Ecology site GreenUPGrader shares a report from Oak Ridge National Laboratory that suggests ways to reduce fuel consumption used for heat.
Basically, use the heat from technology that's already in use.
From the report, an example:
"In the prototype system, water is pumped through “microchannels” within the data center’s computers. This water cools off the computers, saving the cost of air conditioning to accomplish the same purpose. This water, now carrying the heat from the computers, then gets pumped out of the data center to nearby homes, where it provides heat. According to a report in IEEE Spectrum, “a 10-megawatt data center could produce enough energy to heat 700 homes.”"