Balcony solar vs. rooftop solar: what does each really cost?

A plug-in solar kit is a panel or two, a small inverter, and a cord. Hang it on a railing, plug it in, and it starts feeding your home.

Kits sold in the U.S. cost a few hundred dollars to a few thousand. A rooftop system costs tens of thousands. That makes the kit look like a bargain.

But a kit is also much smaller. So the fair test is what each costs per watt, and then what each costs per kilowatt-hour it actually makes.

Per watt, the kit wins

Watt for watt, kits are cheaper. You pay for the parts and shipping, with no installer, permit, or roof work.

Kit prices vary a lot. Bright Saver, a nonprofit, sells at cost to members who pay $29 a year. Craftstrom's 1,200 W kit runs $2,391. EcoFlow's 400 W kit listed at $799 but was sold out when we checked.

The fair test is what each costs per kilowatt-hour it actually makes.

Per kilowatt-hour, it's close

A rooftop panel is tilted toward the sun. A balcony panel usually hangs straight down, and loses a lot for it.

In Los Angeles, a panel on a south-facing railing makes about 60% of what the same panel makes tilted at 30°. See the numbers by city.

So spread each system's price over every kWh it makes in its lifetime:

Both are a fraction of what the grid charges. That's the real case for either.

The catch: power you don't use

A plug-in kit saves money only when something in your home uses its power at the moment it's made. The rest flows out through your meter.

No state plug-in law we read pays you for it. Utah, Virginia, Maine, and New Hampshire keep kits out of net metering outright.

A small kit is mostly used at home. A big one often isn't:

A bigger kit makes more power, but on a sunny afternoon your fridge, router, and TV can only use so much of it. Bright Saver's kits stop at 360 W for a different reason, what an ordinary outlet circuit can safely take, but it means almost all of their power gets used at home.

How long until it pays for itself

Our estimate for Los Angeles, panels on a south-facing railing, at California's average rate of 34¢ per kWh:

• 360 W kit, member price: about 3 to 4 years. It saves about $116–$129 a year.
• 360 W kit, list price: about 5 to 6 years.
• 1,200 W kit: about 9 to 14 years. At the U.S. average rate, 16 to 26 years.

The range depends on how much your home runs in the daytime. Lower rates, more shade, or a panel facing east or west all stretch it out.

Work out yours: the balcony solar predictor uses your ZIP, your balcony's direction, and your own electric plan.

What changed for rooftop solar

Rooftop solar lost its biggest discount this year. The 30% federal credit for homeowners ended for systems installed after December 31, 2025.

A rooftop system also needs a permit, an inspection, and your utility's permission to operate. A qualifying plug-in kit, in a state that has passed a plug-in law, needs no permission to operate, and often no permit. Check your state.

And rooftop solar under net metering gets credit for what it sends to the grid. A plug-in kit doesn't.

The bottom line

A small kit that your home uses all of is as cheap as rooftop solar. A big kit only pays if someone is using power while the sun is out.