| 1. |
- Welsch, Manuel, et al.
(author)
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Smart and Just Grids for sub-Saharan Africa : Exploring options
- 2013
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In: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 20, s. 336-352
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Journal article (peer-reviewed)abstract
- In 2009, an estimated 585 million people had no access to electricity services in sub-Saharan Africa. Unlike many other regions of the world, under current assumptions, that figure is expected to rise significantly to about 652 million by 2030-an unsustainable and unacceptable situation. Knowing of the intrinsic linkages between access to energy services and development, national governments and regional organisations have identified the urgent need for accelerated electrification rates. Some of the established and emerging concepts, systems and technologies grouped under the term 'Smart Grids' may offer an important contribution to achieving universal access to electricity. We argue that these Smart Grid advances may enable sub-Saharan African countries to leapfrog elements of traditional power systems and accelerate and improve electrification efforts. We introduce the notion of Just Grids to reflect the need for power systems to contribute towards equitable and inclusive economic and social development without marginalising the poor. The paper reviews the literature, and identifies specific options that could be implemented in sub-Saharan Africa. After selecting criteria that focus on potential impact as well as requirements for their implementation, a qualitative first-pass assessment of the potential of these options is made. This paper provides support for policy development, and suggests areas for further, more detailed research.
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| 2. |
- Vlasko-Vlasov, V. K., et al.
(author)
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Magnetic circuit for Abrikosov vortices : Vortex motion in a periodic labyrinth of magnetic T and I-shaped elements under a superconducting film
- 2022
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In: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 557
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Journal article (peer-reviewed)abstract
- We explore tailored labyrinth-like vortex motion in a niobium film placed on top of periodic arrays of T and I -shaped permalloy elements by imaging the vortex distribution in magnetic fields applied perpendicular to the superconducting layer under different in-plane polarizations of the TI structure. At low temperatures, we observe pronounced meandering of vortex motion around the TI elements. Remarkably, vortices can easily penetrate the sample along the TI columns even though the average vortex pinning in the patterned area is larger than in a bare niobium film. Accordingly, at temperatures close to the superconducting transition temperature, Tc, the voltage-current curves in the patterned area show an earlier departure from the zero-resistivity state at small currents, followed by slower growth with increasing current as compared to the un-patterned film. We present a model based on magnetostatic interactions between magnetic charges at the edges of the polarized TI-elements and single magnetic charges of induced vortices to account for this behavior. We expect that similar magnetic structures imposing labyrinth-like vortex motion could be used for collective entanglement of vortices envisioned in quantum circuit operations.
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