Tuesday 3 August 2010

Gloomy summer

In late June, the Sun shone well and my array of panels were reaping over 20 units of power daily. Since then, the Scottish summer has broken and wave after wave of Atlantic maritime fronts have washed over us. We get a front every two to three days and the associated cloud has kept a lid on power generation.

On 20 June, my 30-day average peaked at 15.7 units. Now at the start of August, the 30-day average is down to 10.4, helped in large part by poor Glasgow weather for the two weeks we were away in the Western Isles, when daily power averaged only 9.4 units.

Another interesting figure is that my daily average since the panels were installed is at 12.57 unit and gently falling as the days begin to shorten and the Sun gets lower. A good heatwave would help but there's no sign of it. Still, I'm well clear of the 6.85 average that the government estimated. Here's a chart of daily usage since I started. The two smoother displays represent the 30-day average (orange) and the overall average (yellow). The straight line towards the right is the generation over the 14 days we were on holiday. Since I wasn't there to take a daily reading, I've had to take the total generation over the two weeks and divide it by the number of days. Its low value indicates how poor the weather was at home while we enjoyed the sunshine in Lewis.



There's not really any other news at the moment. The next reading to go the FiTs people will be in September and I expect it will yield £450.