The Pacific Northwest May Store Excess Wind Energy in Volcanic Rocks
Too Much Wind Can Throw Off the Grid
by Rebekah Severson, age 15
For thousands of years, we have
known the power of winds. In Greek mythology, the demigod Aeolus captured gusting
winds in hollowed-out mountains, and released them by stabbing his sword into
the earth. Today, scientists harken back to this notion, asking, can we store
wind in rock?
research from the Bonneville Power Administration (BPA) and the U.S Department
of Energy’s Pacific Northwest National Laboratory suggests excess wind power
could be stored for long periods of time, far below the surface of the earth, in porous rock.
Pacific Northwest region is a huge supplier of renewable energy. With strong
winds and roaring rivers, Mother Nature gifts this region with abundant sources
of natural energy. These energy sources are then harvested with wind turbines
and hydroelectric dams. But the region may have too much of a good thing.
With the ever-fluctuating
supply of renewable energy sources, like wind and water, surpluses can throw
the energy grid off-balance. Some wind farmers have been forced to shut down
turbines to cope. They then lose tax credits and millions of dollars in revenue
due to decreased production.
system called Compressed Air Energy Storage (CAES) could be the answer. CAES
plants allow surplus wind energy to be pumped underground, stored there, and
released when needed. The air is then heated to increase its volume and velocity
as it is released aboveground. This way energy suppliers could put surpluses to
good use when wind supply is low. CAES is already in use at two different
sites. The system has been used in Germany since 1978 and Alabama since 1991.
At these sites, CAES stored energy in salt caverns left empty by mining. The
study for the Pacific Northwest is examining the possibility of using the same
technology as well, but with a twist. Wind energy would be stored in naturally
permeable volcanic rocks instead.
talking about air far below the water table, in the kinds of places where you
would find things like fossil fuels,” said Haresh Kamath, the energy storage
program manager with the Electric Power Research Institute.
this idea isn’t new, its execution is. The two proposed Pacific Northwest sites
would require two different approaches. The site north of Boardman, Oregon is
located near a natural gas pipeline, which would provide heating for expanding
the air’s volume and velocity. The site in Yakima Canyon would incorporate a
new design using geothermal energy instead. The energy would not only heat the
air but also power a chiller for cooling, making its air compressors run more
putting these porous rocks to use works, excess wind energy could be stored for
months. This would be extremely beneficial for energy suppliers like BPA. Even
half a day of storage for renewable energy sources can make a difference. Last
May, BPA sold power for extremely low rate - less than $1 per megawatt hour.
“We could have
sold it for $35 if we could have saved it ‘til the afternoon,” said Steve
Knudson, who managed a recent study for BPA.
this power would also be helpful during times when other renewable energy
sources are running low, such as during droughts.
change, if we see dramatic shifts in the amount of rainfall and snowpack, it’s
just one more reason to store [wind energy] and have it when we need it,” says
Joel Scruggs, a spokesman for BPA.
13% of this region’s power supply comes from wind, adding this flexibility to
the energy grid could greatly improve power availability in the Pacific
[Source: National Geographic]