Mike Adams – Natural News June 16, 2012
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
Four out of five people reading this will not believe this information because it is so counter-intuitive. I spoke with architects and engineers who didn’t even know this information. They were all proven wrong. If you install a grid-tie solar system, the entire system is immediately useless when the grid goes down. You will have zero power, even if the sun is shining. Your solar array only functions when grid power is up, get it? That’s the way grid-tie systems are hard-wired. There is no BYPASS function. Grid down = solar array down, period.
What’s the reason behind all this? Because if the main power grid is down, the assumption is that a power line worker may be working on the line somewhere. If a local solar customer is feeding electricity back up the line, that can be dangerous — even deadly — to a power line worker. Thus, all grid-tie solar equipment sold today includes the “safety feature” of automatically shutting down when the grid goes down.
Or at least that’s the official explanation from the solar power companies, because there’s no explanation as to why these inverters have to shut off the local supply of power from the PV panels. Why not let the homeowner continue to have electricity from their own solar panels even if the power grid is down?
“Off-grid” systems allow precisely that. These systems, which do not tie into the power grid, run on a combination of solar panels, batteries and often a backup generator running on gasoline, diesel or propane.
Off-grid systems are ridiculously expensive to own and operate, mostly due to the cost of batteries. Today’s battery technology remains stuck in the 1800’s, meaning that even so-called “deep cycle” batteries will still last only 5 – 10 years. If you do the math on the cost of batteries for a typical off-grid system running a household of four people, you’ll come to the surprising figure that batteries alone can cost you $500 / month, each and every month that you use an off-grid system (that’s the total cost of the batteries divided by the number of months they will last).
That’s why most people don’t go with off-grid systems. Grid-tie systems cost significantly less, especially with solar panels now at rock-bottom prices thanks to China dumping them onto the U.S. market below manufacturing cost. (Right now is a great time to buy solar panels, before new tariffs kick in.)
Batteries can be eliminated in such a system by having a standby generator. The solution I personally recommend, as I have researched this in considerable detail, is to purchase a 20kw Generac generator and acquire a 1,000-gallon propane tank to power it. If you practice some simple energy conservation techniques (such as limiting use of air conditioners or heaters), you can run a typical household for 2-3 months on 1,000 gallons of propane. And if you have solar panels to help along the way, that could be stretched to 4-6 months since you’d only be using the propane fuel at night or when the sun isn’t shining.