Plug-In Solar Panels Explained: How Balcony Solar Works, Where It's Legal and Is It Safe

Plug in solar panels are small solar kits, usually one to four panels with microinverters, that connect to a standard 120-volt wall outlet and push electricity into your home's circuits, so you buy a little less power from the utility while the sun is up. In the U.S. they are new: Utah's 2025 law allows devices up to 1,200 watts without a utility interconnection agreement, and several more states passed similar laws in 2026. They will not power your home in an outage and they are much smaller than rooftop solar, but they suit renters and apartment owners who cannot install a full system.

Key takeaways

• Utah's H.B. 340 caps plug-in devices at 1,200 W, requires a standard 120 V outlet and certification by a recognized lab, and exempts them from interconnection and net metering rules.
• NCCETC reported seven more states enacted plug-in solar laws in Q2 2026, and lawmakers in three more states enabled it in Q3 2026.
• UL 3700, the safety standard for plug-in solar, was published in December 2025; the first U.S. microinverter certified to it was announced in July 2026.
• A 1,200 W kit at 120 V puts up to 10 amps onto a branch circuit, which is why circuit choice and certification matter.
• Savings come only from power you use while the panels produce; in Utah, exports are not covered by net metering.

How plug in solar panels work

A plug-in kit has three parts: solar panels, a microinverter that turns the panels' DC power into 120 V AC, and a cord that plugs into an outlet. When the panels produce, the microinverter syncs with your home's power and feeds electricity into that circuit. Your fridge, router or TV uses that solar power first, and the utility supplies only the rest.

Unlike a portable power station, a typical plug-in kit has no battery. It does not store energy for the evening, and it shuts off when the grid goes down. Utah's law requires devices to include a feature that prevents the system from energizing the building during a power outage, which protects utility workers and anyone touching the plug.

That makes plug-in solar a bill-trimming tool, not a backup tool. If backup is your goal, see our guide to solar generators.

Where plug-in solar is legal in 2026

Utah was first. According to Utah Clean Energy, H.B. 340, "Solar Power Amendments," passed the legislature unanimously in 2025. It defines a "portable solar generation device" as one that:

• Has a maximum power output of 1,200 watts
• Connects through a standard 120-volt AC outlet
• Is used for the customer's own consumption
• Meets the National Electrical Code
• Is certified by Underwriters Laboratories or an equivalent lab

These devices are exempt from utility interconnection requirements and from net metering program requirements, and the utility is not liable for damage or injury caused by the equipment.

Other states followed. The NC Clean Energy Technology Center's 50 States of Solar report counted 37 plug-in solar actions in 25 states in Q2 2026, and seven states enacted legislation that quarter: Colorado, Connecticut, Maine, Maryland, New Hampshire, Vermont and Virginia. New Jersey and New York had passed bills awaiting the governor's action at that time, and NCCETC reported in October 2026 that lawmakers enabled plug-in solar in three additional states during Q3. Rules differ by state, so read your own state's law and your utility's guidance before you buy. Our Utah solar page covers the first state to allow it.

Sizing math: what plug in solar panels can produce

Plug-in kits are small by design, so it helps to do the math before buying.

Current on the circuit

Amps equal watts divided by volts. A kit at Utah's 1,200 W maximum on a 120 V outlet delivers up to 1,200 / 120 = 10 amps. Try other sizes with our watts to amps calculator.

Energy per day

Daily energy is roughly panel watts times peak sun hours. As an illustration only, a 1,200 W kit getting 4 peak sun hours would make about 4.8 kWh on a clear day before losses; a balcony that faces east or west, or sits in partial shade, will get less. For a location-specific estimate, use the PVWatts calculator from the National Laboratory of the Rockies at pvwatts.nlr.gov.

How much you actually save

You save only on the solar power your home uses at the moment it is produced. If the kit makes 600 W while your home is using 300 W, the extra 300 W flows out to the grid. In Utah those exports are outside net metering, so do not count on credit for them. Check your home's daytime baseline with our kWh calculator: a fridge, freezer, router and other always-on devices are the loads a plug-in kit offsets best.

Plug-in solar vs rooftop solar vs a power station

Feature	Plug-in solar kit	Rooftop solar	Portable power station with panel
Typical size	Up to 1,200 W under Utah's law	Several kilowatts	A few hundred watts of panels
How it connects	Standard 120 V outlet	Hard-wired, utility interconnection	Not connected to home wiring
Utility approval	Not required in Utah	Required	Not required
Works in an outage	No; must not energize the building	Only with a battery and backup setup	Yes, for devices plugged into it
Export credit	Not under Utah's net metering rules	Per your utility's tariff	None
Who it suits	Renters, condos, small budgets	Homeowners seeking large savings	Backup and camping

Is plug-in solar safe? What UL 3700 covers

Safety is the main debate. In a letter to Vermont lawmakers, UL Solutions listed overcurrent conditions, GFCI incompatibility and touch safety among the hazards, and warned that plug-in equipment can circumvent or degrade protective features required by the electrical code.

Here is a simplified way to picture the overcurrent concern. A household branch circuit has a breaker that trips when the current drawn through it gets too high. Power fed in by a solar kit at the outlet can supply loads on that same circuit without passing through the breaker, so the wiring could carry more current than the breaker sees. That is why standards focus on overload protection and installation practices.

UL 3700, the Outline of Investigation for Interactive Plug-In Photovoltaic Equipment and Systems, was published in December 2025. UL Solutions launched a testing and certification program based on it on January 8, 2026, saying the criteria cover construction, performance and labeling, and include features to protect against overloads, prevent current flowing in the wrong direction and reduce accidental contact with live parts. In July 2026, Hoymiles announced its HiFlow Pro, described as the first U.S. microinverter certified to UL 3700; it is rated 360 W, and up to four units can run together for 1,200 W.

Practical safety tips:

1. Buy only a kit certified to the standard your state requires; in its letter to Vermont lawmakers, UL Solutions urged policymakers to require UL 3700 certification.
2. Follow the manufacturer's instructions on which outlet and circuit to use. Avoid extension cords and power strips unless the instructions allow them.
3. Do not exceed your state's wattage limit or connect more than one kit to a circuit unless the manufacturer allows it.
4. Secure panels against wind, especially on balconies and railings, and check building or HOA rules.
5. Have a licensed electrician check older wiring and the circuit you plan to use before plugging anything in.

Is plug-in solar worth it?

Plug-in solar makes the most sense when you cannot put panels on a roof, when your home has steady daytime use for the kit to offset, and when your state's law clearly allows it. It makes less sense if your daytime use is low, your balcony is shaded, or your state has not yet authorized it.

Compare the kit price against the value of the kWh it will actually displace at your rate, and remember there is no federal residential clean energy credit to help: the IRS says it is not allowed for expenditures made after December 31, 2025. Our cost to run pages can help you see which always-on appliances a kit could cover.

Next steps

Check whether your state has authorized plug-in solar, add up your daytime baseline use with the kWh calculator, and compare the result with a kit's expected output from PVWatts before you buy. If you own your home and want larger savings, a rooftop quote may be worth comparing too.