated market structure, and high transmission costs for a small-population state. It also makes plug-in solar economics among the most favorable in the country for early adopters willing to install when the law takes effect in late July.
See New Hampshire's plug-in solar law details, effective date, and estimated annual savings at NH's rates.
New Hampshire solar law details →What SB 540 does
New Hampshire’s law covers plug-in solar devices up to 1,200W. The structure:
No utility pre-approval. NH utilities, including Eversource NH and Liberty Utilities, cannot require interconnection approval or charge interconnection fees for qualifying systems.
Landlord and HOA protections. Landlords and HOAs cannot prohibit qualifying plug-in solar systems. Reasonable placement restrictions are still permitted.
July 27, 2026 effective date. Standard utility rules apply until then.
The law was notable for its bipartisan support in a Republican-controlled legislature. The bill passed with backing from both parties, citing energy affordability for renters and homeowners as the primary rationale. New Hampshire energy policy is often described as skeptical of renewable mandates, which made SB 540’s passage a signal that plug-in solar is finding support beyond the usual climate-focused constituencies.
The economics at New Hampshire’s rates
New Hampshire averages about 28.1¢/kWh residential. Manchester and Concord get roughly 4.4 peak sun hours per day, slightly below the national average.
For an 800W south-facing system:
800W x 4.4h x 0.85 = 2.99 kWh/day production At 70% self-consumption: 2.09 kWh/day At 28.1¢/kWh: $0.59/day, or $215/year
A $900 kit pays back in about 4.2 years. Among the enacted states, New Hampshire sits just below Maine and Connecticut for plug-in solar economics, all three driven by the same cause: high electricity rates combined with reasonable (not excellent) sun exposure.
New Hampshire’s deregulated market
Like Maryland, New Hampshire has a deregulated retail electricity market. About 60% of NH residential customers have switched from default utility rates to a competitive supplier. If you are on a competitive supply contract, your effective rate may be higher or lower than the 28.1¢/kWh statewide average.
One characteristic of deregulated markets: variable-rate customers who did not lock in a fixed rate have seen significant price volatility over the last several years. Plug-in solar provides a hedge against that volatility, since the savings are determined by your rate at the time of consumption, not a fixed price from when you signed a contract.
Installation context for NH renters
New Hampshire’s housing stock is predominantly single-family homes, but Manchester, Nashua, and Concord have significant apartment inventory. For apartment renters with south-facing balconies, the July 27 effective date means you can plan your install for August or September to take advantage of the remaining summer sun.
For homeowners who want to add a plug-in supplement to an existing rooftop system: New Hampshire’s Eversource has been relatively accommodating to expansion kits added to existing interconnected systems. A plug-in system on a garage roof or south-facing patio, sized under 1,200W, is a straightforward addition once the law is in effect.
The plug-in solar readiness checker includes New Hampshire in its state-law assessment and will flag the July 27 effective date.
Check whether your New Hampshire home or apartment qualifies for plug-in solar under SB 540.
Check your NH readiness →Related: Solar Panels for Renters: A 2026 State Guide | Connecticut Plug-In Solar Law: What HB 5340 Does
Dana Whitmore
Energy Engineer & Billing Analyst · Optiwatt Energy Advisor
Dana has spent the past three years analyzing residential electricity billing data across PG&E, SCE, and SDG&E service territories. She's reviewed billing records for thousands of California households, and built the simulation engine that powers this site's rate-plan comparisons. She holds a degree in Electrical Engineering and lives in the Bay Area.