A lot of meteorological records that are kept – wind, precipitation, snowfall, temperature – but I didn’t realize that sunshine was one of them.
Silly me! The Blue Hill Observatory in Massachusetts says that March tied for the sunniest on record with 1915: 243 hours of the stuff, 68% of the possible total during daylight and 19 percentage points over the long-term average.
It makes sense to keep track of that since it has such an effect on vegetation drying out – and solar panels. Production on my rooftop array was 25% above last year’s March, and others are reporting similar jumps.
It’s looking more and more like we could have another dry-to-drought summer here.
Return to the Concord Monitor
These are data for our array in Tamworth, not representative by any means.
March 2019 1.36 MWh
March 2020 1.19 MWh
March 2021 1.32 MWh
March 2019 was also a month of heavy snows, and the panels were covered with snow for at least two days.
One might argue that debris on the panels has reduced output, but our daily energy production maxima in a month are also unchanged.
Jim,
Your March solar output is surprising in its consistency. Here’s mine:
March 2018 746 KWh
March 2019 841 KWh
March 2020 857 KWh
March 2021 1,010 KWh
The power generated for the month of April has never exceeded 900 KWh, so March 2021 exceeded all the previous March and April outputs by more than 10% and was typical of what is generated in May through August.
I wonder why we had such different results. Could one or more of your panels (or micro inverters) died? That happened to me last year so it may be something to check out.
There are solarimeter networks established around the world. Several years ago I saw a line-graph of daily solarimeter data from the U.S. network showing a very steady ‘base level’ over several months; with a HUGE spike for about a one-week period.
Q: Want to guess when that HUGE spike occurred?
A: The week of the Sept 11, 2001 attack on the US; when all air traffic was grounded (except a few military missions) and all high-altitude exhaust contrail effects disappeared.
Think of the implications of eliminating those high-altitude contrails worldwide.
The post-9/11 grounding of aircraft was a huge “natural experiment” – I’ve seen it cited in a number of climate/meteorology articles