LONDON (Reuters) - Germany's Siemens has won a five-year deal worth up to 833 million pounds ($1.2 billion) to build and service wind turbines for Scottish Power's East Anglia ONE project off the eastern coast of England, Scottish Power said on Wednesday. The contract, for 102 turbines each capable of generating 7 megawatts of electricity, was Europe's largest single contract for the supply of offshore wind turbines, said Scottish Power, which is owned by Spain's Iberdrola . The turbine blades will be manufactured at Siemens' Hull factory in northern England, a 160-million pound compound to be opened in 2017 to meet Britain's huge demand for offshore wind equipment. Britain, the world's largest market for offshore wind projects, plans to have over 10 gigawatts of offshore wind capacity in production by 2020. Scottish Power plans to start building the 715-megawatt East Anglia ONE wind farm off the coast of Norfolk in 2017, with the turbines set for installation by 2019 and the wind farm operational by 2020 the utility said. When completed the East Anglia ONe project is expected to generate enough electricity to power around 500,000 homes. Scottish Power has secured a guaranteed price for the electricity produced at the wind farm of 119 pounds/megawatt hour (MWh) under the government’s contracts-for-difference scheme to incentives low-carbon power production. Electricity prices in Britain currently trade around 37 pounds/MWh.