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Guédez, Rafael
Publications (10 of 10) Show all publications
Benmakhlouf, Y., Guédez, R., Wallmander, J. & Laumert, B. (2019). A methodology to assess the market potential and identify most promising business cases for small scale CSP plants with thermal energy storage. In: AIP Conference Proceedings: . Paper presented at 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018. American Institute of Physics (AIP), 2126, Article ID 130001.
Open this publication in new window or tab >>A methodology to assess the market potential and identify most promising business cases for small scale CSP plants with thermal energy storage
2019 (English)In: AIP Conference Proceedings, American Institute of Physics (AIP), 2019, Vol. 2126, article id 130001Conference paper, Published paper (Refereed)
Abstract [en]

This study presents a methodology to quantify the market potential for a novel distributed CSP technology with thermal energy technology. The system in question relies on the Stirling engine for power production, which is fed by heat collected from a heliostat field and stored in an integrated latent heat storage unit. Selected countries in the MENA region are investigated to identify best prospective business cases for such a technology. With a global market potential above 40 GW in the whole MENA, industrial sectors such as mining and cement hold the best prospects in terms of market share. The achievable costs of generation vary depending on the DNI of the sites considered but prove to be lower compared with conventional distributed generation (diesel gensets or PV-BEES). However, several countries in the MENA, although having high DNI resource, still offer low electricity utility prices to industrial customers for distributed CSP to become competitive with on-grid electricity procurement. A scenario analysis coupled with a multi criteria selection of the optimal business case quantifies the amount of subsidies necessary to reach competitiveness.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
Series
AIP Conference Proceedings, ISSN 0094-243X
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-262565 (URN)10.1063/1.5117643 (DOI)2-s2.0-85070646541 (Scopus ID)9780735418660 (ISBN)
Conference
24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018
Note

QC 20191025

Available from: 2019-10-25 Created: 2019-10-25 Last updated: 2019-10-25Bibliographically approved
Pan, C. A., Guédez, R., Dinter, F. & Harms, T. M. (2019). A techno-economic comparative analysis of thermal oil and molten salt parabolic trough power plants with molten salt solar towers. In: AIP Conference Proceedings: . Paper presented at 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018. American Institute of Physics (AIP), 2126, Article ID 120014.
Open this publication in new window or tab >>A techno-economic comparative analysis of thermal oil and molten salt parabolic trough power plants with molten salt solar towers
2019 (English)In: AIP Conference Proceedings, American Institute of Physics (AIP), 2019, Vol. 2126, article id 120014Conference paper, Published paper (Refereed)
Abstract [en]

This study presents a comparison between thermal oil and molten salt parabolic trough power plants as well as molten salt solar towers. Although higher temperature differences in solar towers enable higher power cycle efficiencies, the necessity of large solar fields for increasing turbine capacities and capacity factors pose a limitation through increased attenuation losses. This effect is amplified when unfavourable atmospheric conditions with visibilities of e.g. 15km are present to the extent where 200 MW parabolic trough power plants with molten salt as heat transfer fluid can achieve lower levelised costs of electricity and higher capacity factors than solar towers. Additionally, solar towers require a significantly larger solar field and thus land area as compared to molten salt parabolic through power plants. Moreover, both molten salt parabolic troughs and solar towers outperform thermal oil parabolic trough systems in terms of LCOE and capacity factors.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
Series
AIP Conference Proceedings, ISSN 0094-243X ; 2126
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-262568 (URN)10.1063/1.5117632 (DOI)2-s2.0-85070614006 (Scopus ID)9780735418660 (ISBN)
Conference
24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018
Note

QC 20191024

Available from: 2019-10-24 Created: 2019-10-24 Last updated: 2019-10-24Bibliographically approved
Kesseli, D., Wagner, M., Guédez, R. & Turchi, C. S. (2019). CSP-plant modeling guidelines and compliance of the system advisor model (SAM). In: SolarPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems. Paper presented at 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018. American Institute of Physics (AIP), Article ID 170006.
Open this publication in new window or tab >>CSP-plant modeling guidelines and compliance of the system advisor model (SAM)
2019 (English)In: SolarPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems, American Institute of Physics (AIP), 2019, article id 170006Conference paper, Published paper (Refereed)
Abstract [en]

Accurately modeling risks, costs, and electricity output is essential to the financing and advancement of concentrating solar power projects. To address this need, a group of CSP experts created a guideline document, titled SolarPACES Guideline for Bankable STE Yield Assessment [1]. To make this information more accessible and allow stakeholders to test specific models against the recommendations, the guidelines have been condensed into a spreadsheet-based checklist. The checklist was applied to NREL's System Advisor Model (SAM) software, providing useful feedback to both the checklist group and the SAM development team. This study showed strong agreement between SAM and the guidelines, demonstrated the use of the guidelines in model validation, and resulted in several recommended improvements to SAM.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
Series
AIP Conference Proceedings, ISSN 0094-243X ; 2126
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-262570 (URN)10.1063/1.5117676 (DOI)2-s2.0-85070577159 (Scopus ID)9780735418660 (ISBN)
Conference
24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018
Note

QC 20191024

Available from: 2019-10-24 Created: 2019-10-24 Last updated: 2019-10-24Bibliographically approved
Trevisan, S., Guédez, R., Bouzekri, H. & Laumert, B. (2019). Initial design of a radial-flow high temperature thermal energy storage concept for air-driven CSP systems. In: AIP Conference Proceedings: . Paper presented at 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018. American Institute of Physics (AIP), 2126, Article ID 200031.
Open this publication in new window or tab >>Initial design of a radial-flow high temperature thermal energy storage concept for air-driven CSP systems
2019 (English)In: AIP Conference Proceedings, American Institute of Physics (AIP), 2019, Vol. 2126, article id 200031Conference paper, Published paper (Refereed)
Abstract [en]

The present work deals with the initial design and performance evaluation of a novel thermal energy storage concept consisting of a packed bed of rocks with a radial gas flow, suitable for the a generation of air-driven concentrating solar power plants. In doing so, this article also presents a state of the art of most promising packed bed concepts, highlighting their advantages and disadvantages, all considered in the design of the new proposed system. A thermomechanical model of the concept was developed and used in simulations to assess its behavior during both charging and discharging processes, as well as to evaluate the influence of critical design parameters. This same model was used to compare the technical performance of the concept against that of more conventional packed-beds with axial-flow. Results show that the novel concept is able to outperform the other systems by enabling a theoretical reduction of 46% and 50% in radiation losses and pressure drops, respectively, thus calling for future investigations, including an in-depth thermos-mechanical study and life-cycle analysis of the concept prior to building a lab-scale prototype.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
Series
AIP Conference Proceedings, ISSN 0094-243X ; 2126
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-262567 (URN)10.1063/1.5117746 (DOI)2-s2.0-85070627314 (Scopus ID)9780735418660 (ISBN)
Conference
24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018
Note

QC 20191025

Available from: 2019-10-25 Created: 2019-10-25 Last updated: 2019-10-25Bibliographically approved
Gan, P. G., Monnerie, N., Brendelberger, S., Roeb, M., Guédez, R., Laumert, B. & Sattler, C. (2019). Modeling, simulation and economic analysis of CSP-driven solar fuel plant for diesel and gasoline production. In: AIP Conference Proceedings: . Paper presented at 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018. American Institute of Physics (AIP), Article ID 180009.
Open this publication in new window or tab >>Modeling, simulation and economic analysis of CSP-driven solar fuel plant for diesel and gasoline production
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2019 (English)In: AIP Conference Proceedings, American Institute of Physics (AIP), 2019, article id 180009Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The present research focuses on modeling of solar thermal driven fuel production plant with CO2 and H2O as raw materials to produce synthetic gas (syngas) which is converted into hydrocarbons through Fischer-Tropsch process either with Fe and Co catalyst to produce diesel, gasoline and kerosene. The solar reactor uses cerium oxide (CeO2) as a metal-redox and operates at 1773 K and 1300 K for reduction and oxidation step respectively under non-stoichiometric condition. The plant is analyzed by performing a quasi-steady state simulation under boundary condition that the Fischer-Tropsch reactor should operate with the capacity factor of 0.95 or 8350 hours annually. A storage tank is used to store and regulate the flow of syngas going into the Fischer-Tropsch reactor. Sensitivity analysis is carried out, particularly on solar reactor conversion and solid-to-solid heat exchanger efficiency. Another sensitivity analysis is to combine PV and CSP as the external electricity source. The production cost is finally calculated using annuity method with constant discount rate.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
Series
AIP Conference Proceedings, ISSN 0094-243X
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-262564 (URN)10.1063/1.5117689 (DOI)2-s2.0-85070648587 (Scopus ID)9780735418660 (ISBN)
Conference
24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018
Note

QC 20191025

Available from: 2019-10-25 Created: 2019-10-25 Last updated: 2019-10-25Bibliographically approved
Trevisan, S., Guédez, R. & Laumert, B. (2019). Preliminary assessment of integration of a packed bed thermal energy storage in a Stirling - CSP system. In: SolarPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems. Paper presented at 24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018. American Institute of Physics (AIP), 2126, Article ID 200032.
Open this publication in new window or tab >>Preliminary assessment of integration of a packed bed thermal energy storage in a Stirling - CSP system
2019 (English)In: SolarPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems, American Institute of Physics (AIP), 2019, Vol. 2126, article id 200032Conference paper, Published paper (Refereed)
Abstract [en]

The present work deals with the thermodynamic analysis of four different integration schemes for a packed bed thermal energy storage in a Stirling - CSP system. Simplified models for the different systems' configurations have been developed and analyzed in steady and transient working conditions. Particularly, a parallel and serial connection between the power and the storage unit have been compared, showing a trade-off between the contemporaneity of power production and storage and the usefulness of the storage itself accordingly to the working temperature constraints for the power unit. It is shown that a closed parallel system configuration is the most promising solution as it allows for a longer production during night time and an higher net energy production, it is therefore worth of further investigations.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2019
Series
AIP Conference Proceedings, ISSN 0094-243X ; 2126
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-258139 (URN)10.1063/1.5117747 (DOI)2-s2.0-85070630739 (Scopus ID)9780735418660 (ISBN)
Conference
24th SolarPACES International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2018; Casablanca; Morocco; 2 October 2018 through 5 October 2018
Note

QC 20191007

Available from: 2019-10-07 Created: 2019-10-07 Last updated: 2019-10-07Bibliographically approved
Payaro, A., Naik, A. A., Guédez, R. & Laumert, B. (2018). Identification of Required Cost Reductions for CSP to Retain Its Competitive Advantage as Most Economically Viable Solar-Dispatchable Technology. In: Mancilla, R Richter, C (Ed.), INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2017): . Paper presented at 23rd International Conference on Concentrating Solar Power and Chemical Energy Systems (SolarPACES), SEP 26-29, 2017, Santiago, CHILE. AMER INST PHYSICS, Article ID 040028-1.
Open this publication in new window or tab >>Identification of Required Cost Reductions for CSP to Retain Its Competitive Advantage as Most Economically Viable Solar-Dispatchable Technology
2018 (English)In: INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2017) / [ed] Mancilla, R Richter, C, AMER INST PHYSICS , 2018, article id 040028-1Conference paper, Published paper (Refereed)
Abstract [en]

The present study evaluates and compares the optimum configurations for both PV-batteries and molten salt tower concentrating solar power plants that minimize the levelized cost of electricity for a suitable location for deployment of both solar technologies nearby Ouarzazate, Morocco, when considering two capacity factor objectives, namely 50% and 85%, and cost-projections for 2020 and 2030. Required target cost reduction rates for each of the main blocks in the tower plant (i.e. the solar field, the storage and the power block) are identified for guaranteeing its competitive advantage as the most economically viable solar-only technology at both capacity factor objectives investigated. It is shown that the larger the capacity factor requirement is, the more competitive the solar thermal technology would be. Specifically, the case-study shows that for an 85% capacity factor objective, tower plants would be more competitive even when considering the most pessimistic and optimistic cost projections for the solar thermal and PV-batteries sub-components, respectively. Nevertheless, it was also determined that in order to ensure being the most competitive solar-only technology at a 50% capacity factor objective by 2030, the costs of the solar field of the solar tower plants should reach values as low as 20-50 (sic)/m(2), depending on the scenario, which means approximately a three to seven fold decrease of the costs as of 2017. At last, recommendations to solar thermal technology owners and developers are provided, and a short discussion regarding the viability and limitations of using battery electric storage systems for utility-scale solar plants is presented.

Place, publisher, year, edition, pages
AMER INST PHYSICS, 2018
Series
AIP Conference Proceedings, ISSN 0094-243X ; 2033
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-257839 (URN)10.1063/1.5067064 (DOI)000481681200055 ()2-s2.0-85057136481 (Scopus ID)978-0-7354-1757-1 (ISBN)
Conference
23rd International Conference on Concentrating Solar Power and Chemical Energy Systems (SolarPACES), SEP 26-29, 2017, Santiago, CHILE
Note

QC 20190905

Available from: 2019-09-05 Created: 2019-09-05 Last updated: 2019-10-21Bibliographically approved
Guédez, R., Garcia, J. A., Martin, F., Wiesenberg, R. & Laumert, B. (2018). Integrated Solar Combined Cycles vs Combined Gas Turbine to Bottoming Molten Salt Tower Plants - A Techno-economic Analysis. In: Mancilla, R Richter, C (Ed.), INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2017): . Paper presented at 23rd International Conference on Concentrating Solar Power and Chemical Energy Systems (SolarPACES), SEP 26-29, 2017, Santiago, CHILE. AMER INST PHYSICS, Article ID 180006-1.
Open this publication in new window or tab >>Integrated Solar Combined Cycles vs Combined Gas Turbine to Bottoming Molten Salt Tower Plants - A Techno-economic Analysis
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2018 (English)In: INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2017) / [ed] Mancilla, R Richter, C, AMER INST PHYSICS , 2018, article id 180006-1Conference paper, Published paper (Refereed)
Abstract [en]

The present work deals with the techno-economic analysis of a novel 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 model has been elaborated using in house simulation tools that simultaneously encompass meteorological, demand and required dispatch data. A range of possible designs are evaluated for a suitable location with both good solar resource and vast natural gas resources in order to show the trade-offs between the objectives of achieving low carbon-intensive and economically competitive designs. These were compared against more conventional integrated solar combined cycles of equivalent capacity factors. It is shown that the novel concept is worth further investigating as it is able to outperform the more conventional cycle while simultaneously offering additional flexibility to grid-operators.

Place, publisher, year, edition, pages
AMER INST PHYSICS, 2018
Series
AIP Conference Proceedings, ISSN 0094-243X ; 2033
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-257837 (URN)10.1063/1.5067178 (DOI)000481681200169 ()2-s2.0-85057129538 (Scopus ID)978-0-7354-1757-1 (ISBN)
Conference
23rd International Conference on Concentrating Solar Power and Chemical Energy Systems (SolarPACES), SEP 26-29, 2017, Santiago, CHILE
Note

QC 20190905

Available from: 2019-09-05 Created: 2019-09-05 Last updated: 2019-10-21Bibliographically approved
Hansson, L., Guédez, R., Larchet, K. & Laumert, B. (2017). Development and implementation of a dynamic TES dispatch control component in a PV-CSP techno-economic performance modelling tool. In: AIP Conference Proceedings: . Paper presented at 22nd International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2016, 11 October 2016 through 14 October 2016. American Institute of Physics (AIP), 1850, Article ID 160013.
Open this publication in new window or tab >>Development and implementation of a dynamic TES dispatch control component in a PV-CSP techno-economic performance modelling tool
2017 (English)In: AIP Conference Proceedings, American Institute of Physics (AIP), 2017, Vol. 1850, article id 160013Conference paper (Refereed)
Abstract [en]

The dispatchability offered by thermal energy storage (TES) in concentrated solar power (CSP) and solar hybrid plants based on such technology presents the most important difference compared to power generation based only on photovoltaics (PV). This has also been one reason for recent hybridization efforts of the two technologies and the creation of Power Purchase Agreement (PPA) payment schemes based on offering higher payment multiples during daily hours of higher (peak or priority) demand. Recent studies involving plant-level thermal energy storage control strategies are however to a large extent based on pre-determined approaches, thereby not taking into account the actual dynamics of thermal energy storage system operation. In this study, the implementation of a dynamic dispatch strategy in the form of a TRNSYS controller for hybrid PV-CSP plants in the power-plant modelling tool DYESOPT is presented. In doing this it was attempted to gauge the benefits of incorporating a day-ahead approach to dispatch control compared to a fully pre-determined approach determining hourly dispatch only once prior to annual simulation. By implementing a dynamic strategy, it was found possible to enhance technical and economic performance for CSP-only plants designed for peaking operation and featuring low values of the solar multiple. This was achieved by enhancing dispatch control, primarily by taking storage levels at the beginning of every simulation day into account. The sequential prediction of the TES level could therefore be improved, notably for evaluated plants without integrated PV, for which the predicted storage levels deviated less than when PV was present in the design. While also featuring dispatch performance gains, optimal plant configurations for hybrid PV-CSP was found to present a trade-off in economic performance in the form of an increase in break-even electricity price when using the dynamic strategy which was offset to some extent by a reduction in upfront investment cost. An increase in turbine starts for the implemented strategy however highlights that this is where further improvements can be made.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2017
Series
AIP Conference Proceedings
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-216444 (URN)10.1063/1.4984547 (DOI)000417377900222 ()2-s2.0-85023593706 (Scopus ID)9780735415225 (ISBN)
Conference
22nd International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2016, 11 October 2016 through 14 October 2016
Note

QC 20171208

Available from: 2017-12-08 Created: 2017-12-08 Last updated: 2019-10-28Bibliographically approved
Christoph, R., Ferruzza, D., Guédez, R., Dinter, F., Laumert, B. & Haglind, F. (2017). Identification of optimum molten salts for use as heat transfer fluids in parabolic trough CSP plants. A techno-economic comparative optimization. Paper presented at SolarPACES 2017. AIP Conference Proceedings
Open this publication in new window or tab >>Identification of optimum molten salts for use as heat transfer fluids in parabolic trough CSP plants. A techno-economic comparative optimization
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2017 (English)In: AIP Conference Proceedings, ISSN 0094-243X, E-ISSN 1551-7616Article in journal (Refereed) Published
Abstract [en]

Parabolic trough power plants using thermal oil as heat transfer fluid are the most mature concentrating solar power technology and state of the art. To further increase their efficiency and lower costs, molten salts can be used as heat transfer fluid. This results in higher operating temperature differences for improved cycle efficiencies and enables direct thermal energy storage at lower costs due to omission of the oil-to-salt heat exchanger and the need for smaller storage sizes. As a variety of salts are available to choose from, this study uses a multi-objective optimization to identify the most suitable heat transfer fluid for three locations in South Africa, Spain and Chile. The lowest values for the levelized costs of electricity (LCOE) can be found in Chile using Solar Salt as heat transfer fluid (75.0 $/MWhe). Generally, Solar Salt offers the lowest LCOE values followed by thermal oil and Hitec. The results also suggest that the choice of the heat transfer fluid is dependent on the direct normal irradiance (DNI) at each location. Thermal oil is competitive with Solar Salt in small systems at locations with low DNI values, whereas Hitec can be cheaper than thermal oil in large systems at locations with high DNI. Furthermore, it is also investigated at which freeze alert temperature set point the activation of the freeze protection system is optimal. The results indicate that this temperature should be chosen close to the solar field inlet temperature for small systems, while it can be lowered significantly for large systems to reduce electricity consumption from the freeze protection system.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2017
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-250235 (URN)10.1063/1.5067028 (DOI)000481681200019 ()2-s2.0-85057123580 (Scopus ID)978-0-7354-1757-1 (ISBN)
Conference
SolarPACES 2017
Note

QC 20190420

Available from: 2019-04-26 Created: 2019-04-26 Last updated: 2019-09-05Bibliographically approved
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