Tesla does deal with Vermont utility to reduce electricity bills with Tesla batteries

• Tesla signed a deal with Vermont's largest utility Green Mountain Power.
• The utility hopes the deal will reduce peak load electricity costs.
• The fee will be $15 per month, or one-time $1,500 charge, for 10-year plan.

Tesla has signed another deal with a utility, partnering with a Vermont utility to offer customers backup electricity for a fee.

The California-based sustainable energy company will install several of its nearly 4,000-pound Tesla Powerpack battery units on utility land, and offer the much-smaller Powerwall battery packs for up to 2,000 individual customers. The deal is the latest with utilities in the United States and abroad.

Vermont utility Green Mountain Power delivers electricity to three-quarters of the state's population. For a monthly fee of $15, or a one-time $1,500 fee, customers will receive backup power to their home for next 10 years, Tesla said. (Ten years is the warranty period during which Tesla guarantees their advertised performance level.)

A portion of the Stafford Hill solar power project gathers energy from the sun in Rutland, Vt., on Tuesday, Sept. 15, 2015. With the completion of the project developed by Green Mountain Power, Vermont's largest electric utility, the city of Rutland claimed it has more solar capacity, 7.8 megawatts, per capita than any other city in the New England region.

Wilson Ring | AP

At the end of the program, Tesla will take back the batteries, said Green Mountain Power spokeswoman Kristin Carlson.

Further deals may be in the works.

"Obviously, we are looking to grow this program," Carlson said, "because we see this as our new energy future."

Tesla said the batteries will eliminate the need for traditional, manually controlled, and fossil-fuel burning, backup generators.

Green Mountain expects the electricity batteries will also allow the utility to reduce peak energy load by 10 megawatts, the equivalent to taking 7,500 homes off the grid.

This will allow the utility to more cheaply meet the highest levels of demand — often on hot days when homes and businesses run air conditioners.

"There is a time, usually in the summer when there is peak energy use, and that is when energy is most expensive," Carlson said. "So anything we can do to lower that will save money for customers."

Green Mountain Power also plans to dispatch electricity aggregated from the batteries into New England's wholesale electricity markets when not needed by its own customers. Carlson said this will result in further savings for Green Mountain customers.

Tesla has done energy storage deals with utilities in such places as Connecticut, California, Hawaii and the U.K.