Prompted by the oil crises of the 1970s, a wind-power industry
flourished briefly in the United States. But then world oil prices
dropped, and funding for research into renewable energy was cut. By the
mid 1980s US interest in wind energy as a large-scale source of energy
had almost disappeared. The development of wind power at this time
suffered not only from badly designed equipment, but also from poor
long-term planning, economic projections that were too optimistic and
the difficulty of finding suitable locations for the wind turbines.
Only now are technological advances beginning to offer hope that wind
power will come to be accepted as a reliable and important source of
electricity. There have been significant successes in California, in
particular, where wind farms now have a capacity of 1500 megawatts,
comparable to a large nuclear or fossil-fuelled power station, and
produce 1.5 per cent of the state’s electricity.
Nevertheless, in the US, the image of wind power is still distorted
by early failures. One of the most persistent criticisms is that wind
power is not a significant energy resource. Researchers at the Battelle
Northwest Laboratory, however, estimate that today wind turbine
technology could supply 20 per cent of the electrical power the country
needs. As a local resource, wind power has even greater potential.
Minnesota’s energy commission calculates that a wind farm on one of
the state’s south western ridges could supply almost all that
state’s electricity. North Dakota alone has enough sites suitable for
wind farms to supply more than a third of all electricity consumed in
the continental US.
The prevailing notion that wind power is too costly results largely
from early research which focused on turbines with huge blades that
stood hundreds of metres tall. These machines were not designed for ease
of production or maintenance, and they were enormously expensive.
Because the major factors influencing the overall cost of wind power are
the cost of the turbine and its supporting systems, including land, as
well as operating and maintenance costs, it is hardly surprising that it
was thought at the time that wind energy could not be supplied at a
commercially competitive price.
More recent developments such as those seen on California wind farms
have dramatically changed the economic picture for wind energy. These
systems, like installations in Hawaii and several European countries,
have benefited from the economies of scale that come through
standardised manufacturing and purchasing. The result has been a
dramatic drop in capital costs: the installed cost of new wind turbines
stood at $1000 per kilowatt in 1993, down from about $4000 per kilowatt
in 1980, and continues to fall.
Design improvements and more efficient maintenance programs for large
numbers of turbines have reduced operating costs as well. The cost of
electricity delivered by wind farm turbines has decreased from about 30
cents per kilowatt-hour to between 7 and 9 cents, which is generally
less than the cost of electricity from conventional power stations.
Reliability has also improved dramatically. The latest turbines run more
than 95 per cent of the time, compared with around 60 per cent in the
early 1980s.
Another misconception is that improved designs are needed to make
wind power feasible. Out of the numerous wind turbine designs proposed
or built by inventors or developers, the propeller-blade type, which is
based on detailed analytical models as well as extensive experimental
data, has emerged as predominant among the more than 20,000 machines now
in commercial operation world-wide. Like the gas-driven turbines that
power jet aircraft, these are sophisticated pieces of rotating
machinery. They are already highly efficient, and there is no reason to
believe that other configurations will produce major benefits.
Like other ways of generating electricity, wind power does not leave
the environment entirely unharmed. There are many potential problems,
ranging from interference with telecommunications to impact on wildlife
and natural habitats. But these effects must be balanced against those
associated with other forms of electricity generation. Conventional
power stations impose hidden costs on society, such as the control of
air pollution, the management of nuclear waste and global warming.
As wind power has been ignored in the US over the past few years,
expertise and commercial exploitation in the field have shifted to
Europe. The European Union spends 10 times as much as the US government
on research and development of wind energy. It estimates that at least
10 per cent of Europe’s electrical power could be supplied by
land-based wind-turbines using current technology. Indeed, according to
the American Wind Energy Association, an independent organisation based
in Washington, Denmark, Britain, Spain and the Netherlands will each
surpass the US in the generating capacity of wind turbines installed
during the rest of the decade.
