Monthly wholesale electricity prices and demand in New England, June 2017
Friday, July 21, 2017 at 2:51PM
ISO New England in Industry News & Developments, monthly prices, wholesale prices

June’s average wholesale electricity price was the seventh-lowest monthly average since 2003

Compared to the near record-low prices of June 2016, natural gas and wholesale electricity prices rose slightly in June--but were still among the lowest monthly prices seen since 2003. The average wholesale power price during June was $23.93 per megawatt-hour (MWh)*, the 7th lowest since the region’s current energy markets were launched in 2003. Still, the June price was about 13% higher than the June 2016 price—which was the 3rd lowest since 2003, at $21.24/MWh. The average monthly price of natural gas was the 11th lowest since 2003, compared to the June 2016 average natural gas price, which was the 8th lowest.

Drivers of Wholesale Electricity Prices

In general, the two main drivers of wholesale electricity prices in New England are the cost of fuel used to produce electricity and consumer demand.

Power Plant Fuel: Fuel is typically one of the major input costs in producing electricity. Natural gas is the predominant fuel in New England, used to generate 49% of the power produced in the region last year, and natural gas-fired power plants usually set the price of wholesale electricity in the region. As a result, average wholesale electricity prices are closely linked to natural gas prices.

The average natural gas price during June was $2.46 per million British thermal units (MMBtu),** up 6.8% from the June 2016 average Massachusetts natural gas index price of $2.30/MMBtu. The Mass. index price is a volume-weighted average of trades at four natural gas delivery points in Massachusetts, including two Algonquin points, the Tennessee Gas Pipeline, and the Dracut Interconnect. The June average natural gas price was down 18.5% from the May 2017 monthly average of $3.02/MMBtu.

Electricity Demand: Demand is driven primarily by weather as well as economic factors. Energy usage during June 2017 held steady at 10,244 gigawatt-hours (GWh), up only 0.7% from the 10,176 GWh used in June 2016. The average temperature during June was 68˚ Fahrenheit (F) in New England compared to the 67˚F average recorded during the previous June. The average dewpoint, a measure of humidity, came in at 55˚F, compared to 52˚F in June 2016. The number of heating degree days (HDD)*** and cooling degree days (CDD) both came in at 57 in June, compared to 29 HDD and 17 CDD in June 2016. The normal June level is 55 HDD and 50 CDD in New England.

Peak demand for the month was recorded at 23,889 MW on June 13 during the hour from 4 to 5 p.m., when the temperature in New England was 91°F and the dewpoint was 65°. The June 2017 peak was up 19.6% from the June 2016 peak of 19,966 MW, set during the hour from 4 to 5 p.m. on June 29, 2016, when the temperature was 81°F and the dewpoint was 60°.

Peak demand is driven by weather, which drives the use of heating and air conditioning equipment. The all-time peak demand in New England was 28,130 MW, recorded during an August 2006 heat wave, when the temperature was 94°F and the dewpoint was 74°. Air conditioning use is far more widespread than electric heating in New England, so weather tends to have a relatively greater impact on the summer peak than the winter peak. The all-time high winter peak was 22,818 MW, recording during a cold snap in January 2004 when the temperature was -1°F and the dewpoint was -20°.

Fuel Mix: The mix of resources used in any given time period depends on price and availability, as well as supplemental resource commitments needed to ensure system stability. Natural gas-fired and nuclear generation produced most of the 8,860 gigawatt-hours (GWh) of electric energy generated within New England during June, at about 45% and 33%, respectively. Hydroelectric resources in New England generated 9%. Renewable resources generated about 10% of the energy produced within New England, including 6% from wood, refuse, and landfill gas; 3% from wind; and 1% from solar resources. Coal units generated 0.5%, and oil-fired resources produced 0.2% of the energy generated within New England. The region also received net imports of about 1,515 GWh of electricity from neighboring regions.

June 2017 and Percent Change from June 2016 and May 2017
June 2017
Change from June 2016
Change from May 2017
Average Real-Time
Electricity Price
$23.93 +12.7% -18.7%
Average Natural Gas Price
$2.46 +6.8% -18.5%
Peak Demand
23,889 MW +19.6% +18.4%
Total Electricity Use
10,244 GWh +0.7% +11.7%
Weather-Normalized Use****
10,148 GWh -4.1% +12.2%
*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 1 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. ***A degree day is a measure of heating or cooling. A zero degree day occurs when no heating or cooling is required; as temperatures drop, more heating days are recorded; when temperatures rise, more cooling days are recorded. The base point for measuring degree days is 65 degrees; each degree of a day’s mean temperature that is below 65 degrees is counted as one heating degree day. A day’s mean temperature of 45 degrees equals 20 heating degree days. ****Weather-normalized demand indicates how much electricity would have been consumed if the weather had been the same as the average weather over the last 20 years.


Article originally appeared on ISO Newswire (
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