Plug-in solar for apartments: how to choose a kit in the US

We don’t rank plug-in kits, because we haven’t tested them, and in late 2026 the US market is still sorting out which products are fully certified. What we can do is walk you through the five checks that decide whether a kit is a good buy for your apartment, then show you what’s on sale and how the certification picture looks.

Step 1: check your state’s law

This comes first because it decides everything else. By November 2026, plug-in solar laws were in force in Utah, Maine, Vermont, Maryland and Connecticut. Colorado, Virginia, New Hampshire and California start on 1 January 2027, and New Jersey on 1 March 2027. Our US rules guide has the details for each state.

If your state isn’t on the list, plugging a kit into your wiring generally needs your utility’s approval. Don’t buy on the assumption that it’ll be fine.

The law also sets the size you can buy. Most states cap kits at 1,200 W. Maine is stricter: kits up to 420 W can simply be plugged in, while bigger ones need an electrician and a dedicated outlet.

Step 2: check the certification

UL 3700 is the first US safety standard written for plug-in solar. It was published at the end of 2025, and several state laws now require it or an equivalent listing. Before it existed, the best you could look for was a microinverter certified to UL 1741, the standard for rooftop solar inverters.

Two things to watch:

• Component or system? Some listings cover only the microinverter, not the panels, cables and mounts as a system. Several states and reviewers draw that line, and some sellers have paused sales in states that want the whole system certified.
• Claims in ads. “UL compliant” or “meets UL standards” isn’t the same as being listed. Look up the model in UL’s Product iQ database or ask the seller for the certificate number.

Step 3: pick the right size

Kits are sold by panel watts, but what matters for the law and for your wiring is the microinverter’s AC output. A kit with 1,600 W of panels behind a 1,200 W inverter is a 1,200 W kit.

Bigger isn’t automatically better in an apartment. You save money on solar power you use at the moment it’s made, and apartments often have a small daytime load: a fridge, a router and a few things on standby, maybe 150 to 250 W, more when the air conditioning runs. Anything above that flows back to the grid, usually for little or nothing.

Power from the kit enters your wiring at the outlet, so the circuit it’s on carries the kit’s current on top of whatever comes from the panel box. That’s the reason for the size limits, and why bigger kits are better on an outlet with little else plugged into the same circuit.

Step 4: work out where the panels go

Orientation matters more than anything you can buy:

• South-facing is best, east or west loses some output but works, and north-facing balconies are rarely worth it.
• Shade from the floor above, a neighboring building or a tree can cut output sharply, even if it only covers part of a panel.
• Panels hung on a railing sit nearly vertical, which typically gives less over a year than a tilted panel. Some mounts let you angle them out.

Check the weight and wind rating of the mount, keep everything inside your balcony, and route the cable so a sliding door can’t crush it. Our guide to mounting balcony solar panels shows how much each angle costs in output. Then put your address, panel direction and tilt into PVWatts. It’s free, it comes from a US Department of Energy lab, and it gives you a realistic yearly figure.

Step 5: get your landlord or HOA on board

Most state laws don’t override your lease. Colorado and New Jersey are exceptions so far, and even there, landlords and associations can still set reasonable conditions. Everywhere else, ask in writing before you attach anything. A short note helps: what the kit is, how it mounts (no drilling, if that’s true), that it’s certified, and that you’ll remove it when you leave.

Kits on sale in 2026

These are some of the names you’ll see. We haven’t tested them, and the certification status below comes from manufacturer statements and trackers as of September 2026, so check UL’s database before you buy.

Prices for complete kits from established brands ran from about $870 to $1,280 in mid-2026, according to one tracker, with a few smaller or less established kits listed around $700. Expect prices to fall as more products get certified.

What a kit will save in an apartment

Here’s a rough example. Take a balcony in a state with 4 peak sun hours a day and electricity at 18 cents per kWh, and assume the near-vertical railing mount costs about a quarter of the yearly output.

• 400 W kit: about 370 kWh a year. Most of it gets used in the home, say 85%, which saves around $57 a year.
• 1,200 W kit: about 1,120 kWh a year. A small apartment uses maybe half of that as it’s made, so around $100 a year.

At 30 cents per kWh, closer to what households pay in California and parts of New England, those figures rise to about $95 and $170. So a plug-in kit can pay for itself, but slowly in states with cheap power, and a smaller kit that matches your daytime load often gives the better return per dollar. Our guide to whether plug-in solar is worth it has more scenarios.

If your main goal is keeping the fridge and Wi-Fi running in an outage rather than trimming the bill, a plug-in kit won’t help: it switches off when the grid does. A portable power station is the better tool for that. See how long a power station runs a fridge.