The centralized nature of the current electric grid is sub-optimal in many ways, including the distance that electricity must be transmitted from its original source and the impact a single failure at one substation can have on many far-flung users. Microgrids are a potential solution to these issues, much like the internet is a huge collection of networks with massive redundancy. The resiliency and security benefits are meaningful, but ultimately the long-term feasibility of microgrids will be determined by their ability to generate electricity at prices competitive with the scale provided by huge generation facilities.
A microgrid combines various loads with distributed energy resources and advanced control equipment to allow portions of the electric grid to operate independently from the larger grid network, or to “island” in the case of the macrogrid going down. Islanding capability is attractive to universities, hospitals and military installations aiming to protect their critical loads. It’s also attractive to communities looking to survive the next storm, a dynamic that is spurring the development of a new, potentially controversial microgrid model.
Interest in microgrids has soared in recent years as extreme weather events like Superstorm Sandy have battered the United States and as the price of solar, combined heat and power plants and other decentralized energy sources has dropped…In the United States, military microgrids will be a key market driver. More than 40 U.S. military bases already have microgrids in operation, or that are in the planning or study stage. College campuses across the country have also established microgrids, including Princeton University; University of Missouri, St. Louis; and University of California, San Diego.
Single customer, or “campus-style,” projects used at schools, military bases and even individual buildings are becoming a popular microgrid application. A new, more complex microgrid model in development is one that serves multiple customers over several properties and crosses over public rights of way on the distribution system. The Maryland report calls these “public purpose microgrids,” which are designed to power a community’s essential operations as well as services that maintain quality of life. According to Hopper of MEA, this includes places like grocery stores, pharmacies and gas stations. “If you don’t have power for a week but you have a generator, after the first day when you run out of gasoline it doesn’t really matter,” she said. “Or if you can be somewhat comfortable in your home even if you don’t have power, but you run out of your medication and you don’t have anywhere to get it that’s a serious quality of life issue.” The idea is to link up several community assets to create an “oasis of safety,” said Hopper. “Those are the kinds of microgrids we are really looking at because those are not really being done yet.”