Tesla, Green Mountain Power launch battery-aggregation program

Rumors of behind-the-meter battery storage have often been exaggerated. Long the Holy Grail of the solar industry, stories of successful residential storage opportunities being almost within reach have raised hopes before, only to be dashed on the realities of cost and deployment difficulty.

Tesla Energy, in partnership with Vermont utility Green Mountain Power (GMP), is trying to shatter that dynamic once and for all.

The two companies have joined forces to provide battery storage options for GMP’s customers through a bundling of Tesla’s  Powerpack batteries on its utility-scale solar installations while providing Powerwall batteries at its customers’ homes – all for $15 per month (or a $1,500 one-time fee).

GMP says the program will lower its customers’ costs by reducing transmission and capacity costs during peak energy times. It also says the program will shave up to 10 MW of peak load – the equivalent of taking an average of 7,500 homes off the grid – during times when the grid is working the hardest to supply electricity.

To create the program, GMP will install Powerpacks on utility land and provide up to 2,000 Powerwall batteries to its customers, providing them backup power to their home for the next 10 years and eliminating the need for fossil-fuel powered backup generators.

It also says program will increase the grid’s reliability, in a state that has become entirely powered by renewable energy. U.S. Department of Energy data from 2016 shows that Vermont met 97% of its electric demand with in-state wind, solar, hydroelectric power and biomass, while importing 3% of its electricity.

This sets GMP against the dominant paradigm in the Trump Administration. Trump appointees  in the Department of Energy, the Environmental Protection Agency and the Office of Energy Efficiency & Renewable Energy  have all claimed that reliable grids need fossil fuel “baseload” power including coal.

This is a myth. The experiences of other nations and states with high penetrations of renewable energy show that if anything, high levels of wind and solar correlate with higher levels of grid reliability, and that “baseload” coal and nuclear plants are not needed.