Combination hot water solution on a plate

According to Stokvis Energy Systems, solar thermal water heating systems are highly efficient because evacuated tube solar collectors are designed to maximise the solar energy absorbed while minimising heat loss through radiation.

However, solar systems require some form of storage and, says Stokvis, this is not necessarily the most efficient way to deliver hot water when the primary heat source is from a boiler.

One answer is a hybrid water heating system using solar thermal technology combined with a low water content plate heat exchanger to provide hot water instantaneously, 'topping up' water temperature without the need for storage, other than that required for the Solar input.