The operation of the Solar Billy is very basic. Fill with water, sit outside facing the sun. After as little as 45mins you can have water hot enough to make a cup of coffee!

The heart of the Solar Billy is an evacuated tube which is specifically designed to absorb sunlight and convert it into heat. The evacuated tube has a vacuum formed between the two glass layers and so acts as an insulating flask, so when the water is hot, it stays hot for hours, even in cold weather.

The following slideshow outlines the basic steps of operation.