Marchwood Power Station, located near Southampton beside the River Test estuary, is an 898 MW combined cycle gas turbine (CCGT) plant generating electricity for the National Grid. Built on the site of a former oil-fired station demolished in the 1990s, it began operation in 2010 and employs around 45 people. The plant uses River Test water for cooling, with gas and exhaust steam driving two turbines in sequence to maximise efficiency.

Developed by Marchwood Power Ltd, a joint venture between SSE and ESB International, the station cost around £380 million to build. It was officially opened on 28 January 2010, marking one of the UK’s most advanced high-efficiency CCGT plants at the time.

In 2013, ESB sold its 50% stake to a subsidiary of Munich Re for €180 million, leaving the plant under joint ownership with SSE. Today, Marchwood remains a key part of southern England’s energy infrastructure, balancing supply and demand with flexible, low-emission gas generation.