How Not to Short Circuit the Clean Energy Transition

Inverter-based wind, solar, and battery storage present a number of interesting challenges with increased deployment.?A very significant amount of attention has been focused on decreasing inertia, and I personally believe this challenge is well on its way to being solved as we better understand the potential opportunities for the use of fast frequency response, new synchronous machines, and other measures to maintain frequency stability. (See our video and report on that topic).?

An issue that hasn’t received as much attention is system protection and short circuit strength.?When a short circuit occurs on the grid, we have historically relied on the inherent ability of synchronous generators to provide high levels of fault current that can be easily detected and addressed with fuses, circuit breakers, and other relatively robust and low-cost devices.?But inverter-based resources don’t inherently have this capability. As more wind and solar are deployed, we will eventually need to address the decline in fault current capability if we want to maintain a safe grid.

We just released a short paper at the National Renewable Energy Laboratory that provides a basic overview of this topic, along with a short video.?It discusses the problem and a range of possible solutions. No math or anything, just a simple explanation that’s intended for a general audience.?So check it out, and I’d be curious to know what other topics folks might be interested in seeing us discuss.