1. WIND ENERGY
Greta Leppänen, Tomas Rinne, Matias Laine, Tuukka Haapakoski, Alexander Wikström, Vilhelmiina Schroderus

2. Physical Idea Behind The Wind Power
Power of an windturbine can be calculated from: P = ½ApV,
Where:
A = area of the blade
p = the density of the air
V = velocity
There's a technical challenge in the wind power: the energy of the wind is proportional to the third power of the velocity of the wind.
This means, that the turbines can only work during suitable velocity of the wind - otherwise they are turned off..
Wind power is produced by wind turbines: they convert kinetic energy to mechanical energy. The generator converts it to electrical power, i.e. wind power.
These powerplants obey the law of Betz's – no turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind.

4. Usage
In annual installations of the EU in % of the new installations was accounted by wind energy, since 2000 the EU has always installed more than one third of wind energy from total new power sources installed. At the moment there is 131 GW onshore and 11 GW offshore of wind power in the EU.

5. The United States has a wind energy capacity of 75 000 MW
The United States has a wind energy capacity of MW. This capacity is only exceeded by China and the EU. The US wind energy sector has had and average annual growth of 25.8% over the last ten years. Today wind energy amounts for 4.44% of all electricity produced in the United States.
China is the world leader in wind power, accounting for about third of the world total, with a capacity of MW. This represents 3.3% of the electricity consumed domestically. It is estimated that the full potential capacity for wind energy in China is MW. In 2015 China increased its capacity with
MW.

6. In the above image there are different types of wind turbines.

7. Pros Clean source of energy. Renewable and free source of energy.
Cost effective.
Extra money for lands owners.
Some consider the modern design of the wind turbines to even be beautiful (individual opinion).
Does not take up much space.

8. Cons
Wind can be very unreliable. You will always need a base energy source, which produces energy more reliably.
The edges of wind turbines can actually be unsafe for natural life, especially birds.
Noise (about decibels).
Ugly (individual opinion).
Expensive to set up.
In extreme winds the blades could be damaged and cause a safety hazard for people near it.
Is only suitable for certain locations, for example at the coast were the wind is always quite strong.
Sometimes you have to chop down trees in order to install the wind turbine.

9. Future of wind power New inventions come up all the time, for example:
-exporting the wind turbines further out of the sea
-Vortex, which is bladeless wind turbine. It promises to produce wind energy without killing birds or making noise and to save manufacturing and operation costs.
The European Wind Energy Association (EWEA) has made binding targets of increasing wind power from 106 GW (2012) to 230 GW in 2020 and to 735 GW in 2050
EWEA also has made targets to increase the wind power's percentage of EU's electricity demand from 7% first to 15-17% and then 50%

10. Sources Foil : EWEA statistics 2015
Foil 4 pictures: EWEA , Wind power by country
Foil 8: Vortex (accessed )
Foil 7 picture: Greta Leppänen
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Foil 9: Ewea targets (accessed )
Foil 3 picture: Partnerships for renewables
Foil 2: Wikipedia, IB Physics Data Booklet (2016)