| 1. |
- Aichmayer, Lukas, et al.
(författare)
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Micro Gas-Turbine Design for Small-Scale Hybrid Solar Power Plants
- 2013
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Ingår i: Proceedings of the ASME Turbo Expo 2013. San Antonio, USA. June 3-7. - : ASME. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- Hybrid solar micro gas-turbines are a promising technology for supplying controllable low-carbon electricity in off-grid regions. A thermoeconomic model of three different hybrid micro gas-turbine power plant layouts has been developed, allowing their environmental and economic performance to be analyzed. In terms of receiver design, it was shown that the pressure drop is a key criterion. However, for recuperated layouts the combined pressure drop of the recuperator and receiver is more important. The internally-fired recuperated micro gas-turbine was shown to be the most promising solution of the three configurations evaluated, in terms of both electricity costs and carbon emissions. Compared to competing diesel generators, the electricity costs from hybrid solar units are between 10% and 43% lower, while specific CO2 emissions are reduced by 20 – 35%.
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| 2. |
- Guédez, Rafael, et al.
(författare)
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Reducing the Number of Turbine Starts in Concentrating Solar Power Plants through the Integration of Thermal Energy Storage
- 2013
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Ingår i: Proceedings of the ASME TurboExpo 2013. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- The operation of steam turbine units in solar thermal power plants is very different than in conventional base-load plants. Due to the variability of the solar resource, much higher frequencies of plant start-ups are encountered. This study provides an insight to the influence of thermal energy storage integration on the typical cycling operation of solar thermal power plants. It is demonstrated that the integration of storage leads to significant reductions in the annual number of turbine starts and is thus beneficial to the turbine lifetime. At the same time, the effects of storage integration on the electricity costs are analyzed to ensure that the designs remain economically competitive. Large storage capacities, can allow the plant to be shifted from a daily starting regime to one where less than 20 plant starts occur annually. Additionally, the concept of equivalent operating hours is used to further analyze the direct impact of storage integration on the maintenance planning of the turbine units.
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| 3. |
- Guédez, Rafael, et al.
(författare)
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Thermoeconomic Optimization of Solar Thermal Power Plants with Storage in High-Penetration Renewable Electricity Markets
- 2013
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Ingår i: Energy Procedia. - : Elsevier BV.
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Konferensbidrag (refereegranskat)abstract
- Unlike most of renewable energy technologies, solar thermal power plants with integrated thermal energy storage are able to store heat from the sun and thereby supply electricity whenever it is needed to meet the demand. This attribute makes concentrating solar power ideally suited to compensate for fluctuations in other renewable energy sources. In order to analyze this market role, three scenarios were modeled, with low, medium and high penetrations of non- dispatchable renewables (i.e. wind and solar photovoltaics). The demand that cannot be met by these variable sources is met by a solar thermal power plant with heat provided either by a solar field and storage system or a back-up gas burner. For each scenario, the size of the solar field and storage were varied in order to show the trade-off between the levelized generation costs of the system, the annual specific CO2 emissions and the share of renewable electricity generation. The results show that, regardless of the scenario, there exist optimum plant configurations with viable costs whilst simultaneously ensuring a considerable reduction in CO2 emissions. Furthermore, it is shown that the limited flexibility of the power block prevents the system from reaching higher levels of sustainability. Lastly, the results were compared with an equivalent combined cycle power plant, showing that solutions involving solar thermal power can be justified in environmental terms only if large storage units are integrated into the plants.
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| 4. |
- Sandoz, Raphael, et al.
(författare)
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Air-Based Bottoming-Cycles for Water-Free Hybrid Solar Gas-Turbine Power Plants
- 2013
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Ingår i: Proceedings of the ASME TurboExpo 2013. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- A thermoeconomic model of a novel hybrid solar gas- turbine power plant with an air-based bottoming cycle has been developed, allowing its thermodynamic, economic, and environmental performance to be analyzed. Multi-objective optimization has been performed to identify the trade-off between two conflicting objectives: minimum capital cost and minimum specific CO2 emissions. In-depth thermoeconomic analysis reveals that the additional bottoming cycle significantly reduces both the levelized cost of electricity and the environmental impact of the power plant (in terms of CO2 emissions and water consumption) when compared to a simple gas-turbine power plant without bottoming cycle. Overall, the novel concept appears to be a promising solution for sustainable power generation, especially in water-scarce areas.
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| 5. |
- Spelling, James, 1987-, et al.
(författare)
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A Comparative Thermoeconomic Study of Hybrid Solar Gas-Turbine Power Plants
- 2013
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Ingår i: Proceedings of the ASME Turbo Expo. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- The construction of the first generation of commercial hybrid solar gas-turbine power plants will present the designer with a large number of choices. To assist decision making, a thermoeconomic study has been performed for three different power plant configurations, namely simple- and combined- cycles as well as simple-cycle with the addition of thermal energy storage. Multi-objective optimization has been used to identify Pareto-optimal designs and highlight the trade-offs between minimizing investment costs and minimizing specific CO2 emissions. The solar hybrid combined-cycle plant provides a 60% reduction in electricity cost compared to parabolic trough power plants at annual solar shares up to 20%. The storage integrated designs can achieve much higher solar shares and provide a 7 – 13% reduction in electricity costs at annual solar shares up to 90%. At the same time, the water consumption of the solar gas-turbine systems is significantly lower than conventional steam-cycle based solar power plants.
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| 6. |
- Spelling, James, 1987-
(författare)
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Hybrid Solar Gas-Turbine Power Plants : A Thermoeconomic Analysis
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The provision of a sustainable energy supply is one of the most importantissues facing humanity at the current time, and solar thermal power hasestablished itself as one of the more viable sources of renewable energy. Thedispatchable nature of this technology makes it ideally suited to forming thebackbone of a future low-carbon electricity system.However, the cost of electricity from contemporary solar thermal power plantsremains high, despite several decades of development, and a step-change intechnology is needed to drive down costs. Solar gas-turbine power plants are apromising new alternative, allowing increased conversion efficiencies and asignificant reduction in water consumption. Hybrid operation is a furtherattractive feature of solar gas-turbine technology, facilitating control andensuring the power plant is available to meet demand whenever it occurs.Construction of the first generation of commercial hybrid solar gas-turbinepower plants is complicated by the lack of an established, standardised, powerplant configuration, which presents the designer with a large number ofchoices. To assist decision making, thermoeconomic studies have beenperformed on a variety of different power plant configurations, includingsimple- and combined-cycles as well as the addition of thermal energy storage.Multi-objective optimisation has been used to identify Pareto-optimal designsand highlight trade-offs between costs and emissions.Analysis of the simple-cycle hybrid solar gas-turbines revealed that, whileelectricity costs were kept low, the achievable reduction in carbon dioxideemissions is relatively small. Furthermore, an inherent trade-off between thedesign of high efficiency and high solar share hybrid power plants wasidentified. Even with the use of new optimised designs, the degree of solarintegration into the gas-turbine did not exceed 63% on an annual basis.In order to overcome the limitations of the simple-cycle power plants, twoimprovements were suggested: the integration of thermal energy storage, andthe use of combined-cycle configurations. Thermal energy storage allowed thedegree of solar operation to be extended, significantly decreasing carbondioxide emissions, and the addition of a bottoming-cycle reduced the electricitycosts. A combination of these two improvements provided the bestperformance, allowing a reduction in carbon dioxide emissions of up to 34%and a reduction in electricity costs of up to 22% compared to a combination ofconventional power generation technologies.
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