When a computer works on a group of programs,it can get very hot.Cooling the computer can cost a lot.So some scientists wonder what would happen if the heat from the computer could beused. Large Internet companies such as Google and Microsoft have thousands of computers.As these computers deal with information,they produce lots of heat,so they need huge cooling systems .These systems send the heat in to the air. A company in Holland thinks paying to make the computers work and then paying again to cool them are a waste of energy.So the company developed a special device-thee-Radiator. Boaz Leupe,head of the company,says that e-Radiator works as a heating system and saves money.He explains that the energy is used twice-once to heat the home and once to cool the computer and that the users don't have to pay to cool their computers. Five homeowners in Holland are testing the heating system in their homes. "We pay for the computer using,so,in that way,homeowners get heating for free,"Boaz says.Jan Visser is one of the homeowners."If you use the computer more,the e-Radiator producers more heat,"he says,"It cannot provide enough heat if you don't use your computer often."But he is ready to try it.It's a great help for his family. The company says e-Radiators produce heat temperatures of up to 55degC.It says the system could save its users about 440 a year. The e-radiator is mainly used  _  .
to drive the computer to help Microsoft to heat the computer to provide heat