Plug-In Solar Glossary: What you Need to Know

6 de octubre de 2026

Here we break down some of the terms related to plug-in solar.

Term	Definition
AC (alternating current)	The type of electricity that comes out of your wall outlets.
AC output	How much power the inverter sends into your home's wiring, measured in watts. State caps like 1,200 W usually refer to this number, not to the panels' rating.
Anti-islanding	A safety feature that makes a solar system stop sending power when the grid goes down, so utility workers are not exposed to live lines.
Balcony Solar	Another term for plug-in solar, usually referring to small solar systems mounted on a balcony railing that connects to your home through an outlet.
Bidirectional meter	An electric meter that can measure power flowing both into and out of your home.
Branch circuit	The wiring from your breaker panel to a group of outlets or lights.
Circuit breaker	A switch in your panel that can flip off to protect your home if there is too much current in the circuit's wiring.
Dedicated circuit	A circuit with one breaker that serves one outlet and nothing else. See Dedicated circuit explained.
DC (direct current)	The type of electricity solar panels make. The inverter converts it to AC power that you can use in your home.
Export / Backfeed	Power your solar system sends back out through your meter to the grid, instead of using it in your home.
Extra power	Solar power your home does not use at that moment. Whether it is credited, ignored, or billed depends on your meter and your state.
GFCI (ground-fault circuit interrupter)	A device that shuts off power in a fraction of a second if electricity leaks to the wrong place.
Interconnection agreement	A formal contract with your utility to connect a power source to the grid. Many state plug-in laws say you do not need one.
Inverter	A device that converts solar power (DC) into household power (AC). A microinverter is a small one attached to a single panel or small group of panels.
Landlord notice	Written notice a tenant gives a landlord before installing a system, where a state law requires it.
Listed (or certified)	Tested by an independent lab, marked, and included in the lab's public directory, with regular factory inspections. See Plug-in solar certifications.
Net metering	A billing arrangement where your utility credits you for extra solar power you send to the grid, usually on a meter that runs both ways. Many state plug-in laws exempt plug-in systems from net metering, so extra power may earn no credit. See your state guide.
NEC (National Electrical Code)	The national safety code for electrical wiring that many states adopt into their building codes.
NRTL (nationally recognized testing laboratory)	An independent lab approved to test products for safety, such as UL Solutions, Intertek, or CSA Group.
Outline of Investigation	A preliminary safety standard used to test products before a final standard is published. UL 3700 is currently one.
Overload	More current flowing through a wire than it is rated to carry, which can cause overheating.
Plug-in solar	A small solar system, usually 1,200 watts or less, that connects to your home through an outlet instead of a permanent wiring installation. Also called balcony solar or portable solar.
Power control system (PCS)	A feature or device that monitors a circuit and limits solar output to prevent overload.
Proprietary receptacle	A special outlet and plug designed as a matched pair, which cannot be plugged into a standard outlet. The UL 3700 outline calls for one, and installation by an electrician.
Rapid shutdown	The ability to quickly de-energize a solar system's wiring.
Receptacle	The technical word for an electrical outlet.
Service address	The home or unit where your electric service is provided. Many state limits apply per service address or per meter.
State building code	The statewide rules for construction and electrical work. Some plug-in laws say building codes will be updated later to cover plug-in solar.
UL 1741	The established safety standard for inverters that connect to the grid, including anti-islanding.
UL 3700	An outline covering whole plug-in solar systems that users install themselves. See Plug-in solar certifications.
Watt (W) and kilowatt-hour (kWh)	Watts measure power at one moment. Kilowatt-hours measure energy over time, and are what your electric bill charges for.
Zero export	A design that keeps a system from sending power out to the grid, so everything it makes is used inside the home.