As climate change generates more extreme weather events and the United States shifts to more electric vehicles, there is more demand on the nation’s three regional power grids than ever before. Renewable energy is on the rise in an effort to offset the demand for more electricity, but reliability has been a concern. Therefore, many groups are experimenting with futuristic models of electric grids that incorporate renewable energy.
One such experiment by the Department of Energy at the National Renewable Energy Laboratory (NREL) got a surprise while preparing to add a hydrogen energy storage system and EV charging stations at its 300-acre Flatirons Campus: a transformer blew.
Typically, outside power is required to restart a power system after a blackout. Using renewable energy to restart a large power system had never been done before. But rather than wait weeks to bring in a huge diesel-powered generator to do the job, the NREL engineers and researchers restored power using renewable energy—without using a generator.
Using a practice called “islanding,” they restarted small pieces of the model one at a time. First, they used smaller batteries to recharge the Flatirons’ massive lithium-ion battery, which produced enough power to turn on computers in the control room and allowed the engineers to restart the campus’ solar array. They also produced enough power to activate the wind turbines at the facility.
According to researchers, the key was reprogramming the inverters—electronic devices that connect renewable energy sources to the grid. The “smart” inverters enabled this renewable model grid to repower itself.
The realization’s significance is that it can serve as a blueprint on a larger scale for future grid emergencies such as weather events, equipment failure or cyberattacks.
The Electric Power Research Institute (EPRI) is an independent, non-profit energy research and development organization working toward a goal of reducing greenhouse gas emissions from electricity production to zero by 2050. With 108 gigawatts (GW) of installed wind power and more than 40 GW of utility-scale solar power in the United States, EPRI senior technical leader Erik Ela believes grid operators need to have confidence that renewable energy will have the capability to safely and reliably respond to and keep the grid up and running. The response to this unexpected blackout may provide the confidence necessary to rely on and further develop renewable grid solutions.