David Hansen wrote:

8--------
Early adopters retrofitting houses will undoubtedly bring the price
down, as we see in other fields.


So it's sensible to watch and wait about solar hot water until either a rise
in fuel prices or lowering costs of solar or both make the idea viable.
I've been doing that since about 1977 when I was planning to build and
install a very cheap home made system using old radiators and suchlike for
fun (I had a big south facing garden so they didn't need to go on the
roof). It never happened for other reasons but I've continued to consider
solar. I like the idea, but so far I've not been able to see a financial
benefit even on a DIY installation.

So I'll just wait a bit longer.

Edgar