Spanish Power Tower Produces Baseload
During the last week of June, the Gemasolar central tower receiver system in Fuentes de Andalucía near Seville achieved a landmark: It became the first solar system to produce steady power for 24 hours.
Using molten-salt heat-storage technology to produce 19.9 MW round the clock, it became the first true baseload solar system in the world.
The 140-meter tower (460 feet), heated by 2,650 heliostats on 185 hectares (457 acres), concentrates sunlight at about a 1000-1 ratio. Salt is heated directly in the receiver, without the usual oil heat-transfer fluid. That means the salt can be pushed to 500°C (932°F).
Because the insulated storage tank loses less than 1 percent of its heat content daily, useful steam can be generated up to 15 hours after sunset.
The plant’s operator, Torresol Energy, expects to produce electricity 24 hours a day for most of the summer. The target is 6,500 hours a year, which would be a capacity factor of 74 percent — better than older coal plants. That would be about 130 gigawatt-hours annually, enough to power the equivalent of 25,000 Spanish homes.
Torresol Energy is a joint venture between Masdar, Abu Dhabi’s clean energy initiative, and Sener, a Spanish engineering and construction company.