Maryland became the fifth US state to legalize plug-in solar on May 12, 2026, when Governor Wes Moore signed HB 1532, the Utility RELIEF Act, as Chapter 353. Unlike some other enacted states, Maryland’s law took effect immediately upon signing.
The Utility RELIEF Act is notable for two things: it covers plug-in solar as part of a broader package of consumer electricity protections, and it includes a provision that exempts the smallest systems (391W and under) from the UL certification requirement entirely. For renters who want to start with a single small panel without worrying about certification paperwork, that is a meaningful practical difference.
See Maryland's full plug-in solar law details, watt limits, and estimated annual savings at Maryland's rates.
Maryland solar law details →What HB 1532 covers
The Utility RELIEF Act allows systems up to 1,200W to connect to a standard outlet without utility pre-approval or fees. The main provisions:
No utility pre-approval. Maryland utilities cannot require customers to file for interconnection approval before installing a qualifying plug-in system. The existing interconnection process, which can take weeks and involve fees, does not apply.
No landlord prohibition. Landlords cannot ban qualifying systems. The law applies broadly to rental properties, not just larger complexes.
Small system exemption. Systems at or below 391W are exempt from the UL certification requirement. This is unique to Maryland among enacted states. A single 370W panel with an uncertified inverter technically qualifies under this exemption, though using a UL-listed inverter is still strongly recommended for safety.
Immediate effective date. Most other enacted states had delayed effective dates of several months. HB 1532 took effect the day the governor signed it.
What Maryland’s deregulated market means for plug-in solar savings
Maryland is one of about 18 states with a deregulated electricity market. About 370,000 Maryland households have switched from the default utility rate to a competitive retail electricity provider.
For plug-in solar economics, deregulated customers need to check their current supply rate. Default utility rates in Maryland (BGE, Pepco, Delmarva) average around 16.8¢/kWh. Competitive retail rates vary by provider and contract term. If you are on a variable-rate retail contract, your supply rate may be higher or lower.
At the standard 16.8¢/kWh rate, an 800W south-facing system in Baltimore (4.5 peak sun hours/day) produces:
800W x 4.5h x 0.85 = 3.06 kWh/day production At 70% self-consumption: 2.14 kWh/day x $0.168 = $0.36/day, or $131/year
Households in Columbia or Bethesda with rates from a competitive retail provider running 20–22¢/kWh (not uncommon in 2026) push that to $155–$170/year. The balcony solar calculator lets you input your actual rate rather than the statewide average.
The 391W exemption in practice
Under most state laws, you need a UL 1741-certified microinverter. The certification exists for good reasons: it ensures anti-islanding protection and other safety features.
Maryland’s 391W exemption was likely included to lower the barrier for the very first wave of adopters using single-panel setups. The 391W threshold roughly corresponds to a single panel paired with a 300–400W microinverter.
In practice: do not skip the UL listing to save $30 on a cheaper inverter. Even systems under 391W benefit from anti-islanding protection. The exemption means Maryland will not require certification, not that uncertified hardware is safe.
What still applies
Maryland’s law does not grant unlimited access. Landlords can still impose reasonable placement restrictions, like requiring panels to be on a balcony rather than mounted on the building face. The renter notification requirement applies before installation.
The law also does not provide net metering for plug-in systems. Any surplus you export to the grid is not compensated, so sizing the system to match your daytime consumption rather than trying to maximize export is the right approach.
The plug-in solar readiness checker includes Maryland’s law in its state assessment and will flag the 391W exemption if you select a small starter system.
Check whether your Maryland home or apartment is set up for plug-in solar, and see what size system makes sense for your space.
Check your Maryland readiness →Related: Solar Panels for Renters: A 2026 State Guide | Virginia Plug-In Solar Law: What HB 395 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.