395 research outputs found
High concentration PV system
The aim of the European funded project HICON (High Concentration PV Power Systems) has been to develop, set up and test a new high concentration – 1000x or more – PV system. This system uses an actively cooled large-area receiver consisting of III-V solar cells. Two technology fields have been integrated: The high concentration of the sunlight has been obtained by using technologies experienced in solar thermal systems like parabolic dishes or tower systems. The high concentration photovoltaic receiver is based on the III-V solar cell technology. To deal with the high concentration, Monolithic Integrated Modules (MIMs) [1-3] have been further developed and assembled to Compact Concentrator Modules (CCM). The CCM prototypes have been tested in a solar furnace (PSA) and in a parabolic dish (BGU). The results of the project will be presented in this paper.peer-reviewe
Tantalum carbide as a novel support material for anode electrocatalysts in polymer electrolyte membrane water electrolysers
Technoeconomic analysis of a methanol plant based on gasification of biomass and electrolysis of water
International audienceMethanol production process configurations based on renewable energy sources have been designed. The processes were analyzed in the thermodynamic process simulation tool DNA. The syngas used for the catalytic methanol production was produced by gasification of biomass, electrolysis of water, CO from post-combustion capture and autothermal reforming of natural gas or biogas. Underground gas storage of hydrogen and oxygen was used in connection with the electrolysis to enable the electrolyser to follow the variations in the power produced by renewables. Six plant configurations, each with a different syngas production method, were compared. The plants achieve methanol exergy efficiencies of 59-72%, the best from a configuration incorporating autothermal reforming of biogas and electrolysis of water for syngas production. The different processes in the plants are highly heat integrated, and the low-temperature waste heat is used for district heat production. This results in high total energy efficiencies (~90%) for the plants. The specific methanol costs for the six plants are in the range 11.8-25.3 €/GJ. The lowest cost is obtained by a plant using electrolysis of water, gasification of biomass and autothermal reforming of natural gas for syngas production
A Roadmap for Astrophysics and Cosmology with High-Redshift 21 cm Intensity Mapping
In this white paper, we lay out a US roadmap for high-redshift 21 cm
cosmology (30 < z < 6) in the 2020s. Beginning with the currently-funded HERA
and MWA Phase II projects and advancing through the decade with a coordinated
program of small-scale instrumentation, software, and analysis projects
targeting technology development, this roadmap incorporates our current best
understanding of the systematics confronting 21 cm cosmology into a plan for
overcoming them, enabling next-generation, mid-scale 21 cm arrays to be
proposed late in the decade. Submitted for consideration by the Astro2020
Decadal Survey Program Panel for Radio, Millimeter, and Submillimeter
Observations from the Ground as a Medium-Sized Project.Comment: 10 pages (plus a cover page and references), 6 figures. Submitted as
a APC White Paper for Astro202
Computer simulation of intergranular stress corrosion cracking via hydrogen embrittlement
Scaling factors for channel width variations in treelike flow field patterns for polymer electrolyte membrane fuel cells - An experimental study
To have a uniform distribution of reactants is an advantage to a fuel cell. We report results
for such a distributor with tree-like flow field plates (FFP). Numerical simulations have
shown that the width scaling parameters of tree-like patterns in FFPs used in polymer
electrolyte membrane fuel cells (PEMFC) reduces the viscous dissipation in the channels. In
this study, experimental investigations were conducted on a 2-layer FF plate possessing a
tree-like FF pattern which was CNC milled on high-quality graphite. Three FF designs of
different width scaling parameters were employed. IeV curves, power curves and impedance spectra were generated at 70%, 60% and 50% relative humidity (25 cm2 active area),
and compared to those obtained from a conventional 1-channel serpentine FF. It was found
that the FF design, with a width scaling factor of 0.917 in the inlet and 0.925 in the outlet pattern, exhibited the best peak power out of the three designs (only 11% - 0.08 W/cm2
lower than reference serpentine FF). Results showed that a reduction of the viscous
dissipation in the flow pattern was not directly linked to a PEMFC performance increase
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