Almost everyone agrees that electrical energy storage is the key to finally putting fossil fueled generating plants out of business. The cost of renewable power is dropping month by month but there has to be a way to store excess electricity for use when the sun goes down or the wind stops blowing. The renewable energy division of General Electric is working with Absaroka Energy to build a new pumped hydro storage facility near the town of Martinsdale in the central Montana.
The facility amounts to a large water based battery. It will store energy by pumping water through a giant man-made tunnel from a low lying lake to a reservoir 1,000 feet higher on the top of Gordon Butte. Reversing the flow will quickly generate electricity when demand increases and prices are high or when renewable energy sources stop supplying power to the grid. Both the lake and the reservoir will hold 1.3 billion gallons of water, enough to generate as much as 400 megawatts of electricity. Cities as far away as Seattle and Portland could be the beneficiaries of all that energy.
The Gordon Butte project will use enormous turbines built by GE Renewable Energy that can be either a pump or a generator as conditions require. “To be sure, pumped hydro storage has been around for a while,” says Matt Pevarnik, managing director for U.S. Hydro at GE Renewable Energy. “But the technology keeps getting better. The Gordon Butte site will become one of the most advanced pumped storage installations in the U.S.” Overall cycle efficiency — the average difference between energy from the electric grid used for pumping water to the upper reservoir and electricity generated by the turbines when the water runs downhill — is projected to be as high as 80%.
Traditional hydro projects can take a decade or more to get licensed but the Gordon Butte installation will be a closed loop project. Because it will be built “off-stream” and won’t use any natural waterways, it was easier to get it approved. The Montana project was licensed in just three and a half years. A traditional pumped hydro project can take up to 10 years before gaining regulatory approval.
The U.S. Department of Energy estimates that projects already in the planning stages could triple pumped storage capacity in the US from 22 gigawatts to 62 gigawatts when they are finished. The DOE estimated the U.S. will need 100 gigawatts of stored power by 2050 when renewables expected to generate as much as 80% of all the electricity in the United States. A train that hauls concrete blocks up and down a mountain in Nevada is also part of the energy storage picture.
The Gordon Butte is already home to six GE wind turbines that generate 9.6 megawatts of electricity. Average wind speeds in the area average 20 miles per hour. The installation will help create much needed employment opportunities in rural Montana in addition to contributing to the further greening of America’s electrical grid.
Tesla is also deeply involved in the energy storage business. Its Powerpack grid scale storage batteries are already powering the islands of Kauai in Hawaii and Ta’u in American Samoa. Tesla’s batteries are not inexpensive but they can be installed in a matter of months once the order is placed. The prospects for renewable energy in America supported by grid storage solutions just keep getting brighter.
Source and image credit: GE Reports