Solar Energy System Terms

25 Solar Terms To Help You Become Your Own Energy Expert

Array / PV Array – A power-generating unit, rated in maximum DC output (Watts), that consists of any number of interconnected photovoltaic modules (solar panels).

Automatic Shutoff / Rapid Shutdown – A safety feature for solar systems that is installed in or around buildings to prevent electric shock to first responders and/or workers who maintain electrical lines.

Balance of System (BOS) – Includes all components of a solar panel system other than the panels themselves. This can include, wiring, mounting brackets/racking, inverter(s), switches, design, installation, site preparation, land for ground mounted systems, and related costs.

Ballasted Mount – A solar panel system mount that is used to reduce, or avoid completely, penetrations in the roof. This mounting method can be used on flat roofs or roofs with a very slight incline where the weight of the solar system and additional material secure the system to the structure.

Current at Maximum Power (lmp) –  The current at which maximum power is available from a solar panel.

Conduit – A protective cover for electrical wiring.

Dual-Axis Tracking System – A mounting system that pivots both vertically and horizontally to allow a photovoltaic array to track and point toward the sun, increasing the absorption of radiation.

Electric Conduit Path – Interconnects solar panels, inverters, and an electrical panel box.

Ground Mount – Secures solar panel systems to the ground rather than a structure’s roof. Ground mounts add cost, but can be necessary if there is limited space or heavy shading on the rooftop.

Inverter – A device that converts direct current (DC) produced by solar panels to alternating current (AC), which is used in your home.

Junction Box / PV Junction Box – A protective enclosure that houses electrical components of the solar panel system to prevent damages caused by environmental conditions.

Junction Diode – A semiconductor device with a junction to allow current to flow in one direction better than the other. All solar cells are junction diodes.

Main Disconnect – A switch, typically located near or inside the panel (but not always), that controls the flow of electrical power to your home.

Monitoring System – A device that measures and displays your solar system’s kilowatt-hour production. Often in real-time and at the panel level, many monitoring systems have apps that allow users to track their system’s performance on their cellphone or computer.

Mounting Hardware – Another term for Racking Hardware.

One-Axis Tracking – A mounting system that can pivot the PV array in one direction to track the sun and increase the absorption of radiation.

PV System – A power system that uses photovoltaics to supply solar power. A PV system consists of solar panels and the balance of system (BOS) to be fully functional.

Racking Hardware – Hardware consisting of brackets, rails, and other components that are used to secure solar panels on buildings, roofs, or the ground.

Roof Mount – A mounting method where solar panels are secured to the roof of a structure. This is most common for residential solar system installations.

Secure Power Supply – A feature on an inverter that can be switched on and allow power to be fed directly from the PV system into the home during a grid outage. Power will only be fed into the home when the sun is out and there is ample solar irradiation.

Solar Canopies – A mounting structure great for aesthetics or for utilizing roof space. Similar to a Ground Mount, this structure raises the PV array higher off the ground.

Solar Carports – A structure that is built to cover parking areas with a PV system. This adds cost to a roof mounted PV system, but sometimes is necessary due to lack of space of heavy shade on the rooftop.

Solar/ PV Panel or Module – An assembly of solar cells and other necessary parts such as interconnections and terminals designed to generate direct current (DC) power from sunlight.

System Size – Typically measured in DC kilowatts (kW) for residential solar systems, this is the maximum rated DC power output. Residential solar system sizes can range anywhere from 5 kW to 20 kW depending on kilowatt-hour consumption.

System Specifications – Refers to the electricity a PV system will produce in kilowatt-hours and the percentage it will offset from the current electricity provider.

Tracker or Tracking Array – A system that allows PV arrays to automatically follow the sun to increase the absorption of radiation.

Wiring – A system of wires that provides electrical circuits for a PV system