Sunlight falling on each tube is collected as heat by the copper plate. The tubes can be rotated to put the plate at the best angle to catch the sun. Inside each tube, mounted on the plate is a copper tube which screws into the manifold. The copper tube contains alcohol which conducts heat from the copper to the water in the manifold above.
The solar thermal system heats the water in the cylinder via one heating coil. This means it can easily be used in conjunction with a traditional boiler or immersion heater, for occasions when the solar thermal is not producing hot water, e.g. during the night.