Watson A.Name - \"Watt Sun, the Dark Remover\" wrote:
....
My apt. owner put solar water heater panels on the roof more than ten
years ago, and I don't think they've been cost effective. The
neighborhood vandals threw rocks at one and broke it, so they had to pur
chicken wire over the panels to prevent damage. The cats used the foam
pipe insulation to sharpen their claws, so it's gone for about two feet
up from the roof. The controller and storage tanks are not working as
they should, so I would guess that the system needs repair. All in all,
even with the rebates, it wasn't as good as it was made out to be.
....

In the 80's there were a lot of government rebate programs to promote
the use of solar water heaters. This gave rise to many installers who
existed simply to exploit the rebates and as a result they installed
shoddy equipment and gave buyers unrealistic expectations. Once the
government rebates dried up these predatory companies disappeared
and their warranties along with them. This is why there was such a glut
of broken down solar water heaters and people completely dissatisfied
with the entire idea. This doesn't mean that they can't be cost
effective. I've seen many solar water heaters that have been in
continuous use for 20+ years with only minimal maintenance and the
owners of these appear to be satisfied.

Anthony