Whoa! Heatwave Savings for All GMP Customers Could Reach $500,000 Thanks to Innovation and Storage

It was oppressive and super-hot outside, a few days into the July heatwave, when Mike Wheeler looked at an app on his phone. It showed him that the two Tesla Powerwalls – essentially big batteries – in his basement were draining power. It might seem like a bad thing, but he was smiling. This is exactly what was supposed to happen.

“It was so cool! I thought, ‘it’s going to grid right now,’“ Wheeler said.

Wheeler got those Powerwall batteries through a partnership with Green Mountain Power. They provide backup power for his home, like a generator would during an outage. But, instead of using oil or gas, Powerwalls get their charge by storing energy from either the electrical grid, or from a customer’s solar panels.

Hundreds of GMP customers, just like Wheeler, now have this kind of clean, cutting edge back up power in their homes. And, all those Powerwalls played a big role in cutting carbon and costs for all customers during the heatwave. What Mike Wheeler was seeing on his app, was GMP sharing access and leveraging the stored energy in those Powerwalls to put back on the grid during those high use heatwave days. GMP also used energy from larger batteries at its solar facilities in Rutland in Panton to try to “beat the peak” – all of that power deploying at one time to reduce demand and cut costs directly for customers.

The result? The equivalent of taking 5,000 homes off the grid – and that created savings for all GMP customers that could reach $500,000.

“This is a game changer. We’re thrilled that our work to be on the edge of innovation and deploy these new technologies in partnership with customers and communities is really paying off for all of the customers we serve,” said Mary Powell, GMP’s president and CEO.  “During the heat wave, we were able to leverage these innovations to think differently about managing the energy system affordably, allow our customers to use their cooling systems to stay safe and comfortable, all while lowering the peak, ensuring the stability and safety of the grid, and driving down costs.”

Along with GMP’s solar-storage facilities in Rutland and Panton and about 500 Tesla Powerwalls, GMP also has partnerships with thousands of customers to tap into stored energy in their water heaters or reduce electricity flow through their EV chargers when power demand is high, increasing savings for all customers. During the hours of peak demand, this helped GMP offset approximately 17,600 pounds of carbon, the equivalent of not using about 910 gallons of gasoline. GMP’s everyday power sources are 90 percent carbon free.

Customer Mike Wheeler likes the energy sharing partnership he has with GMP. “We signed up to have Powerwall battery backup at home so our family can get through occasional outages and not rely on a fossil fuel generator. But, knowing our choice to get a Powerwall helped all GMP customers to cut costs during the heatwave is a great extra benefit, like you’re doing something for the common good.”

GMP customers pay $15 per month for a Powerwall, or a one-time payment of $1,500. That’s significantly less than the $7,000 to $8,000 it would cost to buy the battery on your own and have it installed.

According to ISO-NE, regional power demand hit its peak so far this year between 5 p.m. and 6 p.m. Thursday, July 5. The yearly regional peak hour is used by ISO-NE to calculate annual grid costs for utilities, so reducing power demand during that hour can produce significant savings for customers. 2018 is not over, so GMP will continue to monitor demand, and deploy its growing network of stored energy to offset carbon and costs for customers.

“This is what our energy future looks like, and it is here now. GMP is delivering on the promise of innovations to drive those costs down during peak demand times, and that is key to help all customers save money. Our goal is to continue to expand our network of stored energy and low-carbon solutions to benefit all of our customers,” Powell said.

Learn more about GMP’s Powerwall program.