Yes, Navitron prices make it at least close to practical but it is
still expensive. I'd love to know how good they are - how can Navitron
be so cheap? Is there a catch?
Anyway, my calculations are done using Navitron pricing -
£395 for the collector + £100 delivery then £200 for a dual coil
cylinder then a controller, temp sensors, pipes, pump etc you are
looking at the best part of a grand for the bits.
I recon I can save £50/year with SDHW which is where I get the 20 year
payback without including maintenance costs.
Yes, spiraling fuel costs will reduce this and I am sure I could save
some of the costs for instance by using a solar panel to drive the pump
- no need for the diff controller/sensors or even by making my own
controller.
Any commercially installed systems I have seen are twice this price
although maybe using Navitron panels will reduce this but even with a
grant this will still be more expensive so not a short term
proposition. It is criminal that grants are not available to DIY'ers.
There should be a law against DIY-ism.