800 W vs 1,200 W: what's allowed where
Britain caps plug-in solar at 800 W; most US laws allow 1,200 W, and Colorado 1,920 W. But each law measures the limit a little differently, and some have a lower tier with fewer rules.
Last checked: · each row links to the state page and its sources
| Where | Limit | What the law measures | Lower tier |
|---|---|---|---|
| Great Britain | 800 W | Maximum rated AC output (800 VA in the product specification); one device per household | none |
| Colorado | 1,920 W | Maximum power output to the grid; one system per address | ≤ 391 W: exempt from PV installation rules and rewiring-type code provisions |
| Utah | 1,200 W | Maximum power output; standard 120 V outlet | none |
| Maine | 1,200 W | Combined inverter output (AC) per service address | ≤ 420 W: no electrician or utility notice needed |
| Virginia | 1,200 W | Maximum power output per customer (per unit in multi-family housing) | ≤ 391 W to the outlet: exempt from listing provisions requiring alterations |
| Maryland | 1,200 W* | Output back to the building's electric system; one per meter | ≤ 391 W: same exemption as Virginia |
| Connecticut | 1,200 W | Maximum power output; 120 V outlet; one per meter | none |
| New Hampshire | 1,200 W | Maximum inverter output, AC; one per metered customer | none |
| Vermont | 1,200 W | Combined inverter capacity per meter | none found |
| New Jersey | 1,200 W | "Devices of up to 1,200 watts" (Governor's release) | Reported 400 W tier (unverified) |
| California | 1,200 W | Total AC output per dwelling (reported) | not reported |
| New York (bill) | 1,200 W | Aggregate continuous AC inverter nameplate output to the grid | none |
* Maryland's chapter law prints the section twice, once with 1,200 W and once with 391 W; the Public Service Commission describes 1,200 W. Details on the Maryland page.
Official texts: UT · ME · VA · MD · CO · CT · NH · VT · NJ · CA · NY · UK (read 2026-11-03)
What the numbers mean for you
- The limit is on output, not panels. Most laws count what the inverter puts into your wiring (AC). Several don't mention panel wattage at all, so ask the maker how its kit stays under your state's limit.
- Bigger is not always better. A balcony railing kit faces one way and often stands upright. In our calculator, 800 W of upright, south-facing panels makes about 360 to 940 kWh a year depending on the state, before any is wasted.
- One kit per home. Most limits are per meter, address, customer or household, so two "800 W" kits can break a 1,200 W limit.
Common questions
Can I add a battery to a plug-in solar kit?
It depends on where you live. Maine's law covers plug-in battery systems with export capacity of 1,200 W or less. Britain's rules exclude plug-in batteries. The other laws we read talk only about solar devices, so a battery may fall under ordinary rules; check with your utility.
Why do several states use 391 W?
Virginia, Maryland and Colorado give devices at or below 391 W an exemption from listing or code provisions that would require rewiring. The laws state the number but not the reason, so we don't guess.