This startup helps turn electric school buses into battery backups for a stressed grid

• Hundreds of thousands of school buses are needed in the U.S. even though they sit idle for much of the day.
• Turning the electric ones into grid backup batteries gives them a new life and gives school districts a much-needed financial boost.
• Synop connects to the chargers, the buses, and the grids, monitoring vehicle depots and chargers to see when it works best to use the vehicles as chargers. Last summer it worked with Highland school buses in Beverly, Mass.

Extreme heat from climate change is putting more stress on the nation's electrical grids, so new technology is now stepping up to relieve that stress.

One option is called vehicle-to-grid charging, V2G, which is where an electric vehicle acts like a large-scale battery back-up. So an electric school bus with an energy-dense battery can fuel the grid, much like a Mophie backs up a cell phone.

A startup called Synop has built software to optimize the timing, energy amounts, and costs of this technology on a large scale, and is now implementing it with fleet vehicle companies. Synop connects to the chargers, the buses, and the grids, monitoring vehicle depots and chargers to see when it works best to use the vehicles as chargers. Last summer it worked with Highland school buses in Beverly, Mass.

Hundreds of thousands of school buses are needed in the U.S. even though they sit idle for much of the day. Turning the electric ones into grid backup batteries gives them a new life and gives school districts a much-needed financial boost. The buses can charge overnight, when grid stress is lower and charging is cheaper, and then send the energy back during the day, when air conditioners are stressing the grid. It can therefore sell the energy back at a higher rate.

"We helped deliver 10 megawatt hours of energy back into the grid, and we did that every single day for the entire duration of the summer," said Andrew Blejde, co-founder of Synop. "Really that's about charging when it's cheap and selling energy back when it's most advantageous." 

"This is battery electric storage that happens to already be on wheels," said Duncan McIntyre, founder and CEO of Highland Electric Fleets.

Highland is expanding its fleet of electric school buses across the northeast, and McIntyre said he expects to expand the V2G capabilities as well.

 "It helps local utilities meet demand, but it also creates income for school districts, and it makes electric school buses more affordable," said McIntyre.

Investors in Synop are Wireframe Ventures, Obvious Ventures, Congruent Ventures and Better Ventures. Total funding so far is at $10.1 million.

CNBC climate producer Lisa Rizzolo contributed to this piece