On paper at least, ERCOT ought to have had plenty of power. In 2010 it reported 84,400 megawatts (MW) of total generation capacity, well over last summer’s peak demand of 68,294MW. In theory, this is enough to produce some 740 billion kilowatt hours (kWh) of electricity a year—more than double the 319 billion kWh that ERCOT’s customers actually demanded during 2010. In electricity generation, however, aggregates and averages carry little weight. One problem is that wind energy accounted for 9,500MW of ERCOT’s total capacity, and the wind does not blow all the time. It tends to be strongest at night, when demand is low. Moreover, power firms are required by regulators to maintain a safety margin over total estimated demand—of 13.75%, in ERCOT’s case—in order to ensure reliable supply.The article then goes on for 4 more columns, discussing very creative improvements in pumped-storage hydropower (pumping water to a higher reservoir at night, when power demand is low, and letting it flow down to generate power during the day, when it's needed); compressed-air energy storage; advanced rail energy storage; and pumped heat electricity storage, among others. Some have efficiencies in the 80% range, which isn't bad--it's certainly cheaper than having to buy electricity on the spot market to avoid rolling blackouts, and paying 30x the normal price for doing so!
If only it were easier for ERCOT and other utilities to store excess energy, such as that produced by wind turbines at night, for later use at peak times. Such “time shifting” would compensate for the intermittent nature of wind and solar power, making them more attractive and easier to integrate into the grid. Energy storage also allows “peak shaving”. By tapping stored energy rather than firing up standby generators, utilities can save money by avoiding expensive spot-market purchases.
I hope something good comes from at least one of these technologies.