Substitution strategies for reducing the use of rare earths in wind turbines

Pavel, Claudiu C.; Lacal‐Arántegui, Roberto; Marmier, A.; Schüler, Doris; Evangelos, Tzimas; Buchert, Matthias; Jenseit, Wolfgang; Blagoeva, Darina

doi:10.1016/j.resourpol.2017.04.010

Cited by 175 publications

(94 citation statements)

References 17 publications

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“…The other 77% of globally installed wind turbines have electromagnetic generators which utilize primarily steel and copper, which are not considered critical materials, for their functionality [10]. In comparing the two primary categories of wind turbines, the gearless, direct-drive turbines considered in this study operate best at low speeds and have better overall efficiency, lower weight, and less maintenance requirements [10]. Geared turbines will tend to operate at higher speeds and on smaller turbines (<5 MW) [10].…”

Section: Clean Energy Production Technologiesmentioning

confidence: 99%

Critical Material Applications and Intensities in Clean Energy Technologies

Leader

Gaustad

2019

Clean Technol.

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Clean energy technologies have been developed to address the pressing global issue of climate change; however, the functionality of many of these technologies relies on materials that are considered critical. Critical materials are those that have potential vulnerability to supply disruption. In this paper, critical material intensity data from academic articles, government reports, and industry publications are aggregated and presented in a variety of functional units, which vary based on the application of each technology. The clean energy production technologies of gas turbines, direct drive wind turbines, and three types of solar photovoltaics (silicon, CdTe, and CIGS); the low emission mobility technologies of proton exchange membrane fuel cells, permanent-magnet-containing motors, and both nickel metal hydride and Li-ion batteries; and, the energy-efficient lighting devices (CFL, LFL, and LED bulbs) are analyzed. To further explore the role of critical materials in addressing climate change, emissions savings units are also provided to illustrate the potential for greenhouse gas emission reductions per mass of critical material in each of the clean energy production technologies. Results show the comparisons of material use in clean energy technologies under various performance, economic, and environmental based units.

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Section: Clean Energy Production Technologiesmentioning

confidence: 99%

Critical Material Applications and Intensities in Clean Energy Technologies

Leader

Gaustad

2019

Clean Technol.

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“…Sifat magnet NdFeB dapat ditingkatkan dengan menggunakan unsur LTJ seperti Dy dan Pr. Namun kelangkaan Dy dan Pr menyebabkan harga LTJ tersebut sangat mahal (Sheridan et al 2014;Pavel et al 2017 Magnet awal mengandung unsur tanah jarang 7,11%wt Praseodimium (Pr) dan 22,92%wt Neodimium (Nd). Bahan magnet permanen dengan kandungan Nd dan Pr merupakan magnet permanen dengan energi produk yang tinggi (Havwini, Humaidi, and Muljadi 2013).…”

Section: Pendahuluanunclassified

PENINGKATAN KOERSIVITAS DAN REMANEN PADA MAGNET PERMANEN Nd-Fe-B DENGAN PROSES DIFUSI BATAS BUTIR

et al. 2019

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AbstrakSalah satu karakteristik magnet permanen tipe NdFeB adalah rentan terhadap kenaikan temperatur, seperti halnya yang terjadi pada aplikasi motor listrik. Penambahan unsur Dy pada tipe ini menjadi penting dalam usaha meningkatkan koersivitas dan temperatur curie. Akan tetapi, penambahan unsur Dy secara konvensional memerlukan biaya tinggi serta terjadinya penurunan nilai sifat remanen. Penelitian ini dilakukan dengan tujuan menambahkan unsur Dy untuk meningkatkan koersivitas magnet permanen dengan cara difusi batas butir dengan biaya yang lebih rendah dari pada cara konvensional dan tidak menurunkan sifat remanen secara signifikan. Penelitian ini dimulai dengan mengkarakterisasi dan mengamati struktur mikro awal dari magnet permanen tipe NdFeB dengan alat SEM-BSE dan VSM. Kemudian dilakukan proses difusi Dy dengan cara melapisi permukaan magnet dengan campuran DyF3-LiF dengan variasi perbandingan 0%-0% (tanpa lapisan); 44%-56% dan 100%-0%. Setelah itu, pada setiap variasi lapisan dilakukan perlakuan panas anil 750 o C dengan variasi waktu penahanan selama 2,5; 5; 7,5 dan 10 jam yang diikuti dengan post anil 550 o C selama 1 jam. Hasilnya, nilai koersivitas magnet meningkat dari 10,7 kOe menjadi 13,5 kOe pada sampel yang dianil pada variasi waktu penahanan 5 dan 7,5 jam. Sedangkan nilai remanen juga terjadi peningkatan dari 13,2 kG menjadi 14,7 kG pada sampel yang di anil dengan waktu penahanan selama 10 jam. Energi maksimum produk magnet pada sampel yang mengalami proses difusi (43,6 MGOe) lebih tinggi dari sampel yang tidak dilakukan difusi batas butir (43,1 MGOe).Kata kunci : difusi batas butir, dysprosium (Dy), koersivitas, magnet NdFeB, remanen AbstractOne of the characteristics of the NdFeB type permanent magnet was susceptible against the increase of temperature such as in electric motor applications. It is important to add Dy elements to increase coercivity and temperature curie. However, the addition of Dy elements conventionally requires high costs and reduces remanent significantly. The purpose of this study was to improve coercivity without a significant decrease in remanence by adding Dy elements with grain boundary diffusion. The microstructure of the NdFeB type permanent magnet was characterized and observed with SEM-BSE and VSM. Then, the surface of NdFeB type permanent magnet was coated with DyF3-LiF with variation ratio of 0%-0% (without coating); 44%-56% and 100%-0%. After that, each variation was annealed at 750 o C for holding time of 2.5; 5; 7.5 and 10 hours followed by post-annealing 550 o C for 1 hour. As a result, the magnetic coercivity increase from 10.7 kOe (initial magnet) to 13.5 kOe at variation of holding time of 5 and 7.5 hours. While the remanence also increased from 13.2 kG

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“…It is commonly taken that doubly-fed induction generators (DFIGs) are the workhorse wind generators in the wind power industry [3]. But with the advent of larger direct-drive wind turbines, permanent magnet synchronous generators (PMSGs) are becoming increasingly relevant due to their propensity for improved torque density designs and operational efficiency performance [4,5]. However, with the growing popularity of PMSGs comes the fact that the high cost of rare earth PMs facilitated by a monopolised market structure, with recent impulsive price swings, is one reason for recent alternative non-PM solutions, so-called rare earth-free wind generator technologies [5].…”

Section: Introductionmentioning

confidence: 99%

“…In South Africa, manufacturing and installation of wind turbines translates to premium on the imported raw materials or technology, at least, of the rare earth PMs mostly deployed in such designs. Based on estimations, 23% of global installed wind turbines use PMSGs which are designed with rare earth elements [5]. Therefore, for large wind turbines, the PM content mass, implying cost, will increase as the power level increases, especially for direct-drive wind generator systems as illustrated in Figure 1 [5,9].…”

Section: Introductionmentioning

confidence: 99%

“…Based on estimations, 23% of global installed wind turbines use PMSGs which are designed with rare earth elements [5]. Therefore, for large wind turbines, the PM content mass, implying cost, will increase as the power level increases, especially for direct-drive wind generator systems as illustrated in Figure 1 [5,9]. To this end, there is the possibility of designing wind generators with cheaper excitation technologies such as wound-field (WF) electromagnets which can be locally produced, and in this way the localisation drive of wind power infrastructure could be enhanced in the long run.…”

Section: Introductionmentioning

confidence: 99%

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Potentials of locally manufactured wound-field flux switching wind generator in South Africa

Akuru

Kamper

2019

J. energy South. Afr.

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The China-based monopoly of high-energy permanent magnet materials used in modern wind generators impact the economic viability and local content value of most wind turbines installed in South Africa, especially large installations. It is possible to design with less expensive excitation technologies using locallysourced wound-field electromagnets, which might promote local content. This study involves the optimum design performance comparison of the wound-field flux switching machine (WF-FSM) technology based on two variants -Design I and II (D-I and D-II) -the difference being in the arrangement of their DC woundfield coils. The machines are evaluated using finite element analyses (FEA) with optimum performance emphasised on design parameters such as torque density, efficiency and power factor. The selected design targets are meant to improve the performance to cost fidelity of the proposed wind generator variants. In 2D FEA, D-II can produce up to 18.8% higher torque density (kNm/m 3 ) and 17.1% lesser loss per active volume (kW/m 3 ) than D-I. In 3D FEA, the torque density of D-II remains higher at 10.6%, but its loss per active volume increases by 15% compared to D-I. The discrepancy observed in 2D and 3D FEA is due to an underestimation of the end-winding effects in D-II. The power factor of D-II is higher than D-I, both in 2D and 3D FEA, which may translate to lower kVA ratings and inverter costs. A higher total active mass ensues for the studied WF-FSMs than a conventional direct-drive PMSG, but avoiding rare earth PMs translate to significantly lower costs. Highlights• Two WF-FSM variants -D-I and D-II -are optimally compared in FEA for wind generator applications at medium-scale power level. • D-I displays better loss per active mass while D-II displays better torque density and power factor. • Both WF-FSM variants yield heavier but relatively cheaper wind generators when compared to a conventional PMSG.

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Substitution strategies for reducing the use of rare earths in wind turbines

Cited by 175 publications

References 17 publications

Critical Material Applications and Intensities in Clean Energy Technologies

Critical Material Applications and Intensities in Clean Energy Technologies

PENINGKATAN KOERSIVITAS DAN REMANEN PADA MAGNET PERMANEN Nd-Fe-B DENGAN PROSES DIFUSI BATAS BUTIR

Potentials of locally manufactured wound-field flux switching wind generator in South Africa

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