March has arrived. A month ago I reported this was a dismal winter for solar power. The first week was a mass of clouds, and in the following two months the clouds helped us earn just 70.5 percent of what we would “normally” be expected to make in that time frame.
Was February any better?
Well, the sun did come out a little more frequently. And the days do start getting longer. So we did earn more money in February. Our meter reading stands at 2722 kilowatt hours. At the end of January, it stood at 1489, which means that we generated 1233 kilowatt hours in February.
But February is normally one of the sunniest months of the year, and we should have generated 1668 kilowatt hours. That is a shortfall of 435; at $0.642 per kilowatt hour that MicroFIT pays, that means we fell short by $280 (for a cumulative total of $682).
So we generated just 79.7 percent of what we “should” have (according to the official PVwatts chart). At least that is better than the 70.5 percent rate of the previous two months.
So, yes, the sun came out more in February. But not enough.
Was all of our shortfall due to clouds? No. I did report that we had some problems with the Deger tracker not kicking in in the morning. The service folks came by to have a look. Their best guess is that there is a manufacturing defect in the east-west sensor module, perhaps a weak sensor.
If that is what it is, we know that it is responsible for failing to turn the panels to face the sun for at least an hour on some mornings, and is responsible for at least a 25 kilowatt hours shortfall (the mornings that I noticed) and probably more than that. What we don’t know is whether the weak sensors have delayed some of the mid-day rotations, which would have gone unnoticed, so that the panels might not have been functioning always at full strength.
Hopefully the part will be replaced soon, and these first few days of March (in like a Lion, this year) will give way to a plethora of sun, so that I can report much, much better results a month from now.