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Saini, Puneet
Publications (10 of 25) Show all publications
Muhammad, Y., Saini, P., Knobloch, K., Frandsen, H. L. & Engelbrecht, K. (2023). Rock bed thermal energy storage coupled with solar thermal collectors in an industrial application: Simulation, experimental and parametric analysis. Journal of Energy Storage, 67, Article ID 107349.
Open this publication in new window or tab >>Rock bed thermal energy storage coupled with solar thermal collectors in an industrial application: Simulation, experimental and parametric analysis
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2023 (English)In: Journal of Energy Storage, ISSN 2352-152X, E-ISSN 2352-1538, Vol. 67, article id 107349Article in journal (Refereed) Published
Abstract [en]

Heating accounts for approximately 50 % of all final energy consumption worldwide. To decarbonise heating, renewable energy sources must be employed. To account for intermittency of renewable energy sources and provide operational flexibility, low cost and versatile thermal energy storage unit integrated systems are required. Rock-based high temperature thermal energy storage (up to 600 °C) integrated with high temperature solar thermal collectors provide a solution to reduce natural gas consumptions in steam boilers for medium temperature (100 °C–250 °C) industrial processes. This study develops and validates a two-dimensional model of an existing vertical flow 1 MWh high temperature thermal storage unit using experimental data. A parametric study is performed to evaluate the key design parameters and their effect on the temperature profile and charge efficiency. The charge efficiency was found to be in the range of 77–94 %. This pilot scale model is upscaled in the numerical model to an industrial level 330 MWh storage where the output temperature and flowrate are presented for a constant power output, taking into consideration the residual input heat from the solar thermal collectors.

National Category
Environmental Engineering
Identifiers
urn:nbn:se:du-45975 (URN)10.1016/j.est.2023.107349 (DOI)
Available from: 2023-05-08 Created: 2023-05-08 Last updated: 2023-08-28Bibliographically approved
Saini, P. (2023). Solar integrated heating systems: Applications in buildings and industries. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Solar integrated heating systems: Applications in buildings and industries
2023 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

“Heat is half” of the global final energy consumption, and the decarbonization of the heating sector is critical to achieving climate goals. This thesis employs a system modelling approach to evaluate renewable heating systems. The overarching goal is to reduce fossil fuel reliance by integrating renewable energy technologies, such as solar thermal, photovoltaics, photovoltaic thermal, heat pump, and thermal energy storage in different system concepts. Two primary sectors are addressed: buildings, with a focus on utilizing solar collectors and heat pumps for heating systems in multifamily houses by recovery of waste heat; and industries, utilizing solar collectors for steam generation below 200 °C. The work is centred around five primary research questions, addressing the technical and economic feasibility of the mentioned technologies and their roles in decarbonization.

Two system arrangements were simulated to address the heating demands of buildings: a) Centralized heat pump that utilizes ventilation air as a heat source, serving three multifamily buildings, and b) A fifth generation district heating system that utilizes industrial waste heat as its source. The techno-economic performance of these systems was evaluated. The results suggest that the economic viability of such arrangements largely depends on critical factors that include the costs of heat pump sub-stations, prevailing electricity prices, and the cost of waste heat. Incorporating solar air heating collectors and optimizing flow controls enhance both component and system energy efficiency. Moreover, integrating photovoltaic systems, up to a specific capacity, is advantageous as it offers reductions in heating costs.

For industrial steam generation, the importance of the solar fraction in technological comparisons is highlighted. Parabolic trough collector and heat pump for steam generation are compared for 34 locations in the European Union, using solar fraction as an indicator. The results highlight the economic competitiveness of both technologies for a wide range of boundary conditions. However, heating costs from solar thermal collectors increase at higher solar fractions, primarily due to the storage costs. This trend sets an economic limit on the maximum feasible solar fraction. As a result, hybrid systems combining solar thermal collectors with steam heat pumps offer a promising combination to achieve a high renewable fraction for industrial applications.

Concerns about CO2 emissions from the electricity grid, and its reliability in many countries, necessitate the exploration of alternative system concepts to meet a higher fraction of heating demand. One such novel energy system combines a parabolic trough collector, photovoltaic, and thermal energy storage (using water and sand as storage media) to reach a combined solar fraction of 90 %, while remaining cost-competitive with fossil fuels. The techno-economic performance of solar thermal collectors is system dependent, largely influenced by their integration within industrial systems. Two novel indicators are introduced to quantify the integration incompatibilities, offering insights into the dynamics for specific integration point. Using this method for a case study resulted in an optimized configuration, improving the overall system performance.

Collectively, the results are expected to be leveraged by relevant stakeholders to advance the cause of heating decarbonization in buildings and industries.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2023. p. 137
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 2316
Keywords
Solar heating systems, Renewable heating systems, Decarbonization, Solar thermal, Techno-economic analysis, Thermal energy storage.
National Category
Energy Engineering
Identifiers
urn:nbn:se:du-47224 (URN)978-91-513-1914-8 (ISBN)
Public defence
2023-11-23, 310, Dalarna university, Borlänge, 13:00 (English)
Opponent
Supervisors
Available from: 2023-11-07 Created: 2023-11-07 Last updated: 2023-11-07Bibliographically approved
Saini, P., Huang, P., Fiedler, F., Volkova, A. & Zhang, X. (2023). Techno-economic analysis of a 5th generation district heating system using thermo-hydraulic model: A multi-objective analysis for a case study in heating dominated climate. Energy and Buildings, 296, Article ID 113347.
Open this publication in new window or tab >>Techno-economic analysis of a 5th generation district heating system using thermo-hydraulic model: A multi-objective analysis for a case study in heating dominated climate
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2023 (English)In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 296, article id 113347Article in journal (Refereed) Published
Abstract [en]

A 5th generation district heating (5GDH) system consists of a low-temperature network used as a heat source for de-centralized heat pumps to serve heating demand. Until now, there is a lack of studies looking into the economic aspect of implementing the 5GDH concept. The performance characteristics, system dynamics, and economic feasibility of the 5GDH system are insufficiently investigated in cold climates. This paper aims to bridge the research gap by performing the techno-economic analysis of a 5GDH system using a case study based in Tallinn, Estonia. A detailed thermo-hydraulic simulation model is constructed in TRNSYS and Fluidit Heat. In addition, the uncertainty and sensitivities on the economic performance are analysed using Monte Carlo method implemented in Python. The study further analyses the effectiveness of using solar power technologies in reducing the cost of heating. For designed boundary conditions, the system can deliver heat at levelised cost of heating (LCOH) of 80 €/MWh. Integration of photovoltaic up to a limited capacity results in 1 % reduction when compared to the base case LCOH. The economic benefit of photovoltaic thermal is lower compared to photovoltaic. This study can provide a benchmark for the application of 5GDH systems in heating dominated regions.

Keywords
5GDHC; Techno-economic analysis; Monte Carlo analysis; PV; PVT
National Category
Energy Engineering
Identifiers
urn:nbn:se:du-46441 (URN)10.1016/j.enbuild.2023.113347 (DOI)001046454200001 ()2-s2.0-85164720487 (Scopus ID)
Available from: 2023-07-13 Created: 2023-07-13 Last updated: 2023-11-07Bibliographically approved
Saini, P., Kivioja, V., Naskali, L., Byström, J., Semeraro, C., Gambardella, A. & Zhang, X. (2023). Techno-economic assessment of a novel hybrid system of solar thermal and photovoltaic driven sand storage for sustainable industrial steam production. Energy Conversion and Management, 292, Article ID 117414.
Open this publication in new window or tab >>Techno-economic assessment of a novel hybrid system of solar thermal and photovoltaic driven sand storage for sustainable industrial steam production
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2023 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 292, article id 117414Article in journal (Refereed) Published
Abstract [en]

Decarbonising industrial heat is a significant challenge due to various factors such as the slow transition to renewable technologies and insufficient awareness of their availability. The effectiveness of commercially available renewable heating systems is not well defined in terms of techno-economic boundaries. This study presents a techno-economic assessment of a novel system designed for steam production at a food and beverage plant. The proposed system is combines parabolic trough collectors with pressurized water thermal storage and photovoltaic-driven high-temperature sand storage. The technological components within the hybrid system complements each other both economically and practically, resulting in cost and land area savings. To evaluate the proposed system, simulations were performed using a model developed in TRNSYS and Python. The combined system exhibits better economic and land use performance than when these technologies are used individually. Specifically, the system has a high solar fraction of 90% while remaining competitive with the existing boiler fuel cost. The study emphasizes the importance of multi-technology approaches in developing practical solutions for industrial heat decarbonization. The findings can guide industries in a transition to sustainable heat sources and contribute to global efforts in mitigating climate change.

National Category
Energy Engineering
Identifiers
urn:nbn:se:du-46464 (URN)10.1016/j.enconman.2023.117414 (DOI)001039354600001 ()2-s2.0-85172667530 (Scopus ID)
Available from: 2023-07-17 Created: 2023-07-17 Last updated: 2023-11-07Bibliographically approved
Saini, P., Ghasemi, M., Arpagaus, C., Bless, F., Bertsch, S. & Zhang, X. (2023). Techno-economic comparative analysis of solar thermal collectors and high-temperature heat pumps for industrial steam generation. Energy Conversion and Management, 277, Article ID 116623.
Open this publication in new window or tab >>Techno-economic comparative analysis of solar thermal collectors and high-temperature heat pumps for industrial steam generation
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2023 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 277, article id 116623Article in journal (Refereed) Published
Abstract [en]

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achieve the climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus on sustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of natural gas supplies. Therefore, there is a need for less vulnerable and less price-volatile solutions for heating. This paper focuses on two decarbonization technologies for industrial process heat supply: a) electricity-driven steam-generating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers in generating steam, and b) solar parabolic trough collector (PTC), which can produce heat economically and at a minimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelized cost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTC collector's solar fraction limit (SFlimit) is defined to indicate when the LCOH for these two technologies is equal. This allows for distinguishing between the economic stronghold of each technology. The evaluation is carried out through the annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVE are used for the solar thermal part. Boundary conditions for European geographical constraints have been applied to establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reach cost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guide to quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries

National Category
Energy Systems
Identifiers
urn:nbn:se:du-44979 (URN)10.1016/j.enconman.2022.116623 (DOI)000921273200001 ()2-s2.0-85145687377 (Scopus ID)
Available from: 2023-01-05 Created: 2023-01-05 Last updated: 2023-11-07Bibliographically approved
Saini, P., Hedstrom, A., Arpagaus, C., Bless, F. & Bertsch, S. (2022). A hybrid system of steam generating heat pump and solar parabolic trough collectors for process heating: Techno-economic analysis for a brewery. In: : . Paper presented at High temp heat pump symposium 2022, Copenhagen, Denmark (pp. 309-322).
Open this publication in new window or tab >>A hybrid system of steam generating heat pump and solar parabolic trough collectors for process heating: Techno-economic analysis for a brewery
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2022 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The industrial sector consumes nearly 32% of the World’s final energy. A further breakdown revealsthat 26% of the energy is consumed as electricity and 74% as heat, generated mainly from fossil fuels.Therefore, several technologies focus on providing low carbon heating for industrial processes. For example, a relatively new technology for steam generation is electrically-driven high-temperature heatpumps (HTHP). In

Keywords
Process heat decarbonization, solar thermal, steam generating heat pump, techno-economic analysis
National Category
Environmental Engineering
Identifiers
urn:nbn:se:du-41981 (URN)
Conference
High temp heat pump symposium 2022, Copenhagen, Denmark
Available from: 2022-07-27 Created: 2022-07-27 Last updated: 2023-03-17Bibliographically approved
Gambardella, A. & Saini, P. (2022). A novel method for assessing the techno-economicalcompatibility of solar thermal integrations. In: : . Paper presented at Eurosun 2022.
Open this publication in new window or tab >>A novel method for assessing the techno-economicalcompatibility of solar thermal integrations
2022 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

In this work we present a method to evaluate the compatibility of a solar thermal integration in an industrial process. We introduce two indicators to quantify in a comprehensive way all the financial and technicalboundaries influence on the design choices and on the costs of a solar thermal integration.Both the indicators are measures of the divergence of an integration from a fictive (yet technically possible)ideal case and from a “do-nothing” case. In this way, the incompatibilities of the integration are associated tothe consequences that the non-ideal factors have on both costs and performances. Moreover, the value of the indicators is normalized between a minimum and a maximum being the “do-nothing” and the ideal cases respectively.We then used these indicators on a real case scenario to compare the pros and cons of two different solarthermal integration approaches (hot water vs steam) to a beer brewery in southern Europe.The results show that retrofitting part of the existing appliance to be fed with hot water rather than steamenhances the compatibility of solar thermal with the brewery. Nevertheless, we measured no relevant improvement to the compatibility of solar thermal when designing a brewery from scratch with the same characteristics but were the solar thermal system could have been integrated “ad-hoc” rather than retrofitted

Keywords
solar thermal integration, compatibility, low pressure industries, brewery
National Category
Energy Engineering
Identifiers
urn:nbn:se:du-42956 (URN)
Conference
Eurosun 2022
Available from: 2022-10-28 Created: 2022-10-28 Last updated: 2023-11-07Bibliographically approved
Shah, J., Saini, P. & Han, M. (2022). Analysis And Performance Mapping Of “Component To System” For A Parabolic Trough Collector Applied To Process Heating Applications. In: ISEC 2022: . Paper presented at International Sustainable Energy Conference 2022, 5-7 July, Graz, Austria (pp. 487-488).
Open this publication in new window or tab >>Analysis And Performance Mapping Of “Component To System” For A Parabolic Trough Collector Applied To Process Heating Applications
2022 (English)In: ISEC 2022, 2022, p. 487-488Conference paper, Published paper (Refereed)
Abstract [en]

The slogan “Heat is half” is of importance to keep in mind that nearly 50 % of the final energy use is in the form of heat. The global efforts for future decarbonised heating systems are based on hydrogen and electrification of heating etc. Solar thermal technology is a key component of greener industrial heating solutions. Solar thermal technologies for process heating application has decade long history of implementation and are gaining significant interest from all around the world. The performance prediction of solar thermal technologies on the system level is more complicated compared to photovoltaic, due to the effect of performance on system boundary conditions such as variation in meteorological parameters, load demand, temperature levels, thermal storage type. The central focus of this paper is on the use of a parabolic trough collector (PTC) for process heating applications in the medium temperature range. The aim of this paper is to map the performance of PTC collector into an industrial system, and to analyse the decrease in collector thermal output from component level to system level. The simulations are implemented in TRNSYS and MATLAB. The results are visualized using QGIS tool to generate the heat map for performance parameters for a range of solar fractions.

National Category
Environmental Engineering
Identifiers
urn:nbn:se:du-41798 (URN)
Conference
International Sustainable Energy Conference 2022, 5-7 July, Graz, Austria
Available from: 2022-07-01 Created: 2022-07-01 Last updated: 2023-03-17Bibliographically approved
Zarza, E., Alarcón, D., Frasquet, M. & Saini, P. (2022). Integration schemes and BOPs more commonly used in commercial SHIP applications: This is a report from SHC Task 64 / SolarPACES Task IV: Solar Process Heat and work performed in Subtask B: Modularization. International Energy Agency (IEA)
Open this publication in new window or tab >>Integration schemes and BOPs more commonly used in commercial SHIP applications: This is a report from SHC Task 64 / SolarPACES Task IV: Solar Process Heat and work performed in Subtask B: Modularization
2022 (English)Report (Other academic)
Abstract [en]

The main objective of the Subtask B in the new Task 64/IV is the definition of modularized and “normalized” components/subsystems for applications in the field of Solar Heat for industrial Processes (SHIP), e.g. for the balance of plant (BOP), solar field, thermal energy storage and hydraulic circuit. The methodology to achieve this goal is composed of three steps: 

1. Identification of components/subsystems that are used in commercial SHIP projects more often, taking into consideration the inputs delivered by the partners and information existing in current databases 

2. Development of modular/standardized designs for these components/subsystems 

3. Distinction between low and medium temperature SHIP applications 

Step 1 was based on the analysis of the integration schemes that are more likely to be used in next commercial SHIP projects. It was assumed when preparing the work plan of Subtask B that during this analysis a small number of integration schemes would be identified as good candidates for next commercial projects. However, the integration schemes so far proposed by most of the industrial partners involved in Subtask B were quite different from each other, thus showing that the next commercial projects may use very different integration schemes, in both low and medium temperature range. To check to what extent this is true, the integration schemes so far proposed by the industrial partners are shown in this document (Section 2), together with information about the integration schemes used in the commercial projects included in the data base: www.ship-plants.info (Section 3). 

For the above reasons, it was decided within Subtask B to adopt a new strategy. This new approach was based on the analysis of BOP options depending on the fluid required in the industrial process and the working fluid used in the solar field. 

Once the list of these fluids was identified, the industrial partners were asked to perform an integration analysis of those combinations that were part of their business portfolio. Section 4 covers the contributions received to date.

Place, publisher, year, edition, pages
International Energy Agency (IEA), 2022
Keywords
solar heating for industrial applications
National Category
Energy Engineering
Identifiers
urn:nbn:se:du-42957 (URN)10.18777/ieashc-task64-2022-0001 (DOI)
Projects
IEA SHC Task 64 Solar process heating
Available from: 2022-10-28 Created: 2022-10-28 Last updated: 2023-03-17Bibliographically approved
Saini, P., Ghasemi, M., Arpagaus, C., Bless, F., Bertch, S. & Zhang, X. (2022). Techno-economic comparative analysis of solar thermal collectors and high-temperature heat pumps for industrial steam generation. In: : . Paper presented at Eurosun 2022.
Open this publication in new window or tab >>Techno-economic comparative analysis of solar thermal collectors and high-temperature heat pumps for industrial steam generation
Show others...
2022 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achievethe climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus onsustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of naturalgas supplies. Therefore, there is a need for less vulnerable and less price volatile solutions for heating. This paperfocuses on two decarbonization technologies for industrial process heat supply: (a) electricity-driven steamgenerating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers ingenerating steam, and (b) solar parabolic trough collector (PTC), which can produce heat economically and at aminimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelizedcost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTCcollector's solar fraction limit is defined to indicate when the LCOH for these two technologies is equal. This limitallows distinguishing between the economic stronghold of each technology. The evaluation is carried out throughthe annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVEare used for the solar thermal part. Boundary conditions for European geographical constraints have been appliedto establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reachcost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guideto quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries.

Keywords
High-Temperature Heat Pump; Parabolic Trough Collector; Solar Fraction; Techno-economic analysis
National Category
Energy Engineering
Identifiers
urn:nbn:se:du-42955 (URN)
Conference
Eurosun 2022
Available from: 2022-10-28 Created: 2022-10-28 Last updated: 2023-03-17Bibliographically approved
Projects
Autokarakterisering av PED:er för digitala referenser mot iterativ processoptimering (PED-ACT)Soldriven fjärrvärme med groplager för svenska förhållanden
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