Last summer, we wrote about the National Renewable Energy Laboratory (NREL) in Golden, Colorado. The facility is a collection of green energy experiments, including wind power, solar panels, and hydrogen energy storage. The goal of NREL is to demonstrate how the US could create truly scaled and reliable renewable energy infrastructure.

One lingering concern researchers have is how communities will be able to restore wind- and solar-rich grids after blackouts. Recently, an unexpected transformer blow-up offered an opportunity for the researchers to put their theories and concerns to the test in a real-time situation. And it turns out renewables exceeded expectations. 

When the transformer blew, many engineers called for a diesel-powered generator to be brought in to get the facility up and running again. Ben Kroposki, director of power system engineering, proposed using the emergency as a way to see if renewables could pull through in similar real-world situations. 

Using a practice called “islanding,” the engineers restarted small system components and then used those to jumpstart larger facility components. Using small batteries, they recharged the facility’s primary lithium-ion battery which in turn provided enough power to activate computers in the campus control room and restart the solar array. 

All said and done, the process took about a week of trial and error to successfully get the systems back online without the use of combustion energy, but it demonstrated that all-renewable grids can in fact withstand unexpected blackouts and even recover from them without resorting to non-renewable sources. Now, the researchers are equipped with a plan of action should a renewable grid ever go down. 

“What we’ve done here can really be a good blueprint for cyberattacks, extreme weather, equipment failure events of various kinds and, you know, how do you get the system back up quickly,” said Daniel Laird, who directs NREL’s wind power center.