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Winter 2016/2017 recap: Power system performs well during generally mild weather

New England’s power system performed well during winter 2016/2017, though colder temperatures in December led to higher natural gas and wholesale electric prices compared to the prices seen during the record-setting warm weather of winter 2015/2016.

While January and February were milder than normal, temperatures in December 2016 averaged 32.4°F, more than 10°F colder than the previous December. Over the course of the winter New Englanders used 30,933 gigawatt hours (GWh) of electricity, slightly less than the 31,328 GWh used during the previous winter (which, as a leap year, included one extra day in February), but significantly less than the 33,709 GWh used during the much colder 2014/2015 winter, according to ISO New England data.

December’s colder weather led to increased demand for natural gas in the region, raising the price for the fuel, which, in turn dramatically drove up average prices for wholesale electricity in New England.  Wholesale prices averaged $53.83 per megawatt-hour (MWh) during December 2016, more than double the exceptionally low December average price of $21.35/MWh a year earlier. Read Monthly wholesale electricity prices and demand in New England, December 2016 for more information.

The higher prices in December were largely responsible for the overall 45 percent increase the region saw in average wholesale prices this winter. During the winter months—December, January and February—regional wholesale prices averaged $39.89/MWh, compared to $27.58/MWh during winter 2015/2016. The total cost of wholesale energy from December 2016 through February 2017 was $1.37 billion, 34% more than the $1.02 billion for the same three-month period the previous winter.

Winter peak demand occurred on Thursday, December 15, 2016, at 19,581 MW, just slightly above the previous winter’s peak of 19,561 MW on February 15, 2016. The all-time peak in winter demand occurred on January 15, 2004, at 22,818 MW.

For the fourth year in a row, a winter reliability program was in effect to help augment fuel adequacy in New England. Read the results of the 2016/2017 program.

Winter 2016/2017 and Percent Change from Winter 2015/2016
Winter 2016/2017
Change from Winter 2015/2016
Average Wholesale
Electricity Price

$39.89 +45%
Average Natural Gas Price
$5.24 +54%
Peak Demand
19,581 MW +0.1%
Total Electricity Use
30,933 GWh -1.3%
Total Value of Energy Markets
$1.37 billion
  * One megawatt (MW) of electricity can serve about 1,000 average homes in New England. A megawatt-hour (MWh) of electricity can serve about 1,000 homes for one hour. One gigawatt-hour (GWh) can serve about one million homes for one hour.
** A British thermal unit (Btu) is used to describe the heat value of fuels, providing a uniform standard for comparing different fuels. One million British thermal units are shown as MMBtu.