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March 12, 2008
Sustainability Roundup: Sodium Battery and Whale Turbines
Sulfur Batteries
Energy storage will be a critical component of a low carbon energy economy. Storage devices will be needed at all scales: from laptop batteries to electric vehicles to electric utility systems.
Most consumers are aware of the batteries they need in electronics and computing hardware. We also know that future electric vehicles will require higher capacities at lower cost. Less known are the energy storage systems used by utilities...
These large scale devices are able to to discharge megawatts very quickly and help to reduce electricity costs significantly by storing energy when there is less demand and discharging when it is needed. This process enables the load of the grid to be more level, reducing the need for expensive generators that are used for short times.
Some of these large-scale storage systems were originally pioneered in Japan and are now gaining acceptance overseas. One of the these technologies is based on sodium sulfur technology, which was pioneered NGK Insulators. Today there are over 30 installations in Japan but gaining attention around the world.
For the first time, sodium sulfur batteries are being deployed in the US and they are being linked to wind generators.
Jim Fraser writes about this development 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.
投稿者 econetworks : March 12, 2008 04:13 PM
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