Millette runs conduit from the inverter to the transformer.
Tim Healey/JLC Millette runs conduit from the inverter to the transformer.

BUILDER sister publication Journal of Light Construction has an interesting piece on the use of a Tesla Powerwall battery system for power backup and energy efficiency management in Vermont. The Tesla Powerwall sells for $3000 for a 7KWH unit, $3500 for 10 KWH.

It has been almost a year since Tesla Motors introduced the Powerwall, a backup battery power source for homes and small businesses. Now, Vermont’s public utility, Green Mountain Power (GMP), is starting its pilot program to install 500 Powerwall units for customers.

And as JLC learned from GMP executive Josh Castonguay, the Powerwall isn’t just a cool accessory for homeowners with solar panels on their roofs. Whether it’s paired with a solar array or not, GMP sees the Powerwall as a practical way to protect rural homeowners against local power outages, and also as a way for the utility to match the variable loads in its service area to the variable solar and wind sources that now make up more than 15% of GMP’s generating capacity.

JLC recently went on site with electricians Scott Millette and Brian Ritz (Peck Electric, Burlington, Vt.), to see a Powerwall installed in a home. Millette has been installing and servicing electric-car recharging stations for GMP for several years. Putting in Powerwalls is a little different, he said, “but I have no trouble grasping it.”

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