* Spain day-ahead base at 27-mo low on Saturday
* Spain Tuesday day-ahead base 49.41 euros/MWh
* 1,000 MW nuclear plant off line
* Wind power seen rebounding on Wednesday
MADRID, April 16 (Reuters) - Spain’s wind parks provided a record 60.46 percent of demand for electricity early on Monday, national grid manager REE said, after a windy weekend that reduced wholesale power prices to their lowest levels in more than two years.
The new record percentage set at 3:48 a.m. local time (0148 GMT) compared with a previous maximum of 59.63 percent at 2 a.m. on Nov. 11.
The Iberian Electricity Market’s (Mibel) spot exchange OMIE set the benchmark “pool” price in Spain for Sunday at 10.99 euros ($14.38) per megawatt-hour, its lowest since fixing a level of 6.32 euros for Jan. 1, 2010.
Wind power sways the spot market, because producers can sell it at a considerable discount to electricity generated by burning coal and gas.
REE estimated wind power would decline to about 7,500 MW on Tuesday from 12,113 on Monday afternoon, or enough to meet a robust 30.5 percent of demand.
That forced the pool for Tuesday up to 49.41 euros/MWh, a gain of 9.40 euros from the rate set on Sunday for Monday.
REE said that it had to cap wind power output several times on Saturday and Sunday at limits of between 11,000 and 14,979 megawatts.
The grid needs to regulate wind power on very windy days because Spain can export only a limited part of any surplus electricity it generates, and nuclear plants cannot be shut down easily.
A minimum number of coal- and gas-powered plants also need to keep ticking over.
Also driving prices higher was the halt of the 1,000 MW Cofrentes nuclear plant on Saturday for maintenance.
Producers expect wind power to rise again on Wednesday, a factor that may weigh on the pool when it is next fixed on Tuesday. ($1 = 0.7644 euros) (Reporting by Martin Roberts, editing by Jane Baird)