Friday, 24 May 2013
Solar Panel Performance - one year on
We now have one full year's worth of operational data from our five-panel experimental array, rated at 540 Watt-peak (Wp) in total.
So, without further ado, here's the cumulative AC energy graph for the array from 04-May-12 to 03-May-13. Click on the figures to make them larger and easier to read ...
and here's the output on a month-by month basis.
and on a 'unitised' basis, i.e. per installed Watt-peak of capacity.
Our forecast in my post from 04-Nov-12, on the economics of the array, predicted an annual output of 254 kWhr of usable AC electrical energy, but we actually only achieved 241 kWhr in the period.
As we described in a more recent post about a comparison between domestic solar and wind generation, our solar panel installation is set on a low-level roof and the sun does not rise high enough to clear the trees at the bottom of the garden during the depths of winter. The graphs show very little energy production between the start of November and the end of January. This accounts for the lower than expected annual performance.
The middle of last year was generally very poor here in terms of weather, and this year has also started badly, but hopefully things will start to improve very soon and we'll see the sun more often.
We'll post again in a year's time, to see if there's been any improvement in performance during the second year of operations....