The ERP (Effective Radiated Power) of a digital OTA station need only be a fraction of the ERP needed by an analogue OTA station to cover the exact same area.
Further energy savings are realized throughout the entire broadcast procedure due to digital OTA's inherent efficiencies.
Digital OTA is better for the environment in many ways.
Funny you say that because I have had at least one station engineer say the opposite to me much to my surprise. Unless they didn't understand the question, which I doubt.
I can watch a digital station that I can't measure on my SLM. I can't say the same for analog. The noise floor for the meter is -35dbm.
I have estimated that I can receive stations as low as -50dbm (using an attenuator with a known signal and subtracting the additional attenuation from the orginal signal reading).
Occasionally picking up 66.1 (only three times so far and only for a couple of hours at best) is one of the best proofs.
Shutting down the analogs will stop a LOT of the interference we're getting on digital channels.
Goodby Gilligans Island. (at least some of it)