Dinorwig Power Station - Purpose

Purpose

The original purpose of the scheme, it is claimed, was to deal with the difficulty that National Grid would have had if the large numbers of nuclear power stations then planned had been built. These are technically and economically inflexible, ideally needing to run at full output all of the time and, effectively, storage capacity was needed for some of the night-time power when the demand for power dropped off. Electric night storage heaters and the Economy 7 tariff fulfil a similar purpose.

The stalling of the UK nuclear power programme in the late 1980s and the coincident dash for gas increased the proportion of dispatchable plant on the network, making the use of pumped storage for day/night load balancing less attractive. As a result, a similar facility planned for Exmoor was never built.

Today, Dinorwig is operated not as a peaking station i.e. to help meet peak loads, but rather as a STOR - Short Term Operating Reserve, or Fast Response plant actor, acting in response to short term rapid changes in power demand or sudden loss of power stations. In a common scenario (known as TV pickup), the end of a popular national television programme or advertising breaks in commercial television programmes send millions of consumers to switch on electric kettles in the space of a few minutes, leading to overall demand increases of up to 2,800 MW. In anticipation of this surge, an appropriate number of units at Dinorwig (or other services competing for National Grid Reserve Service duty) may be brought on line as the closing credits start to roll. The monitoring of popular television channels is an important factor in electricity grid control centres.