2022 Summary
Went through 2022 without any updates. But I have another year of data, so we can do year by year comparison to see if anything changed significantly. According to NREL (recall that is the government agency that made the PVWatts software), the median solar panels lose 0.5% efficiency per year. Hmm, that doesn’t sound like too much. Below is my 2021 total output of 7,132 kWh. Taking 0.5% of that, is 36 kWh, which is just over a day of peak production in the summer or 1.5 days in the winter. Not much. A rainy day or two. No way we could confirm efficiency loss in year 2. Weather is a much bigger uncertainty. But we have? data now, so let’s crunch the numbers and see if we showed any loss in production. Below is is 2022 monthly and annual production. Not much to crunch, 2022 output was higher than 2021 by 1.8%. So much for degradation analysis by looking at annual production. Going back to our original PVWatts output prediction, we can see if year 2 was any more or less agreeable tha