How the Wind Generator Magnet is Made.
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How the Wind Generator Magnet is Made

The wind generator magnet is the largest component inside a wind turbine, taking rotational energy from the rotating blades and turning it into electricity. But it's not just the size that sets this particular piece of equipment apart. It's also the way it is made that makes a difference.

The key to this magnet is a rare earth element called neodymium, which has become one of the most valuable materials on the planet. In fact, the demand for neodymium is expected to triple over the next few years, according to Australian mining company Lynas. During its manufacturing, the neodymium is turned into magnets using a powder metallurgy process. This is done in a special furnace under vacuum, which limits the dimensions and magnetic properties of the resulting NdFeB green body. It's not uncommon for the rotor of a large permanent magnet wind power generator to have thousands of these NdFeB magnets. This is because a PM generator doesn't require any external power source to initiate its magnetic field, so it can be powered by the rotational energy of the rotor itself.

This self-excitation also allows for smaller batteries or capacitors to be used, and improves efficiency. It is why the PM generator is a popular choice in renewable energy applications. The high-performance magnets are also able to start a wind turbine in low-speed winds, due to their low cogging torque, which has a direct impact on the cost of wind power generation.

As demand for these rare earth elements continues to grow, concerns have risen about supply chain security and diversification, technological development, and recycling. Some observers expect the price of neodymium oxide to double by 2025, depending on structural reforms in China, how quickly mine production elsewhere ramps up, and the rate of growth for electric vehicles.

Magnets have helped to solve operational and financial constraints in modern wind turbines. For example, their ability to self-excite has allowed designers to eliminate mechanical gearboxes in their turbines. This has reduced their overall weight, increased reliability, and lowered maintenance costs.

In the future, we might see more applications for these technologies to help solve our climate challenges. For example, it's not impossible to imagine a future where wind could play a greater role in the global energy mix.

As the world looks to clean up its energy portfolio, we need technologies like permanent magnets to enable us to get there. This is why it's encouraging that the critical mineral/permanent magnet supply chains and those for other green technologies are developing along similar lines. This includes shared standards, a focus on recycling and midstream processing expertise, and supply chain tracking. It's also why we need to take a holistic approach in how these industries work together. This will ensure we are not only addressing the problems, but helping to create a better world in the process.