Here's something I bet you didn't know...

Of course, it's from Patrick Mannion of EE Times, so it bears further investigation:

WiMAX and metro Wi-Fi are both more energy cost effective than cellular, according to a report by ABI Research (London, U.K.). The observation comes into stark relief against the backdrop of rapidly-increasing energy consumption as carriers move to high-data-rate mobile broadband access.

For those broadband networks, energy costs represent the third most significant operating expense (OPEX) for cellular carriers, and fluctuating energy costs are a significant area of concern for business planners, said the report entitled, "Energy Efficiency Analysis for Mobile Broadband Solutions." The move to higher data rates means that the energy required per subscriber arising from increasing data uptake will push per-subscriber energy OPEX for cellular solutions past acceptable barriers—unless carriers move from a traditional cellular-only approach to one that integrates WiMAX and metro Wi-Fi.

Stuart Carlaw, director of wireless research at ABI Research, says that "From a pure coverage perspective WiMAX is twice as energy-cost-effective and metro Wi-Fi is 50 times more energy-cost-effective than WCDMA. When data traffic is factored into the equation, WiMAX can accommodate 11 times today's average data consumption and still be more energy-cost-efficient compared to WCDMA or HSDPA.

A recent ABI Research study found that the total energy consumption arising from mobile broadband service delivery is forecast to grow from 42.8 billion kilowatt hours (KWh) in 2005 to 124.4 billion KWh in 2011. The Asia Pacific region will account for the majority of this growth.