Uni-Solar » Glossary of Terms
Glossary of Terms

Acronym for Alternating Current. Alternating current is an electric current that reverses direction (sine wave). In the U.S., most household current is single-phase AC at 60 cycles per second. Many businesses in the U.S. that have larger electrical needs use 3-phase AC at 60 cycles per second. Alternating current at 50 Hz is also very common throughout the world.

Having an atomic structure that is not periodic.

Amorphous Silicon
Sometimes abbreviated as “a-Si,” amorphous silicon is a disordered semiconductor material deposited in a plasma-enhanced chemical vapor deposition (PECVD) process to create thin-film solar cells on a substrate.

The unit of electrical current. Can be thought of as the “flow rate” of electricity.

Array (photovoltaic)
A group of modules wired together (in a series and/or in parallel) to form an array of solar modules.

Blocking Diode
Used to prevent undesired current flow. In a PV array, the diode is used to prevent current flow from the battery to the PV array during periods of darkness or low current production.

BOS or Balance of System (photovoltaic)
The parts of a photovoltaic system other than the array. For instance: switches, controls, meters, power conditioning equipment, supporting structure for the array, storage components, etc.

Bypass Diode
A diode connected in parallel with a PV cell to provide an alternative current path in case of cell shading or failure.

Cell (photovoltaic)
The smallest unit of a solar module. A typical a-Si solar cell is rated at 1.5 volts. A typical crystalline solar cell is rated at 0.5 volts.

Charge Monitor/Meter
A device that displays the level of charge in a battery.

Charge Regulator
A device that controls the changing rate and/or state of charge for batteries. Wired between a photovoltaic array and a battery bank. Its main job is to prevent the battery from being overcharged from the PV array, while monitoring the array and/or battery voltage.

Refers to other devices used and needed when building a solar system.

An electronic device that changes a DC voltage to some other DC voltage. For example, a converter may be used to convert the output of a 24-volt device to a 12-volt output.

Having a repeating atomic structure in all three dimensions.

An acronym for Direct Current. An electric current flowing in one direction only.

The atoms are not arranged in a repetitive periodic fashion.

Grid-Connected (photovoltaic)
A photovoltaic system in which the PV array supplies power directly to a load center (i.e. AC Service Panel) in a home or commercial facility. There is no on-site storage device included with a grid-connected photovoltaic system. Instead, all the kilowatt-hours generated by the PV system are either used by the loads connected to the load center in the building or they are pulled into the utility grid power lines via the utility kilowatt-hour meter attached to the building.

An Electronic Device that changes direct current (DC) to alternating current (AC).

1000 watts; a light bulb uses 40-100 watts.

1,000,000 watts

Module (photovoltaic)
PV modules are manufactured and assembled using solar cells, interconnect wire, bypass diodes, encapsulant (which is a top cover over the solar cells) and a protective back sheet behind the solar cells. Most solar modules also include a frame around the edges of the back sheet/top cover assembly. Together, all of these components form the solar PV module.

Named [after S.R. Ov(shinsky) + (electr)onic] – the term used to describe our proprietary materials, products, and technologies.

Parallel Connection
Connection in which the voltage stays the same, but the amperage multiplies.

Peak Power
Maximum power rating for some particular device.

Photovoltaic (PV)
Direct conversion of light into electrical energy.

Photovoltaic Cell
The treated semiconductor material that converts solar irradiance to electricity.

Roll-to-Roll Process
A process where a roll of substrate is continuously converted into a roll of product.

Series Connection
Connection in which the current (amps) stays the same but the voltage multiplies.

Energy from the sun.

Solar Collectors
A device designed to capture light or heat energy from the sun. Solar thermal collectors are used in solar hot water systems (often found in homes) and photovoltaic collectors are used in solar electric systems

Solar Heating
Technologies or systems that take advantage of the heat energy coming from the sun. Solar thermal collectors are used in solar hot water systems (often found in homes) and photovoltaic collectors are used in solar electric systems.

Solar Panel
Another name for a single module or a group of solar modules that are part of a solar electric PV system (syn: solar array).

Stabilized Energy Conversion Efficiency
The long-term ratio of electrical output to light input.

Systems; Balance of Systems
Solar electric systems include the photovoltaic array and the other components that allow these solar panels to be used in homes and commercial facilities where a regulated DC power supply or an AC power supply is required. Components used in solar electric systems include; wire and disconnect devices, charge regulators, inverters, metering, and grounding components.

Thin Film
A very thin layer of material formed on a substrate.

The unit of electromotive force that will force a current of one amp through a resistor or one ohm.

The measurement of the force of electricity.

A measure of electrical power that is determined by multiplying the voltage by the amperage.