Dramatic price reduction is the one barrier with SDHW, and one thats
addressable in the years ahead imho.

Mass produced freezeproof moulded panels can be fitted into the roof so
that they replace an area of tiling, thus cutting their effective cost
for new builds.
Add suitable control as part of some standard CH controllers and the
control costs drop.
Instead of one collector per house, install a large bank of panelling
on flats to supply a communal HW source, and the paperwork and
organisation costs per flat drop, and diversity kicks in, ensuring
quick recovery.
Include a set of minimum cost unglazed panels for prewarming cold
incoming water.

Etc.

If solar cost 1/4 the price it would be worth it today. Energy costs
are on the up, and there are many ways to cut solar costs once it gets
out of the gimmick league. Also manufactured goods costs are coming
down every decade. I reckon they might well become widespread in time.


NT