The Solar Panel You Plug Into a Wall Outlet, and Its 1,200-Watt Ceiling

A contractor-installed rooftop solar system costs $2.60 per watt in the United States. A plug-in kit that hangs on a railing and ends in a 15-foot cord costs about $1.99 per watt, arrives in a box, and in one state needs no permit, no utility approval, and no electrician. The ceiling is what nobody advertises: Utah law caps these systems at 1,200 watts, and at the US average electricity rate, 1,200 watts of solar is worth about $258 a year.

The Machine

A plug-in solar system is three parts. Panels, a grid-tied microinverter that converts DC to 120V AC and synchronizes with your house wiring, and a cord that ends in a standard three-prong plug. You hang the panels, plug the cord into an outlet, and the inverter pushes power onto the circuit. Whatever your appliances do not use flows back through the panel.

The one you can buy today is Craftstrom’s 800 Watt Eco-Line at $1,593.75, from a company based in Houston, Texas. The box holds four 200W Shield Series panels (59 × 28 × 1.5 in., 24.7 lbs each, 22% cell efficiency), two Hedy inverters rated 350W each at 120V, a Smart PowerMeter, and cables. Certification is ETL to UL 1741 and IEEE 1547 — the anti-islanding standard that makes the inverter shut down when the grid does. Ten-year warranty on panels and inverter. It ships in three to four weeks. Mounting hardware is not included.

The Numbers

The benchmark is the thing this replaces at the low end: a contractor-installed rooftop array. EnergySage’s marketplace data, updated August 7, 2026, puts the US average at $2.60 per watt before incentives — an average 12 kW system at $31,135.

The assumptions, in the open. Electricity is the EIA’s 2026 US residential average, 18.41 cents per kWh. Production is Solar.com’s published range for an 800W system in sunny areas, which is a favorable case — a north-facing railing in Ohio is not in that range. Payback divides sticker price by annual savings and ignores incentives and degradation. We did not model the rooftop system’s output: a 12 kW average tells you nothing about a specific roof. DATA NOT AVAILABLE FROM SOURCE.

The interesting number is not price per watt. It is that a 12 kW roof covers a whole house and 800 watts cannot cover a refrigerator’s annual draw.

What Breaks

The legal ceiling is the product. Utah H.B. 340, effective May 7, 2025, defines a plug-in system as “a moveable photovoltaic generation device that has a maximum power output of not more than 1,200 watts” connected “through a standard 120-volt alternating current outlet.” In exchange, an electrical corporation “may not require a customer” to obtain approval, pay fees, or install additional controls. Utah was first, unanimously, and the National Caucus of Environmental Legislators counts at least 31 states weighing bills in 2026, with Virginia’s S.B. 250 already through its legislature. Everywhere without a statute, you are relying on your utility not to read your meter data closely.

Most of the market is out of stock. EcoFlow’s STREAM Microinverter — $369, 1,200W nominal, UL 1741, NEMA 6, 11 lbs — is sold out, and its plug-in installation is permitted in Utah only. The STREAM Ultra battery unit at $1,279 is sold out. US Solar Supplier’s 810W kit at $969 is sold out. The nonprofit Bright Saver sells the cheapest hardware in the country — a 360W kit at $414.17 with a $29 annual membership, $1.23 per watt all-in — but it is a pre-order expected to ship in mid-October, and it does not ship to Alaska, Hawaii, Maine, New York, or Vermont.

Vendor savings claims are rate-dependent, and the rate they assume is not yours. Bright Saver states its 360W kit “generates up to $240/yr.” Its own 180W kit is rated at “up to 270 kWh per year,” so 360W is 540 kWh — and $240 divided by 540 kWh is 44 cents per kilowatt-hour. That is a California bill. At the 18.41-cent national average, the same 540 kWh saves $99 a year, and payback on the kit plus membership stretches from under two years to about four and a half. Our math, from their two published numbers.

It is not backup power. IEEE 1547 anti-islanding means the inverter disconnects the instant the grid goes down, for the safety of the lineworker on the pole. Rocky Mountain Power told Grist in April it is concerned “some products entering the market may not meet the requirements of the bill, potentially creating electrical hazards for utility workers.” When the lights go out, a plug-in array produces nothing.

The circuit is the other cap. Bright Saver limits its kits to 360 watts because a 15-amp branch circuit only tolerates so much back-feed under the National Electrical Code — 3 amps at 120V, per pv magazine USA. Craftstrom’s 800W kit puts roughly 6.7 amps onto whatever outlet you choose. That outlet’s other loads are your problem, and Craftstrom does not ship the mount that holds 99 lbs of panel to a railing.

Who Should Buy This

The renter with a sunny balcony and an expensive utility, first. If you pay California-grade rates, 540 kWh a year is $240 off the bill, the hardware pays for itself in roughly two years, and unlike a roof array it comes with you when the lease ends. Assumptions: south-facing exposure, a landlord who does not object, and a state that has not made this an argument.

The homeowner who wants solar and cannot finance $31,135, second. Eight hundred watts is not a solar system; it is a down payment on the habit. At $184 to $258 a year it will not change your life, but you can buy it on a Saturday, install it by Sunday, and unbolt it when you move.

Not for: anyone who needs power during an outage — this is the wrong machine, categorically. Not for households in cheap-power states, where the ceiling caps annual savings near $100 and payback runs past a decade. Not for anyone who wants to offset a whole house; the law will not let a plug-in system get there. And not for renters in states with no statute, where the honest answer about legality is that nobody has tested it yet.

The Stack

No affiliate links in this issue — our affiliate program applications are still in progress. When a link earns us a commission, we will always say so. Verdicts are never for sale.

If you want plug-in solar working this quarter, Craftstrom’s 800W Eco-Line at $1,593.75 is the one with an active add-to-cart button and a three-to-four week lead time. Budget separately for a mounting system it does not include.

If you want the cheapest watts and can wait, Bright Saver’s 360W kit at $414.17 plus a $29 membership is $1.23 per watt — the lowest price per watt we found anywhere in the US market. It ships in mid-October, and not to five states.

If you live in Utah and want the 1,200W legal maximum in one device, the EcoFlow STREAM Microinverter at $369 is the part to watch. It is sold out today. Bring your own panels.

We earn nothing if you buy any of these. That is how you know the numbers above are straight.

Produced under the editorial standards of editor Nicolás Galindez. Spotted an error? nicolas@readwildtech.com — the editor reads every reply.