switch the electricity off at the mains
21Grid energy storage — is used to manage the flow of electrical energy. For large scale load levelling on an interconnected electrical system, electric energy producers send low value off peak excess electricity over the electricity transmission grid to temporary… …
22coal mining — Coal was very important in the economic development of Britain. It was used as fuel in the factories built during the Industrial Revolution and continued to be important until the 1980s. The main coalfields are in north east England, the north… …
23Transformer — This article is about the electrical device. For the toy line franchise, see Transformers. For other uses, see Transformer (disambiguation). Pole mounted distribution transformer with center tapped secondary winding. This type of transformer is… …
24Uninterruptible power supply — A small free standing UPS …
25Dimmer — For the New Zealand band, see Dimmer (band). A common dual dimmer manufactured by Electronic Theatre Controls (ETC) …
26Power quality — In its broadest sense, power quality is a set of boundaries that allows electrical systems to function in their intended manner without significant loss of performance or life. The term is used to describe electric power that drives an electrical …
27Hydrargyrum medium-arc iodide lamp — Hydrargyrum medium arc iodide, or HMI, is a mercury halide gas discharge medium arc length lamp with a multi line spectra emission. The name implies that hydrargyrum, an archaic term for Mercury (Hg), is held as a vapour mixed with other rare… …
28Television interference (electrical interference) — Television interference is a particular case of electromagnetic interference which affects television reception. Many natural and man made phenomena can disrupt the reception of television signals. These include naturally occurring and artificial …
29High-voltage direct current — HVDC or high voltage, direct current electric power transmission systems contrast with the more common alternating current systems as a means for the bulk transmission of electrical power. The modern form of HVDC transmission uses technology… …
30Manchester Hydraulic Power — An original steam powered hydraulic pump, converted to electrical operation, on display at the Museum of Science and Industry Manchester s Hydraulic Power system was a public hydraulic power network supplying energy across the city of Manchester… …
