Glossary

Reactive power

Reactive power is the electrical power that is required to support magnetic (e.g. in motors and transformers) or electrical fields (e.g. in capacitors), but cannot be used to do work like real (or active) power.

Reactive power compensation

A facility to compensate for reactive power in electrical energy transmission networks; the term ‘static’ signifies that the compensation is carried out without the use of rotating motors such as the synchronous motor. In addition to this, there are various different ways that this reactive power can be controlled (switchable, variable and static reactive power compensation).

Real or active power

Real or active power is the electrical power that is available for transferral into another form of power, e.g. in mechanical, thermal, chemical, optical or acoustic power.

Redispatch management

Redispatch management is used to relieve certain power lines when congestion occurs in the supply network, by relocating the feed-ins via generating units. Redispatch management is used as a preventative measure in operational planning, so as to, for instance, prevent network congestion within the next few hours. Curative redispatching is used during ongoing network operation in order to rectify existing or imminent overloading. Redispatch management is not a market-based procedure, as it does not relay the price signals induced by the congestion to the market participants. The process provides temporary aid, however, it is no substitute for the fundamental rectification of permanent congestion by means of grid expansion.

Reliability of supply

The reliability of supply is the ability of an electricity supply system to fulfil its duties of supply under prescribed conditions and during a given time.

Repowering
The newer generation of wind energy plants yield an output of up to 8 MW. These facilities are also more reliable, quieter and more efficient. The on-site replacement of older wind power stations for newer ones is therefore called repowering.