Page 28 - Fluid Power Engineering

6 Chapter One

Wind energy is among the cheapest sources of renewable energy.
The cost of electricity production using wind is comparable to fossil
fuel–based electricity production. In most cases, the cost is lower or
about the same when cost of greenhouse gas emissions are taken into
account. In addition, wind energy is available in abundance in most
countries.
In addition to the above benefits, wind energy provides income to
farmers, ranchers, and landowners that have sufficient wind resources
on their property. The income is in terms of land lease payments, while
majority of the land is still available for other uses.
Wind turbine generators are available in wide range of capacities,
from small to utility scale. On small scale, wind energy can be used to
power remote locations that do not have access to an electricity grid.

Wind Energy Is Not a Panacea
Despite the significant benefits, wind energy is not a cure-all. The
primary disadvantages of wind are variability of the resource, re-
quirement for large investment in transmission, and impact on the
environment.
Wind energy production depends on wind conditions. Unlike so-
lar energy, which is ubiquitous and can be produced in most locations,
wind energy can be produced economically only in areas that have
average annual wind speeds above 6.5 m/s at 50-m height. For in-
stance, most of the southeast part of the United States has no wind
resources, other than in coastal areas. Even in areas with abundant
wind resources, there is a high degree of diurnal and seasonal vari-
ability. When the wind is not blowing, there is no energy production
and other sources of electricity must be deployed.
People do not like to live in areas that have high wind. Therefore,
high-wind areas are usually far away from population centers. This
implies electricity generated from wind energy must be transported
to population centers, which requires expensive transmission lines. In
conventional methods of electricity generation, fuel is transported to
a population center and electricity is produced close to a population
center. In contrast, wind resource cannot be transported and long-
distance transmission is required.
From an environmental perspective, wind farms can cause harm
to birds, bats, and other wildlife, although most studies suggest that
the harm is minimal. Aesthetic impact is another area of concern if the
wind plant is located in an area of scenic value. Wind farms require
significantly more land per kilowatt compared to fossil fuel–based
electricity plants; however, continued use of the majority of the land
mitigates this concern.