In our never-ending quest to find unusual topics in the Solar worldto interest and entertain our bloggin’ public, we bring you the mostunlikely and far-fetched idea that we could think of … a failedinverter. At least, that’s what we thought just a few weeks ago beforereports started coming in of smoke and sparks from the same invertersthat we felt were previously indestructible. (Don’t worry, they weren’tSkyPower customers.) Granted, it was not all of the inverters, ratherfive reports which came from Xantrex, which is otherwise a very goodcompany. So if it could happen to them, it could happen to anyone.
Inverters change electricity from direct current (solar panels) to alternatingcurrent (residential power grid) using a combination of modern computerswitching and somewhat dated induction technologies. The older tech inthese things placed a lot of the work on capacitors, big ones to makethe change. Capacitors are one of the few electronic components thatactually have moving parts and wear out.
Before we start in on all the bad things that could happen, let’stake a moment to tell you what actually did happen. If the inverters are not quite right for the application, they fall apart. Sometimes they“pop” and sometimes they “smoke.” In this case, they did both Out of the thousands that were placed into service, only five machines were knownto have problems, which is clearly a best case scenario of “What couldpossibly go wrong?”
Underperformance is on the list of bad stuff that could happen. Is it the worst? You might not see it and it robs you of cash a little at atime. It could be years before you notice it … if ever. We’re nottalking about design flaws or construction inefficiencies. We’ll assumethat a good solar guy does it right. This is about crappy pieces ofelectrical stuff in the box, or good stuff that goes bad before it’stime. If the inverter gets progeria, you’re not going to get all thepower you have paid for.
On a more cataclysmic note, your inverter’s computer side could have a stroke and stop talking altogether. No computer, no sensing the grid.No grid phase to match, no power to your house… even if the solar panels are happy and cranking out power like crazy. If the computer in yourinverter takes a dive, all of that power will be lost. That’s why we put all those fat copper wires around everything. It routes the power tothe safety of the ground if something bad like this happens.
If your inverter was installed on the south or southwest side of your house, it could be cooking itself to death. (Dumb duh-dumb dumb.) Aslow simmer or a quicker boil, either way – no juice! An early doom forthe inverter ends up meaning more cost for you.
Now, let’s turn to the really stupid. Inverters are heavy. In thefuture, they will probably be lighter, but for today, they weigh a lot.Your inverter should have a mounting board behind it. We’ll stop herefor a moment and let you go out and check… Ok, are you back now? Did you see the mounting board? It’s there to distribute the weight of thething across more than one of the 2×4’s holding up your house.Otherwise, it could literally fall of the wall. Count the screws — there should be BIG screws, and lots of them. Again, too few and kaboom!Maybe not today, but we’re counting on ten or fifteen years.
The last thing you’d think could go wrong with your inverter issomeone taking it. But alas, if your installer put the inverter on theoutside of your house, there’s a good chance this would eventuallyhappen. Crooks are often stealing copper wire from empty houses. Oncethey start to realize what inverters are and what they’re worth, theywill find yours. Imagine leaving a wide-screen TV outside 24/7 andyou’ll get the idea. Oh, well. That’s what insurance is for. But if your inverter is in the garage, you don’t have to worry about that.
So you see, not much bad stuff that happens with inverters, andnothing that can’t be dealt with and fixed. But we need to handle thedumb stuff up front, and do what we can for the rest. Fuses do blow andinverters do occasionally stop working. With SkyPower systems, weinclude web monitoring of your productivity levels – so, if yourinverter does stop, we’ll see it on the computers at SkyPower Central.Pretty cool! In the in end, your inverter isn’t going to give you muchto worry about.