Solar Thermal Field Research Articles

Monitoring of a MW Class Solar Field Set up in a Brick Manufacturing Process

InSun is an FP7 project that aims to demonstrate the reliability and quality of large solar thermal collector fields to produce industrial process heat at different temperature levels. In three demonstration plants, MW class solar fields with concentrating (Fresnel and parabolic trough) and flat plate collectors are installed, supplying heat to different production processes, at diverse climatic conditions. The new plants will be monitored to assess the performance and optimize the control strategies of the solar installations. One of the demonstration plants is a brick production company located in Italy (Laterizi Gambettola S.r.l.), where the installation of Fresnel collectors is foreseen, to reduce the consumption of natural gas, currently employed for the generation of process heat.After planning and commissioning, the solar field is now being monitored. Results in terms of temperatures, mass flows and control procedures are supervised to evaluate components’ performance and system energy balances. A dedicated procedure is under development, suitable for handling with the huge amount of data available thanks to the monitoring campaign.This paper presents a description of the solar energy integration into the brick production process and of the installed monitoring network. The data analysis procedure is also presented.

On-line Application for the Calculation of Shadows on Collecting Surfaces

The calculation of radiation losses on collecting surfaces due to shadows effect of surrounding objects is a key aspect in the design process of both photovoltaics and solar thermal collecting fields. This aspect is of special relevance in small size installations located in residential areas. Even the calculations procedures involved are well known, they are complicated and need skilled planners that usually cannot be afforded within the constrained budgets of this kind of projects.The authors present a new cloud application available for free at www.omnilus.com designed with the goal of maximum user simplicity while based in detailed calculation procedures. Not only yearly shadow losses are calculated but also monthly averaged values, so that it is possible to use this value to reduce monthly averaged daily solar radiation values used for systems calculation. This work, presents an overlook of the application, details on the calculation procedure used, and one case example.

Prospectives for China's solar thermal power technology development

China's total installed electrical power capacity reached 700 GW by the end of 2007 and is predicted to surpass 900 GW in 2010. The rapid increase in energy demand and increasing global warming have both pushed China to change its current electrical power structure where coal power accounts for nearly 75% of the total electric power generation. China has already become the world's largest solar water heater producer and user. However, there is still much to be done in the solar thermal power field before its commercialization. Solar thermal power technologies including solar power towers, solar parabolic trough concentrators, solar dish/stirling systems, linear Fresnel reflectors, and solar chimneys have been studied in China since the 1980s. A 10 kW dish/stirling project was funded by the Ministry of Science and Technology (MOST) during 2000–2005 with a 1 MW solar power tower and research of trough concentrator metal–glass evacuated tubes supported during 2006–2010. This paper describes a continued solar thermal power development roadmap in China in 5-year intervals between 2006 and 2025.

99/02128 Development of and experience with a new generation of modern coal firing systems in a new high-efficiency combined heat and power station: Kaess, M. et al. Proc. Am. Power Conf., 1998, 60, (2), 626–630

This paper examines flexible operation of solvent-based post-combustion carbon capture (PCC) for the reduction of power plant carbon emissions while minimizing revenue loss due to the reduced power plant electricity output. The study is conducted using a model superstructure enveloping three plants; a power plant, a PCC plant and a solar thermal field where the power plant and PCC plant are operated flexibly under the influence of hourly electricity market and weather conditions. Reduced (surrogate) models for the reboiler duty and auxiliary power requirement for the carbon capture plant are generated and applied to simulate and compare four cases, (A) power plant with PCC, (B) power plant with solar assisted PCC, (C) power plant with PCC and solar repowering – variable net electricity output and (D) power plant with PCC and solar repowering – fixed net electricity output. Such analyses are conducted under dynamic conditions including power plant part-load operation while varying the capture rate to optimize the revenue of the power plant. Each case was simulated with a lower carbon price of $25/tonne-CO2 and a higher price of $50/tonne-CO2. The comparison of cases B–D found that optimal revenue generation for case C can be up to 42% higher than that of solar-assisted PCC (case B). Case C is found to be the most profitable with the lowest carbon emissions intensity and is found to exhibit a constant capture rate for both carbon prices. The optimal revenue for case D is slightly lower than case C for the lower carbon price ($25/tonne-CO2) while it is considerably lower in the higher carbon price ($50/tonne-CO2) scenario. The highest revenue to electricity ratio is found to be for the case where solar repowering is used for power boosting. This study highlights the significant potential of dynamic flexible operation toward deeper reductions in carbon capture costs. This analysis is based on the presence of a carbon pricing scheme currently not present in the Australian market, but which could be realised in the future.

Thermally induced vibrations of long thin- walled cylinders of open section

Directional solar thermal field /sunlight/ effect on coupled nonplanar transverse and torsional vibrations of satellite cylindrical antennas in orbit