Heat Prompts Test on Electricity Usage

A recent heat wave has prompted the town's electric department to test if higher rates will persuade local residents to use less energy when it is in high demand.

Until last week, the daily high temperatures hadn't been high enough to launch the test as part of the . According to officials with the department, July 12 was the first day hot enough to test. Then the near-record temperatures at the end of last week presented an opportune time to test.

The Municipal Light Department has 520 residents participating in the pilot program this summer. Half of those participants are in a so-called treatment group and the other half in a control group. All have the smart meters to help them control their electricity usage

The pilot program is designed to test Marblehead’s demand for electricity during 12 summer weekdays when the most energy is being consumed. These “critical peak” days are typically driven by increased use of air conditioning systems. The total energy demand for Marblehead on these days can be as high as 28,000 kilowatts, which is more than 85 percent higher than the average daily demand.

The pilot program will run this summer and next. During the testing period, participants will pay a lower electric rate of about 9 cents per kilowatt hour for 97 percent of the time, versus the estimated 14 cent standard rate.

To encourage the test households to reduce electricity consumption on peak days, the electric rate for the remaining 12 critical peak days will be $1.05 per kilowatt hour.

Customers who reduce electricity usage during a critical peak day should realize bill savings, said general manager Robert Jolly. But no customer will pay more than they would have on the standard rate.

Peak periods are between noon and 6 p.m. on non-holiday weekdays.

It is a too early to determine if Marbleheaders will use less electricity on hot days, Jolly said.

He wrote in an email: “..we will need several events worth of data points to then run through some pretty sophisticated models to determine if there is behavior change. I don't expect we will be able to determine load reductions until the end of the summer pilot program.”

Funded by a $1.3 million matching U.S. Department of Energy grant, the EnergySense pilot program is among the first of its kind in the region that reflects the actual cost of electricity delivery on critical peak days and offers customers price incentives to reduce household energy usage during specific peak periods.

Jolly views the EnergySense pilot program as a way for Marblehead customers to conserve energy and opt into lower-rate electric plans.

The light department, like most electric utilities, buys energy at higher costs during these peak demand days, which results in higher energy costs for all customers. By purchasing less energy at these high rates on peak demand days, Marblehead can cut its energy costs and share the savings with its customers, Jolly said.