Net Energy: 3 Year Update

I just finished my third year with solar panels on my roof. I'm happy to report that everything is great, I'm helping the environment and I don't have to do anything at all.  That's not entirely true, I wash the panels about three times/year but it takes less than 20 minutes each time (and less than 20 gallons of water).  So one hour of work per year to cancel out all of the CO2 emission from my house. That's pretty good.

So here's the tally of electrical energy produced compared to electrical energy consumed.

Year	Energy Produced (kWh)	Energy Consumed (kWh)
2012-2013	3915	3613
2013-2014	4027	3157
2014-2015	3937	3483

So, it looks like my average production is about 3960 kWh/year with only a few percent change per year (the first year would probably have been higher if not of a palm tree that was taken down) and my average consumption is 3418 kWh/year.  

I should say that my energy consumption this year was affected by one major event.  I could not use my (natural gas) heater during much of the winter because some skunks tore through the ducts under my house.  So I used an electric space heater during half of January and February. I think my electrical energy consumption was bumped up by about 200 kWh because of this. If we subtract the 200 kWh, the consumption is pretty close in line with the previous year, though not quite as low.  But that's ok.  A lot has happened this year.  We just had a baby, so for 8 of the last twelve months, somebody has been home all day every day, we've been lighting more rooms, running baby monitors, cooking/cleaning more, etc. And we've been running the A/C a bit more than normal.

And still, it looks like a typical year produces about 4.0 MWh and we will consume 3.3 MWh, leaving 0.7 MWh to spare.  That's enough energy to drive an electric car about 2000 miles each year on our excess (and we've already bagged ~5000 miles of excess energy in the bank).