We are very close to choosing our solar hot water system and installer. It is something we were thinking about even before we went for the solar PV, and when the latter system was designed, we made sure there would be plenty of room for thermal collectors. Now that we have whittled down our oil consumption, solar hot water is the natural next step.
And how much we’ve whittled it down became obvious last week. An enthusiastic referral brought in a last-minute installer for a site visit – we have nine estimates already lined up, but a tenth can’t hurt. This lady was very down-to-earth and she loved our small home, with the wood stove, the insulation, and the PV array, of course.  When we told her how much oil we use for hot water, and for that and heating, she said: “that’s not possible.” Then I told her about the Riot, and she looked around again, and believed it. “I’m glad you told me,” she said, for the sizing of the system.
According to our August Riot, when we had a full house (5 adults, one child), we used about 10 gallons of oil for heating water. Over the year, our total consumption of oil (hot water and heating) is about 200 gallons. That is about 25% of the US National Average.
So, we’ve reduced our barrel of oil (in the first year of our Riot – before we had the wood stove – we used about 600 gallons of oil in general, that’s 75% of the US National Average) to a bucket of oil (200 gallons), and now we’re looking at reducing it even further, to… half a bucket of oil (since it turns out, then, that we use about half of our oil for heating water and half for heating the house).
Now it’s just a matter of deciding what we want as a secondary backup (for when the sun isn’t quite up to heating the water enough): oil, electrical (we do have *some* solar PV overproduction), or heat pump?
I’ll keep you updated!
PS. We also just we filled up our two oil tanks (the previous owner needed two so her 50-year-old furnace could overheat her uninsulated house) with 358 gallons of BioHeat, a biofuel. May it last us three years, even more!