Glossary · Kits and equipment

What Is Plug-In Solar (PIPV)? Balcony Solar and Plug-In PV Explained

Plug-in solarAlso called balcony solar or plug-in PV (PIPV)

A small solar system, one to a few panels and a microinverter, that connects to your home through a plug instead of being wired in by an installer.

  1. PanelsOn a railing, a stand or a low roof.DC
  2. MicroinverterTurns the panels' DC into the AC your home uses.AC
  3. Plug and receptacleFeeds a branch circuit, not the breaker panel directly.
  4. Your appliancesFridge, router, TV: they use the solar power first.
  5. Meter and gridYou buy that much less from your utility.
A plug-in system from panel to grid. The power is used by whatever is running in your home first; the grid makes up the rest.

At a glance

Parts
Panels, a microinverter, a cord to a 120 V receptacle; some add a battery
First US law
Utah, in 2025; California followed in 2026
California
Up to 1,200 W AC per home from January 1, 2027, if certified (SB 868)
Safety standard
UL 3700, certification open since January 2026

Plug-in solar is rooftop solar’s small, portable cousin. A kit is usually one to a few panels on a stand or a railing mount, a microinverter that turns their direct current into household alternating current, and a cord that connects to a receptacle, as the California Assembly’s analysis of SB 868 describes it. Some kits add a battery.

What does PIPV mean?

PIPV stands for plug-in photovoltaic, the industry’s name for the same thing. UL Solutions uses it in its white paper on plug-in systems, and it’s in the title of UL 3700, the Outline of Investigation for Interactive Plug-In PV (PIPV) Equipment and Systems. State laws use their own names, such as “portable solar generation device” or “plug-in photovoltaic device”; our plug-in solar laws by state covers what each law allows.

How is it different from rooftop solar?

Rooftop systems are several kilowatts, wired into your electrical panel by a licensed installer and connected under an interconnection agreement with your utility. A plug-in system is a fraction of that size, you set it up yourself, and it moves with you. Where a state has passed a plug-in solar law, it can connect without utility approval or fees, within a cap: 1,200 W AC per home in California from January 1, 2027 (SB 868).

Why “balcony solar”?

The name comes from Europe, especially Germany, where people in apartments hang panels on their balcony railings. In the US the same kit works in a backyard, on a patio or on a shed roof, which is why we say plug-in solar.

Is it safe?

That’s what certification is for. Home wiring was designed for power flowing one way, and UL Solutions’ white paper lists the risks of feeding power back through a receptacle: overloads the breaker can’t see, live plug blades and ground-fault protection that assumes one-way current. UL’s answer is a certification program for whole plug-in systems, opened in January 2026. Our guide to what plug-in solar is covers the rest, and the calculator shows what it would save where you live.

Updated by the Plugged Sun editorial team

Sources

  1. SB 868 (Wiener), as amended April 7, 2026: bill analysis (Official document, California Assembly Committee on Utilities and Energy, 2026)
  2. SB 868: Electricity: portable solar generation devices (status, chaptered text and digest) (Source, CalMatters Digital Democracy, 2026)
  3. Plug-In Photovoltaic (PIPV) Systems: Safety Considerations for Residential Use (Source, UL Solutions, 2025)
  4. UL Solutions Debuts Testing and Certification Framework for Safer Plug-In Solar Across the United States (Source, UL Solutions, 2026)
  5. UL 3700, Outline of Investigation for Interactive Plug-In PV (PIPV) Equipment and Systems, Edition 2 (Source, UL Standards & Engagement, 2026)

Where Plug-in solar comes up