That's some heavy lifting (

One of the main barriers to the diffusion of renewable energy sources such as wind and solar power is their inherent variability. If excess energy produced could be stored cheaply and used during times of lower production, this issue could be largely mitigated. Several technologies are under development as possible options for storing energy from the grid, including batteries that store energy in chemicals, mechanical flywheels that store energy as rotational energy, and hydroelectric dams that convert mechanical energy into electrical energy by retaining and channeling rivers.

And, on the bizarre end of the spectrum, we can find a hydraulic water storage system proposed by physicist Dr. Eduard Heindl, a professor at Furtwangen University in Germany.

Heindl’s idea is to store potential energy by using water as a hydraulic fluid to transfer power underground. A project would involve carving out a gigantic cylinder of dense rock, such as granite, by drilling two underground circular tunnels with 500-meter radiuses, one tunnel several hundred meters deep and another at a 1-kilometer depth directly underneath the first. A saw mill would be lowered into the tunnels connected to a saw mill at the surface via a wire saw. The saw mills would work away at the rock to separate the cylinder from the deposit. A seal would then be placed within the first tunnel to close off the system to prevent the loss of potential energy.

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energy storage, grid infrastructure, technology series

The most important renewable energy project in the United States this year could be a transmission line.

The Unsung Hero of Renewables Growth in Nevada

The One Nevada Transmission Line (ON Line), which the U.S. Department of Energy (DoE) announced February 15 that it would support with a $343 million loan guarantee, is supposed to be just the initial piece of the 570-mile Southwest Intertie Project (SWIP) that will connect Wyoming, Idaho, and Nevada to the large consumption centers of Southern California and the Southwest. The project is expected to cost roughly $500 million. The 500 kilovolt, 235-mile line will have the capacity to carry 600MW, while SWIP as currently planned could eventually carry over 2,000MW.

The groundbreaking ceremony for the ON Line was actually held last October, and the line is expected to become operational by the end of 2012. ON Line is a joint venture of NV Energy and Great Basin Transmission LLC, the company behind SWIP. The groundbreaking was a well-attended affair, with the likes of Senator Harry Reid and U.S. Interior Secretary Ken Salazar present. U.S. Energy Secretary Steven Chu personally announced DoE’s decision to award the loan guarantee, the first ever from the Department for a transmission project.  

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geothermal, grid infrastructure, Ken Salazar, Nevada, renewable energy, solar, Stephen Chu, transmission, U.S. Department of Energy, U.S. Department of the Interior, United States, wind

China’s National Energy Administration (NEA) recently released its latest energy outlook, which highlights the progress made in 2010 and foresees a busy 2011. While development of new and renewable energy sources is the focus of China’s long-term energy plan, the Chinese government is still struggling to figure out exactly how fast those sectors should grow. Learning from previous experiences, China’s top decision makers are taking a more practical – and in our opinion, more rational – approach to creating a low-carbon economy. 

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12th Five-Year Plan, carbon intensity, China, Chinese Electricity Council, energy intensity, energy outlook, grid infrastructure, National Energy Administration, non-fossil fuels, renewable energy, ultra high voltage, wind power