Microgrids will Bring Greater Flexibility

When large, complex electric utility grids fail, they collapse with a bang, says Satish Ranade of NMSU’s Electric Utility Management Program. But the time is not far off when a power outage won’t necessarily mean a total blackout – at least for some areas.

“Say a feeder that brings power to our subdivision fails and we know it will take the utility eight hours to come and fix it,” Ranade said. “We are not in trouble, because I may have fuel cells under my kitchen counter. My neighbor has a micro-turbine in his utility room. Another neighbor has a diesel generator in the backyard and another has a solar system.”

With the right distribution configuration and electronic communications, a microgrid like this could quickly restore some of the lights and critical loads such as the neighborhood water pump. Ranade and colleague Joydeep Mitra are working on several fronts to make this vision a reality.

“Our term for this is ‘customer-driven microgrid,’” Ranade said. “We are changing the paradigm here. It is not very difficult now for people to have wind generators, solar power, batteries for storing energy, diesel generators, fuel cells, at their house. The electric grid systems of tomorrow will be designed to accommodate this kind of power generation.”

Mitra received a National Science Foundation CAREER Award to research microgrid designs. The technology exists to make them work, he said – the “smart” breakers, the two-way metering capability, the power electronics, communication and control systems, and safety measures needed to allow small, local generating systems to serve local needs during a utility outage, or to feed power to the larger grid.