Green-light this water power

It didn't make page one headlines, but New England is in line to get a new infusion of electricity that will provide more power than the Seabrook nuclear plant, and with limited greenhouse gas emissions. It is the proposal of NStar and Northeast Utilities, which owns the Western Massachusetts Electric Co., to contract with Hydro-Quebec for 1,200 megawatts of the Canadian province's abundant hydropower.

New England has long imported Quebec hydropower, especially in the peak summer months, when this region's electricity demand peaks. Under the proposed arrangement, which needs a green light from the Federal Energy Regulatory Commission, the Canadian electricity would be an even greater part of this region's year-round, baseload capacity. Federal approval is needed because the utilities plan a transmission line - on an existing right-of-way -into southern New Hampshire. The line that would be exclusively for this power, so that it could be accessed when needed, and customers not using the power would be spared the line's cost. FERC prefers other utilities have use of lines as well. The commission should give the project its blessing.

The least polluting and least costly way to meet the demand for electricity is to reduce it through conservation and greater efficiency. The utilities acknowledge that. But if they can get a competitive price for the imported hydropower, they can curb New England's dependence on gas-fired power plants, which now supply about 40 percent of the region's electricity. The cost of that fuel is one reason New England electric rates are among the nation's highest.

That is not the only drawback to over-dependence on one fuel. The operator of the region's grid, ISO New England, recently issued a report raising concern about the threat to "system reliability" posed by the large and growing role of natural gas. plays in the region's electricity picture.

Hydropower is not emission-free, but compared to with fossil-fuel power it has the carbon footprint of Cinderella. The trees flooded over in Quebec behind the power dams decompose and emit methane, which bubbles up into the atmosphere. As a greenhouse gas, methane is 27 times as potent as carbon dioxide, but the total greenhouse effect, kilowatt for kilowatt, is still significantly less than a fossil-fuel plant's.

Massachusetts's new green energy law stipulates that a utility using imported hydropower does not get credit for it under the Renewable Portfolio Standard, which is aimed at encouraging solar, wind, and other renewable sources. But the hydropower's reduced carbon emissions would help utilities meet the requirements of the 10-state Regional Greenhouse Gas Initiative.

The utilities' proposal will have other regulatory hurdles to clear before the line is built and power flows south. At this stage at least, the plan deserves FERC's approval.