SMART MICROGRIDS - THE FUTURE OF SUSTAINABLE POWER

Fueled by renewable resources and controlled by smart algorithms, microgrids stand to overhaul how we produce, consume, and share energy.

- MICHELLE Z. DONAHUE

When the cable from the mainland that supplies power to Isle au Haut, Maine, was laid down on the seafloor to replace aging diesel generators, the community was told it had a 15- to 20-year lifespan. That was in 1983.

For the last decade, confronted by the creeping urgency of replacing a power line that could fail any day despite careful maintenance, the community debated how to best keep the lights on in the future. On the menu were a new cable, diesel generators, fuel cells, wave-energy generators, wind, solar, and batteries.

Cost was the primary concern. With a full-time resident population of only 70 people or so and a summertime crowd of 200 to 300, Isle au Haut faced a steeper-than-usual capital infrastructure upgrade.

“When we went through the costs for almost any option, the economics were just really nasty,” said Jim Wilson, president of the private, for-profit cooperative Isle au Haut Electric Power Company. But as the cost of renewable technologies plummeted, certain options began to make more sense.

A solar-and-battery system would run the community around $1.8 million. A new cable: double that. A diesel system would triple the cost. So four years ago, the co-op members voted unanimously to pursue building a 300-kilowatt system made up of 900 solar panels, with a 1-megawatt graphene supercapacitor battery to store and supply excess power. Residents can also add on their own solar panels along with battery systems (and/or water tanks to store excess energy as heat).

In most places, that might be the end of the story. But there’s a hidden aspect to this solar project that tweaks it into next-wave territory: Behind each of the 140 or so electric meters on the island will be units loaded with machine-learning software developed by Kay Aiken at Maine-based Introspective Systems.