I've got a steam heated brick house with a flat roof.I was planning on building some solar hot air boxes to supplement the heat in the winter. Then I started reading about parabolic /trough solar steam generators.Does anyone think its possible to to make enough steam on a sunny day with a big enough array to pipe it in to the steam system and actually fill the radiators?
It's theoretically possible, but it wouldn't work very well because:
1. You could only generate steam for 6 hours during the day.
2. Your storage tank would have to operate near the boiling point. Tanks that hot really hurt system efficiency because they lose heat too quickly.
For these reasons, no one that I've ever heard of has tried it.
Money would be better spent on conversion to a 96% efficient hydronic system first. Then conventional solar could be added.
Superinsulated Passive solar house, Buderus in floor backup heat by Mark Eatherton, 3KW grid-tied PV system, various solar thermal experiments