music friday, 2007 edition
what i watched last week

solar panel update

We’ve had the panels running for about ten days now, and have eight days of data to work with.

  • From November 7-14 of 2012, we averaged 37.75 kWh a day from PG&E.
  • From October 30-November 6 of 2013, we averaged 24.5 kWh a day. (We had more people staying here last November.)
  • From November 7-14 of 2013, we averaged 10.75 kWh a day.

So we’ve taken roughly 70% off our electrical usage from a year ago, and more than 50% off our usage from the period just before the solar panels kicked in.

The website that monitors our panel usage includes tidbits like this:

  • Since starting solar, we’ve reduced emissions equivalent to not driving a car for 179 miles.
  • We’ve reduced our carbon footprint equivalent to 181 pounds of CO2.
  • We’ve reduced emissions equivalent to planting two seedlings grown for ten years.

Keep in mind, it’s November in Berkeley. The daily power produced varies according to the amount of sun we get (i.e. how much fog there is). We’ll make more power in the summer time.

The PG&E bill will be lower by more than 50%, since they use a tiered system where you pay more for energy you use over a certain baseline. Our solar system is constructed to reduce our usage to approximately the baseline, so the 50% or more that we don’t use will reduce the bill by a lot more than 50%.