Utah passed the first explicit plug-in solar law in the United States in March 2025. HB 340 was signed by Governor Spencer Cox and took effect in May 2025. Since then, six more states have enacted nearly identical laws, all modeled on what Utah built.
Understanding Utah’s law is worth the effort not just for Utah residents, but because it is the template. When legislators in Virginia, Maine, Colorado, Maryland, Connecticut, and New Hampshire drafted their plug-in solar bills, they largely copied Utah’s framework. The differences between the states are mostly in watt limits and effective dates. The underlying structure is the same.
See Utah's current plug-in solar law details, savings estimates, and what UL certification is required.
Utah solar law details →What HB 340 does
HB 340 creates a new legal category in Utah code for “plug-in solar devices”: portable solar generation systems that connect to a home through a standard 120V outlet, under 1,200W, with a UL-certified microinverter.
The core provisions:
1,200W cap with UL certification required. The system must use a microinverter with UL 1741 or equivalent listing. This requirement specifically addresses the anti-islanding concern that utilities raised during the legislative process.
No utility interconnection required. Rocky Mountain Power and other Utah utilities cannot require an interconnection application, approval process, or fee for qualifying systems. The existing interconnection process, which applies to rooftop solar and other distributed generation, is explicitly exempted for plug-in systems under the cap.
No net metering for plug-in systems. This is the tradeoff. Any electricity a plug-in system exports to the grid, during hours when home consumption is lower than production, is not compensated. The system owner essentially gifts that power to the utility.
Renter protections. Landlords cannot prohibit qualifying installations. HOAs also cannot block them.
Why Utah passed this in 2025 when other states hadn’t
Several factors came together. The sponsor, Rep. Raymond Ward, had been following Germany’s balcony solar market, which grew from essentially zero in 2020 to hundreds of thousands of systems by 2024. The key insight from Germany was that the main barrier was not technology or consumer interest; it was regulatory: utilities required interconnection agreements for even a 300W panel on an apartment balcony, treating it the same as a 10kW rooftop array.
HB 340 solved that by creating a new category that is treated more like an appliance than a power plant. The UL certification requirement addressed the safety concerns utilities raised, and the no-net-metering tradeoff removed the financial objection utilities had to allowing unmetered grid connections.
The bill passed both chambers with unanimous bipartisan support. That unusual political alignment, Republicans citing individual property rights and energy independence, Democrats citing renter access and carbon reduction, became the political template that other states later used.
The economics at Utah’s rates: modest but real
Utah has among the lowest residential electricity rates in the country at 11.6¢/kWh. That significantly changes the plug-in solar economics compared to high-rate states.
Salt Lake City gets outstanding solar resources: roughly 5.8 peak sun hours per day, comparable to Colorado and some of the best in the country.
For an 800W south-facing system in Salt Lake City:
800W x 5.8h x 0.85 = 3.95 kWh/day production At 70% self-consumption: 2.77 kWh/day At 11.6¢/kWh: $0.32/day, or $117/year
A $900 kit pays back in about 7.7 years. That is longer than most other enacted states. A Utah renter who plans to move in three years gets less value from plug-in solar than a Maine renter with the same setup. For Utah homeowners who will be in place for a decade and who value energy independence, the economics are still positive.
One Utah-specific consideration: Rocky Mountain Power (Berkshire Hathaway Energy subsidiary) offers TOU rates to residential customers. Peak hours run roughly $0.18–$0.22/kWh in summer afternoons, versus off-peak at $0.09/kWh. A plug-in system producing during peak hours effectively offsets more expensive power, improving the economics by 20–40% for customers who have enrolled in TOU rates.
Utah’s role in the national rollout
By the time Maine became the second state in April 2026, eleven months had passed since Utah’s law took effect. Manufacturers and distributors had been watching Utah to see if consumers would actually buy systems and whether utilities would create problems for customers who installed them.
The Utah experience showed two things: consumer interest was real, and utilities, while not enthusiastic, were not actively penalizing customers who installed qualifying systems. That evidence gave other state legislatures the data points they needed to move forward.
The pattern accelerated in spring 2026. In a six-week period from April 6 to May 20, four states signed plug-in solar laws. By June, seven states were enacted. The Utah model went from a single-state experiment to the foundation of a national legislative framework in about 14 months.
The plug-in solar readiness checker includes the current status of all enacted states, including Utah’s rules since May 2025.
Check your Utah home or apartment's readiness for plug-in solar, including the UL certification requirements under HB 340.
Check your Utah readiness →Related: Solar Panels for Renters: A 2026 State Guide | Plug-In Solar Panels: Are They Worth It?
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.