Environmental Engineering Reference
In-Depth Information
A wind turbine is subjected to a large variety of dynamic loads due to wind fl uc-
tuations in speed and direction and numerous starts and stops of the system.
Some primary parts or components have to withstand heavy fatigue loads [79].
Advanced high-strength, fatigue-resistant materials are vital to some key com-
ponents in modern large wind turbines due to the continuous increase in blade
length, hub height, and turbine weight.
As a complex engineering system, a wind turbine must be designed at the
system level rather than part/component level as a common practice in some
turbine manufacturers.
6.7 Cost of electricity from wind power
Although the wind power industry appears to be booming in recent years world-
wide, achieving continuous cost reduction in wind power generation continues to
be a challenge and a key focus for the wind industry.
Wind power is characterized by low variable costs and relatively high fi xed
costs. The main factors governing wind power economics are [80]:
Investment costs, including wind turbines, foundations, and grid connection
Operation and maintenance (O&M) costs, including regular maintenance,
repairs, insurance, spare parts, and administration
Wind turbine's electricity production cost, which highly depends on the wind
turbine capacity, wind farm size, and average wind speed at the chosen site
Wind turbine lifetime
Discount rate
Among these, the most important factors are the wind turbines' electricity produc-
tion and their investment costs. The trends towards lager wind turbines and larger
wind farms help reduce both investment and O&M costs per kilowatt-hour (kWh)
produced.
Though the price of electricity from wind has fallen approximately 90% over
the last 30 years because of the developments of wind technology, it is still more
expensive than those from coal or natural gas. It has been predicted by Electric
Power Research Institute that even for plants coming online in 2015, wind energy
would cost nearly one-third more than coal and about 14% more than natural
gas [81]. This is the greatest obstacle for wind power to increase its share in the
electric power market. A recent study [82] indicates that wind energy in US today
still depends on federal tax incentives to compete with fossil fuel prices, and
technology progress could dominate future cost competitiveness.
The global fi nancial and economic crisis, which started from early 2008, has
dramatically altered the pace of wind development. With reduced power consump-
tion, the prices of fossil fuels (e.g. coal and natural gas) have greatly decreased,
putting even more pressures on the wind power industry to continuously drive
down wind power costs for staying competitive in the present challenging
economic times.
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