Definition
Plug-in solar — also called balcony solar — is a small solar system that connects to your home through an ordinary outlet rather than being wired into your electrical panel. No roof, no installer, no permit in a growing number of places.
How it differs from rooftop solar
| Plug-in solar | Rooftop solar | |
|---|---|---|
| Typical cost | $285–2,500 | $15,000–30,000 |
| Installer needed | No | Yes |
| Need to own the property | No | Yes |
| Takes it with you | Yes | No |
| Output | Offsets background load | Can cover a whole home |
| Tax credits | Usually not eligible | Usually eligible |
Who it is actually for
- Renters — the only form of solar available to you, and it moves house with you.
- Apartment dwellers — a balcony railing is all the mounting surface required.
- Anyone testing the water — a few hundred dollars to find out whether solar suits you, rather than fifteen thousand.
- Shaded or awkward roofs — where a full system does not pencil out.
Who it is not for. If you own a suitable roof and intend to stay, a full system produces far more and usually qualifies for incentives a plug-in kit does not. See plug-in vs rooftop.
Why it is suddenly everywhere
Two things happened at once. Panel and microinverter prices fell far enough to make small systems sensible, and the regulatory position started opening up — Utah first, with other states moving. Europe got there years earlier; the US market is catching up fast.