Vermont utility says program saved $500K during heat wave
An innovative program in Vermont that uses batteries in customers’ homes as a “virtual power plant” paid off to the tune of almost half a million dollars during the recent heat wave, according to the utility running the project.
“During that peak usage, peak hour, every megawatt that we can knock off is a real savings. That one hour is a very significant cost,” said Josh Castonguay, vice president and lead innovation officer for Green Mountain Power, which has a quarter-million customers in Vermont.
At times during the heat wave that covered much of the first week of July, the utility – often known as GMP – drew electricity out of about 500 Tesla Powerwall batteries installed in the home of about 400 customers and fed it into the grid. This meant GMP had to buy less electricity from power plants when the wholesale price of power in New England, which changes every five minutes depending on demand and supply, was particularly high.
This had a double price benefit. It saves on the momentary energy charge, but more importantly it can reduce the utility’s payment to the bulk transmission system in New England. That charge is based on usage during the hour of the year when the most electricity was being used.
The peak demand hour so far in 2018 occurred from 5 to 6 p.m. July 5. By drawing power from customer batteries as well as other sources including its own battery systems during that peak, GMP will cut its annual grid costs, explaining a large portion of the nearly $500,000 it says it saved. If a higher peak hour happens later in the year, that number can change.
Much more: https://www.concordmonitor.com/green-mountain-power-18869126.aspx