Wind power, the world's fastest growing energy source, is a deceptively simple technology. Behind the tall, slender towers and steadily turning blades lies a complex interplay of lightweight materials, aerodynamic design and computer controlled electronics. Power is transferred from the rotor through a gearbox, sometimes operating at variable speed, and then to a generator (although some turbines avoid a gearbox by use of direct drive).
Wind power today
Two decades of technological progress have resulted in state-of-the-art
wind turbines that are modular and rapid to install. Today, a single
modern wind turbine is 100 times more powerful than its equivalent two
decades ago, and now wind farms provide bulk power equivalent to
conventional power stations.
By the beginning of 2004, global wind power installations had reached a
level of 40,300 MW. This provides enough power to satisfy the needs of
around 19 million average European households, close to 47 million
people.
As the market has grown, wind power has shown up to a 50 percent drop
in production costs over the past 15 years. Now, at optimum sites
wind can be competitive with new coal-fired plants and in some
locations can challenge gas.
Wind power by 2020
With installed wind capacity growing at 30 percent over the past few
years, it is an entirely realistic goal to for wind to provide 12
percent of the world's energy by 2020. Along the way, this would
create two million jobs, and save more than 10,700 million tonnes of
carbon dioxide emissions.
Thanks to continuing improvements in the average turbine size and
capacity, by 2020 the cost of wind power on good sites is expected to
drop to 2.45 euro cents per kilowatt hour (kWh) – 36 percent less than
its 3.79 euro cents/kWh cost in 2003. Grid connection is not included
in these costs, but is a factor for virtually any new energy site, not
just wind.
Wind power beyond 2020
The world’s wind resources are extremely large and well distributed
across almost all regions and countries. Using current technology, wind
power could supply an estimated 53,000 Terawatt hours (TWh) per year.
This is more than twice the projected world energy demand in 2020 -
leaving substantial room for growth in the industry even decades from
now. The US alone has enough wind potential to supply its
energy needs three times over.
Advantages of wind:
Environmentally friendly - A reduction in the levels of climate change
causing carbon dioxide emissions is the most important environmental
benefit from wind power generation. However, it is also free of
the other of other pollutants associated with fossil fuel and nuclear
plants.
Extremely good energy balance - The carbon dioxide emissions related to
the manufacture, installation and servicing over the average 20 year
lifecycle of a wind turbine are “paid back” after the first three to
six months of operation – which means more than 19 years of energy
production at virtually no environmental cost.
Quick to deploy - Construction of a wind farm can be completed within a
matter of weeks, with large cranes installing the turbine towers,
nacelles (housing) and blades on top of reinforced concrete foundations.
Reliable and renewable resource – Wind to drive the turbines will
always be free of charge, and unaffected by swings in the price of
fossil fuels. It also doesn't need to be to be mined, drilled for
or transported to the generating station. As world fossil fuel
prices rise, so does the value of wind power, and its generating costs
will only drop.
Furthermore, in larger projects, using proven medium sized turbines, an
operational availability of 98 percent is consistently achieved using
wind. Meaning only a two percent down time for repairs - a far better
performance record than what can be expected from a conventional power
plant.
Variability of wind
The variability of the wind has produced far fewer problems for
electricity grid management than sceptics had anticipated. Swings
in energy demand and the need to protect against failures of
conventional plants actually require more flexibility of the grid
system than wind power, and real world experience has shown that
national power systems are up to the task. On windy nights, for
example, wind turbines account for up to 50 percent of power generation
in the western part of Denmark, but the load has proved manageable.
The creation of super-grids also reduces the problem of wind
variability by allowing changes in wind speed in different areas to be
balanced against each other.
Moving forward
Despite its recent rapid growth the future of wind power is not
guaranteed. Although there is some wind power today in 50
countries, most of the progress so far has been thanks to the efforts
of just a few, led by Germany, Spain, and Denmark. Other
countries will need to improve their wind power industries dramatically
if global targets are to be met. Therefore, the prediction of 12
percent of the world's energy from wind power by 2020 should not be
seen as a sure thing, but as a goal – one possible future we can chose
if we are willing.
Find out how you can help on our
Take Action page.
More information:
www.yes2wind.com
Greenpeace report:
Windforce 12