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.

Grid islanding

12/19/16

“What happens when a solar powered system experiences a blackout from the surrounding grid?”

Solar panels are truly an exquisite technology. Not only do they allow for energy independence from oil, but they also allow for energy independence from the surrounding grid! Because solar panels are self-sustaining, if you were to hook enough up to your residential area, you could provide enough electricity that you would not need to take from your local electric company, and even have enough to supply energy back! There is one large disadvantage to this, however. If a blackout were to happen, the electric grid would go down except for self-generating units such as solar panels, which would be islanded. This technology would continue to funnel electricity to the grid, an action that would open the potential for injury to repair workers. As such, most modern day solar panels come equipped with anti-islanding technology to prevent such a case from happening.