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-- a _kt75 | reprint Download: Quarterly Notes on Sustainable Water Management - Q01/2014 A race is under way to unlock one of the world's biggest untapped sources of clean energy—the ocean—with China emerging as an important testing ground. That could heighten competition with Western companies, especially if Chinese businesses begin using technologies developed with joint-venture partners to expand rapidly. The European Union so far has led efforts to harness the sea to make electricity, for which there are three principal techniques : underwater turbines that draw power from the ebb and flow of tides, surface-based floats that rely on wave motion and systems that exploit differences in water temperature. The world's first commercial, grid-connected tidal-flow generator was installed in Northern Ireland in 2008. Germany's Siemens AG , a big investor in wave and tidal power, predicts that tidal currents alone could someday power 250 million households world-wid

-- a _kt75 | reprint download: Quarterly Notes on Sustainable Water Management - Q01/2014 .   An analysis of a number of hydraulic fracturing sites in southwestern Pennsylvania has found that methane was being released into the atmosphere at 100 to 1,000 times the rate that the Environmental Protection Agency estimated. The study , published Monday in the Proceedings of the National Academy of Sciences, found that drilling operations at seven well pads emitted 34 grams of methane per second, on average, much higher than the EPA-estimated 0.04 grams to 0.30 grams of methane per second. The researchers, who were attempting to understand whether airborne measurements of methane aligned with estimates taken at ground level — the method commonly used by the EPA and state regulators — flew a plane over the region of the Marcellus Shale for two days in June 2012. “The researchers determined that the wells leaking the most methane were in the drilling phase, a period