Cleantech Blogroll Review: Sulfur, Flipper, and Cellulose

by Frank Ling

Sulfur Batteries

The EPA has banned sulfur in gasoline but not in batteries. Sulfur, in the form of a sodium salt, has been used as large-scale storage systems. Pioneered in Japan, these batteries are gaining acceptance in the US as a reliable form of energy storage.

Due to the intermittent nature of wind energy, storage systems are needed to make wind power more reliable. The sodium sulfur battery is not only affordable and compatible with these turbines, they are robust and responsive to the output of the generators.

Jim Fraser writes in the Energy Blog:

The 50-kilowatt battery modules, 20 in total, will be roughly the size of two semi trailers and weigh approximately 60 tons. They will be able to store about 6.5 megawatt-hours of electricity, with a charge/discharge capacity of one megawatt. When the wind blows, the batteries are charged. When the wind calms down, the batteries can be used to supply energy to the grid as needed.

Such systems will can power up to 500 homes for over six hours.

Whale Inspired Wind Turbines

The shape of sea creatures have inspired the design of ships. Now, they are also inspiring the design of blades used in wind turbines.

Like the wings of an airplane, the blades can also suffer from drag, reducing it’s overall efficiency. Now, a company in Canada has developed a new design that greatly improves the efficiency.

Hank Green writes in EcoGeek:

Using these little “tubercles,” a new firm in Toronto has created fan blades that have 32% less drag and are, overall, 20% more efficient at moving air. The new design could lead to similar gains in wind turbines, though the testing and certification process for turbine efficiency takes some time.

For an in-depth analysis of the science behind these modified blades, take a look at the paper recently published in Physical Review Letters.

Cellulosic Ethanol Dead on Arrival?

Clearly, cellulosic ethanol would have much more environmental benefits to corn-based fuel. Scientists believe that cellulosic technology may be viable within five to 10 years but there are many logistical issues that have yet to be solved.

Robert Rapier in R-Squared Energy Blogwrites:

…you still have to haul all of this biomass to the plant, convert the cellulose (and get a low concentration of ethanol for your efforts), and then get rid of a sopping wet mess of waste biomass. Sure, it can be burned – if you spend a lot of energy drying it first. Because of the very nature of the process, I don’t believe this challenge will be solved…

Frank Ling is a postdoctoral fellow at the Renewable and Appropriate Energy Laboratory (RAEL) at UC Berkeley. He is also a producer of the Berkeley Groks Science Show.

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