Horizon Nuclear Power is a British energy company expecting to build new nuclear power stations in the United Kingdom. It is an E. ON UK and RWE npower joint venture established in 2009 with its head office in Gloucester. In 2009 it announced intentions to install about 6 000 MWe of new nuclear plant adjacent to the existing Oldbury and Wylfa nuclear power stations. Horizon is evaluating building either Areva 1 650 MWe EPR reactors or Westinghouse 1 100 MWe AP1000 reactors.