In article , says...
All I can say is that IMHO the consensus among those here that can count
beyond ten without taking their socks off, is that none of them will
ever realistically pay for themselves in this country. Even WITH a grant.

While that's almost certainly true of commecially available systems, if
you can make your own solar HW system with scrounged bits you could
probably save a bit of money - but it's not going to be a lot.

--
Skipweasel.
Never knowingly understood.