scholarly journals Design and test validation of a novel low-cost quartz window for reducing heat losses in concentrating solar power applications

2019 ◽  
Author(s):  
Shaun D. Sullivan ◽  
James B. Kesseli
2020 ◽  
Vol 12 (15) ◽  
pp. 6223
Author(s):  
Emmanuel Wendsongre Ramde ◽  
Eric Tutu Tchao ◽  
Yesuenyeagbe Atsu Kwabla Fiagbe ◽  
Jerry John Kponyo ◽  
Asakipaam Simon Atuah

Electricity is one of the most crucial resources that drives any given nation’s growth and development. The latest Sustainable Development Goals report indicates Africa still has a high deficit in electricity generation. Concentrating solar power seems to be a potential option to fill the deficit. That is because most of the components of concentrating solar power plants are readily available on the African market at affordable prices, and there are qualified local persons to build the plants. Pilot micro-concentrating solar power plants have been implemented in Sub-Saharan Africa and have shown promising results that could be expanded and leveraged for large-scale electricity generation. An assessment of a pilot concentrating solar power plant in the sub-region noticed one noteworthy obstacle that is the failure of the tracking system to reduce the operating energy cost of running the tracking control system and improve the multifaceted heliostat focusing behavior. This paper highlights the energy situation and the current development in concentrating solar power technology research in Africa. The paper also presents a comprehensive review of the state-of-the-art solar tracking systems for central receiver systems to illustrate the current direction of research regarding the design of low-cost tracking systems in terms of computational complexity, energy consumption, and heliostat alignment accuracy.


Author(s):  
Andrea Ambrosini ◽  
Timothy N. Lambert ◽  
Marlene Bencomo ◽  
Aaron Hall ◽  
Kent vanEvery ◽  
...  

Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures < 600°C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.3 at receiver surface operating temperatures), be stable in air, and be low-cost and readily manufacturable. Recent efforts at Sandia National Laboratories have begun to address the issue of more efficient solar selective coatings for tower applications. This paper will present an overview of these efforts which address the development of new coatings on several fronts.


Author(s):  
Robert Pitz-Paal ◽  
Ju¨rgen Dersch ◽  
Barbara Milow ◽  
Fe´lix Te´llez ◽  
Alain Ferriere ◽  
...  

Beside continuous implementation of concentrating solar power plants (CSP) in Europe, which stipulate cost reduction by mass production effects, further R&D activities are necessary to achieve the cost competitiveness to fossil power generation. Therefore the cost range of 15–20 cents€/kWh for the currently planned CSP systems in Europe has to be decreased by a factor of 2–4. The European Concentrated Solar Thermal Roadmap (ECOSTAR) study that is conducted by leading CSP research institutes in Europe intends to stipulate the direction for R&D activities in the context of cost reduction. It uses a common methodology approach, based on an annual performance model to identify the most essential technical innovations that will reduce the cost of seven different CSP system concepts, which are currently under promotion world wide. The potential of innovative concepts for solar light weight concentrators, low-cost thermal energy storage concepts, solar receivers/absorbers and power cycles are in the main focus of interest. The results of the study include a description of the value of CSP power, the sensitivity of the electricity cost information, a list of innovations that have been investigated and recommendations for the focus of further R&D work.


2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Gregory S. Jackson ◽  
Luca Imponenti ◽  
Kevin J. Albrecht ◽  
Daniel C. Miller ◽  
Robert J. Braun

Oxide particles have potential as robust heat transfer and thermal energy storage (TES) media for concentrating solar power (CSP). Particles of low-cost, inert oxides such as alumina and/or silica offer an effective, noncorrosive means of storing sensible energy at temperatures above 1000 °C. However, for TES subsystems coupled to high-efficiency, supercritical-CO2 cycles with low temperature differences for heat addition, the limited specific TES (in kJ kg−1) of inert oxides requires large mass flow rates for capture and total mass for storage. Alternatively, reactive oxides may provide higher specific energy storage (approaching 2 or more times the inert oxides) through adding endothermic reduction. Chemical energy storage through reduction can benefit from low oxygen partial pressures (PO2) sweep-gas flows that add complexity, cost, and balance of plant loads to the TES subsystem. This paper compares reactive oxides, with a focus on Sr-doped CaMnO3–δ perovskites, to low-cost alumina-silica particles for energy capture and storage media in CSP applications. For solar energy capture, an indirect particle receiver based on a narrow-channel, counterflow fluidized bed provides a framework for comparing the inert and reactive particles as a heat transfer media. Low-PO2 sweep gas flows for promoting reduction impact the techno-economic viability of TES subsystems based on reactive perovskites relative to those using inert oxide particles. This paper provides insights as to when reactive perovskites may be advantageous for TES subsystems in next-generation CSP plants.


Author(s):  
Austin Fleming ◽  
Zhiwen Ma ◽  
Tim Wendelin ◽  
Heng Ban ◽  
Charlie Folsom

Concentrating solar power (CSP) plants can provide dispatchable power with the thermal energy storage (TES) capability for greater renewable-energy grid penetration. To increase the market competitiveness, CSP technology needs to increase the solar-to-electric efficiency and reduce costs in the areas of solar collection from the heliostat field to the receiver, energy conversion systems, and TES. The current state-of-the-art molten-salt systems have limitations regarding both the potential for cost reduction and improvements in performance. Even with significant improvements in operating performance, these systems face major challenges to satisfy the performance targets, which include high-temperature stability (>650°C), low freezing point (<0°C), and material compatibility with high-temperature metals (>650°C) at a reduced cost. The fluidized-bed CSP (FB-CSP) plant being developed by the National Renewable Energy Laboratory (NREL) has the potential to overcome the above issues with substantially lower cost. The particle receiver is a critical component to enable the FB-CSP system. This paper introduces the development of an innovative receiver design using the blackbody design mechanism by collecting solar heat with absorber tubes that transfer the radiant heat to flowing particles. The particle and receiver materials can withstand temperatures of >1000°C because the receiver can use low-cost materials, such as ceramics and stainless steel, and the solid particles can be any low-cost, stable materials such as sand or ash for particle containment and TES. The heated particles can be stored in containers for TES or supply heat for power generation. This study investigated the performance of convection, reflection, and infrared (IR) re-radiation losses on the absorber solar receiving side. We developed a flux model to predict the reflection losses from the absorber tubes based on the NREL SolTrace program, and conducted thermal modeling by using the Fluent Software. This paper presents the thermal modeling and results on the receiver performance. The receiver configuration may have broad applications for different heattransfer fluids (HTFs), including gas, liquid, or the solid particle-based system in our receiver development.


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