That happened to one of Invenergy’s wind farms in January,
when congestion rose on the transmission lines and it could not
export its electricity—even when it offered to pay utilities $22
per megawatt-hour to take it. Meanwhile, new solar projects
in the region are expected to add another 2,200 megawatts of
capacity, with an additional 7,000 under study. Having spent
billions of dollars on a transmission system, the state is now
faced with spending hundreds of millions more to expand it—a
demonstration of just how costly and complicated it is to shift
from fossil fuels to renewable energy, even where the conditions are optimal.
TOO MUCH WIND?
Even if wind farms sometimes have to pay customers to take
power off their hands, they can make money because of the federal tax credit for wind developers. But that subsidy will begin
phasing out next year before expiring completely in 2020. That’s
when the true economics of wind power will become evident.
Power from wind generally remains more costly than power from
fossil fuels. Especially at today’s low electricity prices, driven by
a glut of natural gas, it’s hard to envision how all these new wind
farms sprouting in the badlands can be competitive without
“significant direct and indirect support at the state and federal
level,” says Kenneth Starcher, former director of the Alternative
Energy Institute at West Texas A&M University.
Then there are the physical challenges. Although it might
seem as though someday getting 35 percent of the nation’s
power from wind is feasible, relying on wind for more than 20
or 25 percent of the total is difficult because of wind’s variability, which affects the system in multiple ways. Since the grid
operator must match supply to demand on a minute-by-minute
basis, reserve power—mostly natural-gas plants, these days—
must compensate when the wind stops blowing, ramping up
quickly to fill in the gap. (That can also happen when there’s too
much wind: when it blows harder than 64 miles an hour, the
turbines shut down to prevent damage.) Requiring generators
to keep fossil-fuel plants running even when there’s no market for their power effectively adds to the overall cost of wind.
Wind’s variability also affects the power quality—the ability of
the grid to provide electricity within certain ranges of voltage
Because of such problems, the eastern half of the U.S. could
not rely on intermittent renewable sources for more than one-third of its electricity even with massive investments in new
transmission lines, according to a new study from the National
Renewable Energy Laboratory.
“Is it possible to have too much wind, in terms of problems
or challenges the system operator will have? The answer is yes,
absolutely,” says Bill Cannon, vice president of the U.S. division
of Sumitomo, which has built and owns wind farms. “The more
wind you have, the bigger the challenge. As far as what is the
perfect amount of wind, I don’t think anybody has that answer.”
Above: Cows graze near Nolan.
Right: An older wind technology
on display in the town of Coleman.