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Spelling, J., Guedez, R. & Laumert, B. (2015). A Thermo-Economic Study of Storage Integration in Hybrid Solar Gas-Turbine Power Plants. Journal of solar energy engineering, 137(1)
Open this publication in new window or tab >>A Thermo-Economic Study of Storage Integration in Hybrid Solar Gas-Turbine Power Plants
2015 (English)In: Journal of solar energy engineering, ISSN 0199-6231, E-ISSN 1528-8986, Vol. 137, no 1Article in journal (Refereed) Published
Abstract [en]

A thermo-economic simulation model of a hybrid solar gas-turbine (HSGT) power plant with an integrated storage unit has been developed, allowing determination of the thermodynamic and economic performance. Designs were based around two representative industrial gas-turbines: a high efficiency machine and a low temperature machine. In order to examine the trade-offs that must be made, multi-objective thermo-economic analysis was performed, with two conflicting objectives: minimum investment costs and minimum specific carbon dioxide (CO2) emissions. It was shown that with the integration of storage, annual solar shares above 85% can be achieved by HSGT systems. The levelized electricity cost (LEC) for the gas-turbine system as this level of solar integration was similar to that of parabolic trough plants, allowing them to compete directly in the solar power market. At the same time, the water consumption of the gas-turbine system is significantly lower than contemporary steam-cycle based solar thermal power plants.

National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-149667 (URN)10.1115/1.4028142 (DOI)000348145600008 ()2-s2.0-84906658625 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 20140926

Available from: 2014-08-25 Created: 2014-08-25 Last updated: 2017-12-05Bibliographically approved
Aichmayer, L., Spelling, J. & Laumert, B. (2015). Preliminary design and analysis of a novel solar receiver for a micro gas-turbine based solar dish system. Solar Energy, 114(4), 378-396
Open this publication in new window or tab >>Preliminary design and analysis of a novel solar receiver for a micro gas-turbine based solar dish system
2015 (English)In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 114, no 4, p. 378-396Article in journal (Refereed) Published
Abstract [en]

The solar receiver is one of the key components of hybrid solar micro gas-turbine systems, which would seem to present a number of advantages when compared with Stirling engine based systems and photovoltaic panels. In this study a solar receiver meeting the specific requirements for integration into a small-scale (10 kWel) dish-mounted hybrid solar micro gas-turbine system has been designed with a special focus on the trade-offs between efficiency, pressure drop, material utilization and economic design. A situation analysis, performed using a multi-objective optimizer, has shown that a pressurized configuration, where the solar receiver is placed before the turbine, is superior to an atmospheric configuration with the solar receiver placed after the turbine. Based on these initial design results, coupled CFD/FEM simulations have been performed, allowing detailed analysis of the designs under the expected operating conditions. The results show that the use of volumetric solar receivers to provide heat input to micro gas-turbine based solar dish systems appears to be a promising solution; with material temperatures and material stresses well below permissible limits.

Keywords
Solar receiver, Micro gas-turbine, Mutli-objective optimization, Coupled CFD/FEM analysis
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-161705 (URN)10.1016/j.solener.2015.01.013 (DOI)000353080700033 ()2-s2.0-84924066245 (Scopus ID)
Note

QC 20150324

Available from: 2015-03-13 Created: 2015-03-13 Last updated: 2018-04-17Bibliographically approved
Guedez, R., Spelling, J. & Laumert, B. (2015). Reducing the Number of Turbine Starts in Concentrating Solar Power Plants through the Integration of Thermal Energy Storage. Journal of solar energy engineering, 137(2)
Open this publication in new window or tab >>Reducing the Number of Turbine Starts in Concentrating Solar Power Plants through the Integration of Thermal Energy Storage
2015 (English)In: Journal of solar energy engineering, ISSN 0199-6231, E-ISSN 1528-8986, Vol. 137, no 2Article in journal (Refereed) Published
Abstract [en]

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 (TES) 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 (EOHs) is used to further analyze the direct impact of storage integration on the maintenance planning of the turbine units.

Place, publisher, year, edition, pages
ASME Press, 2015
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-148156 (URN)10.1115/1.4028004 (DOI)000348145600003 ()2-s2.0-84904977331 (Scopus ID)
Note

Qc 20140925

Available from: 2014-08-01 Created: 2014-08-01 Last updated: 2017-12-05Bibliographically approved
Spelling, J. & Laumert, B. (2015). Thermo-economic evaluation of solar thermal and photovoltaic hybridization options for combined-cycle power plants. Journal of engineering for gas turbines and power, 137(3), 031801
Open this publication in new window or tab >>Thermo-economic evaluation of solar thermal and photovoltaic hybridization options for combined-cycle power plants
2015 (English)In: Journal of engineering for gas turbines and power, ISSN 0742-4795, E-ISSN 1528-8919, Vol. 137, no 3, p. 031801-Article in journal (Refereed) Published
Abstract [en]

The hybridization of combined-cycle power plants with solar energy is an attractive means of reducing carbon dioxide (CO2) emissions from gas-based power generation. However, the construction of the first generation of commercial hybrid power plants will present the designer with a large number of choices. To assist decision making, a thermo-economic study has been performed for three different hybrid power plant configurations, including both solar thermal and photovoltaic hybridization options. Solar photovoltaic combined-cycle (SPVCC) power plants were shown to be able to integrate up to 63% solar energy on an annual basis, whereas hybrid gas turbine combined-cycle (HGTCC) systems provide the lowest cost of solar electricity, with costs only 2.1% higher than a reference, unmodified combined-cycle power plant. The integrated solar combined-cycle (ISCC) configuration has been shown to be economically unattractive.

Keywords
Photovoltaic, Solar thermal, Thermo-economic
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-153750 (URN)10.1115/1.4028396 (DOI)000350144900011 ()2-s2.0-84907855006 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 20150211

Available from: 2014-10-08 Created: 2014-10-08 Last updated: 2017-12-05Bibliographically approved
Guedez, R., Spelling, J. & Laumert, B. (2014). Enhancing the Economic Competitiveness of Concentrating Solar Power Plants through an Innovative Integrated Solar Combined-Cycle with Thermal Energy Storage. In: Proceedings of the ASME TurboExpo 2014: . Paper presented at ASME Turbo Expo 2014, Turbine Technical Conference and Exposition, GT 2014; Dusseldorf, Germany, 16-20 June 2014. , 3A
Open this publication in new window or tab >>Enhancing the Economic Competitiveness of Concentrating Solar Power Plants through an Innovative Integrated Solar Combined-Cycle with Thermal Energy Storage
2014 (English)In: Proceedings of the ASME TurboExpo 2014, 2014, Vol. 3AConference paper, Published paper (Refereed)
Abstract [en]

The present work deals with the thermoeconomic analysis of an innovative combined power cycle consisting of a molten- salt solar tower power plant with storage supported by additional heat provided from the exhaust of a topping gas- turbine unit. A detailed dynamic model has been elaborated using an in house simulation tool that simultaneously encompasses meteorological, demand and price data. A wide range of possible designs are evaluated in order to show the trade-offs between the objectives of achieving sustainable and economically competitive designs. Results show that optimal designs of the novel concept are a promising cost-effective hybrid option that can successfully fulfill both the roles of a gas peaker plant and a baseload solar power plant in a more effective manner. Moreover, designs are also compared against conventional combined cycle gas turbine power plants and it is shown that, under specific peaking operating strategies, the innovative concept can not only perform better from an environmental standpoint but also economically.

National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-148157 (URN)10.1115/GT2014-26098 (DOI)000362057900041 ()2-s2.0-84961310706 (Scopus ID)978-0-7918-4565-3 (ISBN)
Conference
ASME Turbo Expo 2014, Turbine Technical Conference and Exposition, GT 2014; Dusseldorf, Germany, 16-20 June 2014
Note

QC 20150305

Available from: 2014-08-01 Created: 2014-08-01 Last updated: 2016-08-29Bibliographically approved
Topel, M., Spelling, J., Jöcker, M. & Laumert, B. (2014). Geometric Modularity in the Thermal Modeling of Solar Steam Turbines. In: Proceedings of the SolarPACES 2013 International Conference: . Paper presented at International Conference on Solar Power and Chemical Energy Systems, SolarPACES 2013, Las Vegas, NV, United States, 17 September 2013 through 20 September 2013 (pp. 1737-1746). Elsevier, 49
Open this publication in new window or tab >>Geometric Modularity in the Thermal Modeling of Solar Steam Turbines
2014 (English)In: Proceedings of the SolarPACES 2013 International Conference, Elsevier, 2014, Vol. 49, p. 1737-1746Conference paper, Published paper (Refereed)
Abstract [en]

To optimize the start-up schedules of steam turbines operating in concentrating solar power plants, accurate predictions of the temperatures within the turbine are required. In previous work by the authors, thermal models of steam turbines have been developed and validated for parabolic trough solar power plant applications. Building on these results, there is an interest to increase the adaptability of the models with respect to different turbine geometries due to the growing trend of having larger steam turbines in parabolic trough and solar tower power plants. In this work, a modular geometric approach has been developed and compared against both the previous modeling approach and 96h of measured data from an operational parabolic trough power plant. Results show a large degree of agreement with respect to the measured data in spite of the different detail levels. The new model allows for simple and fast prediction of the thermal behavior of different steam turbine sizes and geometries, which is expected to be of significant importance for future concentrating solar power plants.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
steam turbine, thermal stresses, start-up, finite element method
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-126931 (URN)10.1016/j.egypro.2014.03.184 (DOI)000340733700178 ()2-s2.0-84902271058 (Scopus ID)
Conference
International Conference on Solar Power and Chemical Energy Systems, SolarPACES 2013, Las Vegas, NV, United States, 17 September 2013 through 20 September 2013
Funder
Swedish Energy Agency
Note

QC 20140922. QC 20160129

Available from: 2013-08-22 Created: 2013-08-22 Last updated: 2017-08-11Bibliographically approved
Guedez, R., Spelling, J., Laumert, B. & Fransson, T. (2014). Optimization of Thermal Energy Storage Integration Strategies for Peak Power Production by Concentrating Solar Power Plants. In: PROCEEDINGS OF THE SOLARPACES 2013 INTERNATIONAL CONFERENCE: . Paper presented at SolarPACES 2013 Concentrating Solar Power and Chemical Energy Systems; Las Vegas, USA, 17-20 September, 2013 (pp. 1642-1651). , 49
Open this publication in new window or tab >>Optimization of Thermal Energy Storage Integration Strategies for Peak Power Production by Concentrating Solar Power Plants
2014 (English)In: PROCEEDINGS OF THE SOLARPACES 2013 INTERNATIONAL CONFERENCE, 2014, Vol. 49, p. 1642-1651Conference paper, Published paper (Refereed)
Abstract [en]

The integration of thermal energy storage systems in concentrating solar thermal power plants allows power production to be shifted from times where there is low demand to periods where electricity prices are higher. Although increasing the total investment, thermal energy storage can therefore enhance profitability of the solar power plant. The present study presents optimum power plant configurations for a given location considering different price-based grid integration strategies. Such optimum plant configurations were determined using a thermo-economic optimization approach where the operating strategy was set such that electricity was generated once the market price exceeds a given price level, defined as the minimum price selling indicator. Plants were optimized for different indicator values to cover designs from base load and peak power production. For each of these price-operating strategies, optimum plant configurations were found by varying two solar-related design parameters, namely the solar multiple and the storage size, whilst simultaneously evaluating the economic performance of each design. Finally, an economic analysis was performed for each of the optimum power plants, assuming financial conditions throughout the lifetime of the power plant. Results show that the optimum plant configurations vary with respect to the chosen operating strategy. Optimum configurations for peak power production yielded relatively smaller storage units than that of the optimum baseload plants. Furthermore, the study demonstrates that under current cost estimations, and for the specified location, concentrating solar thermal power is not an attractive option for utility-grid investors. However, it is shown that when considering a reduction in investment costs or the possibility of having renewable electricity incentives such as the investment tax credit treasury cash grant, concentrating solar thermal power plants can become an economically viable technology.

Series
Energy Procedia, ISSN 1876-6102 ; 49
Keywords
Concentrating Solar Power, CSP, Thermal Energy Storage, TES, peak power production, operating strategy
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-126930 (URN)10.1016/j.egypro.2014.03.173 (DOI)000340733700168 ()2-s2.0-84902253168 (Scopus ID)
Conference
SolarPACES 2013 Concentrating Solar Power and Chemical Energy Systems; Las Vegas, USA, 17-20 September, 2013
Note

QC 20141003

Available from: 2013-08-22 Created: 2013-08-22 Last updated: 2014-10-03Bibliographically approved
Pihl, E., Spelling, J. & Johnsson, F. (2014). Thermo-Economic Optimization of Hybridization Options for Solar Retrofitting of Combined-Cycle Power Plants. Journal of solar energy engineering, 136(2), 021001
Open this publication in new window or tab >>Thermo-Economic Optimization of Hybridization Options for Solar Retrofitting of Combined-Cycle Power Plants
2014 (English)In: Journal of solar energy engineering, ISSN 0199-6231, E-ISSN 1528-8986, Vol. 136, no 2, p. 021001-Article in journal (Refereed) Published
Abstract [en]

A thermo-economic optimization model of an integrated solar combined-cycle (ISCC) has been developed to evaluate the performance of an existing combined-cycle gas turbine (CCGT) plant when retrofitted with solar trough collectors. The model employs evolutionary algorithms to assess the optimal performance and cost of the power plant. To define the trade-offs required for maximizing gains and minimizing costs (and to identify ‘optimal’ hybridization schemes), two conflicting objectives were considered, namely, minimum required investment and maximum net present value (NPV). Optimiza- tion was performed for various feed-in tariff (FIT) regimes, with tariff levels that were either fixed or that varied with electricity pool prices. It was found that for the givencombined-cycle power plant design, only small annual solar shares (?1.2% annual share, 4% of installed capacity) could be achieved by retrofitting. The integrated solar combined-cycle design has optimal thermal storage capacities that are several times smaller than those of the corresponding solar-only design. Even with strong incentives to shift the load to periods in which the prices are higher, investment in storage capacity was not promoted. Nevertheless, the levelized costs of the additional solar-generated electricity are as low as 10 ce/kWh, compared to the 17–19 ce/kWh achieved for a reference, nonhybridized, “solar-only” concentrating solar power plant optimized with the same tools and cost dataset. The main reasons for the lower cost of the integrated solar combined-cycle power plant are improved solar-to-electric efficiency and the lower level of required investment in the steam cycle. The retrofitting of combined-cycle gas turbine plants to integrated solar combined-cycle plants with parabolic troughs represents a viable option to achieve relatively low-cost capacity expansion and strong knowledge building regarding concentrating solar power.

Place, publisher, year, edition, pages
ASME Press, 2014
Keywords
Capacity expansion, Combined-cycle plants, Concentrating solar power, Concentrating solar power plant, Conflicting objectives, Knowledge building, Optimal performance, Thermoeconomic optimization
National Category
Energy Engineering
Research subject
Energy Technology
Identifiers
urn:nbn:se:kth:diva-148151 (URN)10.1115/1.4024922 (DOI)000344518400001 ()2-s2.0-84888116812 (Scopus ID)
Note

QC 20140911

Available from: 2014-08-01 Created: 2014-08-01 Last updated: 2017-12-05Bibliographically approved
Guédez, R., Spelling, J., Laumert, B. & Fransson, T. (2013). Reducing the Number of Turbine Starts in Concentrating Solar Power Plants through the Integration of Thermal Energy Storage. In: Proceedings of the ASME TurboExpo 2013: . Paper presented at ASME Turbo Expo 2013, Turbine Technical Conference and Exposition, GT 2013; San Antonio, Tx, United States, 3-7 June 2013.
Open this publication in new window or tab >>Reducing the Number of Turbine Starts in Concentrating Solar Power Plants through the Integration of Thermal Energy Storage
2013 (English)In: Proceedings of the ASME TurboExpo 2013, 2013Conference paper, Published paper (Refereed)
Abstract [en]

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.

National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-126925 (URN)10.1115/GT2013-94562 (DOI)2-s2.0-84890162042 (Scopus ID)978-079185518-8 (ISBN)
Conference
ASME Turbo Expo 2013, Turbine Technical Conference and Exposition, GT 2013; San Antonio, Tx, United States, 3-7 June 2013
Note

QC 20140107

Available from: 2013-08-22 Created: 2013-08-22 Last updated: 2015-03-04Bibliographically approved
Guédez, R., Spelling, J. & Laumert, B. (2013). Thermoeconomic Optimization of Solar Thermal Power Plants with Storage in High-Penetration Renewable Electricity Markets. In: Energy Procedia: . Paper presented at 2013 ISES Solar World Congress, SWC 2013; Cancun; Mexico; 3 November 2013 through 7 November 2013. , 57
Open this publication in new window or tab >>Thermoeconomic Optimization of Solar Thermal Power Plants with Storage in High-Penetration Renewable Electricity Markets
2013 (English)In: Energy Procedia, 2013, Vol. 57Conference paper, Published paper (Refereed)
Abstract [en]

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.

Series
Energy Procedia, ISSN 1876-6102
Keywords
Solar Thermal Power, Concentrating Solar Power, Thermal Energy Storage, Electricity Demand, Renewable Energy
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-126929 (URN)10.1016/j.egypro.2014.10.208 (DOI)000348253200059 ()2-s2.0-84922279172 (Scopus ID)
Conference
2013 ISES Solar World Congress, SWC 2013; Cancun; Mexico; 3 November 2013 through 7 November 2013
Note

QC 20150326

Available from: 2013-08-22 Created: 2013-08-22 Last updated: 2016-08-29Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3458-2112

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