Thursday's heat wave and high demand for electricity in the eastern United States pushed wholesale power prices above price caps set by federal regulators, The Wall Street Journal reported on Friday.

The high prices, upwards of 1 dollar a kilowatt hour for a commodity often priced in pennies, occurred sporadically Thursday in spot markets run by the New York Independent System Operator and PJM Interconnection LLC, the grid operator for the mid- Atlantic region and parts of the Midwest, the report said.

In New York City, the price of wholesale power paid by Consolidated Edison Inc. rose as high as 1.33 dollars a kilowatt hour during the afternoon, more than 10 times an average price. In the Washington, D.C., area, prices rose above 1.17 dollars a kilowatt hour.

The price caps are set by the Federal Energy Regulatory Commission to limit the price that power-generating companies can charge to utilities and major customers buying from the grid. They are allowed to charge more, but only if justified by higher costs, such as when they run older, less-efficient plants to meet demand.

High demand this year may have the effect of spurring more plant construction, though some experts said they feared the necessary plants still may not get built fast enough, because it takes at least two to three years to get permits and equipment, the report also noted.

Source: Xinhua