Objective. The objective of the present study is to evaluate the environmental performance of solar thermal systems for domestic hot-water supply from life cycle perspective. Energy ratios and life ...cycle CO2 emissions of two different types of solar thermal system are analyzed, namely, the integrated solar thermal system and the separated solar thermal system that supply 40% of the total hot-water demand of a four people household. This analysis uses the material and energy data collected from eight manufacturers of solar thermal systems to reflect the present reality. Results and Discussion. The analysis shows that the life cycle CO2 emissions of solar thermal systems are 25-37% less than those of domestic gas boilers. Energy ratios of solar thermal systems are more than one, while that of a gas boiler system is 0.9. This is because solar thermal systems require less gas consumption compared to a domestic gas boiler. Moreover, comparison between the two different types of solar thermal systems reveals that the life cycle CO2 emissions and energy consumption of the separated solar thermal system are more than those of the integrated solar thermal system mainly because the separated type consumes electricity for pumps to circulate the heat medium. Furthermore, The effects on CO2 emission of the change in heat supply rate by the solar thermal systems are analyzed. The analysis finds that the more the heat supply rate increases, the less the CO2 emissions of the solar systems are. When the solar thermal systems supply 60% of the total hot-water demand, the life cycle CO2 emissions of solar thermal systems are 25-37% less than in the case of 40% supply. Conclusions. The present study reveals that both the integrated and separated solar thermal system are superior to gas boiler from viewpoints of energy ratios and life cycle CO2 emissions. Furthermore, comparison between the integrated and separated solar thermal system finds the former has better environmental performance than the latter.
There exist various desalination systems that work at operating temperatures of 60 to 80°C. As an example, the multi-effect ambient pressure desalination system with free convection of air may be ...mentioned. It is described in /1/ and /2/. Like other concepts and desalination systems, it is very well suited for operation with thermal solar collectors, thus using renewable energy resources. For solar thermally driven desalination systems, special corrosion-free collectors have to be developed. The paper describes the work carried out so far at the Fraunhofer ISE in Germany.
Chapter 10 deals with solar thermal power systems. Initially, the general design considerations are given followed by the presentation of the three basic technologies. These include the parabolic ...trough collector system, which includes a description of the PTC power plant and outlook of the technology; the power tower systems and the dish systems. This is followed by the thermal analysis of the basic cycles of solar thermal power plants. Subsequently, solar updraft tower systems are examined, which include the initial steps and first demonstration, and the thermal analysis. Finally, solar ponds are examined, which is a form of large solar collector and storage system that can be used for solar power generation and include practical design considerations, salty water transmission estimation, methods of heat extraction, description of two large experimental solar ponds, and applications of solar ponds.
In Germany, solar thermal systems (STS) have only diffused to a minor extent yet. This paper analyzes, which demand side factors are decisive for the further proliferation of this environmentally ...benign technology. Making use of a consumer survey in North-West Germany in 2007, we examine the following parameters: positive environmental attitude, knowledge of the applicability of STS to satisfy consumer needs, and the presence of STS among peer consumers. Drawing upon theoretical foundations from innovation economics and evolutionary consumer theory, we posit that these variables play a different role at distinct stages of the product's diffusion process. Among nonowners, concrete plans to purchase a system within the subsequent two years are distinguished from the general interest to invest into this technology within the next five years. Probitmodels are estimated to test our hypotheses. Our results do not indicate a strong take-off of product diffusion within the next years. By generating interest for the product, knowledge and environmental attitude as well as household income are important determinants of prospective adoptions on the part of the potential imitators. However, only the behavior of peers appears to act as a trigger to the diffusion of this technology.
Koncept u četiri koraka za otkrivanje i dijagnozu kvarova (FDD) u velikim solarnim toplinskim sustavima je razvijen u okviru tekućih istraživačkih aktivnosti na Sveučilištu Kassel. Ovaj koncept ...kombinira različite opće pristupe za otkrivanje i dijagnozu kvarova u jednoj strukturi. Osim toga, uvodi se sustavna kategorizacija podataka i preciznija terminologija prema razlikovanju između veličina dobivenih iz osjetnika, mjerenih veličina, svojstava i simptoma za pojedine elemente sustava.
Solar energy has experienced phenomenal growth in recent years due to both technological improvements resulting in cost reductions and government policies supportive of renewable energy development ...and utilization. This study analyzes the technical, economic and policy aspects of solar energy development and deployment. While the cost of solar energy has declined rapidly in the recent past, it still remains much higher than the cost of conventional energy technologies. Like other renewable energy technologies, solar energy benefits from fiscal and regulatory incentives and mandates, including tax credits and exemptions, feed-in-tariff, preferential interest rates, renewable portfolio standards and voluntary green power programs in many countries. Potential expansion of carbon credit markets also would provide additional incentives to solar energy deployment; however, the scale of incentives provided by the existing carbon market instruments, such as the Clean Development Mechanism of the Kyoto Protocol, is limited. Despite the huge technical potential, development and large-scale, market-driven deployment of solar energy technologies world-wide still has to overcome a number of technical and financial barriers. Unless these barriers are overcome, maintaining and increasing electricity supplies from solar energy will require continuation of potentially costly policy supports.
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