Piping cold

Solar energy for heating water has been around for centuries, but solar ´cooling´? There is something counter-intuitive to it a sort of energy alchemy seemingly at odds with physics, but solar thermal cooling is indeed the hottest new twist in the rapidly expanding field of solar energy applications. Worldwide there have been several attempts at solar chillers dating back to the mid-1800s, but these were not developed further because oil and coal energy was so cheap. Solar thermal arrays look like photovoltaic panels, but are essentially comprised of water-and-glycol-filled tubes that absorb heat energy from the sun. The heated fluid is circulated to a storage tank, where the heat is transferred via a heat exchanger to warm water for domestic use solar thermal for hot water production.