One of the slew of emails that came in over the weekend was from Stacey, a local architect. Stacey asks:
I just read the SF Chronicle article about your Sunset neighborhood house. Thank you very much for your efforts in going sustainable. I think this is a very important thing to be doing.
However, I have a question for you. Since your house’s main energy consumption component is heating, why did you spend $20,000 on a PV system when you could have spent half that on a solar thermal system to heat your hot water instead of using natural gas (a non-renewable, carbon emitting fuel)? You would save much more energy doing that than those PV panels will ever produce. In the total energy/polution equation, this would have greatly reduced your house’s energy consumption and carbon emmisson. The solar thermal would have had a much faster payback as well, despite the incentives being less than PV, particularly considering how you are utilizing hot water to heat the house.
An outstaning question, my response below. But I ask you, gentel reader,wWhat do you think about PV vs Solar Thermal systems?