 Because mechanical refrigeration is energy intensive , active collectors are typically restricted to places where there is no supply of water that can be desalinated or purified at a lower cost and that are sufficiently far from a supply of fresh water to make transport uneconomical . Such circumstances are uncommon , and even then large installations such as that tried in the 1930s at Cook in South Australia failed because of the cost of running the installation – it was cheaper to transport water over large distances . 
