Natural News | June 17 2012

Natural News ~ A lot of people believe they are becoming “power independent” by installing grid-tie solar systems, but what many don’t realize is that virtually all such systems are designed to actively go offline when the power grid goes offline.

A “grid-tie” solar system is one that ties into the power grid, pulling electricity from the grid when needed, then pushing excess electricity back into the grid when the local customer isn’t using the full capacity being generated by PV panels (photovoltaic). As long as the grid stays up, it’s a clever solution because it reduces or even eliminates the customer’s electric bills while generating “clean” energy.

Because of the very fact that these systems are tied into the power grid, however, they all have a safety feature that disconnects them from the grid when the grid goes down. In other words, if the power grid goes offline, your entire grid-tie solar array becomes instantly useless and you can’t power a laptop computer even if you have $100,000 worth of solar panels sitting on your roof. In a grid-tie system, they all are instantly shut off.

Let me be clear, because some people reading this article seem to vastly misunderstand the issue: When the power grid goes down, your entire PV array is instantly disabled by your grid-tie inverters, and you cannot use your PV array for anything! Even if the sun is shining, you will have no power from it, period. Understand?

Some early comments to this story suggested that people could simply install a throw switch that would divert the PV array to local use only. This is NOT allowed by local electrical code! Such a system is very difficult to engineer in a safe manner and would almost certainly violate local codes in nearly all U.S. cities. It simply will NOT pass inspection and will not be allowed in most areas. I spoke with top solar consultants to confirm this. At best, such a system would exist in a “grey area” of regulatory approval, I was told.

Again, most people reading this story still do not understand what I’m saying here, and I’ve backed this up with conversations with top solar experts and equipment providers around the world. When the power grid goes down, virtually all grid-tie systems go down with it. Your solar panels are instantly rendered useless and cannot be used until the city power grid is restored.

It’s a “safety” feature

Continue reading →