crossy
Solar Addict
Background
Myself and JAS live about 20km apart as the crow flies, at this time of year in Thailand there's no localised storm activity so we get broadly similar weather. Although our systems are of different capacities the panels are oriented in roughly the same direction and angle. We also tend to clean our panels on a sort of regular basis.
The factor we used to determine if cleaning made a measurable difference was Total Daily Solar Generation which would be in kWh.
What we did
Testing took place over two 2-day periods.
Period 1 - 27th and 28th February 2023
JAS cleaned his panels on the morning of the 28th, I did nothing (my system is the control or weather-reference).
27th JAS = 21.92kWh Crossy = 40.60kWh
28th JAS = 23.31kWh Crossy = 38.30kWh
The reference output went down by about 4.25%
If we apply that factor to JAS output on the 28th we get a corrected output of 24.71kWh.
So, the effective change from cleaning is about +12.7%
Period 2 - 4th and 5th March 2023
This time I cleaned my panels on the morning of the 5th and JAS did nothing (so his system is the reference)
4th JAS = 23.22kWh Crossy = 35.9kWh
5th JAS = 22.39kWh Crossy = 37.9kWh
The reference output went down by 3.6%
Applying that factor to my system output on the 5th gives a corrected output of 39.30kWh
So, the effective change from cleaning is about +9.5%
Conclusion
It's not a particularly good test methodology and neither set of panels was particularly dirty (JAS panels were probably a bit dirtier than mine), but there does seem to be a correlation between cleaning them and a not insignificant increase in output.
Of course, this does assume that I've done my sums correctly, which is why I've included our measurements if anyone wants to pull my maths apart ?
We will do the same test again when we clean again, actual schedule hasn't been decided as yet, probably about a month unless things look particularly grubby.
Myself and JAS live about 20km apart as the crow flies, at this time of year in Thailand there's no localised storm activity so we get broadly similar weather. Although our systems are of different capacities the panels are oriented in roughly the same direction and angle. We also tend to clean our panels on a sort of regular basis.
The factor we used to determine if cleaning made a measurable difference was Total Daily Solar Generation which would be in kWh.
What we did
Testing took place over two 2-day periods.
Period 1 - 27th and 28th February 2023
JAS cleaned his panels on the morning of the 28th, I did nothing (my system is the control or weather-reference).
27th JAS = 21.92kWh Crossy = 40.60kWh
28th JAS = 23.31kWh Crossy = 38.30kWh
The reference output went down by about 4.25%
If we apply that factor to JAS output on the 28th we get a corrected output of 24.71kWh.
So, the effective change from cleaning is about +12.7%
Period 2 - 4th and 5th March 2023
This time I cleaned my panels on the morning of the 5th and JAS did nothing (so his system is the reference)
4th JAS = 23.22kWh Crossy = 35.9kWh
5th JAS = 22.39kWh Crossy = 37.9kWh
The reference output went down by 3.6%
Applying that factor to my system output on the 5th gives a corrected output of 39.30kWh
So, the effective change from cleaning is about +9.5%
Conclusion
It's not a particularly good test methodology and neither set of panels was particularly dirty (JAS panels were probably a bit dirtier than mine), but there does seem to be a correlation between cleaning them and a not insignificant increase in output.
Of course, this does assume that I've done my sums correctly, which is why I've included our measurements if anyone wants to pull my maths apart ?
We will do the same test again when we clean again, actual schedule hasn't been decided as yet, probably about a month unless things look particularly grubby.
