Capture wind underground not carbon!

4 new projects show the viability of storing captured wind energy underground. So why are we still investing in far more expensive carbon capture?

Fri, Mar 12 2010 at 1:58 PM EST

Image: ISEP

Coal profiteers are working hard to peddle CCS (carbon capture storage) using billions of American taxpayer dollars to legitimatize the continued use of the dirtiest fuel on Earth by proposing to "bury" CO2 gases from coal plants in deep underground caverns, trapping those gases theoretically forever. I'm not saying we couldn't muster the manpower, money, energy resources, and engineering prowess to accomplish this Herculean feat (prowess which we do not currently possess). I'm just asking ... isn't there a better use of our time and money?

Take underground compressed air storage, CAES. This technology is similar to CCS in that it repurposes underground mines, salt domes, caverns and other geological air pocket formations. But unlike CCS, it is not mythology.

Underground compressed air storage has been in use for decades and is a proven technology. It essentially coverts power from any number of fuel sources, most typically natural gas, into compressed air which it turns out is an efficient way to store energy. The compressed air can be released on demand, creating an even flow of power to the grid.

Sounds like a perfect solution for storing wind power, right? It is. Wired reports that venture capital and DOE grants have funded four new CAES projects for wind power in the past four months. Even the Department of Homeland Security loves CAES. A 2007 report states that "CAES is the least cost, utility-scale, bulk-storage system available. If other factors such as its low environmental impact and high reliability are considered, CAES has an overwhelming advantage."

One such project, ISEP in Iowa, explains the technology on their website:

ISEP will use the energy from a large wind power facility located in Iowa where there are good wind resources. This wind energy will be used to store air in an underground geologic structure. During peak power demands, the stored air will be released, mixed with a fuel and used to power combustion turbines that produce environmentally friendly and economical electricity ... Wind turbines, deep underground air storage, and efficient combustion turbines will be used by ISEP to take the variability of wind and turn it into clean energy on demand. The project will enable utilities and their customers to add additional renewable energy to their power supplies.

Another big difference between CAES and CCS is that the compressed air stores energy from a clean source of fuel, while CCS stores waste from a dirty source. So if there exists only a limited number of underground formations suitable for storage, why wouldn't we leverage our manpower, money, energy resources and engineering prowess to accomplish the latter? Simple logic, right?