Drax power station
Drax Power Station Viewed from the east in October 2007
Location of Drax power station
Official name	Drax power station
Country	England, United Kingdom
Location	Drax, North Yorkshire
Coordinates	53°44′9″N 0°59′47″W / 53.73583°N 0.99639°W / 53.73583; -0.99639Coordinates: 53°44′9″N 0°59′47″W / 53.73583°N 0.99639°W / 53.73583; -0.99639
Status	Operational
Construction began	1973 (Phase 1) 1985 (Phase 2)
Commission date	1974-75 (Phase 1) 1986 (Phase 2)
Owner(s)	Central Electricity Generating Board (1974-1990) National Power (1990-1999) AES Corporation (1999-2003) Drax Group plc (2005-present)
Operator(s)	Drax Power Limited
Turbine information
Manufacturer(s)	C. A. Parsons and Company Siemens
Power station information
Primary fuel	Bituminous coal
Secondary fuel	Biomass
Tertiary fuel	Petcoke
Generation units	6 x 660 MW
Power generation information
Installed capacity	1975: 1,980 MW 1986: 3,960 MW
Website www.draxpower.com

Drax is a large coal-fired power station in North Yorkshire, England, capable of co-firing biomass and petcoke. It is situated near the River Ouse between Selby and Goole, and its name comes from the nearby village of Drax. Its generating capacity of 3,960 megawatts is the highest of any power station in the United Kingdom and Western Europe, providing about 7% of the United Kingdom's electricity supply.

Opened in 1974 and extended in the mid-1980s, the station was initially operated by the Central Electricity Generating Board, but since privatisation in 1990 the station has changed owner several times, and is currently operated by Drax Group plc. Completed in 1986, Drax is the most recently built coal-fired power station in England, and by implementing technologies such as flue gas desulphurisation, is one of the cleanest and most efficient coal-fired power stations in the UK.^[1] However, because of its large size, it is also the UK's single largest emitter of carbon dioxide.

In an attempt to reduce these emissions, the station is currently (c.2010) co-firing biomass and underwent a turbine refurbishment between 2007 and 2012. In 2012 the company announced plans to convert up to three generating units to solely biomass fired power burning 7.5 million metric tons of biomass imported from the United States and Canada.^[2]

History [edit]

Delivery of a Babcock steam drum, during construction (1974)

After the Selby Coalfield was discovered in 1967 the Central Electricity Generating Board built three large power stations to utilise its coal.^[3] These were an expansion of the station at Ferrybridge, a new station at Eggborough, and the power station at Drax. The station at Drax, near Selby was constructed on the site of Wood House.^[4]

Construction [edit]

Drax power station was constructed in two similar phases, each of three generating units. The first phase of construction, was begun in from 1973.^[5] Costain constructed the station's foundations and cable tunnels; Sir Robert McAlpine laid the roads in and about the station, as well as building the ancillary buildings; Mowlem laid the deep foundations; Alfred McAlpine built the administration and control buildings; Balfour Beatty undertook general building works and James Scott installed cabling.^[6] Although the first phase was not completed until 1975, the station's first generating set began generating electricity in 1974.^[5][7]

The second phase of construction began several years later in 1985.^[5] Tarmac Construction undertook the civil engineering works; Holst Civil Engineers built the chimney; N.G. Bailey installed cabling; Reyrolle, English Electric and South Wales Switchgear produced and installed the station's switchgear, English Electric also manufactured the generator cooling water pumps; T.W. Broadbent maintained the site's temporary electrical supplies, and the Sulzer Brothers manufactured the boiler feed pumps.^[6] This second and final phase was completed in 1986.^[7] In both stages the boilers were made by Babcock Power Ltd and the generators by C. A. Parsons and Company. Following the completion of the station, Mitsui Babcock fitted flue-gas desulfurization (FGD) equipment at the station between 1988 to 1995.^[5]

Post-privatisation [edit]

On privatisation of the UK's electric supply industry in 1990, the operation of Drax Power Station was transferred from the Central Electricity Generating Board to the privatised generating company National Power. They sold it on to the AES Corporation in November 1999 for £1.87 billion (US$3 billion).^[1] AES relinquished ownership of the station in August 2003, after falling into £1.3 billion of debt. Independent directors continued the operation of the station to ensure security of supply.^[8] In December 2005, after refinancing, ownership passed to the Drax Group.^[1]

In 2009, Drax Group submitted a planning application for the 300 MW biomass fuelled Ouse Renewable Energy Plant to be located next to the existing power station.^[9] Government approval was obtained in mid 2011.^[10] In February 2012 the company ceased planning development of the plant, citing logistics costs, and uncertainty concerning government financial support for biomass fuels.^[11][12]

Design and specification [edit]

Turbine hall (left: outside, right: inside) The taller light coloured building behind is the boiler house

The station's main buildings are of steel frame and metal clad construction. The main features of the station consists of a turbine hall, a boiler house, a chimney and twelve cooling towers. The station's boiler house is 76 m (249 ft) high, and the turbine hall is 400 m (1,300 ft) long.^[13][14] The reinforced concrete chimney stands at 259 metres (850 ft) high, with a diameter of 9.1 metres (30 ft), and weighs 44,000 tonnes. It consists of three flues, each serving two of the station's six boilers. When finished, the chimney was the largest industrial chimney in the world, and is still the tallest in the United Kingdom.^[15] The twelve 114 metres (374 ft) high natural draft cooling towers stand in two groups of six to the north and south of the station. They are made of reinforced concrete, in the typical hyperboloid design, and each have a base diameter of 92 m (302 ft).^[16][17] Other facilities on the site include a coal storage area, flue gas desulphurisation plant and gypsum handling facilities.

Drax power station is the second largest coal-fired power station in Europe, after Bełchatów Power Station in Poland. Drax produces around 24 terawatt-hours (TWh) (86.4 petajoules) of electricity annually. Although it generates around 1,500,000 tonnes of ash and 22,800,000 tonnes of carbon dioxide each year, Drax is the most carbon-efficient coal-fired powerplant in the United Kingdom.^[18]

Fuel supply [edit]

Coal supply and transport [edit]

The station's rotary coal loader feeding the plant from the stockyard.

The station has a maximum potential consumption of 36,000 tonnes of coal a day.^[19] In 2011, it consumed 9.1 million tonnes of coal.^[20] This coal comes from a mixture of both domestic and international sources, with domestic coal coming from mines in Yorkshire, the Midlands and Scotland, and foreign supplies coming from Australia, Colombia, Poland, Russia and South Africa.^[21]

When the station first opened, the majority of the coal burned there was taken from various local collieries in Yorkshire. These collieries included: Kellingley, Prince of Wales, Ackton Hall, Sharlston, Fryston, Askern and Bentley. However, since the miners' strike in the mid-1980s, all but one of these mines have shut, with the pit at Kellingley being the only one of these still open.^[22] UK Coal had a five-year contract to supply the station with coal. This contract ended at the end of 2009. They supply the station with coal from Kellingley, Maltby and, until its closure in 2007, Rossington. Coal was also brought to the station from Harworth Colliery until it was mothballed, and is still supplied by Daw Mill in Warwickshire.^[23]

The foreign coal is brought to the station via various ports in the UK, and it is taken from these ports to the power station by railway. GB Railfreight have a contract with Drax Group to move coal brought to Port of Tyne to the power station. This contract has been celebrated by the company naming one of their locomotives Drax Power Station.^[24] DB Schenker Rail (UK) haul coal to the station from the nearby ports of Hull and Immingham, and from Hunterston Terminal on the west coast of Scotland.^[22][25] Freightliner Group move coal imported through Redcar.^[26]

All of the coal is delivered to the station by train. Trains reach the station using a 7.2 km (4.5 mi) long freight only section of the closed Hull and Barnsley Railway, which branches away from the Pontefract Line at Hensall Junction.^[27] A balloon loop rail layout is used at the station so that wagons of coal do not need to be shunted after being unloaded. Merry-go-round trains are used, so that wagons can be unloaded without the train stopping, as it passes through an unloading house. On average, there are 35 deliveries a day, 6 days a week.^[28]

In addition to burning coal, Drax also co-fires coal with biomass and petroleum coke ('petcoke').

Biomass [edit]

The station tested co-firing biomass in the summer of 2004, and in doing so was the first power station in the UK to be fuelled by wood. The initial trial of 14,100 tonnes of willow was locally sourced from nearby Eggborough.^[29] Since the trial, the station's use of biomass has continued. The station uses direct injection for firing the biomass, whereby it bypasses the station's pulverising mills and is either injected directly into the boiler or the fuel line, for greater throughput of biomass.^[30] In 2009 a target was set for 12.5% of the station's energy to be sourced from biomass, the shift to biomass was intended to contribute to the station's aim to cut its CO₂ emissions by 15%.^[31] The station burns a large range of biomass fuels, but among them, the most used are wood pellets, sunflower pellets, olive, peanut shell husk and rape meal. The majority of the station's biomass comes from overseas.^[32]

Full firing with biomass [edit]

In September 2012 Drax Group announced the conversion to full firing with biomass of three of its six units at the Selby plant. The first unit is scheduled to be online by June 2013, the second unit in 2014, and the third by 2017. A biomass supply is secured for the first unit. The company is "confident" of a supply for the second unit, and is seeking sources for the third. The cost is estimated at £700 million ($1.13 billion), including modifications to fuel mills and boilers and the construction of storage structures and conveyors for the wood pellet fuel. Each unit will consume about 2.3 million tonnes of biomass yearly, reaching an estimated annual total of 7.5 million tonnes in 2017. This is equivalent to two-thirds of Europe's entire energy biomass consumption in 2010, and requires 1,200,000 ha (Bad rounding here4,600 sq mi) of forest to supply on a continuous basis.^[33][34] North America will be the source of the vast majority of the biomass, although some will be domestic willow and elephant grass.^[35] As of 2013 there were plans to produce 1 million metric tons a year of wood pellets at pelletizing plants at Morehouse Parish, Louisiana, and Gloster, Mississippi which would be shipped by road and rail to port facilities at Baton Rouge, Louisiana then shipped in 50,000-metric-ton cargo ships to the Humber ports on England's east coast then by rail to Drax.^[2][36] Pellets would be ground to dust before use.^[2]

Drax Group's decision was enabled by a new UK government policy, effective in April 2013, to award 1.0 tradable ROCs (renewable obligation certificates) per megawatt of power generation from coal power plants that are fully converted to burn biomass instead. Drax CEO Dorothy Thompson stated the company intends to become a predominately biomass fuelled energy producer.^[37]

Petcoke [edit]

The station started to trial the co-firing of petcoke in one of its boilers in June 2005.^[38] The trial ended in June 2007.^[32] Over this period the boiler burned 15% petcoke and 85% coal. Petcoke was burned in the station to make the price of the station's electricity more competitive as the price of running the station's FGD equipment was making the station's electricity more expensive. The Environment Agency (EA) granted permission for the trial in June 2004, despite the plans being opposed by Friends of the Earth and Selby Council.^[38] To meet their concerns, the station's emissions were constantly monitored through the trial, and they were not allowed to burn petcoke without operating the FGD plant to remove the high sulphur content of the fuel's emissions. The trial proved that there were no significant negative effects on the environment, and so in late 2007, Drax Group applied to move from trial conditions to commercial burn.^[32] The EA granted permission in early 2008 after agreeing with Drax's findings that the fuel had no significant negative effects on the environment.^[32][39] The station can now burn up to 300,000 tonnes of the fuel a year, and stock anything up to 6,000 tonnes of the material on site.^[39]

Electricity generation [edit]

Generator unit No. 2

Coal is fed into one of thirty coal bunkers, each with a capacity of 1,000 tonnes of coal.^[40] Each bunker feeds two of the station's sixty pulverisers, each of which can crush 36 tonnes of coal an hour.^[41] The station has six Babcock Power boilers, each weighing 4,000 tonnes.^[7][41] The powdered coal from ten pulverizers is blasted into each boiler through burners, which are ignited by propane. In 2003 the original burners were replaced by low nitrogen oxide burners.^[19] Each of the six boilers feed steam to a steam turbine set. Each steam turbine consists of one high pressure (HP) turbine, one intermediate pressure (IP) turbine and three low pressure (LP) turbines. The HP turbines generate at 140 megawatts (MW). Exhaust steam from them is fed back to the boiler and reheated, then fed to the 250 MW IP turbines and finally passes through the 90 MW LP turbines.^[7] This gives each generating set a generating capacity of 660 MW, and with six generating sets, the station has a total capacity of 3,960 MW. Each of the generating units is equipped with the Advanced Plant Management System (APMS), a system developed by RWE npower and Thales, and implemented by Capula.^[42]

The station also has six gas turbines installed. These standby turbines provide backup for breakdowns, or shut downs in the National Grid. Their annual output is generally low, generating 75 MW.^[17][43] and three of the units have been mothballed and are out of operation, but they could be refurbished.^[17] Emissions from these units are released through the stations second, smaller chimney, to the south of the main stack.^[44]

Between 2007 and 2012 all the power stations high and low pressure turbines were replaced by Siemens according to a £100 million replacement program.^{[45][46][47][48]}

Cooling system [edit]

Water is essential to a thermal power station, as water is heated to create steam to turn the steam turbines. Water used in the boilers is taken from two licensed boreholes on-site. Once this water has been through the turbines it is cooled using condensers. Water for these condensers is taken from the nearby River Ouse.^[17] Water is pumped from the river to the power station by a pumphouse on the river, north of the station.^[49] Once it has been through the condenser, the water is cooled by one of the station's natural draft cooling towers, with two towers serving each generating set. Once cooled, the water is discharged back into the river.^[17]

Waste products [edit]

Flue gas desulphurisation [edit]

A train of gypsum heading from the station to Kirkby Thore on the Settle-Carlisle Railway.

All six units are served by independent wet limestone-gypsum flue gas desulphurisation (FGD) plant, which was installed between 1988 and 1996. This diverts gases from the boilers and passes them through a limestone slurry, which removes at least 90% of the sulphur dioxide (SO₂) from the gases. This is equivalent to removing over 250,000 tonnes of SO₂ from the station's emissions each year. The process requires 10,000 tonnes of limestone a week.^[50] This limestone is sourced from Tunstead Quarry in Derbyshire.^[51] A byproduct of the process is gypsum, and 15,000 tonnes of it is produced by the station each week. This goes to be used in the manufacture of plasterboard.^[50] The gypsum is sold exclusively to British Gypsum, and it is transported by rail to their plants at Kirkby Thore (on the Settle-Carlisle Railway), East Leake (on the Great Central Main Line) and occasionally to Robertsbridge (on the Hastings Line).^[51] DB Schenker transport the gypsum to the plants.^[52]

Ash use and disposal [edit]

Pulverised fuel ash (PFA) and furnace bottom ash (FBA) are two byproducts made through the burning of coal. Each year, the station produces about 1,000,000 tonnes of PFA and around 220,000 tonnes of FBA. Most of this ash is sold on, with all FBA and 85% of PFA being sold.^[53] Under the trade name Drax Ash Products, the sold ash is sold to the local building industry, where it is used in the manufacture of blocks, cement products, grouting and the laying of roads.^[54] The ash is also used in other parts of the country. Between 2005 and 2007, PFA was used as an infill at four disused salt mines in Northwich in Cheshire. 1,100,000 tonnes of PFA was used in the project, which was to avoid a future risk of subsidence in the town. Ash was delivered to the salt mines by DB Schenker in ten trains a week, each carrying 1,100 tonnes of PFA.^[53] Following a trial in January 2010, PFA is also transported to Waterford in Ireland by boat. One ship a month will transport 1,200 tonnes of PFA from the station to Ireland for the manufacture of construction materials. This will replace 480 lorry journeys annually and is deemed more environmentally friendly.^[55]

The unsold PFA is sent by conveyor belt to the Barlow ash mound, which is used for disposal and temporary stockpile. Three conveyors feed the mound, with a total capacity of delivering 750 tonnes of PFA an hour.^[53] Some FGD gypsum is disposed of on the mound, if it is not of a high enough grade to be sold on. The mound itself is notable as it has won a number of awards for its nature conservation work.^[54]

Environmental effects [edit]

Drax power station is the largest CO₂ emitter in the UK. (The image is that of a cloud of water vapour also emitted by the station)

The environmental effects of coal burning are well documented, the most significant of which is global warming, caused by the release of carbon dioxide (CO₂) into the Earth's atmosphere. Coal is considered to be "easily the most carbon-intensive and polluting form of energy generation available".^[56] In 2007 Drax produced 22,160,000 tonnes of CO₂, making it the largest single source of CO₂ in the UK.^[32][57] Between 2000 and 2007, there has been a net increase in carbon dioxide CO₂ of over 3,000,000 tonnes.^[32] Drax power station also has the highest estimated emissions of nitrogen oxides (NO_x) in the European Union.^[58]

In 2007, in a move to try to lower the station's CO₂ emissions, Drax Group signed a £100 million contract with Siemens Power Generation to re-blade the station's steam turbines over the course of four years. This is the largest steam turbine modernisation ever undertaken in the UK, and will increase the station's efficiency. This, coupled with the co-firing of biomass, is part of a target to reduce the station's CO₂ emissions by 15% by 2011.^[59]

Protests and industrial action [edit]

Climate Camp [edit]

On 31 August 2006, over 600 people attended a protest against the power station's high carbon emissions. It was coordinated by the Camp for Climate Action group. At least 3,000 police officers from 12 forces were reported to have been drafted in for the duration of the protest, to safeguard electricity supplies and prevent the protesters from shutting the station down. Thirty-nine people were arrested during the protest after trying illegally to gain access to the plant.^[60]

Train protest [edit]

At 8:00 am on 13 June 2008, more than 30 climate change campaigners halted an EWS coal train en route to Drax power station by disguising themselves as rail workers by wearing high-visibility clothing and waving red flags. Stopping the train on a bridge crossing the River Aire, they scaled the wagons with the aid of the bridge's girders. They then mounted a banner reading "Leave it in the ground" to the side of the wagon and tied the train to the bridge, preventing it moving. They then shovelled more than 20 tonnes of coal on to the railway line. The protest lasted the whole day, until several protesters were removed from the train by police that night. The station's management said that the protest had no effect on power station's output. The action was also coordinated by Camp for Climate Action.^[61]

Worker strike [edit]

On 18 June 2009, less than 200 contractors walked out of or failed to show up at Drax Power Station in a wildcat strike, none of which were Drax Power employees, showing solidarity with workers at the Lindsey Oil Refinery in Lincolnshire where 51 workers had been laid off while another employer on the site was employing. A spokeswoman said the strike did not affect the station's electricity output.^[62]

Future [edit]

Biomass power station [edit]

Drax Group have applied for planning permission to build a new 300 MW power station, fuelled entirely by biomass, to the north of the current power station site. The Ouse Renewable Energy Plant is expected to burn 1,400,000 tonnes of biomass each year, saving 1,850,000 tonnes of CO₂ emissions per annum. If the plans go ahead, 850 construction jobs will be created and 150 permanent jobs created once opened through direct and contract employment.^[63] Plans were submitted for review by the Department of Energy and Climate Change in July 2009. If planning permission is granted, construction may begin in late 2010 and is expected to last up to three and a half years.^[64] Two other similar plants are planned by Drax at the ports of Hull and Immingham.^[65]

Carbon capture and storage [edit]

On 17 June 2009, Secretary of State for Energy and Climate Change Ed Miliband announced that all UK coal-fired power stations may be fitted with carbon capture and storage (CCS) technology by the early 2020s or face closure. Due to the outcome of the 2010 general election, it is unclear if this remains government policy. Drax currently has made no statement on the viability of CCS technology at the power station. If it was necessary to install CCS technology at Drax, it would potentially require the construction of new turbines and boilers, and a secure way of transporting CO₂ emissions 64 km (40 mi) to the Yorkshire coast.^[66] Drax Power Limited are sponsoring development studies into the technology and its application.^[67]

Wind farm [edit]

In August 2010, the Wind Prospect Group announced plans to build a twelve turbine wind farm near the power station. Known as the Rusholme wind farm, each of the turbine's hubs will stand at 60 m (200 ft), with 40 m (130 ft) blades, giving them each a total height of 100 m (330 ft).^[68]

See also [edit]

Wikimedia Commons has media related to: Drax Power Station

• List of power stations in England
• Timeline of the UK electricity supply industry
• List of tallest buildings and structures in Great Britain
• Energy use and conservation in the United Kingdom
• Energy policy of the United Kingdom
• Eggborough Power Station

References [edit]

v t e Electricity generation in Yorkshire and the Humber Power stations Biomass Active Drax (co-fires) Eggborough (co-fires) Ferrybridge C (co-fires) Glanford Markham Grange Proposed/Future Blackburn Meadows Brigg Drax Ouse Stallingborough Coal Active Drax Eggborough Ferrybridge C Closed Blackburn Meadows Bradford Doncaster Elland Ferrybridge A & B Foss Island Huddersfield Keadby Kirkstall Mexborough Neepsend Rotherham Sculcoates Skelton Grange Thornhill Thorpe Marsh Wakefield Proposed/Future Ferrybridge D Hatfield Gas Active A.H. Marks Castleford Conoco Phillips East Knapton Glanford Brigg Immingham Keadby Killingholme Salt End South Humber Bank Thornhill Hydro Active Settle Closed Linton Falls Proposed/Future Linton Falls Incinerators/Waste Active Kirklees Newlincs Sheffield Wheldale Closed Foss Island Proposed Allerton Park Quarry Wind Active Royd Moor Out Newton Proposed/Future Drax Keadby Humber Gateway Sober Hill Westermost Rough Organisations Drax Group Pre-nationalisation electric power companies Yorkshire Electricity