What's interesting is that, depending on how a house is heated and how power is generated in an area, having a low power PC might be worse for the environment.

What's interesting is that, depending on how a house is heated and how power is generated in an area, having a low power PC might be worse for the environment. I'm thinking older houses heated with natural gas but where electricity is mostly supplied by renewables. In this case, it's better to heat less and have the PC act as a heater, that performs computations as a side effect!