CWmike writes: Reducing energy consumption in data centers, particularly with the prospect of a federal carbon tax, is pushing vendors to explore an ever-growing range of ideas. HP engineers say that biogas may offer a fresh alternative energy approach for IT managers. Researchers at HP Labs presented a paper (download PDF) on using cow manure from dairy farms and cattle feedlots and other 'digested farm waste' to generate electricity to an American Society of Mechanical Engineers conference, held this week. In it, the research team calculates that 'a hypothetical farm of 10,000 dairy cows' could power a 1 MW data center — or on the order of 1,000 servers. One trend that makes the idea of turning organic waste into usable power for data centers is the moves by several firms to build facilities in rural locations, where high-speed networks allow them to take advantage of the cost advantages of such areas. But there are some practical problems, not the least of which is connecting a data center to the cows. If it does happen, the move could call for a new take on plug and play: plug and poo.