As you gaze upwards at the leaden skies and I await the next dose of BS from @bexleyconservatives BiB will pour further gloom on your day by confirming what you were already beginning to suspect. This is the worst summer for sunshine for a very long time.
My friend who died on Sunday morning may not have been able to navigate Bexley Council’s rotten website but he wasn’t at all bad at computer programming. When I had my solar panels installed on 7th January 2011 he rapidly knocked up a program that interrogated the inverter and posted the results both as raw statistics and a 15 minute histogram to the web. Thus I can tell you what the light levels have been in Belvedere (strictly speaking the amount of electricity generated) for every 15 minute segment of the day for nearly seven years.
January 2017 was the brightest January in all those seven years. It was 1% brighter than 2014 and 2% brighter than 2012. January’s days being so short and the sun elevation being so low means that very little electricity is generated however bright January may be so there is little money to be made.
February was the dullest since 2011 which was slightly worse. March 2017 wasn't good being bettered by 2015, 2014 and 2012.
Aprils have been remarkably consistent, they have all been the same within one or two percent. Then came May 2017. Worst ever May by quite a margin.
There is an EU inspired prediction for solar power generation that takes every factor into account. Latitude, longitude, roof elevation, direction faced; everything down to the make and model number of the panels.
June is potentially the most lucrative month because the sun is high and the days are long. It is when real money can be made but June has always been a disappointment by EU standards. June 2017 was the third best in seven years but only 2% above 2014 so not really very good.
July was a washout. Tied with 2012 but 25% behind what it could have been. August is going the same way. Slightly better than 2011 and a whole 13% better than 2015 but rubbish overall.
In terms of total electricity generation 2017 is running about two and a half weeks behind all but one of the six previous years.
I clearly remember 1976. Now that was a summer.