On 09/01/2019 12:36, fred wrote:
On Wednesday, January 9, 2019 at 12:01:39 PM UTC, dennis@home wrote:
On 08/01/2019 22:11, fred wrote:
How effective are these ? Are they much of an improvement over the old types ?


Because its a heat pump it can work in the dark, but you get better
efficiency when the sun shines on them.

If you just want hot water then normal passive solar panels are somewhat
easier.

Given all the above would photo electric panels (or whatever they are called) be more cost effective ?


They were better because you got a lot of payments for the electricity
even if you used it all yourself.

As for being green then passive solar water heating is probably greener
than solar PV.