Saturday, 4 May 2013

Solar generation. Is April the cruellest month?

"April is the cruellest month."

This is the first line of T. S. Eliot's poem "The Waste Land." 

Some consider this poem, published in 1922, to be the greatest of the 20th century.

                      Here is the beginning of the poem. 

April is the cruellest month, 
breeding Lilacs out of the dead land, 
mixing Memory and desire, 
stirring Dull roots with spring rain. 
Winter kept us warm, covering 
Earth in forgetful snow, feeding 
A little life with dried tubers.

What an earth has this got to do with solar energy, I can hear you collectively shouting at me!

Well quite a lot, if you believe in climate change and the way it's affecting our environment. Most of us remember the phrase "April showers", we expect the weather in the UK in early spring to be decidedly variable even by our standards. 

In 1922 when T. S. Eliot wrote this poem he was reflecting a view of the seasons which he could be fairly confident in bringing the possibility of better times, but be still haunted by the specter of winter.
The graph below shows average monthly daylight hours. These figures are based on years of data and take into account the minor fluctuations which occur on a cyclical basis.  

Remember what a terrible summer we had in 2012? I mention this because I was astonished to discover that April 2013 was equal in output to July 2012.
This sounds ridiculous when you consider all the long summer days of July and August, but if you look at my monthly kWh output below you'll see the pattern is completely different from the the one above.


April shouldn't be a high output month for solar energy. So, should we accept that this year is an anomaly, or is it an indication that seasons and weather patterns are changing?
Living in the East Midlands my 12 months output for 2012-2013 will be lower than 2011-2012. It's still going to be higher than the figures quoted by the installers, but it's still a bit of a disappointment. 

How are YOUR figures? Are they lower than the previous 12 months?
It would be interesting to hear your experience.

Twitter: (@solaricarus)


  1. Did you mean that April's output was as good as July 2012 (not June)? It was the same for me, April's output of 411 kWh was 17% more than I obtained in April last year. In July last year I got 424 kWh. However, let's not forget that summer 2012 was rather poor for output, May was the best month that year for me. And the first 4 months of this year have seen a modest (3%) improvement on the same months last year. I'm hoping to do rather better in May, June and July this year!

    1. Well done Chris.
      I rely on your "sub-editor" skills to make up for my lapses!

      Interesting that your experience in Lancashire nearly mirrors mine in the East Midlands. My April output in 2013 was 21% higher than 2012, also like you May 2012 was the best, so there's hope yet this month.

      Unlike you, my first 4 months output are massively down.
      January= minus 53%
      February= minus 5%
      March=minus 54%
      April= PLUS 21%

      Roll on summer...

  2. Similar figures for my solar generation - also in the East Mids (Leicester) - Apr 13 was +22% of Apr 12, but Jul 12 (276 kwh) did beat Apr 13 (256 kwh). May (so far) is looking to be another bumper month!