Studies showing the rapid consolidation of business and consumer IT into energy-efficient power centers vastly underestimate the amount of electricity used to run everything from smartphones to mainframes—and the vast majority of that power that comes from generators driven by coal.
A 2007 Environmental Protection Agency report estimated that datacenters accounted for 1.5 percent of U.S. energy use and would double by 2012. That study—and others highlighting rapid growth in datacenters to run both private and public clouds—doesn’t take into account the power it takes to run individual mobile or computing devices and the wireless networks used to connect them, according to a study released this week by consulting firm Digital Power Group under the sponsorship of the coal-promoting National Mining Association and American Coalition for Clean Coal Electricity.
The study—a meta-analysis of other research into the growth of electricity used for IT and its sourcing—argues that the global ecosystem for information and communication technologies uses nearly 10 percent of all electricity generated worldwide. Of that rapidly increasing power use, 80 percent ends up consumed by individuals or distributed work groups rather than in comparatively power-efficient datacenters, the report argues.
A 2007 study from the Environmental Protection Agency estimated that datacenters use 1.5 percent of all electricity generated in the U.S.—a number that would double by 2012. While datacenter hardware, cooling systems and other highly concentrated sources of energy use have become more efficient users of power (and in many cases, have increased their use of renewable energy), the bulk of power used worldwide for IT devices dwarfs the volume used for datacenters, and comes mostly from coal rather than wind, water or solar generation, according to the report.
The amount of power needed to charge the battery on a tablet or cell phone is negligible, but the amount required to stream an hour of video per week across wireless networks is more than would be required to power two refrigerators for a full year, according to an EPA Energy Star report cited by Digital Power. Most of that energy goes not into powering a single device, but the power demand of a chain of other devices on which it depends, not to mention the power needed for wireless networks. “Turning on a light does not require dozens of lights to turn on elsewhere,” the study reads. “However, turn on an iPad to watch a video and… devices all of the country, even all over the world simultaneously light up throughout a vast network.”
Energy consumption related to the “wireless cloud” will grow almost 470 percent between 2012 and 2015, according to the report, from the University of Melbourne’s Center for Energy Efficient Telecommunications (CEET) (PDF).
The amount of carbon dioxide pumped into the atmosphere by power plants supplying that electricity is equivalent to putting an additional 4.9 million cars on the road. Ninety percent of that increase will be due to wireless networks, compared to 9 percent from datacenters, even under estimates that U.S. companies spend $450 billion per year for new datacenter space and that datacenter power consumption increased 19 percent in 2012 alone.
The Digital Power Group report—perhaps unsurprisingly, given its backers—concludes that coal will continue to be a primary source of power for the rapidly growing IT economy and that more of the focus on power consumption should be put toward finding cleaner ways to use coal as a source.
The University of Melbourne study, meanwhile, concludes that any source of power generation that adds more carbon dioxide to the atmosphere would be harmful and that the focus of IT power efficiency efforts should be on real sources of waste, not simply the most obvious consumers. “By focusing debate and analysis on data centres, industry risks obscuring the true energy cost of cloud services and impairing any effort to make them more sustainable,” wrote Kerry Hinton, deputy director of CEET. ”Any attempt to make cloud computing more sustainable must target the most inefficient parts of the system.”
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