wrote
Rod Speed wrote
Matthew Maddock wrote

We are moving to France in a few months to a house that needs
renovating etc. There is no existing hot water system, so that got me
thinking that instead of putting in the usual electric water heating system
that is common in France, a solar system might be nice.

They're hardly ever good value where mains power is available.

I've seen consistent proclamations that a solar DWH system is the
best buy for the money that can be made after pure conservation.

Only by one eyed fools who havent got a clue about the basics.

And those comaprisons are verses natural gas. I would
expect solar verses electric to be a very good proposition.

It isnt. Largely because the MUCH higher capital cost cant
be justified economically. In spades in France where the
bulk of electrical power comes from nukes which dont even
consume natural resources in the generation of the power.

And then there's the resouces wasted with the relatively high
tech approach to solar hot water in the system being discussed.

Why would you think that isn't true?

Its mostly basic economics. The MUCH higher capital cost with
the system being discussed wont even pay for the electricity
that would otherwise be used if you have to borrow that money,
or even if you just forego the interest on the extra cash etc.

http://www.builditsolar.com

Just another rabid one eyed pack of lies on the economics.

Solar does make good economic sense with SOME situations,
most obviously with solar pool heating where the capital cost
is minimal, and the losses very high.

Solar can also make sense with air heating, particularly when its
designed into the house before construction, but its hardly ever
good value for water heating when offpeak mains power is available.