Commercial, Distributed Energy Resources, Microgrids  -  December 11, 2018

Martha’s Vineyard to modernize with microgrids

The Martha’s Vineyard Transit Authority is implementing a plan to modernize its public transit system. The agency is currently replacing its fleet of 33 diesel buses with battery electric models and will develop a combination of solar panels, battery storage and induction charging to power the fleet.

This combination, known as a single-user microgrid, allows the system to disconnect from the main grid during power outages and use its stored electricity and solar-generated power. A report by Energy News Network explained that typically, solar installations that are connected to the grid are designed to turn off during outages for safety reasons.

Buses will power up at inductive charging stations planned for three or four stops, where charging plates will be embedded in the ground. The bus will park over the plate and the electricity will transfer wirelessly to the vehicle. The report said, “In the time it takes passengers to load and unload, the bus should be able to take on about 30 kilowatts, enough to keep it going until its next opportunity to charge.”

The report noted that the system is designed to maximize resilience, especially important on an island, where resources can’t be easily brought in from neighboring towns. Additionally, falling costs for electric buses, battery storage, and solar panels increase the appeal of microgrids.

In addition to its fame as a vacation destination, Martha’s Vineyard has 17,000 year-round residents spread out across six towns that are connected by bus service. The first six electric vehicles are already in operation, with another six scheduled for next summer. The remaining diesel vehicles will be replaced by electric buses as they are retired.