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What Size Plug-In Solar Kit Do I Need?
Enter your monthly electricity use from your bill. We compare common kit sizes so you can see which gives the best value for your home and stays within your state's limit.
Compare kit sizes
| Kit | Makes per year | Share of your use | Saves per year | Within state limit? |
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How to choose the right size
Bigger isn't always better. A plug-in kit only saves money on power your home uses at the same moment the panels produce it. Your always-on load — fridge, freezer, router, standby devices — is often 100–300 W, and more when air conditioning or cooking is running. If the kit regularly produces more than that, the extra goes to the grid, usually unpaid.
- 400 W — one panel. Lowest cost, nearly all of its output is used at home. Good for small apartments and tight balconies.
- 800 W — the sweet spot for many homes: enough to cover daytime base load in most households.
- 1,200 W — the maximum in most states. Best if someone is home during the day or you run AC, laundry or EV charging while the sun shines.
The "Is someone home" setting changes how much of the output we assume you use yourself (65%, 80% or 90%). These are rough estimates — a smart plug or your utility's hourly usage data will show your real daytime use.
Frequently asked questions
Is 800 watts of plug-in solar enough?
For many homes, yes. An 800 W kit covers a typical daytime base load and sends little power to the grid unpaid. If someone is home during the day or you run AC at midday, 1,200 W may pay off better, where your state allows it.
How many panels are in a plug-in solar kit?
Usually one to three panels of about 400 W each, connected to a micro-inverter that plugs into an outlet. Check that the kit's total inverter output fits your state's limit.
Can plug-in solar cover my whole bill?
Rarely. A 1,200 W kit typically covers roughly 5–20% of an average US home's use, depending on sun, placement and how much you use during the day. It's best thought of as trimming your bill, not replacing it.
Last updated October 6, 2026.