Terminology Series   A

If you’re new to Renewable Energy, you’ll likely come across a whole host of new phrases, abbreviations and terms. To help you adapt, we’ve collated a list of the terminology you may need to know, beginning with the letter A.


A term used in the Solar Power sector to describe a material in Photovoltaic devices that easily absorbs photons.


An abbreviation for ‘alternating current’ which refers to a type of electrical current in which the direction of electricity is reversed regularly.

Activated shelf life

Refers to the time limit in which a charged battery can be stored before its capacity decreases below a usable level.

Activation voltage(s)

The voltage required for the charge controller (a component within a photovoltaic system used to control the flow of current from the battery) to act and prevent the batteries from over-charge and over-discharge – which would cause damage.


A term used to measure how capable a power system is of supplying the energy required. Planned and unplanned outages of system components will be considered.

Adjustable set point

Refers to a feature that allows the voltage levels at which a charge controller will become active to be altered.


An abbreviation for ‘Alternative Fuel Vehicle’ which refers to a vehicle that runs on a fuel alternative to traditional petrol or diesel.

Ambient heat (or heat pumps)

Refers to the process of extracting energy from the air, ground or water and subsequently converting it to energy that can be used elsewhere – for example, to heat space via underfloor heating.

Ampere (Amp)

Refers to the unit of measurement for electrical currents.


A term used to measure the amount of electrical current flowing for an amount of time.

Ampere hour meter

An instrument that monitors the electrical current with time.

Ancillary services

Refers to services that assist the grid operator in maintaining balance to the system. These include regulation, contingency reserves and in some regions, supplemental operating reserve. It could also refer to the provision of reactive power or frequency response.


Can refer to the positive electrode in a battery, the earth or ground in a cathodic protection system or the positive terminal of a diode.


An abbreviation for ‘Application Programming Interface’ which is the term used to describe how one computer programme communicates with another. When in use, an API can enable software programmes to connect with the internet to request and/or exchange information.

Arc ASCII Grid format

A specific interchange format consisting of a header that specifies the geographic domain and resolution, followed by the grid cell values.


Refers to the second phase in a renewable energy project’s development life cycle. The Assessment phase determines if a site is suitable for development and includes an analysis of power capacity along with long term performance.


A term used to describe an energy source's potential to generate power. For example, in wind power, available describes the amount of the time that the wind turbine is functional.

NES Fircroft and Renewable Energy

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