How to install plug-in solar
There's no wiring here beyond plugging a cord into an outlet you already have. What actually varies is where the panel goes, which outlet qualifies, and what certification the law in your state asks the device to carry. This page covers those three things and nothing past them; for the actual legal electrician's work, see an electrician.
What is in the kit
A plug-in system is one or two panels, rated anywhere from about 200 Wp to 1,600 Wp combined, a microinverter that converts the panel's DC output to grid-synchronized AC, mounting hardware for a railing or fence, and a cord that terminates in a standard plug. Some kits now ship with a matched plug-in battery; see theplug-in batteries page for what that adds.
Where it goes
Railing, fence, and ground mounts are all common; a south-facing wall or rail outperforms west, and west outperforms a flat mount against the rail itself. The existing guide on plug-in solar and load shifting makes the point directly: the same 800 W kit puts out far more under a clear southern sky, tilted toward the sun, than strapped flat against a balcony rail under the same sky. Angle is free; it just has to be chosen before the panel goes up, because most mounting hardware isn't built to be re-angled seasonally.
The outlet
Every law in this guide describes the connection as a cord into a standard outlet, typically a 120 V receptacle, not a hard-wired circuit. The conservative rule, and the one most installation guides recommend regardless of what the law requires, is one device per circuit: don't share the outlet with another plug-in system or put it on an extension cord or power strip.
Every law also requires the device to stop energizing the circuit during a grid outage, the outage-isolation feature, so the cord is never live when the grid it's plugged into isn't. That's a function of the inverter and its certification, not something you configure. The underlying wiring standard for any interconnected generating source, rooftop or plug-in, is NEC Article 705; a certified plug-in inverter is built to meet it, which is one reason this page doesn't walk through wiring beyond the cord and the outlet.
What certification to look for
UL 3700 is the standard written specifically for a cord-connected inverter that backfeeds a branch circuit: overcurrent protection, touch safety, and ground-fault detection. "NRTL listed" means the testing was done by a Nationally Recognized Testing Laboratory, UL itself, Intertek, CSA, and a few others accredited by OSHA for this purpose, not by the manufacturer.
As of August 2026, no complete system, panel plus inverter plus mount, had been certified as a unit. Certification exists at the component level: the first microinverter certified to UL 3700, a Hoymiles model, was announced in July 2026. Check the inverter's own listing, not a marketing claim about the kit as a whole.
State thresholds that change the job
Beyond the basic outlet-and-certification pattern, a handful of states set a threshold that changes what you have to do:
- Maine lets you self-install up to 420 W with no utility notification; from 420 W to its 1,200 W cap, a licensed electrician and a notification to the utility within 30 days are required, with no approval needed.
- Vermont requires a smart meter on the account before the device qualifies for its exemption.
- Colorado caps a single device at 1,920 W and allows one device per address; a second kit doesn't stack under the same exemption.
- Connecticut allows one device per meter, the same one-per-address logic as Colorado, at its 1,200 W cap.
- Maryland and New Jersey exempt the smallest systems, 391 W and under in Maryland, 400 W and under in New Jersey, from the certification requirement entirely, while still capping the exemption-free tier at 1,200 W.
See the full state table for every cap, date, and source.
Landlords and HOAs
Virginia bars a landlord of more than four units from an outright ban, though it may still set reasonable rules on size and placement. New Jersey bars a landlord from prohibiting a tenant who pays their own electric bill, including on a leased balcony or patio. Colorado voids any HOA covenant or rule that unreasonably restricts installation, and Vermont does the same for HOA rules and deed restrictions. California's law has no landlord or HOA provision at all, so a lease or covenant there is governed by whatever it already says.
After it is in
Once the panel is plugged in, connect a production sensor if your inverter or plug reports one. Hungry Machines forecasts a registered panel's output from the weather immediately; a sensor sharpens that forecast into a fit on your array's real yield after a few days, and a shading profile after about ten. Seeplug-in solar and load shifting for how that forecast discounts the rest of your home's schedule.
Frequently asked questions
Do I need an electrician to install plug-in solar?
Usually not, that's the point of the device: the cord goes into an outlet you already have. Maine is the one exception in this guide, it requires a licensed electrician for anything above 420 W, up to its 1,200 W cap, with no requirement below that line. Every other state law here treats the plug itself as the connection and asks only that the device be NEC-compliant and NRTL-certified. If your building's wiring is old, or the outlet you want to use is shared or on an extension cord, that's a reason to have an electrician look at the circuit anyway, not because the law requires it.
Can I run a plug-in panel through an extension cord?
No. Every state law in this guide that addresses the connection at all describes a cord plugged directly into a fixed, standard outlet, not an extension cord or a power strip. An extension cord adds a connection point the outage-isolation feature wasn't tested against and a length of cable rated for a lamp, not for continuous outdoor current. Mount the panel where the cord reaches an outlet on its own, or have an electrician add one.
How do I know a product is actually certified?
Look for the specific component, inverter or microinverter, listed by a Nationally Recognized Testing Laboratory (NRTL) such as UL, Intertek, or CSA, under UL 3700 for the plug-in PV standard. As of August 2026 no complete kit, panel plus inverter plus mounting, had been certified as a system; certification exists at the component level, starting with a Hoymiles microinverter in July 2026. A listing for "the panel" alone doesn't cover the inverter, and a listing for the inverter alone doesn't cover the panel. Ask the seller which specific part carries which certification, and check the date, this list is moving fast.
My state has no plug-in solar law. Can I still install one?
You can, but you're in ordinary interconnection territory: your utility's standard process for a grid-connected generating device applies to an 800 W kit the same way it would to a rooftop system, which usually means an application, possibly a fee, and a wait for approval before you turn it on. See the laws-by-state page for which ten states have replaced that process with a simpler plug-in rule, and ask your utility directly if yours hasn't.
About Hungry Machines
Outsmart your electric bill - Hungry Machines Energy provides an energy management system that shifts HVAC, EV charging, home batteries, and other electric loads to cheaper hours for homes and buildings with solar power or variable electricity rates.