provided water for the condensing plant. In 1929 electricity was installed in the houses of Port Sunlight Village. In the early 1930 the Central Power Station was expanded with three coal-fired boilers and a 6.25 MW generating set. The station then had a rated capacity of 11.5 MW. In the 1950s a connection to the National Grid was installed. When local demand was high electricity could be imported from the grid, and conversely could be fed into the grid when local demand was low. Some of the Unilever manufacturing processes required steam. A 1.3 MW British Thomson-Houston back-pressure generator was installed at the Central Station. This comprised a steam turbine fed with steam at 230 psi (15.9 bar) from the existing boilers. The expanding steam drove an alternator and discharged steam at 50 psi (3.4 bar), which was used in the works processes. In the 1970s the oldest three boilers were decommissioned and part of the boiler house was demolished. The generating plant was decommissioned in 1998 and most of the site was demolished, the 11 kV control room block was retained until new electricity supplies from the National Grid were installed. Merseyside power station To help meet increased demand for electricity and steam Unilever Group built an oil-fired power station (53°20'42.9"N 2°58'33.0"W) on Thermal Road industrial estate Bromborough which was commissioned in 1958. The station comprised: 4 × oil-fired boilers producing 45 tons/h (45 tonnes/h) of steam at 650 psi (44.8 bar) and 450 °C, steam was fed to: 2 × 5 MW generating sets, after expansion in the turbine steam was discharged at 230 psi (15.9 bar) and supplied to the manufacturing plant and also to: 2 × 2.5 MW generating sets, steam was discharged at 110 psi (7.6 bar) and was supplied to the manufacturing plant. The total electricity output was 14 MW and the station was designed to generate 80 GWh of electricity for the company's high voltage network. It supplied steam to 15 local companies and electricity to nearly 50 firms. The overall thermal efficiency of the station was about 78 per cent. The station had three slender concrete chimneys. Oil was supplied to the station by a 4-inch diameter pipeline from Ellesmere Port. The power station used 100,000 tonnes of fuel oil a year. The station cost £2.5 million to build and in 1958 was the largest privately owned power station in the UK.