Environmental Engineering Reference
In-Depth Information
A second major challenge to deploying both wind and solar technologies is
overcoming investors' concern about their higher up-front capital costs. In
particular, wind investors pay substantial up-front capital costs to build a facility
and connect it to the power transmission grid. Constructing a wind farm may cost
less than connecting the facility to the power transmission grid, according to DOE
officials who noted that the connection could cost $100,000 or more per mile, on
average, depending on such factors as the project's size, the terrain, and the
transmission line rating. In addition, in most areas, a wind farm's investors would
pay for upgrading the power transmission grid to carry the extra load, which can
be high because prime wind resources are often found far from large urban areas
that need the electricity. Similarly, the primary barrier to deploying solar
photovoltaic technologies is their up-front purchase costs, which continue to make
them more expensive than traditional energy sources, according to DOE and
industry executives.[23] More recently, the rapidly growing solar energy industry
has experienced an industrywide shortage of solar-grade silicon—the principal
material for making crystalline-silicon photovoltaic cells—because of competition
from other industries, such as computer chip manufacturers. As a result, the price
of silicon wafers on the market has doubled in each of the past 2 years, according
to EIA. The tight silicon supply has also created back orders of several months.
Because photovoltaic manufacturing costs have risen sharply, manufacturers have
changed their business strategies to maintain profits and continue to finance their
plans to expand their production and strengthen their distribution capabilities.
Both wind and solar power also have unique intermittency characteristics that
can constrain their use because the existing power transmission grid was built to
accommodate large central-station power plants located near population centers
that operate full time. This system relies on precisely predicting and controlling
power plant output to avoid blackouts and other disruptions. However, wind and
solar energy are intermittent energy sources because wind speed and sunlight
vary, depending, for example, on the time of day and the weather—on average,
wind turbines operate the equivalent of less than 40 percent of the hours in a year
due to the intermittency of wind. Alternatively, the electricity generated must be
immediately used or transmitted to the power transmission grid because no cost-
effective means exists for storing electricity. DOE is conducting R and D in this
area.
A recent challenge facing the wind industry is mitigating environmental and
community concerns about its adverse effects. While wind energy does not create
the pollution or greenhouse gas emissions associated with fossil fuel power
generation, some wind farms have resulted in the death of birds and bats because
they are located amidst migratory pathways or important habitats.[24] Our 2005
