Energy transition explained

A charge levied on a power supplied, or its customer, for access to a utility's transmission or distribution system. It is a charge for the right to send electricity over another's wires.

A short form for ampere, which is the international base unit for measuring electric current. It provides a measure of the electric charge that is being carried through a wire. It is a critical variable in determining the power being delivered – the formula is: power = current * voltage.

Demand response programs in which customers bid load curtailments in ISO/RTO markets as operating reserves. If their bids are accepted, they are paid the market price for committing to be on standby. If their load curtailments are needed, they are called by the ISO/RTO and may be paid the spot market energy price.

Services procured by the transmission system operator to support the transmission of electric power from generators to consumers. They are used to maintain the proper flow and direction of electricity, address imbalances between supply and demand, and help the system recover after a power system event.

Electricity services needed for the safe operation of the electricity system, such as reserve capacity and voltage control.

Fully electric vehicles (also called EVs) with rechargeable batteries and no gasoline engine.

Capital costs are the initial, one-off financial investment required in order to purchase equipment, construction or similar.

Combined cycle gas turbines are widely used power plants for electricity generation from natural gas. The gas is burnt in a high-temperature gas turbine that is coupled to a generator. The exhaust gas from the turbine is used to raise steam, which is then fed to a conventional steam turbine and a further generator.

The number of supply interruptions recorded as a percentage of customers connected in a year.

The actual real-time capacity of a distribution or transmission – as opposed to the theoretical capacity calculated assuming static and worst-case conditions.

Energy communities are legal entities that enable citizens to benefit from local energy investments and infrastructure. They can be publicly owned or private companies, and there are a wide range of (often complex) community structures. In the EU, they are seen as important to engage citizens in the energy transition, unlock local benefits for communities and bring more resilience to the energy system.