What is a microgrid?
A microgrid is a self-sufficient energy system that serves a discrete area, such as a college campus, hospital complex, business center, or neighborhood. They are usually powered by distributed energy including solar panels, wind turbines, and generators. Microgrids can also incorporate energy storage, typically from batteries, and some have electric vehicle charging stations.
Microgrids are “islandable”, meaning they can disconnect from the central grid and operate independently. This islanding capability allows the campus to maintain consistent power even in the event of large-scale outages.
Microgrids are intelligent: the central brain of the system, the microgrid controller, manages the generators, batteries and nearby building energy systems to deliver power when and where it’s needed. Microgrids can be isolated and local lights can be turned on quickly inside the microgrid using local resources like generators, renewables, and batteries while the rest of the grid outside the microgrid is off.
At Illinois Institute of Technology (Illinois Tech) we have our own microgrid that integrates a high-reliability distribution system, smart metering, and renewable energy sources to boost overall efficiency, demand response, and resiliency. One of the first functioning microgrids in the nation, the Illinois Tech microgrid incorporates solar panels, wind turbines, LED street lights, and charging stations for electric vehicles. If necessary, the Illinois Tech system can disconnect from the broader power grid, making the campus self-sufficient during emergencies such as severe weather events or even cyber attack.
The Perfect Power microgrid project at Illinois Tech
Plans began for the microgrid in 2006, and in 2008, the perfect power project was funded by the U.S. Department of Energy (DOE) and other partners to convert the Illinois Tech campus to a microgrid. The Illinois Tech microgrid was initiated and technically managed by the Robert W. Galvin Center for Electricity Innovation at Illinois Tech. Implementation of individual microgrid tasks was managed and coordinated from within the Facilities Department at Illinois Tech, transforming Illinois Institute of Technology into an example of the future of community electricity distribution.
History of the Illinois Tech microgrid
Illinois Institute of Technology sits about 2.5 miles south of downtown Chicago, bounded by 35th Street on the south, Michigan Avenue on the east, 29th/30th Street on the north, and the Metra Rock Island line on the west. As of 2006, Illinois Tech received electricity feed from the local utility - ComEd - at two substations located on the west end of campus. Starting at the substations, Illinois Tech owns and manages the electricity distribution to almost all campus buildings. The original substations and the technology within them dates back to the implementation of the Mies Van Der Rohe campus plan in the 1940s and 1950s.
Almost all of the electrical distribution was underground or within a building. This underground placement protected the electrical infrastructure from storm damage and similar threats from exposure, however, given the campus's proximity to Lake Michigan and the height of the water table, the underground manholes and duct banks come into regular contact with groundwater. This, combined with the age of the equipment, led Illinois Tech in 2003 to begin the process of renovating the electric grid on campus by replacing the North Substation with modern equipment and controls, during which time ComEd also upgraded their equipment at the substation.
Prior to the implementation of microgrid, any scale of outage response required the Illinois Tech maintenance mechanic to visit the affected area directly and with no information about the condition of the equipment or affected feeders. For the decade preceding the implementation of the Illinois Tech microgrid, the university received sporadic reliability both from the campus infrastructure and the utility feeds to the campus. In sporadic outages, several buildings lost power to laboratory or space conditioning equipment resulting in lost experimental data and subjects. Feeder damage in the residential side of campus caused outages that required the temporary relocation of campus residents to nearby hotels at a cost to the university.
A key element to building a resilient energy system is minimizing the time without power in the event of faults and outages. The Illinois Tech smart microgrids are constructed in a loop system with redundant electricity and distributed generation to ensure constant power delivery even in the event of a fault in the grid. Loops with smart switches, in contrast to line, or radial connections to a substation allow cables to talk to each other during a fault, identify and isolate the fault, and restore power to normal operation within just one tenth of a second. This loop system allows Illinois Tech to greatly reduce the time and costs associated with a loss of power in the event of an outage.
Facts and stats
Prior to the installation of the microgrid, Illinois Tech experienced three or more power outages each year, at a cost of up to $500,000 annually in restoration expenses, lost productivity, and ruined experiments that often cannot be recovered.
The microgrid helps Illinois Tech achieve its Energy Action Plan objectives- including significantly reducing CO2 emissions and improving efficiency in electricity use by 20 percent-by reducing peak demand, distributing energy more efficiently, and leveraging solar and other renewable resources.