There's an intriguing paper published by Microsoft in which the authors argue that it could be possible to send servers used in cloud computing data centres to houses and office buildings and use them as a primary heat source.
The Data Furnace: Heating Up With Cloud Computing
paper believes that the problem of heat generation in data centres can be turned into an advantage with servers placed into buildings to provide low latency cloud computing for offices or residents.
The authors suggest this approach improves quality of service by moving storage and computation closer to the consumer, enhances energy efficiency and eradicates the cost of cooling the servers by reusing their heat.
It's a fascinating example of lateral thinking. There are a number of issues to be resolved if it is ever going to take off such as the physical security of the servers, the need for zero touch management and the fact that data furnaces cannot exceed the power and bandwidth capacity of the buildings where they are housed.
Still, kudos to the authors - Jie Liu, Michel Goraczko, Sean James and Christian Belady at Microsoft Research and Jiakang Lu and Kamin Whitehouse at the University of Virginia Computer Science Department - for even thinking of such an idea. Pity they didn't take the time to go through the article and correct all the references to "Data Furances".