Making the most of a free gift.

In a time of energy shortage, you aren't likely to be impressed by a home which loses 99.9% of the heat supplied to it. And yet your home – the Earth-does just that. Every day, a huge quantity of heat energy, reaches the Earth from the sun. Much of this heat is absorbed, warming up the land and the sea, but then, at night, practically all of the absorbed heat is Lost again. It escapes into space as radiation while the Earth cools down.

With so much free energy being wasted, it's not surprising that

Scientists are trying to find ways of using and storing large quantities of solar heat. A number of methods of napping this heat have been developed, but most of them suffer from one main disadvantage. The equipment used is expensive, which makes the large scale use of solar heat a costly business.

Despite this, solar energy is used for heating homes and other larger buildings in many parts of the world. Even in Britain, where sunshine can hardly be guaranteed, solar heating is being used in many homes. The homes which use solar heating best are those which have been specially designed for that use. They have been built:

To face north and south so that one side of the house receives sunshine most of the day.

With large windows facing south.

The Sun's heat rays travel through the glass and are absorbed inside the home.

With a large greenhouse on the south side.

The air in the greenhouse heats up. It can then be circulated through the house,

With solar panels on the roof.

Water from the house hot water system trickles through the panels. As it does so, the Sun heats it up.

with shutters on the windows

to prevent heat from escaping when the air outside cools.

with very thick walls which warm up during the day and radiate some of the heat into the house at night.

and. of course, with masses of loft insulation.