http://www.zdnetasia.com/news/hardware/0,39042972,62043261,00.htm?scid=rss_z_nw
By Martin LaMonica, CNET News.com
Monday, June 30, 2008 10:52 AM
Someday, the electricity grid will operate with the equivalent of a giant hard drive. But in the short term, grid storage will look more like a PC's cache or RAM, able to serve up small bursts of power to keep things from crashing.
A panel of experts, organized by the New England Clean Energy Council, earlier this week said that the utility storage field has enormous potential. But rapid deployment of storage devices is held back by concerns over technology risk and financial complexity.
Technology optimists say that wide-scale energy storage will change the face of the transmission grid and make wind and solar power more compelling economically.
In this scenario, utilities store electricity made from renewable sources or produced during off-peak times. Then, when demand for electricity peaks in the middle of the day, they could draw from the stored-up charge.
This "peak shaving" practice avoids the need to build new power plants to meet growing demand. Utilities could also idle dirty and expensive "peaking plants," which are only turned on during times of high demand, such as very hot summer days when air conditioners max out the load.
But moving megawatts' worth of electricity around the grid like files on a computer is more theory than practice these days.
"Buying power at night and then selling it during the day--something like that will happen maybe in 30 or 40 years when storage technologies are one-tenth the costs they are today," said Ric Fulop, co-founder and vice president of business development at lithium-ion battery company A123 Systems.
But as utilities try out new technologies for different uses, Fulop and others predicted that storage will start to take hold in a variety of ways.
"I think we will see a lot of deployments in the next few years that will change how the grid works," Fulop said. "Then we'll see utilities jump on the bandwagon."
Two markets for energy storage
A123 Systems, which makes batteries for plug-in hybrids and power tools among other devices, is actively pushing into utility storage with more than 100 people dedicated to the market, said Fulop.
It's targeting what's called grid stabilization, or grid support, where warehouse-size installations of lead-acid batteries are the incumbent technology. That alone is a multimillion dollar market and will pave the way for different grid storage applications, he said.
With grid stabilization, kilowatts' or a couple of megawatts' worth of electricity are pumped onto the grid for a short amount of time, from a few seconds to under an hour. It's used to match grid demand and supply to make generators run more efficiently or to ensure a steady frequency.
Earlier this year, grid operators in Texas had to shut down power to its customers because the wind died down momentarily, effectively cutting off supply from its wind farms, noted Lawrence Gelbien, vice president of technology at utility NStar.
"If you could take the wind power, store it in batteries, and discharge when the wind starts again, then that's a fine application of storage," he said.
Gelbien said that storage units could be deployed in place of installing more "wires and poles" in a place that isn't served with enough electricity to meet demand for only a few days of the year. Because storage devices are movable, they could be redeployed in other places after a few years as the need arises.
Grid support is relatively mature at about US$2.4 billion and growing at 3.3 percent per year, said Lux Research President Matthew Nordan.
Batteries with different chemistries as well as ultra-capacitors, such as the ones being developed by secretive start-up EEStor, serve this end of energy storage, Nordan said.
Flywheels are also a viable alternative. Flywheel maker Beacon Power earlier this month said it expects to have a megawatt-size machine, able to store 15 minutes of power, on the grid by the end of this year.
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