Wind Energy and Copper

Alternative energy sources such as solar, biomass, geothermal and wind power generation have emerged as potential alternatives to address the concerns of climate change and depleting fossil fuel resources. Of which wind energy may have the longest history. People began to harness wind power to pull a boat across the water, grinding grain and pumping water. Wind power today has found new importance with increasing demand for alternative energy sources. Wind energy is a part green energy future and copper plays a large role in making that possible. 

What is Wind Energy?

Wind energy is a form of solar energy. When the sun heats up a certain area of land, the air around that land mass absorbs some of that heat. As air is heated, it rises and cooler air quickly falls to fill in the space. This causes air mass movement.

Wind Turbine

The wind turbine consists of several parts that convert wind energy into electrical energy. Wind turbines consist of a rotor blade, nacelle, tower, and electrical equipment.

Wind Turbine Parts
 (Image Source: http://www.workingwind.com/what-are-the-parts-of-a-wind-turbine)

The rotor blades transform wind energy into rotational energy. The nacelle houses the drive train, gearbox and generator. The turbine sits inside the gearbox. The circular motion of the turbine powers the generator, which then works to convert the kinetic wind energy into electrical energy. 

Wind Energy - How It Works: Wind Power Interactive – National Geographic 

How Copper Helps Make Wind Energy Possible

Copper is an important conductor in wind power generation. Copper is primarily used in coil windings in the stator and rotor portions of generators which convert mechanical energy into electrical energy. The generator in a 5MW wind turbine needs 3.4 tonnes of copper to convert the energy of the wind to electricity.[1] It is also used in the coils of transformers which steps up low voltage AC to high voltage AC compatible with the grid and in the high-voltage power cable conductors. 

It is crucial that wind turbines have a way of dissipating the energy and protecting the mechanical components from lightning strikes. Copper is vital to the electrical grounding system for wind turbine farms. When lightning strikes a turbine blade, the current passes along the blade, through the blade hub in the nacelle (gearbox/ generator enclosure) and down the mast to a grounding system. [2] 

Copper may also be used in the nacelle (the housing of the wind turbine that rests on the tower containing all the main components), auxiliary motors (motors used to rotate the nacelle as well as control the angle of the rotor blades), cooling circuits (cooling configuration for the entire drive train), and power electronics (which enable the wind turbine systems to perform like a power plant). [3] 

Wind energy is one of the growing energy technologies. Wind energy is being generated on the land. But higher wind speeds are available offshore compared to land. Energy produced is directly proportional to the cube wind speed. [4] To use the potential wind power available in the offshore environments, technologies are being developed. But offshore environment means need of more rugged and corrosion resistant components. The need for corrosion protection favors copper nickel cladding as the preferred alloy for the towers. [5][6] 

References:

[1] Copper and Sustainability: http://www.copperinfo.co.uk/environment/sustainability.shtml

[2] Wind Energy Basics: http://www.copper.org/environment/green/casestudies/wind_energy/wind_energy.html

[3] Copper in renewable energy: http://en.wikipedia.org/wiki/Copper_in_renewable_energy [accessed (24th Jan. 2014)]

[4] Offshore Wind Energy: http://www.boem.gov/Renewable-Energy-Program/Renewable-Energy-Guide/Offshore-Wind-Energy.aspx

[5] Copper-nickels: http://www.copperalliance.org.uk/copper-and-its-alloys/alloys/copper-nickels

[6] Copper and Copper Alloys in Offshore Renewable Energy: http://www.copperalliance.org.uk/Webcasts/17e4f30b4be969e487f2ff000044d430/extract/player.html

I wrote this article originally for Experimentation Online - the premier student science newspaper based in Ireland and the UK. Reproduced here because the original website is no longer active.