Saturday 14 July 2012

How do SAP Figures Compare to Actual Solar Panel Output?

When we were getting quotes for our solar panels all installers had to provide standard figures to show the estimated output of the panels. Some installers also provided much higher numbers to justify their installations as being superior.
How do SAP Figures Compare to Actual Solar Panel Output?
How do SAP Figures Compare to Actual Solar Panel Output?
Now that we have had the solar panels for 8 months it is interesting to compare the actual output with the SAP 2009 figures that were provided at the time of installation.

Snow on solar panels
How do SAP Figures Compare to Actual Solar Panel Output in winter?
Our solar panels are 14 Sungrid panels at 215W each giving a total potential output of 3010W (3.01kWp) The SAP 2009 annual yield was quoted at 2479kWh.

So far as of 13 July 2012 we have already generated 1972kWh of electricity in one of the worst British summers since records began with the wettest April and June since 1910. Extrapolating the generation figures over the next few months we could well see a total for the year of 3000kWh.

Solar panel generation - actual month by month output figures for the UK

Solar panel electricity output in the rain
Solar panel electricity output in the rain
Using PV GIS data to calculate the annual estimated output gives a figure of 2905kWh for the electricity produced by our solar panels for the year which again we should be able to beat even with the current amount of rain!

Comparison of predicted solar panel outputs for different estimation methods


SAP 2009                                 2479kWh
PV-GIS                                    2905kWh
Current Estimate on actual:     3000kWh

2 comments:

  1. June total was 249.18kw, but only had 8x250 panels working, until June 25th when all 14 panels were up and working.July has been woeful so far,best day 18.12kw worst day 1.12kw..Look forward to comparing figs..Estimated annual generation is 2951.00 ummm..hope the jet stream sorts it self out

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  2. first day of sunshine..23.13kw Started at 6.30am finished 8.30pm .max output 2.86kw.. didn't reach 3kw so does this mean the best of summer production is over..

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