WHO KNEW Peak Shaving Is Important in the Hot Weather?
We are having many really hot days this summer when the electrical demand for New England reaches peak levels. What this means is that utilities cannot just rely on their ordinary power suppliers to meet the demand. They have to plan ahead for such situations by contracting with standby power generators to be available in case they are needed to meet the increased demand. These generating stations get paid even if they are never used! Often these standby producers are older and bigger polluters such as the Bow coal-fired plant (now closed) that got by for a number of years by being paid to be on standby, even though it was used only a few times a year.
The amount of standby power that the utilities are required to contract for is based on the maximum number of kilowatt hours used in any one-hourperiod of the previous year (the hour of “peak demand.”) There is an auction based on the peak demand in the previous year to contract for standby power for a year a few years later. The utilities pass these costs on to customers as part of the demand charge on the bill. For large business customers (e.g. Dartmouth College) the demand charge is linked to how much electricity that customer used in the hour of peak demand. Thisis not true for residential customers, but reducing peak demand does reduce the total demand charges and reduces pollution.
This is where “peak shaving” comes in. We can reduce the demand for energy by reducing our use at these peak use times. Here are some ways to reduce your energy use. The simplest, easiest and cheapest thing we can all do is to pull our window shades down or close the curtains. This is especially effective when the windows are in direct sunlight. We can also refrainfrom doing the dishes or laundry, keeping lights on, watching TV, charging one’s car and other electric-using activities during the heaviest use time (4-8 PM). One additional idea is to turn the air conditioning down a few degrees below its usual setting in the morning (pre-cooling) and then turning the temperature to a few degrees above its usual setting in the afternoon. Your place will heat up gradually and the air conditioning will not come on until after the peak period.
Pre-cooling with heat pumps is trickier. Heat pumps are most efficient when they maintain a constant temperature. However, if the goal is to reduce electricity use during the peak, pre-cooling will do that even if it somewhat increases total electricity use over the whole day.
These practices do give us some control over the cost of our electricity. What is more, rooftop solar generators contribute more to the grid on these very hot days so help shave the peak as well. That is yet another advantage to solar energy that benefits us all.
Here are a couple references for more information:
https://www.nhpr.org/2026-07-12/rooftop-solar-eases-new-englands-electric-demand-in-heat-wave
350VT shared the following suggestions on how to reduce your electrical
consumption:
https://drive.google.com/file/d/11J69WkWyn4vd_WcMCLqQDUpcaAMfPLE0/view
Finally, if you want to get regular alerts of peak demand days from No Coal
No Gas you can sign up for them here:
https://www.nocoalnogas.org/peakbusters
Happy Peak Shaving!!