Evacuated tube technology was first developed in Australia at the University of Sydney — some 40 years ago.
More recent developments have improved their technical efficiency and they are now rapidly invading the solar hot water market worldwide as Chinese manufacturers have managed to bring down the manufacturing costs to very competitive levels.
So now, at long last, we have a state-of-the-art solar hot water system that is very affordable. They have also stood the test of time, systems installed 40 years ago are still going without maintenance.