Cow power is a term for the conversion of manure to usable energy. The energy produced can supplement the electric power offered by a utility or supply power for a facility, such as a factory or a data center.
Cow power in the electric grid
The Central Vermont Public Service (CVPS) offers customers cow power-derived electricity. Here’s how their process works: Each cow produces up to 30 gallons of manure a day. That manure is contained in an anaerobic digester, in which bacteria convert the manure into methane and other byproducts. Pressure created by the expansion of gases causes the biogas to flow through a pipe to fuel an engine that, in turn, runs a generator. The electricity generated is fed into the CVPS electrical system for distribution. The generator’s waste heat also keeps the digester warm to aid its processing. The byproduct is odorless composted manure, which can replace straw or sawdust for animal bedding or be sold to consumers.
Cow power in the data center
HP representatives delivered a paper, “Design of farm waste-centered demand-driven supply side infrastructure for data centers,” at the 2010 ASME International Conference on Energy Sustainability. The paper described how a dairy farm with 10,000 head of cattle could supply a megawatt (MW) of electricity. 1MW (a million watts) is sufficient to run a typical data center, with enough left over to supply some of the power required to run the farm. In return, the heat produced by the data center can be used for other purposes, such as improving the process of extraction to increase the yield of methane.
According to the United Nations, methane from livestock accounts for 20% of greenhouse gases produced worldwide. Methane is twenty times more potent as a greenhouse gas than carbon dioxide; recent calculations indicate that methane may be responsible for 30% of global warming since the 1750s. Converting methane to energy rather than letting it dissipate into the atmosphere mitigates that effect.
In a discussion of methane’s influence on climate change, NASA climatologist Drew Shindell said, "If we control methane, which the U.S. is already starting to do, then we are likely to mitigate global warming more than one would have thought, so that's a very positive outcome."
See a video about the production of cow power:
See also: electric grid, power usage effectiveness (PUE), Intelligent Power Management (IPM), renewable energy, green data center, green technology glossary, LEED (Leadership in Energy and Environmental Design)