Winter may bring rolling blackouts

Electricity officials are bracing for unprecedented rolling blackouts if New England faces a severe cold snap that overtaxes supplies of natural gas used for both heating homes and generating power.

If the winter is mild, officials foresee few problems maintaining adequate electric supplies, according to a forecast to be issued today. But officials at Independent System Operator New England, the Holyoke organization that manages the six-state electric grid, fear a repeat of brutally cold weather like that of January 2004 that could force them to shut off power to hundreds of thousands of people and businesses for one or two hours at a time to conserve available electricity.

New England set records for wintertime electric and gas demand -- and came close to rolling blackouts -- in January 2004 when temperatures stayed below 10 degrees on three separate days in a single week and hit a 24-year low of 7 below zero at Logan International Airport in Boston.

If a similar cold snap grips the region this winter, especially with gas supplies still restricted because of Hurricane Katrina, ISO New England officials fear they could face a situation where gas demand soars along with wholesale prices. That could lead owners of gas-fired power plants to shut down operations either because the price of gas is too high for them to be able to make money buying it to generate electricity, or because they can make more money reselling gas supplies they have already purchased. Neither move is illegal.

New England has come to rely on natural gas to produce roughly one-third of its electricity, after more than a dozen gas-fired generators were built here since the last 1990s. New England depends on pipelines to bring in gas from Canada and the Gulf of Mexico and tankers bringing liquefied natural gas from Algeria and Trinidad.

''We're pushing the infrastructure in New England to its limits, both the electric infrastructure and the gas-supply infrastructure," said Gordon van Welie, ISO New England chief executive. Van Welie said the ISO can appeal for conservation, encourage some gas-powered plants to switch to oil temporarily to conserve gas supplies, and increase imports of electricity from Canada and New York if possible.

But van Welie acknowledged that scheduled blackouts may be unavoidable. ''One of our tools is controlled outages. Ultimately, our job is to maintain the integrity of the bulk power system."

Previously the ISO has only raised the specter of rolling blackouts during the summer, when electric demand is usually much lower than on hot July and August days. The last chronic rolling blackouts in the United States occurred during California's 2001 electric crisis, caused in part by energy companies including Enron Corp. manipulating markets and withholding electric supplies.

To prevent energy shortages, the Massachusetts Department of Environmental Protection has begun reviewing whether to let four power plants in Bellingham, Dartmouth, Springfield, and Pittsfield that usually burn gas increase their use of more polluting oil this winter. The agency won't decide whether to pursue the change, which alarms some environmentalists and public health advocates, for another two or three weeks, spokesman Ed Coletta said.

Gas utilities including KeySpan Energy Delivery New England and the ISO stress that homeowners and businesses shouldn't fear lacking gas for heating and cooking. Gas utilities hold so-called firm contracts, giving them first priority for gas coming through pipelines and LNG terminals, and keep days or weeks of extra gas in storage tanks. State regulations also prevent gas utilities from seeking to profit by shutting off service and reselling their gas.

Rather, the problem involves gas-fired power plants that do not have long-term gas contracts or have so-called interruptible contracts that let gas suppliers cut off their supply if the gas is needed for home and business heating and other firm contract holders. ISO officials do not know exactly how much electric supply could come offline during a gas-supply crisis.

Natural gas production in the Gulf of Mexico has returned to only about half its levels before hurricanes Katrina and Rita ripped through the region in September and won't be fully restored before March, according to the US Energy Department. New England normally gets about one-quarter of its gas at times of peak winter demand from the gulf.

Angela M. O'Connor, president of the New England Power Generators Association, which represents companies that own about half of the region's electric generating capacity, said even though New England got through the January 2004 crunch without blackouts, ''you have to work with all the parties to plan for the worst and hope it comes to naught. I think you can't be too careful."

Caroline Allen, a spokeswoman for NStar, which provides electricity in Boston and 80 other cities and towns and also natural gas in 51 Eastern Massachusetts communities, said NStar does not anticipate problems.

''We have signed firm, committed gas and electric supply contracts to make sure our customers have the energy they need this winter, and we'll work with the ISO to make sure the market operates the best way it can," she said.

Peter J. Howe can be reached at howe@globe.com.