New England residents kept their air conditioners off during June’s unusually cold and wet weather and that held electricity consumption well below typical June numbers, according to ISO New England Inc., the operator of the region’s bulk power system and wholesale electricity markets.

"With June’s cold, damp weather, most New Englanders probably didn’t bother bringing up the air conditioner from the basement or turning on the central air if they have it. It simply wasn’t needed on most days in June," said Vamsi Chadalavada, senior vice president and chief operating officer of ISO New England Inc. "Demand for electricity peaks in the summer in New England, with consumption driven largely by weather and air-conditioning use, so when residents and businesses don’t turn on the AC, the effect can be seen in lower demand."

New England residents and businesses used 12.2 percent less electricity in June this year compared with June 2008. The 9.9 million megawatt-hours of electricity used last month was 1.4 million fewer megawatt-hours than the 11.3 million MWh of electricity consumed in June of 2008. While the economic slump no doubt played a role in lower consumption this year, the extreme contrast in the weather between this June and June 2008 spelled the difference. One example of weather’s effect is the week of June 8 to 14, 2008, when a heat wave produced the highest demand of the year, compared to the same week this year. In 2008, the average temperature in New England at the time of the daily peak in demand was 83.9 degrees Fahrenheit. This year, from June 7 to 13, the average temperature at the time of the peak was 64.6 degreesa difference of nearly 20 degrees. Average daily peak demand in the second week of June 2008 was 21,538 MW, while the average daily peak in the comparable week this year was 15,817 MW.

In June this year, demand peaked at 18,468 MW on June 26. By comparison, demand peaked last year at 26,111 MW on June 10, 2008, when temperatures soared into the 90s around New England on the third day of a heat wave. In fact, that was the six-state region’s ninth-highest demand day. The region’s all-time record peak was set at 28,130 MW on Aug. 2, 2006, when the temperature reached 95 degrees.

Wholesale prices in June were much lower than in 2008. While lower demand exerts downward pressure on wholesale energy prices, the cost of fuel used to generate electricity is also a significant factor in wholesale prices. In June 2008, when demand was high and fuel prices were climbing to historic highs, the average wholesale price for electricity in the Real-Time Energy Market was $105.74/MWh. Fuel prices have dropped dramatically since July 2008, and average wholesale electricity prices were $34.32/MWh in the real-time market last month.

ISO New England’s annual summer forecast projects the region should have adequate electricity resources to meet consumer demand this summer. But if demand spikes and supplies become tight as a result of a prolonged heat wave with high humidity, or a major transmission line or power plant goes out of service unexpectedly, system operators have a series of steps they can take to bring the system back into balance.