In Our View: Sending Power Underground

Emerging technologies are always exciting to forward-thinking people, and so it is with compressed air energy storage (CAES) systems. As Eric Florip reported in Monday’s Columbian, some of the most advanced scientific minds in the Northwest are researching ways to convert excess wind- and hydro-generated power into compressed air that could be stored underground, then used later when energy demands peak or when the breezes or the water aren’t so powerful.This is a solid, encouraging development that could go a long way toward stabilizing the energy industry. The potential of establishing and maintaining more reliability has led to a $790,000 study by researchers at Bonneville Power Administration and the Richland-based Pacific Northwest National Laboratory. If their research shows CAES to be viable, pumping compressed air (or water) into the vast, porous underground basalt formations of the Northwest could prevent power disputes such as the one that arose in our region last year.

When excess power was accumulated, BPA ordered area wind generators to shut down to avoid overloading the power grid. Understandably, the wind farms objected, and the Federal Energy Regulatory Commission ruled in their favor. On Tuesday, BPA officials proposed paying half the losses incurred by wind power producers, who said the proposal was not enough.

A more stable supply of energy would keep those types of disputes from surfacing, and that’s where CAES could emerge as a big player. The concept, actually, is rather simple. Storage plants would take on extra power and use it to pump compressed air into underground geologic vaults. Later, that pressure would be used to regenerate more than three-fourths of the power that had been stored. A second system being researched by the Northwest scientists involves pumping water into the ground.

Florip’s story in The Columbian described it all as a giant energy bank: “Withdraw when you need it; deposit when you don’t.”

Although CAES technology remains cutting edge, and exciting discoveries occur regularly, the overall technology of pressurizing air or water in containers or underground is more than a century old. With this newer technology, though, a couple of meaningful advantages — at least in preliminary research — have emerged. First, the above-ground area required for storage plants would be relatively small. Although about 10 million cubic meters of underground storage would be required, the buildings and equipment would not need a sprawling footprint. Second, scientists believe there would be no serious seismic impacts of CAES plants and systems in the Northwest, at least not in the eastern parts of Oregon and Washington. There, seismic activity has been relatively dormant.

Another encouraging aspect of CAES systems: They augment the value of renewable energy systems, combining the best attributes of wind farms and hydroelectric dams, even blending the energy produced by both to create a “rainy day” type of energy storage. And nowhere in the equation — at least as viewed here in the Northwest — is fossil fuel entered as a major component.

The current study is expected to reveal some findings late this year. And scientists still have a lot to learn about CAES. It will be interesting to see if a viable system could be used, and if a surplus can counter a deficit in power production. Long-term, the savings might not be significant, but the reliability could help keep rates low and relatively stable.