We understand that solar terminology can get quite complicated. That’s why Energis has put together some very common and some downright confusing solar terms that you may have come across when speaking to a consultant, researching online or looking over a quote for your own solar PV system. Please note that this is not an A-Z glossary of terms, just a general guide of what we think our customers may come across (and possibly need explaining) in their solar investigations!
Central Inverter: Typically, a collection of small inverters that are centrally located in a property.
Circuit Breaker: A device that allows a circuit to open under fault conditions. When there is too much current passing through, this device will open and prevent current flow.
Combiner Box: A component used to combine and house the wiring of several solar strings from the PV array.
Functional Earthing: Ensures optimal performance of the PV array. (Only required by manufacturer specifications).
Grid-connected PV System: A PV System which exports electricity to an electricity grid.
Gross feed-in tariff: The electricity retailer will pay the consumer for all the energy that their PV system generates (if it is exported or not), and the consumer pays for the electricity that they import from the grid.
Irradiance: The total amount of radiant energy per unit area.
Islanding: When a distributed generator (DG) continues to power a location in the electricity network, even though electrical grid power is no longer present within that part of the network.
Junction Box: A box that houses a junction of electrical connections for safety.
Kilowatt Peak (kWp): It is the peak output power of a PV system or panel.
Low Voltage (LV): Systems that use over 120 V DC or 50 V AC.
Maximum Power Point Tracker (MPPT): A device used in conjunction with the inverter to maximize power extraction.
Micro-Inverter: A small type of inverter that is mounted on the back of a module.
Monocrystalline Solar Cells: The most efficient and most costly solar cells.
Multicrystalline Solar Cells (polycrystalline): Considered to be less efficient, but more cost-effective solar cells to make and buy.
Net Feed-in Tariff: The electricity retailer will pay the consumer for all the energy that their PV system exports into the electricity grid, which is the excess of what they might otherwise use (net). The consumer pays for the electricity that they import from the grid.
Solar Azimuth Angle: The compass direction from which the sun is positioned, and the sunlight is incoming.
String Inverter: An inverter containing only one MPPT.
Surge Protection: Components that are typically used to ensure safety and protection of electrical devices from voltage spikes.
Switch Disconnector: A device that is used to ensure that a current can be broken to be completely de-energised for service or other operating conditions.
Voltage: Is the difference between two points, measured in volts (V).
Uninterruptible Power Supply: Acts as an emergency short-term power supply.
Zero Export Meter: This is a device that restricts the quantity of solar power that can be exported to the grid.
