Balcony solar, explained
Balcony solar is a small solar kit, usually one or two panels and a little inverter, that you hang on a railing, wall or patio and plug into an ordinary outlet. The power goes straight into your home’s wiring. Whatever is switched on uses it first. You never switch anything over: the grid fills in the rest, second by second.
Updated October 2026
What’s in the box
- Solar panels. One or two, often 400 to 500 W each. They turn sunlight into electricity.
- A microinverter. A small box behind the panel. It turns the panel’s power into the same kind your outlets use, and keeps it in step with the grid.
- A cable with a plug. It goes into a standard 120-volt outlet.
- Mounts. Brackets for a railing or wall, or a stand that tilts the panel toward the sun.
Some kits add a battery or an app that shows what you’re making. Neither is required. How to choose a kit.
What happens when you plug it in
- Sunlight hits the panel and it starts making power.
- The microinverter checks that the grid is there. If it isn’t, it stays off.
- The power flows through the cable, into your outlet and into the wiring on that circuit.
- Whatever is running in your home uses the solar power first: the fridge, the router, a TV.
- If the panel makes more than your home is using at that moment, the extra flows out through your meter to the grid.
Think of it like water. Your home is a bucket with a small leak that never stops: the fridge, the router, everything on standby. The grid keeps the bucket topped up. A balcony panel is a second tap. When it runs, the grid has to pour in less. When the bucket is full, the extra spills out.
What it saves
For an 800 W kit hanging flat on a south-facing railing, with 250 W of always-on use at home:
| State | Makes per year | Saves per year | Paid back in ($700 kit) |
|---|---|---|---|
| California | 803 kWh | $207 | 3.4 years |
| New York | 669 kWh | $143 | 4.9 years |
| Connecticut | 694 kWh | $157 | 4.5 years |
| Maryland | 702 kWh | $118 | 5.9 years |
| Colorado | 838 kWh | $104 | 6.7 years |
| Virginia | 713 kWh | $93 | 7.6 years |
| Utah | 850 kWh | $83 | 8.4 years |
Your electricity price matters more than your sunshine. And not every kWh counts: about a quarter of what the panel makes is more than the home needs at that moment, and goes to the grid, often for nothing. Savings and payback in detail.
What it can’t do
- Run your whole home. It covers the background load: fridge, router, chargers, standby. Not the AC, the oven or the dryer.
- Keep the lights on in a blackout. It shuts off when the grid goes down. That’s a safety feature.
- Store power for the evening, unless the kit has a battery. When a battery pays.
Is it legal where you live?
Ten states have signed plug-in solar laws, starting with Utah in 2025. Six are in effect now; four more start in 2027. New York’s bill is waiting on the governor. Most laws allow up to 1,200 W and require a kit certified by UL or a similar lab. See the map.
One catch if you’re shopping now. The certification most laws point to, UL 3700, only started in 2026. The first certified parts arrived in July 2026, and complete certified kits are still rare. California expects compliant kits in stores by spring 2027. What to look for.
What it costs
Most kits sell for $600 to $1,500, depending on size, brand and whether there’s a battery. Full cost breakdown.
Common questions
Is balcony solar the same as plug-in solar?
Yes. Balcony solar is the popular name, because so many kits hang on apartment balconies. Plug-in solar is the wider term, and the one most laws use. More on plug-in solar.
Does it work in a blackout?
No. The microinverter switches off when the grid goes down, so no power can flow back onto the lines while crews are working on them. For backup power you need a battery system built for that.
Will my meter run backwards?
Sometimes, but don't count on it. Most plug-in laws say nothing about paying you for extra power, and many utilities pay nothing. That's why we count extra power as $0 unless you tell the calculator otherwise.
How big a kit am I allowed?
Most state laws cap plug-in solar at 1,200 W. Colorado allows up to 1,920 W. Many kits on sale are 800 W, a size borrowed from Europe.
How long does a kit last?
Solar panels usually come with long warranties and lose a little output each year. We assume 0.5% a year in our payback numbers. The microinverter is the part most likely to need replacing first.
Sources
- Solar.com, 2026 Guide to Balcony & Plug-In Solar (state law table, updated October 1, 2026).
- NRG Clean Power, What SB 868 changes for your power bill (UL 3700 and the Hoymiles HiFlow Pro).
- Solar.com, California Legalizes Plug-In Solar: Newsom Signs SB 868.
- Electricity prices: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A (March 2026 data).
- Production and savings: our calculation method.