DIYbanter - View Single Post

wrote:
Just taking this as an example, a DIY kit, with a simple plumbing
arrangement (for those of us with tanks!), with an additional pv

panel to

drive the pump, is £1900.

Excessively expensive. Doesnt have a hope in hell of paying back.

Solar heating can payback very well indeed, but only if you design it
right. I have never seen a commerical system that I would describe as
desgiedn right.

For some odd reason, most solar engineers live in a world where cost
and payback are complete non issues. This problem has dogged solar
energy all along.

There is a good ng for this, alt.solar thermal.

Solar HW is quite tough to make pay; it can be done, but most systems
dont achieve it.

Solar flat panel space heating OTOH captures vastly more heat, costs
less to install, is simple to blue peter, and has excellant payback
figures as long as you design it sensibly, which is easy compared to
DHW heating.

And passive solar design of newbuild (or occasionally retrofit) can be
even better vfm. (When we went to Ladakh one little beacon of optimism
against the rather depressing tide of inappropriate 1st-world model
'development' of that delightful 'subsistence economy' was Helena
Norberg-Hodge's version of our CAT who were promoting such small-scale
appropriate technologies as trombe wall solar heating which could
achieve remarkable increases in comfort in buildings for the price of a
modest amount of glass and wood. (See about halfway down:
http://www.context.org/ICLIB/IC17/NHodge.htm)