Outside the white-walled town of Moura in the rolling plans of southern Portugal, more than 240,000 solar panels covering an area equivalent to 150 football pitches are slowly being manoeuvred into position in what will be the world's biggest photovoltaic power plant. A few kilometres away, at Alqueva, the Guadiana river has been dammed to create the largest reservoir in western Europe and one of 18 hydroelectric power projects under way in Portugal's river valleys. In the north-west Alto Minho region, one of the world's biggest wind farms is under construction. Off the coast, south of Porto, wave energy converters are being moored to the seabed in readiness for the start-up of the world's first commercial wave-driven power plant These projects reflect an ambitious government policy to produce up to 60 per cent of the country's electricity from wind, sun, wave and other renewable sources by 2020. Success will make Portugal a world leader in the move to replace oil, gas and coal with clean energy. "The cost of doing nothing is very high," says Manuel Pinho, the economy minister. "We have to turn the challenge of higher fuel prices and climate change into an opportunity to create jobs, promote new industries and encourage innovation." Portugal is already well ahead of the field. Last year, renewable sources accounted for 40.7 per cent of total electricity production. This compares with about 5 per cent in the UK, for example. Having already passed the 39 per cent target that the European Union has set for Portugal for 2010, the government has voluntarily lifted its clean energy goal to 45 per cent of total power generation by that year, and Mr Pinho believes 55 to 60 per cent by 2020 is "perfectly feasible". In 2005 and 2006, Portugal's wind power capacity increased fourfold, faster than in any other EU country, to more than 2,000 megawatts, making it one of the world's top 10 producers of wind energy in absolute terms. Three of the world's biggest solar power stations are being built in Portugal and