Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable Screening
This work presents an optimization strategy and the cost-optimal design of an off-grid building served by an energy system involving solar technologies, thermal and electrochemical storages. Independently from the multi-objective method (e.g., utility function) and algorithm used (e.g., genetic algo...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-08-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/12/15/3026 |
| _version_ | 1828232632196923392 |
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| author | Paolo Conti Giovanni Lutzemberger Eva Schito Davide Poli Daniele Testi |
| author_facet | Paolo Conti Giovanni Lutzemberger Eva Schito Davide Poli Daniele Testi |
| author_sort | Paolo Conti |
| collection | DOAJ |
| description | This work presents an optimization strategy and the cost-optimal design of an off-grid building served by an energy system involving solar technologies, thermal and electrochemical storages. Independently from the multi-objective method (e.g., utility function) and algorithm used (e.g., genetic algorithms), the optimization of this kind of systems is typically characterized by a high-dimensional variables space, computational effort and results uncertainty (e.g., local minimum solutions). Instead of focusing on advanced optimization tools to handle the design problem, the dimension of the full problem has been reduced, only considering the design variables with a high “effect” on the objective functions. An off-grid accommodation building is presented as test case: the original six-variable design problem consisting of about 300,000 possible configurations is reduced to a two-variable problem, after the analysis of 870 Monte Carlo simulations. The new problem includes only 220 possible design alternatives with a clear benefit for the multi-objective optimization algorithm. The energy-economy Pareto frontiers obtained by the original and the reduced problems overlap, showing the validity of the proposed methodology. The <i>No-RES</i> (no renewable energy sources) primary energy consumption can be reduced up to almost 0 kWh/(m<sup>2</sup>yr) and the net present value (<i>NPV</i>) after 20 years can reach 70 k€ depending on the number of photovoltaic panels and electrochemical storage size. The reduction of the problem also allows for a plain analysis of the results and the drawing of handy decision charts to help the investor/designer in finding the best design according to the specific investment availability and target performances. The configurations on the Pareto frontier are characterized by a notable electrical overproduction and a ratio between the two main design variables that goes from 4 to 8 h. A sensitivity analysis to the unitary price of the electrochemical storage reveals the robustness of the sizing criterion. |
| first_indexed | 2024-04-12T19:24:48Z |
| format | Article |
| id | doaj.art-441ade427c6f42e599b80913e5e71b36 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-12T19:24:48Z |
| publishDate | 2019-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-441ade427c6f42e599b80913e5e71b362022-12-22T03:19:30ZengMDPI AGEnergies1996-10732019-08-011215302610.3390/en12153026en12153026Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable ScreeningPaolo Conti0Giovanni Lutzemberger1Eva Schito2Davide Poli3Daniele Testi4Department of Energy, Systems, Technology, and Construction Engineering (DESTEC), University of Pisa, Largo Lucio Lazzarino, 56122 Pisa, ItalyDepartment of Energy, Systems, Technology, and Construction Engineering (DESTEC), University of Pisa, Largo Lucio Lazzarino, 56122 Pisa, ItalyDepartment of Energy, Systems, Technology, and Construction Engineering (DESTEC), University of Pisa, Largo Lucio Lazzarino, 56122 Pisa, ItalyDepartment of Energy, Systems, Technology, and Construction Engineering (DESTEC), University of Pisa, Largo Lucio Lazzarino, 56122 Pisa, ItalyDepartment of Energy, Systems, Technology, and Construction Engineering (DESTEC), University of Pisa, Largo Lucio Lazzarino, 56122 Pisa, ItalyThis work presents an optimization strategy and the cost-optimal design of an off-grid building served by an energy system involving solar technologies, thermal and electrochemical storages. Independently from the multi-objective method (e.g., utility function) and algorithm used (e.g., genetic algorithms), the optimization of this kind of systems is typically characterized by a high-dimensional variables space, computational effort and results uncertainty (e.g., local minimum solutions). Instead of focusing on advanced optimization tools to handle the design problem, the dimension of the full problem has been reduced, only considering the design variables with a high “effect” on the objective functions. An off-grid accommodation building is presented as test case: the original six-variable design problem consisting of about 300,000 possible configurations is reduced to a two-variable problem, after the analysis of 870 Monte Carlo simulations. The new problem includes only 220 possible design alternatives with a clear benefit for the multi-objective optimization algorithm. The energy-economy Pareto frontiers obtained by the original and the reduced problems overlap, showing the validity of the proposed methodology. The <i>No-RES</i> (no renewable energy sources) primary energy consumption can be reduced up to almost 0 kWh/(m<sup>2</sup>yr) and the net present value (<i>NPV</i>) after 20 years can reach 70 k€ depending on the number of photovoltaic panels and electrochemical storage size. The reduction of the problem also allows for a plain analysis of the results and the drawing of handy decision charts to help the investor/designer in finding the best design according to the specific investment availability and target performances. The configurations on the Pareto frontier are characterized by a notable electrical overproduction and a ratio between the two main design variables that goes from 4 to 8 h. A sensitivity analysis to the unitary price of the electrochemical storage reveals the robustness of the sizing criterion.https://www.mdpi.com/1996-1073/12/15/3026hybrid renewable energy systemsoff-grid buildingselectrochemical storagedynamic simulationmulti-objective optimizationscreening design methodologysolar technologies |
| spellingShingle | Paolo Conti Giovanni Lutzemberger Eva Schito Davide Poli Daniele Testi Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable Screening Energies hybrid renewable energy systems off-grid buildings electrochemical storage dynamic simulation multi-objective optimization screening design methodology solar technologies |
| title | Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable Screening |
| title_full | Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable Screening |
| title_fullStr | Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable Screening |
| title_full_unstemmed | Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable Screening |
| title_short | Multi-Objective Optimization of Off-Grid Hybrid Renewable Energy Systems in Buildings with Prior Design-Variable Screening |
| title_sort | multi objective optimization of off grid hybrid renewable energy systems in buildings with prior design variable screening |
| topic | hybrid renewable energy systems off-grid buildings electrochemical storage dynamic simulation multi-objective optimization screening design methodology solar technologies |
| url | https://www.mdpi.com/1996-1073/12/15/3026 |
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