On the sustainable energy front, two new technologies to be tweaked by …

Brown energy is the polite term being bandied about to describe new methods of capturing the methane gas (a chief component of natural gas, as well as a principle greenhouse gas, more potent in its heat-capturing effects than carbon dioxide) generated by cattle. Polite because it euphemizes the process of collecting gas from thousands of cows and pigs farting and shitting their way to their own annihilation.
But its scatological characteristics aside, it’s impossible not to recognize a certain elegance to the operation, both ecologically:Â
… More utilities are thinking of buying the gas outright. Pacific Gas and Electric has agreed to transport gas from a big digester that Microgy, a digester manufacturer, is building in California. Right now Microgy plans to sell the gas on the open market, but Robert Howard, vice president for gas transmission and distribution, said P.G.& E. may buy some gas itself. “This technology provides pipeline-quality gas and reduces carbon emissions, so of course we’re in favor it,” he said.
The environmental boons are many. According to Agstar, digesters are already keeping 66,000 tons of methane from escaping each year into the atmosphere, while generating enough energy to power more than 20,000 homes.
and economically:
The potential market is huge. Agstar officials say that at least 70,000 dairy and swine farms are big enough to support a commercial digester and could collectively provide enough energy to power more than 560,000 homes, while keeping more than 1.4 million tons of methane out of the atmosphere.
“The business model of producing energy along with food will transform the economics of rural America,” said Michael T. Eckhart, president of the American Council on Renewable Energy, based in Washington.
Indeed, anaerobic digestion yields not just methane, but leftover liquids that farmers can use or sell as fertilizer, waste heat that can heat their homes and barns, and fibrous solids that make excellent bedding for cows. Farmers also save the costs of controlling odors and treating waste. “Two years ago I couldn’t even convince farmers that digesters work,” said Melissa Dvorak, marketing manager for GHD, a company based in Chilton, Wis., that sells digesters. “Now, all they ask is what the payback will be.”
The full article is in the NYTimes, via Treehugger.
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Crowd power is an equally interesting (and less messy) attempt at siphoning energy from the otherwise irreversible slide towards entropy. The imaginative idea is based on tapping into the restless, unceasing energy of the city itself; footfalls, vehicle vibrations, the general ambience of a busy day. Unlike Brown Power, this is still in the prototype phase, but it has received a lot of financial investment already. What they have so far:
[Project engineers] Bates and Price are now in the process of developing a joint partnership to make the idea a reality. The architectural team is working with university research groups to finish two vibration-harvesting prototypes by December. The first is a staircase that will contain hydraulic or piezoelectric technology in the risers. The technology will pick up kinetic energy from commuter footfalls and convert it into an electrical current.
Climbing stairs requires more force, which means there’s more energy to be tapped. Engineering experts from the University of Hull hope to develop a system that will convert at least 50% of the six to eight watts each person typically generates while walking. The current will be stored in a battery, which can be used to provide energy for lighting or electronic devices. The second prototype is a wireless lighting system that will use tiny generators with components designed to resonate at the same frequency as surrounding vibrations. The resonance will either move a magnet relative to a coil or put stress on a crystalline structure inside a generator to produce a current. Light-emitting diodes connected to such vibration harvesters could illuminate the underside of arches.
Full article is here. Also via Treehugger.
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