MADRID - Iberian spot power prices rebounded on Tuesday after falling supplies of wind power forced utilities to use more expensive gas- and coal-fired generators.

Wind parks were providing 5,883 megawatts, or 16.7 percent of Spain's electricity needs, by late afternoon, down from an overnight high of 11,000 MW.

Wind power was forecast to rebound to nearly 9,000 MW on Thursday, which may weigh on the benchmark day-ahead price when the Omel exchange will next fix it on Wednesday morning.

A cold wave which has kept thousands of schoolchildren at home is expected to abate on Thursday, which may also cut demand and further weigh on spot prices in the coming days, dealers said.

In other news, Spain's Industry Ministry said 9,050 MW in renewable energy projects -- mainly wind and thermosolar plants -- would be entitled to subsidies between now and 2013.

The Environment Ministry meanwhile tallied hydropower reserves that would be enough to keep Spain supplied with electricity for about 13 days.

Spain's grid is still short of 2,000 MW of nuclear power because the Almaraz I plant is refueling and not due back until later this week, and the Asco I reactor is offline for maintenance and not expected back until later this week, at the earliest.

The remaining six nuclear plants were producing 5,353 MW, or 12.9 percent of the generating mix, according to data from the national grid operator REE.

Along the curve, calendar-year 2010 declined 0.18 to 40.05 euros/MWh on the Portuguese-based Omip exchange, which accounts for 30 percent of forwards volume.

Spain's power stations were emitting an unusually high 10,999 tonnes per hour of carbon dioxide.

(Reporting by Martin Roberts, editing by Anthony Barker)