Our friends over at Fuel Fix have the scoop on a proposed $8 billion California wind energy project that could blow the socks off the regional renewable energy market. The idea would be to use Wyoming as a site for a new wind farm — which would be one of the largest in the US — and schlep the energy over to Los Angeles on new and existing transmission lines.
But, that’s not what caught our eye. The key to the $8 billion California wind energy project, the thing that helps fulfill the Los Angeles vision of a sustainable, secure energy source, would be a massive compressed air energy storage system using salt caverns in Utah.
Wind In The Sails For Compressed Air Energy Storage
Think of party balloon animals and you’re on the right track. Compressed air energy storage is a relatively low-tech way to create a pressurized system that can be released as needed to generate electricity.
Underground, utility scale compressed air systems have been around for a while, but until recently they were used primarily to store energy from fossil-fueled power plants.
Some of the recent developments in compressed air technology include an “isothermal” system based on above-ground containerized modules, designed for use with grid-supplied energy. A report last year by Navigant predicted dramatic growth in the compressed air market as new technology decouples the field from caverns and other geological features.
The $8 billion California wind energy project marries the old world with new clean energy technology. While its compressed air system in Utah would still hinge on a geological feature, it would be designed specifically for storing wind energy, not energy from an individual fossil power plant or a mixed grid.
Four Cooks In The California Wind Energy Broth
The four companies involved in the project are Pathfinder Renewable Wind Energy, Magnum Energy, Dresser-Rand and Duke-American Transmission.
Duke-American is an interesting creature. We heard from Duke Chairman Jim Rodgers at theBloomberg New Energy Finance conference in New York back in April talking about new business models for utilities to survive in the emerging energy future, and this would be one iteration.
Duke-American is owned partly by Duke Energy, which despite its numerous fossil travails has been plunging forward on renewables. The other part is American Transmission Co., which bills itself as “the nation’s first multi-state transmission-only utility.”
Pathfinder is a Wyoming-based wind company that is already in partnership with Magnum and Dresser-Rand, among others.
Alabama Inspiration For California Wind Energy
In terms of our interest in the project’s energy storage feature, that would be Dresser-Rand.
Dresser-Rand has experience in the geological compressed air field going back to 1991, when it built the still-functional Power South facility in MacIntosh, Alabama. At the time, it was only the second of its kind in the world.
The latest project materials cite operational reliability of 95 percent since 1991, which is pretty impressive considering the age of the facility. We’re guessing that the technology has also improved in the past 23 years, considering that Dresser-Rand is already talking about developing similar systems based under coastal waters.
The Power South facility is hooked up to a coal power plant, but up front in the project materials Dresser-Rand also notes that it is looking forward to considerable growth in compressed air energy storage (CAES) as the wind and solar markets take off.
How The Utah CAES Could Work
Take a look inside the Power South CAES, and that will give you a general idea of how the Utah facility would fit into the California wind energy project.
Basically, it’s a buy low, sell high operation. During off-peak hours when rates are cheaper, the coal power plant keeps humming along, generating excess energy that is used for air compression. The low cost stored energy can then be sold off during the day, when rates are higher.
That setup dovetails neatly with prevailing wind patterns, which tend to rev up at night and tail off during daytime peak hours.
Here’s a bit of detail about Power South from Dresser-Rand (breaks added):
The equipment includes single-stage turbines, standard multi-stage turbines, packaged geared turbine generators and engineered turbine generators, centrifugal and axial compressors, gas turbines, and reciprocating compressors. The train has a centrally located motor/ generator with clutches on both sides. On one side, a low-pressure compressor, intermediate compressor and high-pressure compressor work to store air in a salt dome at pressures up to 1100 psig.
Four stages of compression and three inter-coolers are used to enhance cycle efficiency by minimizing compressor power. When electric power demand peaks during the day, the process is reversed. The compressed air is returned to the surface, heated, and run through high-pressure and low-pressure expanders to power the motor/generator to generate electricity.
Okay, so it’s a little more complicated than we made out at the beginning, but you get the picture.
As for the Utah facility, that would be sited near the town of Delta. It could consist of four vertical storage units carved out of underground salt formations, each about 1/4 mile high (!) and 290 feet in diameter. The energy storage capacity would be equivalent to 60,000 megawatt-hours.
The electricity would be generated by a bank of eight generators. During peak demand the partners anticipate using a “small amount” of natural gas to keep things humming along.
Er…Awkward…
Another interesting thing about this project is that it showcases the maneuvering among some of the biggest names in the energy technology field for the lead position in emerging renewable energy opportunities.
As tipped by Fuel Fix, the global energy tech giant Siemens is hot to acquire Dresser-Rand, ostensibly to get a foothold in the US shale gas and oil market, though we think the company’s strong interest in wind energy is also at play.
Although a shareholder lawsuit could gum up the works, assuming the deal goes through that could make for some awkward family dinners around the $8 billion California wind energy project.
That’s because Siemens rival GE happens to be one among those other Pathfinder partners we mentioned earlier, and competition between the two companies has already been cooking up to a boil over the acquisition of France’s Alstom.
However, don’t expect any dishes to start flying just yet. The California wind energy project is still in the proposal stage, and the four partners don’t expect to have a formal submission on the table until sometime next year.
Source: CleanTechnica. Reproduced with permission.
