It can't be done economically with solar. That's the whole point of the thread article. The example you cite of a solar water heater is a good case in point. Compare the real cost (absent any tax subsidies) of that installation over its limited (as you found out) lifetime and compare it to simply buying the electricity and you'll find that the latter is cheaper.
--Boot Hill
Apples and oranges. Saturnalia is referring to solar thermal. It sounds like what happened is that the pipes simply clogged up. In a custom installation that would be a costly thing to fix. But if that could be mass produced efficiently that would be another story. I wouldn't necessarily mind having a solar assist to my home heating needs if it would cut my gas bill and didn't bankrupt me to fix. Gas is sky high.