I think most Americans don't even know they have had "cheap fossil fuels."
Anyway, I was hoisting collectors onto roofs during that boom in installations. In Colo, we also had 30% additional tax credits, and still it was mostly rural homes with pricey propane that got solar. Many urban and suburban systems underperformed. Analysis showed two problems: Shading from trees, and more variability of HW use than our calcs assumed.
Most of USA has occasional freezing conditions which complicate systems compared to many of the leading countries. California is trying to encourage solar DHW for apartment complexes. A good match.
DHW gallons per day per each home or apartment is down from the 80's due to better washing machines, dishwashers and showerheads, so it can be a lot of complicated work for modest savings on homes with only 2 or 3 occupants. And now, yes, typical (interior, self-contained) HPWHs are great in warm climates because they also provide AC when water is heated. It's cold here and I'm in a two person household so I just use resistance elec, and try to time our use for off-peak when renewables are a larger fraction of our power.
also would be nice to cover hot water consumption in homes - I think most is showers and so how much could we solve this with more efficient shower heads which are climate solution tools in that they require less energy to heat less water?
I've read that now solar + heat pump is cheaper than this overall and more flexible as you can use abundant/cheap solar when at peak and the hot water tank as thermal storage. Have you covered this at all?
I think most Americans don't even know they have had "cheap fossil fuels."
Anyway, I was hoisting collectors onto roofs during that boom in installations. In Colo, we also had 30% additional tax credits, and still it was mostly rural homes with pricey propane that got solar. Many urban and suburban systems underperformed. Analysis showed two problems: Shading from trees, and more variability of HW use than our calcs assumed.
Most of USA has occasional freezing conditions which complicate systems compared to many of the leading countries. California is trying to encourage solar DHW for apartment complexes. A good match.
DHW gallons per day per each home or apartment is down from the 80's due to better washing machines, dishwashers and showerheads, so it can be a lot of complicated work for modest savings on homes with only 2 or 3 occupants. And now, yes, typical (interior, self-contained) HPWHs are great in warm climates because they also provide AC when water is heated. It's cold here and I'm in a two person household so I just use resistance elec, and try to time our use for off-peak when renewables are a larger fraction of our power.
I was wondering why CO has so many solar water heaters. That 30% additional credit you mentioned answers it!
Australia in that first graph twice!
Good catch, thanks!
Are there any provisions for solar water heaters in the IRA Bill?
I believe there's a 30% tax credit: https://www.rheem.com/inflation-reduction-act/
That's not bad. Thanks for the link - very helpful!
also would be nice to cover hot water consumption in homes - I think most is showers and so how much could we solve this with more efficient shower heads which are climate solution tools in that they require less energy to heat less water?
Good point!
also related to this I have a flume water monitor and a bluebot to help monitor actual water consumption in my house
MIchael you may find https://www.ppic.org/publication/water-use-in-california/ interesting if you haven't seen it
I've read that now solar + heat pump is cheaper than this overall and more flexible as you can use abundant/cheap solar when at peak and the hot water tank as thermal storage. Have you covered this at all?
I haven't, but I'd love to see an analysis on it.