Following on from the recent rather dubious claims that Google searches consume similar amounts of electricity to boiling a brew, perhaps it would be worth us all taking a stock check of the costs of Internet TV. I would expect that broadcast TV (either by satellite, cable or terrestrial signal) has inherently low electricity consumption, since a small number of source nodes deliver content simultaneously to a large audience. With Internet delivery, however, each transmission is provided on an individual basis. One server can provide multiple content streams simultaneously, but each of these streams must be individually delivered through the IP-based network of the Internet.
I wouldn't claim to know whether one method of delivery is more efficient than another, but given the strong growth in on-demand and live TV over the Internet I think that its energy costs need to be understood before it becomes a significant delivery platform.