US utility Ameren Corporation and smart grid solutions firm S&C Electric Company successfully conducted a 24-hour islanding test of a microgrid.According to a statement, the test was done on microgrid owned by Ameren illinois in Champaign. In total, the tested microgrid has a capacity of 50KW, includes 225KW of renewable energy generation resources including solar and wind and 250KW/500Wh of battery energy storage system.
The microgrid has been in operation since May.
The test was done on August 3 from 8 am and has shown the ability of the microgrid to provide a seamless transition from grid-connected to island mode.
The test was started with the status of the battery energy storage system at 97%.
Due to energy usage, energy capacity stored in the battery decreased to 90% resulting in the microgrid remotely switching on its wind and solar generation resources to ensure constant energy generation and supply to meet demand.
Throughout the day, the microgrid was able to sustain energy capacity in the battery above 88%.
Ron Pate, senior vice president of operations and technical services at Ameren, said: "We have one of the few microgrids in the world that operates at utility-scale voltages and can seamlessly transition from grid-connected to islanded mode.
"This successful test provided tangible proof that the system can accomplish what it was designed to do. The microgrid isn't theoretical and our tests don't need to be lab simulations. We were able to prove that this technology works and can provide key benefits to our customers."
David Chiesa, senior director of business development at S&C Electric, added: "When designing this microgrid, we were confident that the seamless transition and the ability to run solely on renewable generation would be two of the biggest features to this system.
The microgrid has been designed to operate on 100% renewable energy and direct excess energy into the system’s battery energy storage platform.
Ameren illinois and energy efficiency
In related news, Ameren illinois selected Dominion Voltage to modernise its grid and implement energy efficiency projects.