Alternating Current (AC)

Amperes, or amps, are the unit of measurement for electrical current – the amount of electric charge passing a point in an electric circuit per unit time. 16A and 32A are two of the current ratings used in standardized industrial plugs. The type of supply needed will depend on the amount of kit plugged in and how much current each piece of equipmen [..]

Biodiesel is a fuel that can be used in conventional diesel engines as a replacement for mineral diesel (fossil-fuel derived). It is made from plant or animal oils or fats that have been chemically processed into alkyl esters. Their environmental sustainability depends hugely on what types of plant/animal material the fuel is derived from (and wher [..]

Biofuels

A naturally occurring gas, and also a by-product of burning fossil fuels and biomass, land-use change, and other industrial processes. It is the principal anthropogenic (man-made) greenhouse gas driving climate change. CO2 is the reference gas against which other greenhouse gases are measured and therefore has a ‘Global Warming Potential’ of 1.

There are 6 greenhouse gases recognised in international treaties and documents (such as the Kyoto Protocol and the Intergovernmental Panel on Climate Change). Each of these has a different Global Warming Potential. The combination of the six is expressed as carbon dioxide equivalent - the amount of CO2 that would cause the same amount of warming. [..]

A measure of the impact human activities have on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide (or CO2e).

Used to denote when there is no net release of CO2. For example, growing biomass takes CO2 out of the atmosphere, while burning it releases the gas again. The process is carbon neutral if the amount taken out and the amount released are identical.

A change of climate attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability over comparable time periods. Climate change is attributed predominantly to the release of greenhouse gases (mainly CO2) into the atmosphere.

Direct current is the unidirectional flow of electric charge i.e. current flows only in one direction. It is produced by sources including batteries, solar cells, fuel cells, and some types of generator. Most electronic circuits require a steady DC. Also see ‘Power’.