April 24 was the first anniversary of our solar electric installation. Over the year we generated just over 12 megawatt-hours of electricity.

I haven’t finished analyzing the numbers, but here’s one telling set of statistics:

During the not-quite four months between moving in and installing the solar panels, we paid PG&E $600.37 for 2,785 kWh of electricity over 110 days, an average of $5.46 per day.

During the comparable period this year, we paid PG&E $114.45 for 573 kWh over 112 days, an average of $1.02 per day.

The daily average over the entire year isn’t that low — it looks like about $2.40 from my preliminary calculations — because in the middle of the winter we don’t generate much, and in the middle of the summer we generate a lot but use even more for air conditioning.

I don’t know what our return on investment is, because I haven’t calculated our net savings (what we would have paid PG&E if we hadn’t installed the solar panels, compared to what we did pay). I hope to have that figured out soon.