Remember Merri Solars, the Melbourne bulk buy PV group that featured in ReNew 109? In that issue they reported on the performance of the solar systems they purchased the year before. Since then similar groups have wanted to know how the group has been going, so here’s an update from member Simon Pockley.
Over the last two years the group’s grid-connected PV systems have collectively generated more than 35 megawatt-hours of electricity. Latest performance data continues to show that tilt angle (the main difference between systems) is not a significant performance factor.
The following graph shows how the output of the systems have danced to a very similar tune over the months.
Comparison of average watts per panel, per day 2008-2010
However, all systems generated more kilowatt-hours of electricity last year (2008-2009) than they did this year (2009-2010). Systems in the next graph are ranked by tilt angle, preceded by the number of panels. Is the lower output due to weather conditions (a poor solar year) or to a gradual decline in system performance?
Comparision of total kWh generated in 2008-2009 (light bar) with total kWh generated in 2009-2010 (dark bar)
Merri Solars publish their monthly outputs on a community web site http://merriaction.org. If you’d like to know more, please contact simonpockley@gmail.com.
Read Merri Solars’ ReNew 109 article here
This entry was posted on Thursday, September 23rd, 2010 at 3:46 pm