Real World Solar Generation

I installed an 18 panel (about 2.5 Kw) system in South San Jose.  These are the results of the generation since 2003. We do not use a lot of electricity so this was entirely to cut our carbon footprint.

Click on any of the graphs for a full size image.

Average Daily Production

Not surprisingly the daily generation peaks in the summer.  That is mostly a function of longer days since the peak rate of production is in the spring.

Some comments on the history.  In 2006 and 2008 there were several smoky fires in the vicinity.  In 2006 I did not get up on the roof and clean the cells.  In 2008 and 2013 I did. You can see that it made quite a difference.  From now on I plan to clean the cells about once per month.

Solar Production as of May 2013




Generation Rate

Measuring the generation rate during a single day was informative.  The cells are definitely direction and would like to be pointing directly at the sun.  Like most residential installations my cells are fixed at the azimuth of my roof, but are tilted at about a 45 degree angle from the ground.






The peak rate of generation is the spring.  This can be understood by looking how the sun behaves during a year.