Didcot power stations

Didcot Power Stations
Didcot Power Station Viewed from the south in September 2006
Location of Didcot Power Stations in Oxfordshire
Country	England
Location	Oxfordshire, South East England
Coordinates
Commission date	1968
Operator(s)	Central Electricity Generating Board (1968-1990) National Power (1990-2000) Innogy (2000-2002) RWE npower (2002-present)
Thermal power station
Primary fuel	Coal-fired
Secondary fuel	Natural gas-fired
Tertiary fuel	Biofuel
Power generation
Nameplate capacity	3,360 MW
grid reference SU508919

Didcot Power Stations consist of an active natural-gas power plant (Didcot B Power Station) that supplies the National Grid, and a closed combined coal and oil power plant (Didcot A Power Station). They are situated immediately adjoining each other in the civil parish of Sutton Courtenay, next to the town of Didcot in Oxfordshire (formerly in Berkshire), in the UK. The combined power stations feature a chimney which is one of the tallest structures in the UK, and three hyperbolic cooling towers (three others were demolished in 2014), which can be seen from much of the surrounding landscape.

Didcot A

History

Didcot A Power Station was a coal and gas-fired power station, which ceased operation on 22 March 2013. Designed by architect Frederick Gibberd, a vote was held in Didcot and surrounding villages on whether the power station should be built. There was strong opposition from Sutton Courtenay but the yes vote was carried, due to the number of jobs that would be created in the area. Construction of the 2,000 MWe power station for the Central Electricity Generating Board CEGB began during 1964, and was completed in 1968 at a cost of £104m, with up to 2,400 workers being employed at peak times. It is located on a 300 acres (1.2 km²) site formerly part of the Ministry of Defence Central Ordnance Depot. The main chimney is 650 ft (200 m) tall with the six cooling towers 375 ft (114 m) each.

English Heritage declined to give listed building status to Didcot A Power Station in 2013. Though it recognised there were some interesting features, for example the "carefully designed" setting and Gibberd's detailing, there were better examples elsewhere.

Operation

The station used four 500 MWe generating units. In 2003 Didcot A burnt 3.7Mt of coal. The station burned mostly pulverised coal, but also co-fired with natural gas. Didcot was the first large power station to be converted to have this function. In addition, a small amount of biomass, such as sawdust, was burned at the plant. This was introduced to try to depend more on renewable sources following the introduction of the Kyoto Protocol and, in April 2002, the Renewables Obligation. It was hoped that biomass could replace 2% of coal burnt. In 1996 and 1997, Thales UK was awarded contracts by Innogy (now npower) to implement the APMS supervisory and control system on all of the four units, then enabling optimised emissions monitoring and reporting. Between 2005 and 2007 Didcot installed overfire air systems on the four boilers to reduce emissions of nitrous oxide.This ensured compliance with the Large Combustion Plant Directive.

Some ash from Didcot A was used to manufacture building blocks at a factory on the adjacent Milton Park and transported to Thatcham (near Newbury, Berkshire) for the manufacture of Thermalite aerated breeze blocks using both decarbonized fly and raw ash, but most was mixed with water and pumped via a pipeline to former quarries in Radley.

Environmental protests

2006 Greenpeace Protest

On the morning of Thursday 2 November 2006, 30 Greenpeace trespassers invaded the power station. One group chained themselves to a broken coal-carrying conveyor belt. A second group scaled the 650 ft high chimney, and set up a 'climate camp'. They proceeded to paint "Blair's Legacy" on the side of the chimney overlooking the town. Greenpeace asserted that Didcot Power Station was the second most polluting in Britain after Drax in North Yorkshire, whilst Friends of the Earth describe it as the ninth worst in the UK.

A similar protest occurred early on 26 October 2009, when nine climate change protesters climbed the chimney, and eleven chained themselves to the coal delivery conveyors; the latter group were cut free by police after five hours, but the former waited until 28 October before coming down again — all twenty were arrested, and power supplies continued uninterrupted. The power station was installing improved security fencing at the time.

2013 closure

Didcot A opted out of the Large Combustion Plant Directive which meant it was only be allowed to run for up to 20,000 hours after 1 January 2008 and must close by 31 December 2015 at the latest. The decision was made not to install Flue Gas Desulphurisation equipment which would have allowed continued generation.

Studies did continue into whether there was a possibility that Didcot A might be modernised with new super-clean coal burning capabilities; with RWE partly involved in the study, however in September 2012 RWE Npower announced that Didcot A using its current coal burning capabilities would close at the end of March 2013. On 22 March 2013, Didcot A closed and the de-commissioning process began.

Demolition

The three southern cooling towers of Didcot A were demolished by explosives on Sunday 27 July 2014 at 05:01 BST. The contractors had insisted that the demolition would take place between 3 am and 5 am; the towers were demolished at 5.01am.

There had been a campaign to move the time of the demolition to 6 a.m. or later to enable local people to watch the demolition, but RWE refused. Despite the early morning demolition, many thousands of people turned out locally to watch from numerous vantage points, as well as those who watched the towers come down via a live Internet stream and the event trended heavily on Twitter with the hashtag #DidcotDemolition.

2016 collapse

On 23 February 2016, a large section of the former boiler house at Didcot A power station collapsed while the building was being prepared for demolition. One person was killed, and three people who remain missing as of the following afternoon are believed likely to have died. Four or five people were injured, three seriously. Additionally, around 50 people have been treated for dust inhalation. The rubble from the collapse is 9 metres high and unstable, which along with the instability of the remaining half of the building is hampering search efforts.

The collapse occurred at around 16:00 GMT, and Thames Valley Police declared a "major incident" shortly thereafter. Initial reports of an explosion were ruled out by police after being reported in the media for several hours following the incident.

The boiler house was a steel framed building which had the boilers suspended from the superstructure and above ground level, to allow for their expansion. At the time of the collapse it was being prepared for explosive demolition on 5 March, a process which involved cutting the structure to pre-weaken it.

Didcot B

History

Didcot B is the newer sibling initially owned by National Power, constructed from 1994-7 by Siemens and Atlantic Projects, and uses a (CCGT) type power plant to generate up to 1,360 MWe of electricity. It opened in July 1997.

Specification

It consists of two 680 MWe modules, each with two 230 MW SGT5-4000F (former V94.3A) Siemens gas turbines and two heat recovery steam generators, built by International Combustion (since 1997 known as ABB Combustion Services Ltd), and a steam turbine.

Closure

Owners RWE announced on 9 January 2014 that modules 5 and 6 of Didcot B will cease generation by 31 December 2023 at the latest, to comply with the European Industrial Emissions Directive which takes effect as of January 2016. It is however possible that the life of these modules will be extended if RWE decide to install equipment to further reduce emissions of sulphur dioxide and nitrogen oxides.

2014 Fire

On 19 October 2014, the cooling towers serving one of the steam turbines at Didcot B caught fire. Two of the fifteen fan-assisted cooling towers in the row were completely destroyed, one was seriously damaged, and one suffered light damage. The cause was probably an electrical fault in one of the cooling fans.

Ownership

Following privatisation of the CEGB in the early 1990s, Didcot A passed into the control of what became National Power, who also started construction of Didcot B. Following demerger the plant passed to Innogy (in 2000) and following the takover of Innogy by RWE in 2002 ownership passed to RWE npower.

Architectural reception

Didcot Power Station viewed from Wittenham Clumps, prior to the demolition of Didcot A.

• Didcot A won a Civic Trust Award in 1968 for how well it blended into the landscape, following its construction.
• It was voted Britain's third worst eyesore in 2003 by Country Life readers.
• Radio Oxford received votes for the station when they conducted a survey of the worst building in Oxfordshire, with some listeners referring to it as looking like "somewhere up north".
• British poet Kit Wright has written an "Ode to Didcot Power Station" using a parodic style akin to that of the early romantic poets.
• Artist Roger Wagner painted Menorah, a crucifixion scene featuring the towers of Didcot power station.

See also

• List of tallest buildings and structures in Great Britain
• Energy use and conservation in the United Kingdom
• Energy policy of the United Kingdom

External links

• Map sources for Didcot power stations
• Power Stations Visits — Didcot A
• Power Stations Visits — Didcot A for students
• APMS: Advanced Plant Management System
• Architectural views
• Other CCGTs in southern England