go-green


Upgrading the electric grid with flywheels and air.

by National Geographic:

The modern electric grid is getting some help from some admittedly old-fashioned technology. Flywheels and compressed air don’t sound as sexy as wind turbines and solar cells, but the latter probably won’t go mainstream without the former.

According to a DOE paper, Gyuk said, using “fast storage” technologies such as Beacon’s flywheels could reduce carbon output by 70 percent.

Beacon Power’s flywheel energy storage plant in Stephentown, New York, seen in this aerial view, can respond to a signal from the electric grid in four seconds.

Gene Hunt, of Tyngsboro, Massachusetts-based Beacon Power, notes that fossil fuel generators typically provide frequency regulation services, but they can’t do it quickly. It takes a big coal plant about five minutes to respond to a grid operator’s request, but that’s an eternity in the world of electricity. The signals come in to power plants every four to six seconds.

His company is building a more nimble frequency regulator based on flywheel technology in Stephentown, New York. A flywheel is a wheel or cylinder combined with a motor. The motor spins up the wheel with excess electricity from the grid. When power is needed, the process is reversed, and the wheel’s spinning runs the motor, converting kinetic energy back to electricity. Beacon Power’s system aims to use 200 flywheels networked together to store excess energy from the grid and dispense it when needed. The flywheels can respond to a signal from the grid in four seconds.

Just this week, Beacon announced it had reached a new milestone in the construction of the Stephentown facility: it’s now running at half capacity, or 10 megawatts. The other 10 megawatts will come online in the second quarter of this year, Hunt said.

A compressed air energy storage (CAES) facility would use cheap, off-peak electricity to pump air into an underground cave or aquifer for storage when demand is low. The system then would mete out the air later when demand goes up, likely using a gas turbine to heat the air as it exits the cavern. The electricity that pumped the air in the first place would have been generated by wind, so “you’re using off-peak wind, which might conceivably have been ‘spilled’ otherwise,” said Gyuk.

There are only two compressed air energy storage projects on the grid worldwide: one in Huntdorf, Germany, which has been running for more than three decades, and another in McIntosh, Alabama, which started up in 1991. But, with DOE funding, two more are being studied, in California and in New York.  Studies have been completed for a third project, in Iowa, which is now seeking funding. And a cavern in Norton, Ohio, could theoretically store up to 2,700 megawatts of power.

National Geographic

Each day, it seems humans discover more and more techniques to produce renewable energy. Germany and Alabama are the only locations in the world that produce this kind of technology and it shows, Alabama has a carbon footprint rating of 11 and is the 23rd most populous state. Pretty impressive for a state that has an abundance of coal and natural gas to harvest.

The bottom line is with gaping state budget holes, renewable energy sources are starting to look more and more appealing.