Low-Cost Solar Mirror Substrates and Geometries for Solar Thermal and Photovoltaic Concentrator Applications

2001 ◽  
Author(s):  
David N. Wells
Keyword(s):  
Motion Tracking ◽  
Low Cost ◽  
Float Glass ◽  
Solar Thermal ◽  
Small Scale ◽  
Solar Concentrator ◽  
Hail Damage ◽  
Low Profile ◽  
Cylindrical Reflector ◽  
Cylindrical Mirror

Abstract Two principal approaches to lowering solar concentrator costs are through improved geometry (lower profile, simpler shape), and through simplified methods to make concentrator substrates. The paper discusses issues relating to fabrication of solar concentrator mirrors from inexpensive elastically bent float glass mirrors. Protection from hail damage by a novel shock absorbing back layer is presented. New low-profile concentrator geometry is presented which utilize the low-cost mirror substrates. One new geometry uses a stationary cylindrical reflector with novel arc-motion tracking absorber that appears suitable for mid-sized thermal applications. Another uses the cylindrical mirror with an azimuth-elevation tracking mechanism appears to be suitable for small-scale applications. To get even higher concentration, some low-cost secondary designs are briefly discussed which use refractive tubes or lenses as secondary concentrating elements.

scholarly journals A Low-Cost Motion Capture System for Small-Scale Wave Energy Device Tank Testing

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Francesco Paparella ◽  
Satja Sivcev ◽  
Daniel Toal ◽  
John V. Ringwood
Keyword(s):  
Wave Energy ◽  
Motion Tracking ◽  
Tracking System ◽  
Low Cost ◽  
Measurement Unit ◽  
Small Scale ◽  
Energy Device ◽  
Optical Motion ◽  
Optical Motion Tracking ◽  
Motion Tracking System

The measurement of the motion of a small-scale wave energy device during wave tank tests is important for the evaluation of its response to waves and the assessment of power production. Usually, the motion of a small-scale wave energy converter (WEC) is measured using an optical motion tracking system with high precision and sampling rate. However, the cost for an optical motion tracking system can be considerably high and, therefore, the overall cost for tank testing is increased. This paper proposes a low-cost capture system composed of an inertial measurement unit and ultrasound sensors. The measurements from the ultrasound sensors are combined optimally with the measurements from the inertial measurement unit through an extended Kalman filter (EKF) in order to obtain an accurate estimation of the motion of a WEC.

Dynamic Simulation and Optimization of an Experimental Micro-CSP Power Plant

2015 ◽  
Author(s):  
Matthias Mitterhofer ◽  
Matthew Orosz
Keyword(s):  
Control Strategy ◽  
Low Cost ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Economic Benefits ◽  
Solar Thermal ◽  
Small Scale ◽  
Pinch Point ◽  
Simulation And Optimization ◽  
Dynamic Representation

Small scale solar thermal systems are increasingly investigated in the context of decentralized energy supply, due to favorable costs of thermal energy storage (TES) in comparison with battery storage for otherwise economical PV generation. The present study provides the computational framework and results of a one year simulation of a low-cost pilot 3kWel micro-Concentrated Solar Power (micro-CSP) plant with TES. The modeling approach is based on a dynamic representation of the solar thermal loop and a steady state model of the Organic Rankine Cycle (ORC), and is validated to experimental data from a test site (Eckerd College, St. Petersburg, Florida). The simulation results predict an annual net electricity generation of 4.08 MWh/a. Based on the simulation, optimization studies focusing on the Organic Rankine Cycle (ORC) converter of the system are presented, including a control strategy allowing for a variable pinch point in the condenser that offers an annual improvement of 14.0% in comparison to a constant condensation pinch point. Absolute electricity output is increased to 4.65 MWh/a. Improvements are due to better matching to expander performance and lower condenser fan power because of higher pinch points. A method, incorporating this control strategy, is developed to economically optimize the ORC components. The process allows for optimization of the ORC subsystem in an arbitrary environment, e.g. as part of a micro-grid to minimize Levelized electricity costs (LEC). The air-cooled condenser is identified as the driving component for the ORC optimization as its influence on overall costs and performance is of major significance. Application of the optimization process to various locations in Africa illustrates economic benefits of the system in comparison to diesel generation.

Optimization of Parabolic Heliostat Focal Lengths in a Mini-Tower Solar Concentrator System

2011 ◽  
Author(s):  
Karim Hamza ◽  
Umesh Gandhi ◽  
Kazuhiro Saitou
Keyword(s):  
High Temperature ◽  
Concentration Ratio ◽  
Focal Length ◽  
Low Cost ◽  
Small Scale ◽  
Angle Of Incidence ◽  
Solar Concentrator ◽  
Effective Focal Length ◽  
Unit Energy ◽  
Utility Scale

Solar tower with heliostat mirrors is one of the established setups for utility-scale solar energy harvesting. Advantages of the setup include the capability to reach high temperature, modularity and ease of maintenance for the heliostats, containment of the high temperature zone atop the tower, as well as overall low cost per unit energy. However, downscaling to medium or small scale applications often does not turn out economically feasible with flat mirror heliostats that are the norm in utility-scale systems. This is mainly due to the need to preserve the solar concentration ratio, which in turn means the number of flat mirrors cannot be reduced. Use of parabolic mirrors instead can significantly reduce the required number of mirrors for smaller scale systems, but comes with new challenges. Unlike flat mirrors that have infinite effective focal length, the effective focal length of parabolic mirrors changes with the angle of incidence, which in turn, changes throughout the day and season. The design challenge tackled in this paper is that of optimal selection of the focal lengths of the heliostats in order to maximize the yearly harvested energy while maintaining the concentration ratio within desirable limits. A parameterized system model is developed and a genetic algorithm is implemented for the optimization task. The model is then applied to a demonstration case study of a 10 kW solar concentrator. Results of the study demonstrate the proposed design approach as well as show the promise for effective downscaling of tower and heliostat systems.

Low Cost Dispatchable Heat for Small Scale Solar Thermal Desalination Systems

2019 ◽  
Author(s):  
Jordyn Brinkley ◽  
Roland Winston ◽  
Lun Jiang ◽  
James Palko ◽  
Souvik Roy ◽  
...  
Keyword(s):  
Low Cost ◽  
Solar Thermal ◽  
Small Scale ◽  
Thermal Desalination

Optimal Scheduling of Parabolic Heliostats Aim Targets in a Mini-Tower Solar Concentrator System

2011 ◽  
Author(s):  
Karim Hamza ◽  
Umesh Gandhi ◽  
Kazuhiro Saitou
Keyword(s):  
High Temperature ◽  
Concentration Ratio ◽  
Flux Distribution ◽  
Incidence Angle ◽  
Focal Length ◽  
Low Cost ◽  
Small Scale ◽  
Solar Concentrator ◽  
Design Variables ◽  
Utility Scale

Solar tower with heliostat mirrors is an established technology for utility-scale solar energy harvesting. The setup has several advantages such as the capability to reach high temperature, modularity and ease of maintenance of the heliostats, containment of the high temperature zone, as well as overall low cost per harvested energy. Downscaling to medium and small scale applications is a desirable goal in order to attract more users of the technology. However, the downscaling often does not turn out economically feasible while using flat mirror heliostats, which are the norm in utility-scale systems. This is mainly due to the need to preserve the number (typically several hundred) of mirrors in order to maintain the solar concentration ratio. Use of parabolic mirrors instead can significantly reduce the required number of mirrors for smaller scale systems, but comes with new challenges. Unlike flat mirrors, the effective focal length of parabolic mirrors changes with the incidence angle causing undesirable variations in the concentration ratio and/or flux distribution at the receiver. To overcome this issue, we propose adjustment of the aim targets of the heliostat mirrors. Instead of aiming at the center of the receiver, aim targets are set as design variables and optimized to reduce undesirable peaks in the flux distribution. A special implementation of genetic algorithm is developed and applied to a case study of a nominal 10kW solar concentrator. Results of the study show significant improvement in flux distribution.

Tools of Transformation: Appropriate Technology in U.S. Countercultural Literature

2012 ◽  
Vol 44 (2) ◽  
pp. 75-93
Author(s):  
Peter Mortensen
Keyword(s):  
Low Cost ◽  
Appropriate Technology ◽  
Small Scale ◽  
Environmental Transformation ◽  
Buckminster Fuller ◽  
1960S And 1970S ◽  
The 1960S ◽  
Environmentally Sound ◽  
User Friendly ◽  
Second Wave

This essay takes its cue from second-wave ecocriticism and from recent scholarly interest in the “appropriate technology” movement that evolved during the 1960s and 1970s in California and elsewhere. “Appropriate technology” (or AT) refers to a loosely-knit group of writers, engineers and designers active in the years around 1970, and more generally to the counterculture’s promotion, development and application of technologies that were small-scale, low-cost, user-friendly, human-empowering and environmentally sound. Focusing on two roughly contemporary but now largely forgotten American texts Sidney Goldfarb’s lyric poem “Solar-Heated-Rhombic-Dodecahedron” (1969) and Gurney Norman’s novel Divine Right’s Trip (1971)—I consider how “hip” literary writers contributed to eco-technological discourse and argue for the 1960s counterculture’s relevance to present-day ecological concerns. Goldfarb’s and Norman’s texts interest me because they conceptualize iconic 1960s technologies—especially the Buckminster Fuller-inspired geodesic dome and the Volkswagen van—not as inherently alienating machines but as tools of profound individual, social and environmental transformation. Synthesizing antimodernist back-to-nature desires with modernist enthusiasm for (certain kinds of) machinery, these texts adumbrate a humanity- and modernity-centered post-wilderness model of environmentalism that resonates with the dilemmas that we face in our increasingly resource-impoverished, rapidly warming and densely populated world.

scholarly journals Development of a simplified gas ultracleaning process: experiments in biomass residue-based fixed-bed gasification syngas

2021 ◽  
Author(s):  
Christian Frilund ◽  
Esa Kurkela ◽  
Ilkka Hiltunen
Keyword(s):  
Activated Carbons ◽  
Low Cost ◽  
Fixed Bed ◽  
Carbonyl Sulfide ◽  
Gas Analysis ◽  
Small Scale ◽  
Cleaning Process ◽  
Medium Temperature ◽  
Gas Cleaning ◽  
Adsorption Affinity

AbstractFor the realization of small-scale biomass-to-liquid (BTL) processes, low-cost syngas cleaning remains a major obstacle, and for this reason a simplified gas ultracleaning process is being developed. In this study, a low- to medium-temperature final gas cleaning process based on adsorption and organic solvent-free scrubbing methods was coupled to a pilot-scale staged fixed-bed gasification facility including hot filtration and catalytic reforming steps for extended duration gas cleaning tests for the generation of ultraclean syngas. The final gas cleaning process purified syngas from woody and agricultural biomass origin to a degree suitable for catalytic synthesis. The gas contained up to 3000 ppm of ammonia, 1300 ppm of benzene, 200 ppm of hydrogen sulfide, 10 ppm of carbonyl sulfide, and 5 ppm of hydrogen cyanide. Post-run characterization displayed that the accumulation of impurities on the Cu-based deoxygenation catalyst (TOS 105 h) did not occur, demonstrating that effective main impurity removal was achieved in the first two steps: acidic water scrubbing (AWC) and adsorption by activated carbons (AR). In the final test campaign, a comprehensive multipoint gas analysis confirmed that ammonia was fully removed by the scrubbing step, and benzene and H2S were fully removed by the subsequent activated carbon beds. The activated carbons achieved > 90% removal of up to 100 ppm of COS and 5 ppm of HCN in the syngas. These results provide insights into the adsorption affinity of activated carbons in a complex impurity matrix, which would be arduous to replicate in laboratory conditions.

scholarly journals Research on the Performance of Solar Aided Power Generation System Based on Annular Fresnel Solar Concentrator

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1579
Author(s):  
Heng Zhang ◽  
Na Wang ◽  
Kai Liang ◽  
Yang Liu ◽  
Haiping Chen
Keyword(s):  
Power Generation ◽  
High Efficiency ◽  
Low Cost ◽  
Economic Index ◽  
Partial Replacement ◽  
Solar Concentrator ◽  
Small Disturbance ◽  
Step Size ◽  
Water Matrix ◽  
Cost Utilization

A solar-aided power generation (SAPG) system effectively promotes the high efficiency and low cost utilization of solar energy. In this paper, the SAPG system is represented by conventional coal-fired units and an annular Fresnel solar concentrator (AFSC) system. The annular Fresnel solar concentrator system is adopted to generate solar steam to replace the extraction steam of the turbine. According to the steam–water matrix equation and improved Flugel formula, the variable conditions simulation and analysis of the thermo-economic index were proposed by Matlab. Furthermore, in order to obtain the range of small disturbance, the method of partial replacement is used, that is, the extraction steam of the turbine is replaced from 0 to 100% with a step size of 20%. In this work, a SAPG system is proposed and its thermo-economic index and small disturbance scope are analyzed. The results show that the SAPG system is energy-saving, and the application scope of small disturbance is related to the quantity of the extraction steam and evaluation index.

scholarly journals Modification of a Solar Thermal Collector to Promote Heat Transfer inside an Evacuated Tube Solar Thermal Absorber

2021 ◽  
Vol 11 (9) ◽  
pp. 4100
Author(s):  
Rasa Supankanok ◽  
Sukanpirom Sriwong ◽  
Phisan Ponpo ◽  
Wei Wu ◽  
Walairat Chandra-ambhorn ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Small Scale ◽  
Medium Temperature ◽  
Change Behavior ◽  
Set Up ◽  
Evacuated Tube ◽  
Heating Medium

Evacuated-tube solar collector (ETSC) is developed to achieve high heating medium temperature. Heat transfer fluid contained inside a copper heat pipe directly affects the heating medium temperature. A 10 mol% of ethylene-glycol in water is the heat transfer fluid in this system. The purpose of this study is to modify inner structure of the evacuated tube for promoting heat transfer through aluminum fin to the copper heat pipe by inserting stainless-steel scrubbers in the evacuated tube to increase heat conduction surface area. The experiment is set up to measure the temperature of heat transfer fluid at a heat pipe tip which is a heat exchange area between heat transfer fluid and heating medium. The vapor/ liquid equilibrium (VLE) theory is applied to investigate phase change behavior of the heat transfer fluid. Mathematical model validated with 6 experimental results is set up to investigate the performance of ETSC system and evaluate the feasibility of applying the modified ETSC in small-scale industries. The results indicate that the average temperature of heat transfer fluid in a modified tube increased to 160.32 °C which is higher than a standard tube by approximately 22 °C leading to the increase in its efficiency by 34.96%.

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