W

Water Vapour
A gaseous form of water and an important natural greenhouse gas. It is vital for the maintenance of an inhabitable Earth as, before industrial activity led to an overly severe greenhouse effect, it would have trapped the necessary amount of heat from the sun.
It is also vital for our weather systems as, upon cooling, it leads to cloud formation and precipitation.

Weather
The state of the atmosphere in one location at one time, referring to precipitation and temperature conditions. Weather therefore varies greatly over time and space. This is different to climate, which refers to the same conditions but averaged out over a longer time period and larger region to produce typical conditions, such as Marine West Coast for the UK, Mediterranean or Tundra to name a few.

Wind Energy
A form of renewable energy that transforms kinetic energy from wind to electrical energy using turbines. These turbines are normally arranged in a large number to create wind farms, which can be both on- and off-shore. In terms of size, the larger the wind turbine blades, the more power it can produce. The largest tend to be off-shore, with an upper value of 110metres in diameter, and can produce 5 mega-watts (MW) of power annually, enough to power approximately 1400 homes through the year.

The largest off-shore wind farm in the UK is known as Lynn and Inner Dowsing, which is made up of 54 turbines, each producing around 3.5 MW of power. This will soon be overtaken by the London Array, which is planned to house 341 turbines, creating 1000MW of power annually in total.

To put this in perspective, the electricity consumption in the UK as of 2005 was 39,798,556,000 MW (or 39 billion, 798 million, 556 thousand MW), which, to satisfy using purely wind energy, would require just under 40 million London Arrays. In 2007, 1.5% of the UK’s energy was produced using wind energy, with this figure rising rapidly as the government attempt to meet the 20% target (using all renewable forms of energy) by 2020, set by the EU in 2007.

For more information:

http://www.awea.org/faq/wwt_basics.html#How%20big%20is%20a%20wind%20turbine

http://en.wikipedia.org/wiki/Wind_power_in_the_United_Kingdom