Solar Energy USA

Solar Power Terms & Definitions

Solar Glossary

Balance-of-system (BOS)
The electrical and structural components, aside from the major components, that are required to complete a PV system.

Bimodal PV system
A PV system that can operate in either utility-interactive or stand-alone mode and uses battery storage.

Charge controller
A device that regulates battery charge by controlling the charging voltage and/or current from a DC power source, such as a PV array.

Concentrating solar power (CSP)
A technology that uses mirrors and lenses to reflect and concentrate solar radiation from a large area onto a small area.

Direct-coupled PV system
A type of stand-alone system where the output of a PV module or array is directly connected to a DC load.

Distributed generation
A system in which many smaller power-generating systems create electrical power near the point of consumption.

Dual metering
The arrangement that measures energy exported to and imported from the utility grid separately.

Electric Vehicle Supply Equipment (EVSE)
This is the industry name for an Electric Vehicle charging station.  The terms “EVSE”, “EV Charging Station”, and “Charging Station” all mean the same thing and are interchangeable.

Electrolyzer
An electrochemical device that uses electricity to split water into hydrogen and oxygen.

Evacuated-tube collector
A solar energy collector that uses a series of vacuum tubes to absorb sunlight, preferred in colder, northern climates over flat-plate collectors.

Flat-plate collector
A solar energy collector that absorbs solar energy on a flat surface without concentrating it, and can utilize solar radiation directly from the sun as well as radiation that is reflected or scattered by clouds and other surfaces.

Fuel cell
An electrochemical device that uses hydrogen and oxygen to produce DC electricity, with water and heat as byproducts.

Generator
A device that converts mechanical energy into electricity by means of electromagnetic induction.

Grid
The utility’s network of conductors, substations, and equipment that distributes electricity from its central generation point to the consumer.

Hybrid system
A system that includes an energy source other than an array and (if interactive) the utility.

Integrator
A business that designs, builds, and installs complete PV system for particular applications by matching components from various manufacturers.

Inverter
A device that converts DC power from battery systems or arrays to utility-grade AC power for AC loads or export to the utility grid.

Islanding
The undesirable condition where an interactive inverter continues to supply power to the utility grid during a utility outage.

Load
A device that consumes electricity.

Net metering
A metering arrangement where any excess energy exported to the utility is subtracted from the amount of energy imported from it.

Photovoltaics (PV)
A solar energy technology that uses unique properties of semiconductors to directly convert solar radiation into electricity.

Rectifier
A device that converts AC power to DC power.

Self-regulating PV system
A type of stand-alone system that uses no active control systems to protect the battery, except through careful design and component sizing.

Stand-alone PV system
A type of PV system that operates autonomously and supplies power to electrical loads independently of the electric utility.

Uninterruptible power supply (UPS)
A battery-based system that includes all the additional power conditioning equipment, such as inverters and charge controllers, to make a complete, self-contained power source.

Utility
A company that produces and/or distributes electricity to consumers in a certain region or state.

Utility-interactive PV system
A PV system that operates in parallel with and is connected to the electric utility grid.