English: Drax Power Station, near Selby, was built between 1969-1973 and is Britain's largest power station with a 1.8 gigawatt capacity, composed of two 900 MW generating sets. Power is generated from six NEI/Parsons super-heated steam turbines at 2000psi and 576C. Output voltage is 23.5KV, transformed up to 400KV for onward transmission. The station now operates largely on imported biomass from North America, which is carried by rail from the ports of Tyne, Immingham, Liverpool Bulk Terminal and Hull , with up to 20 train-loads per day, each comprising 23 or 24 W H Davis-built automatic discharge hoppers designed especially for biomass pellets.
Each 75ft long vehicle has five hoppers which are operated from electromagnets at the lineside as the train passes through the discharge point at 0.38 miles per hour. We saw a train from Liverpool, headed by a DB Cargo Class 66 and one from Immingham hauled by a GBRF Class 66 during our visit. Three trains can be unloaded simultaneously if required.
The boilers at Drax consume 5 tonnes of biomass every minute and the station requires between 10 and 20000 tonnes of biomass per day depending on output load requirements. Drax can supply 5-7% of the UK's total power requirement at peak load. One half of the station still operates on coal-firing, but this wiil be progressively converted to biomass and then natural-gas firing in the next few years.