Pretty much all of the electricity used to power computer processors turns into heat, and dealing with that heat is a big problem for data centres. 20-60% of the energy used in data centres is used for air conditioning! 
That wasted heat is also a big opportunity...
A large data centre could provide hot water for 11,000 homes.
But moving heat is hard, it requires new infrastructure or a pre-existing heat network. Moving data is easier, so we've taken the servers to where heat is needed, in people's homes.
We harness the heat, transferring it into domestic hot water tanks, giving families living in fuel poverty free hot water. By removing the air conditioning energy cost and offsetting a hot water heating cost we're able to offer processing that is far more energy efficient.