Development of pumped hydro power storage in Portugal is to be closely linked with a sharp expansion of wind power, according to Carlos Pimenta of the independent centre for energy, environment and transport economics, based in Lisbon. Speaking in Germany at the Hanover trade fair, he said electricity generated by wind farms at night will be used to power pumped storage plant, which delivers water into high level reservoirs so the water can be used to drive turbines during the day to produced peak load power. With relatively little demand for electricity at night, power prices for wind power tend to be low, making the pumped storage option attractive. "This is in preparation for the post renewable energy feed-in tariff days," explained Pimenta. Portugal currently has 6 GW of large hydro capacity, of which several hundred megawatts is pumped storage, mainly driven by cheap nuclear power from Spain. Pumping capacity is to be raised to about 1 GW over ten years, in parallel with a planned increase in wind capacity to around 5 GW by 2012, a target raised from 3 GW last year.