Friday, 30 November 2012

Green energy held up by magnets and environmentalists?

Could the rising tide of wind farms be held up by green concerns.

Could it also be that Global warming will enable the magnets needed to be won from the ground?

What makes a good magnet?

Iron-based / ferrite magnets are cheapness abundant – But; you need an awful lot of ferrite to create a large magnetic field.

Better magnets have been produced by metallurgists mixing up promising elements and putting them in magnetic fields and seeing what happens.
Aluminium-cobalt-nickel or "Alnico" magnets in the 1930s produced  more than doubled the energy density of the best ferrites.
In 1970s the discovery of the magnetic potential of the lanthanide / rare earth led to Magnets made from a mixture of cobalt and the rare earth element samarium that can store more than twice the energy of Alnico magnets.
In the 1990 magnets made of the rare earth element neodymium plus iron and boron produced a magnet the size of a fingertip that could create a magnetic field several thousand times stronger than that of Earth's iron core.
When the likes of Neo was invented It drove up demand to the extent that the availability of rare earths is now a big problem.

Why do we need good magnets?

Huge quantities are being used in green energy technologies; Such as motors/generators for wind turbines, electric cars and bicycles. These have to be both powerful and lightweight. It is only Neo magnets give the performance needed.

Every motor in an electric car needs about 2 kilograms. A wind turbine capable of producing a megawatt of power needs about two-thirds of a tonne.

The demand for Neo magnets for wind turbines is projected to increase more than seven times by 2015.

How can we get more?

The US Department of Energy has a project called REACT Rare Earth Alternatives in Critical Technologies". Its aim is to come up with magnets that use less of rare earth elements or perhaps none at all.

Up until now most of the world supply of rare earths has come from China. Increasing though China wants the elements to use for itself.

In Canada Quest Rare Minerals Ltd holds one of the largest heavy rare earth element deposits in the world but it is located in an unforgiving northern part of Qu├ębec where, oddly enough, Global warming may allow access through the permafrost.

The possibility of mining in Malaysia has been dogged by criticism from environmentalists and residents; Opposition that has galvanized a "green" movement in Malaysia.


New Scientist - We're running out of magnets
IET - Rare earth metals in short supply
Forbs - Largest Rare Earth Metals Deposit Outside Of China Faces Tough Northern Climate - China to subsidise rare earths producers
BBC - Lynas rare earth plant set for Sydney demonstration

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