Although my system wasn’t operational until late February of 2016, the planning for it really got underway at the end of 2015 and, since December marks the month with the shortest daylight period (and theoretically the lowest solar production), the start of 2017 seems as good a point as any to revisit the topic.
In 2016, my system in the high desert of southern California generated 4.6 MWh of electricity. The peak production was in May (566 kWh), due largely to the decrease in panel efficiency with hot ambient temperatures as the desert summer got into full swing in June and July. The lowest production was in December (273 kWh) due to a combination of shorter days and an unusually cloudy weather pattern.
Production by month
Typical May week
Typical December week
As anticipated, by using my swamp cooler and the natural cool nights of the desert I didn’t run my AC much at all this summer, in fact the only times I did run it were when smoke from nearby forest fires made it undesirable to open the windows, leading to a surplus generation. Likewise, increased time spent indoors (using lights, doing projects with electric tools, …), running the blowers on the (propane) furnace, and more heating needs for the hot tub have resulted in a higher daily electrical usage in the winter, and I am generating less than what I consume. Being on a kWh based net metering plan as well as having been away much of the past few months on business travel, I’m currently on track to come out just a bit better than even, but that will depend how the next few weeks go.
All said, I’m still very happy with the solar installation as well as the cloud based monitoring capability that came with my SolarEdge inverter. I have to say that it’s been very easy to forget I even have the system on the roof – aside from quickly rinsing the dust off the panels a couple of times it has been zero maintenance and just quietly does it’s job. I would still prefer to be allowed by the utility to install a larger system so I could have the capability to be net zero, particularly as I would much prefer to run the air-conditioner during the summer and not waste water in the desert for cooling, but the current economics of water vs electricity are skewed so much toward using a swamp cooler that it’s not a battle available to fight.