The honest position
If you own your home, intend to stay several years, and have a roof that faces roughly the right way without heavy shade, rooftop solar is the better investment. It produces far more, and it usually qualifies for incentives a plug-in kit does not.
Plug-in solar wins when any of those conditions fail — and for a very large number of people, at least one does.
| Plug-in | Rooftop | |
|---|---|---|
| Upfront cost | $285–2,500 | $15,000–30,000 |
| Annual output | Modest | Substantial |
| Available to renters | Yes | No |
| Portable | Yes | No |
| Tax credits | Usually not | Usually yes |
| Adds home value | No | Often |
| Commitment | Reversible | 20+ years |
Choose rooftop if
- You own the property and expect to be there five years or more.
- Your roof is unshaded and reasonably oriented.
- You can use the tax credit.
- Your bills are large enough for the payback to work.
Choose plug-in if
- You rent, or live in an apartment.
- You might move within a few years.
- Your roof is shaded, north-facing or unsuitable.
- You want to try solar without a five-figure commitment.
They are not mutually exclusive. A plug-in kit now does not prevent a rooftop system later — and living with one teaches you a great deal about your own consumption before you commit.
A note on who tells you what
Most large solar websites earn their money by selling your details to installers. That gives them a straightforward reason to steer you toward a rooftop quote, whatever your circumstances. Worth remembering when you read a page arguing plug-in solar is not worth considering.