3 ms·
China only has 1/3rd of the worlds extractable deposits. Rare earth minerals is the typical "China Bad" scare story. They reduced the amount they sold because t
by RidingPegasus 8y ago
China only has 1/3rd of the worlds extractable deposits. Rare earth minerals is the typical "China Bad" scare story. They reduced the amount they sold because they wanted it themselves to value-add making electronics/renewables and being the vast majority of world supply it got them a better price.
Much like many other countries on earth do. OPEC even has multiple annual meetings where they all decide to collude on restricting oil supply.
If the rest of the world was truly worried they'd subsidise the industry, as it stands most countries throw away all their rare earths in tailing dams as mining byproduct because it's not worthwhile to extract it.
- strainer 8y agoIn contrast to the common expectation and statements in this article - most turbines are already not using the rare earth magnet design. Study: Substitution strategies for reducing the use of rare earths in wind turbines [1] >According to our estimations about 23% of the global installed capacity in 2015 is based on wind turbines using [permanent magnet] technology. The remaining 77% are using conventional electromagnets generators based on magnetic steel and copper windings, both of them posing no issues about the security of material supply. [1] https://www.sciencedirect.com/science/article/pii/S0301420717300077 https://www.sciencedirect.com/science/article/pii/S030142071...
- petre 8y agoPM rotor generators have several disadvantages: they're heavy; magnetic flux fades in time, moreso under heat; inability to control the rotor's magnetic flux; probably expensive as well.
- rurban 8y agoMostly true, just not the price. A simple stator generator is about half the price of a PMM, and at least half the value.
- strainer 8y agoIn table 3* the study summarizes 4 categories of generator. Low speed Permanent Magnet PMSG Low speed Excited Synchronous EESG Mid to High speed Geared PM PMSG High speed Geared Induction DFIG All these types are currently competitive in large wind turbine installations, with high PM content designs getting selected in quite a minority of cases, despite modest efficiency and maintenance bonuses, even at the current top end of generator scale ~8MW. To get beyond 10MW generators advantages of PM are desired but are also lumbered by relative heaviness besides the price of rare earths. Superconducting Magnets do seem like the way upward then, if reliable 'super-cooling' can be achieved. [*] https://www.sciencedirect.com/science/article/pii/S0301420717300077#t0015 https://www.sciencedirect.com/science/article/pii/S030142071...