They are still cool. I just recently installed one :)
The vacuum tube ones are IMHO the best, but there are also ones that circulate a heat exchange fluid in panels for direct connection to a heat-pump. The advantage of the latter is that you get good efficiency out of them in the winter, but it also means that the heat-pump has to run all the time. My vacuum tubes work fine most of the year with only a small circulation pump running (and smaller systems with a thermo-siphon don’t even need that).
It’s combined with a stand alone air-to-water heat-pump that shares a hot water storage container with the solar thermal panels. Prices are hard to compare and I actually got a small government subsidy for it as well, but the solar thermal vacuum tubes alone should be less than $500 for a typical family home.
They are still cool. I just recently installed one :)
The vacuum tube ones are IMHO the best, but there are also ones that circulate a heat exchange fluid in panels for direct connection to a heat-pump. The advantage of the latter is that you get good efficiency out of them in the winter, but it also means that the heat-pump has to run all the time. My vacuum tubes work fine most of the year with only a small circulation pump running (and smaller systems with a thermo-siphon don’t even need that).
What did you end up spending for it? Are you using it paired with an existing hot water heater?
It’s combined with a stand alone air-to-water heat-pump that shares a hot water storage container with the solar thermal panels. Prices are hard to compare and I actually got a small government subsidy for it as well, but the solar thermal vacuum tubes alone should be less than $500 for a typical family home.