Anti-islanding
12/20/16
“How can we turn off solar power generation when the grid shuts down?”
Grid islanding might be cool for keeping your residential unit powered when the grid experiences a blackout, but feeding electricity through a grid-tied system can be very dangerous to maintenance workers. So how can we develop a system in which the generation unit will shut off when the grid does? Well, let’s use our engineering mindset to solve this problem. One fact about grid-tied inverters is that they can sense the frequency of the incoming current. We also know that when a blackout happens, this current will drop down. So what if we were to program the inverter to recognize when the frequency drops below a certain threshold, it would cut power generation? This is the operating principle behind what renewable energy engineers call anti-islanding, and it is required as a feature for all grid-tied systems in the United States.