This needs to include the energy cost of data transmission to/from cloud data centers as well for a fair comparison. These server farms don't exist in isolation.
I'd say so. It makes a difference when you're doing things like hyping Google for using only renewable energy sources for their cloud data centers. OK, cool, but all the network infrastructure along the way doesn't.
Only somewhat related, but I'm quite certain that on premise solutions would win over most cloud services if the energy cost of data transmission was factored in.
