Как читается ordinary homes can be easily converted to use solar

Как читается ordinary homes can be easily converted to use solar energy. They can make a simple heating system. A flat plate solar collector is fitted to the roof. It must be painted black on one side. Black surfaces absorb energy well, and make sunlight into heat easily. The heat stays between the insulation and glass. Cold water is pumped through tubes in front of the black plate and is warmed up. The hot water can be used for washing, cooking and heating rooms