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Publications (10 of 15) Show all publications
Nikbakht, M. V., Gheibi, M., Montazeri, H., Khaksar, R. Y., Moezzi, R. & Vadiee, A. (2024). Identification and Ranking of Factors Affecting the Delay Risk of High-Rise Construction Projects Using AHP and VIKOR Methods. INFRASTRUCTURES, 9(2), Article ID 24.
Open this publication in new window or tab >>Identification and Ranking of Factors Affecting the Delay Risk of High-Rise Construction Projects Using AHP and VIKOR Methods
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2024 (English)In: INFRASTRUCTURES, ISSN 2412-3811, Vol. 9, no 2, article id 24Article in journal (Refereed) Published
Abstract [en]

Construction projects, especially those for commercial purposes, require thorough planning and control to ensure success within predetermined budgets and timelines. This research, conducted in Mashhad, Iran, employs the analytic hierarchy process (AHP) and VIKOR methods to identify and rank factors influencing delays in high-rise projects. The study, based on a sample of 40 projects, emphasizes the comprehensive nature of our research method. The scale for features in project selection includes societal importance (with different applications including cultural hubs, affordable housing initiatives, and urban renewal for social equity), size (less and more than 20 units in residential projects), and diversity (mixed-use development, inclusive infrastructure, and cultural and recreational spaces), contributing to a comprehensive analysis of construction delays. Expert project managers and engineers provided insights through two questionnaires, and their responses underwent thorough analysis. Our findings not only underscore the significance of factors contributing to project success but also rank their impact on the likelihood of delays. The study reveals that the negative effects of these factors on cost, time, and project quality vary. Time emerges as the most influential parameter, with approximately six times more impact on cost and nine times more on quality. Contractor financial weakness, delays in allocating financial and credit resources, insufficient project resource allocation, contractor technical and executive weakness, and a lack of proper implementation and project control are identified as the most important factors contributing to delays.

Place, publisher, year, edition, pages
MDPI, 2024
Keywords
project delay, time management, quality management, analytical hierarchy process (AHP), VIKOR
National Category
Civil Engineering
Identifiers
urn:nbn:se:mdh:diva-66241 (URN)10.3390/infrastructures9020024 (DOI)001169884000001 ()2-s2.0-85187250429 (Scopus ID)
Available from: 2024-03-13 Created: 2024-03-13 Last updated: 2024-03-20Bibliographically approved
Kamranfar, S., Damirchi, F., Pourvaziri, M., Abdunabi Xalikovich, P., Mahmoudkelayeh, S., Moezzi, R. & Vadiee, A. (2023). A Partial Least Squares Structural Equation Modelling Analysis of the Primary Barriers to Sustainable Construction in Iran. Sustainability, 15(18), Article ID 13762.
Open this publication in new window or tab >>A Partial Least Squares Structural Equation Modelling Analysis of the Primary Barriers to Sustainable Construction in Iran
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2023 (English)In: Sustainability, E-ISSN 2071-1050, Vol. 15, no 18, article id 13762Article in journal (Refereed) Published
Abstract [en]

This paper outlines the obstacles to sustainable construction growth in Iran and thereafter examines the effect and relation between these barriers and the direction of sustainable construction growth as one of the essential objectives for achieving sustainable cities and infrastructure. The study is applied for research purposes that are based on descriptive survey data gathering and correlational data analysis techniques. The statistical population for this study consists of 120 construction-related engineers and university professors who were assessed on a five-point Likert scale. Using SmartPLS software version 4, the responses to the questionnaire were examined. The Kolmogorov–Smirnov assessment was utilized to evaluate the normalcy of the variables, as this assessment is typically employed for this purpose. For data analysis, the PLS (partial least squares) method was used, while SEM (structural equation modeling) methods have been used to assess the study hypotheses. Cronbach’s alpha and the composite reliability coefficient (CR) were applied to determine the instrument’s viability, and the results show that the coefficient connected to all variables is above 7.0, which is an acceptable value. The AVE (average variance extracted) was also used to evaluate the questionnaire’s validity, which was greater than 0.4 and deemed acceptable for coefficients of significance (T-values), coefficient of predictive power (Q2), and coefficient of determination (R2). The obtained results support and confirm all research hypotheses, including that the identified obstacles directly affect the performance of sustainable construction. According to the results of the Friedman test, the legal restrictions variable (CL) is the most significant obstacle to sustainable construction in Iran, with a rank of 4.24. The indicators of political limits (CP) and social and cultural constraints (CSC) came in at second and third, respectively. The results could help government officials make better decisions about where to focus their attention and how to distribute scarce resources. 

Place, publisher, year, edition, pages
Multidisciplinary Digital Publishing Institute (MDPI), 2023
Keywords
smartPLS, sustainability barrier, sustainable construction, sustainable development
National Category
Construction Management
Identifiers
urn:nbn:se:mdh:diva-64514 (URN)10.3390/su151813762 (DOI)001074466900001 ()2-s2.0-85172866586 (Scopus ID)
Available from: 2023-10-11 Created: 2023-10-11 Last updated: 2023-10-18Bibliographically approved
Midemalm, J., Vadiee, A., Uhlemann, E., Georgsson, F., Carlsson-Kvarnlöf,, G., Månsson, J., . . . Johansson, P. (Eds.). (2023). Bidrag från den 9:e utvecklingskonferensen för Sveriges ingenjörsutbildningar. Paper presented at 9:e utvecklingskonferensen för Sveriges ingenjörsutbildningar, 22-23 november 2023, Mälardalens universitet, Västerås. Västerås: Mälardalens universitet
Open this publication in new window or tab >>Bidrag från den 9:e utvecklingskonferensen för Sveriges ingenjörsutbildningar
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2023 (Swedish)Conference proceedings (editor) (Refereed)
Place, publisher, year, edition, pages
Västerås: Mälardalens universitet, 2023. p. 437
National Category
Educational Sciences
Identifiers
urn:nbn:se:mdh:diva-64761 (URN)978-91-7485-620-0 (ISBN)
Conference
9:e utvecklingskonferensen för Sveriges ingenjörsutbildningar, 22-23 november 2023, Mälardalens universitet, Västerås
Available from: 2023-11-16 Created: 2023-11-16 Last updated: 2023-11-22Bibliographically approved
Marashian, S., Vadiee, A., Abouali, O. & Sadrizadeh, S. (2023). Enhancing Indoor Environmental Simulations: A Comprehensive Review of CFD Methods. In: Konstantinos G. Kyprianidis, Erik Dahlquist, Ioanna Aslanidou, Avinash Renuke, Gaurav Mirlekar, Tiina Komulainen, and Lars Eriksson (Ed.), : . Paper presented at 64th International Conference of Scandinavian Simulation Society, SIMS 2023 Västerås, Sweden, September 25-28, 2023. Västerås, Sweden
Open this publication in new window or tab >>Enhancing Indoor Environmental Simulations: A Comprehensive Review of CFD Methods
2023 (English)In: / [ed] Konstantinos G. Kyprianidis, Erik Dahlquist, Ioanna Aslanidou, Avinash Renuke, Gaurav Mirlekar, Tiina Komulainen, and Lars Eriksson, Västerås, Sweden, 2023Conference paper, Published paper (Refereed)
Abstract [en]

Computational Fluid Dynamics (CFD) simulations are extensively used to model indoor environments, including airflow patterns, temperature distribution, and contaminant dispersion. These simulations provide valuable insights for improving indoor air quality, enhancing thermal comfort, optimizing energy efficiency, and informing design decisions. The recent global pandemic has emphasized the importance of understanding airflow patterns and particle dispersion in indoor spaces, highlighting the potential of CFD simulations to guide strategies for improving indoor air quality and public health. Consequently, there has been a significant increase in research focused on studying the transport and dispersion of pollutants in indoor environments using CFD techniques. These simulations are vital in advancing engineers' understanding of indoor environments; however, achieving accurate results requires careful method selection and proper implementation of each step. This paper aims to review the state-of-the-art CFD simulations of indoor environments, specifically focusing on strategies employed for three main simulation components: geometry and grid generation, ventilation strategies, and turbulence model selection. Researchers can select suitable techniques for their specific applications by comparing different indoor airflow simulation strategies.

Place, publisher, year, edition, pages
Västerås, Sweden: , 2023
Series
Linköping Electronic Conference Proceedings 192, ISSN 1650-3686 (print), 1650-3740 (online)
Keywords
Computational Fluid Dynamics (CFD), Indoor environments, Turbulence models, Ventilation strategies
National Category
Fluid Mechanics and Acoustics Building Technologies
Identifiers
urn:nbn:se:mdh:diva-64565 (URN)10.3384/ecp200046 (DOI)
Conference
64th International Conference of Scandinavian Simulation Society, SIMS 2023 Västerås, Sweden, September 25-28, 2023
Available from: 2023-10-20 Created: 2023-10-20 Last updated: 2023-12-11Bibliographically approved
Marashian, S., ZendehAli, N., Vadiee, A., Abouali, O. & Sadrizadeh, S. (2023). Investigation of two different ventilation designs in a single-bed isolation room. In: The 11th International Conference on Sustainable Development in Building and Environment: . Paper presented at The 11th International Conference on Sustainable Development in Building and Environment.
Open this publication in new window or tab >>Investigation of two different ventilation designs in a single-bed isolation room
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2023 (English)In: The 11th International Conference on Sustainable Development in Building and Environment, 2023Conference paper, Oral presentation with published abstract (Other (popular science, discussion, etc.))
Abstract [en]

The recent epidemic of the coronavirus disease showed the increased importance of controlling the transmission of contamination in the ward areas more than before. The performance of the ventilation systems in healthcare facilities can significantly impact the overall healthcare quality. This paper aims to compare two ventilation designs in an isolation room of a hospital and study the indoor airflow pattern. Computational fluid dynamics using ANSYS Fluent software was employed for the numerical simulation of the fluid flow. The simulation included the prediction of flow patterns and particle trajectories with the additional investigation into the impact of considering human thermal plume and modeling particle trajectories considering the turbulent fluctuations using the discrete random walk method in the simulation.  

Keywords
Airflow distribution, Computational Fluid Dynamics, Discrete random walk, Isolation Room, Ventilation designs
National Category
Building Technologies Fluid Mechanics and Acoustics
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-64409 (URN)
Conference
The 11th International Conference on Sustainable Development in Building and Environment
Available from: 2023-10-02 Created: 2023-10-02 Last updated: 2024-06-19Bibliographically approved
Monghasemi, N., Vadiee, A., Kyprianidis, K. & Jalilzadehazhari, E. (2023). Rank-Based Assessment of Grid-Connected Rooftop Solar Panel Deployments Considering Scenarios for a Postponed Installation. Energies, 16(21), Article ID 7335.
Open this publication in new window or tab >>Rank-Based Assessment of Grid-Connected Rooftop Solar Panel Deployments Considering Scenarios for a Postponed Installation
2023 (English)In: Energies, E-ISSN 1996-1073, Vol. 16, no 21, article id 7335Article in journal (Refereed) Published
Abstract [en]

Installing solar photovoltaic panels on building rooftops can help property managers generate renewable energy and reduce electricity costs. However, the existence of multiple efficiency indicators and ambiguity in interpreting these metrics limits the comparison of the performance of individual installation projects. This paper presents a methodology using data envelopment analysis to evaluate suitable candidates for rooftop solar panel installation. This approach integrates rooftop area, solar irradiation, temperature, costs, energy yield, and revenue to evaluate the relative efficiency of each building. To demonstrate the methodology, it was applied to rank 22 residential buildings, revealing the top performers for installation in 2022. The approach was subsequently adapted to assess potential outcomes under deferred implementation up to 2030, encompassing a diverse range of climate and pricing scenarios. Five installations were found to be optimal irrespective of the future scenarios. In addition, a super-efficiency approach was applied to overcome the low level of discrimination among the possible installations and to rank each individual unit uniquely. The analysis is designed to guide property owners in identifying favorable solar photovoltaic investments within their portfolios under changing conditions. 

Place, publisher, year, edition, pages
Multidisciplinary Digital Publishing Institute (MDPI), 2023
Keywords
data envelopment analysis, photovoltaic panels, rooftop solar system, scenario planning
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-64797 (URN)10.3390/en16217335 (DOI)001099586100001 ()2-s2.0-85176342086 (Scopus ID)
Available from: 2023-11-22 Created: 2023-11-22 Last updated: 2023-11-29Bibliographically approved
Vadiee, A. (2022). A non-linear gray-box model of buildings connected to district heating systems. In: Energy Proceedings: . Paper presented at ICAE 2022.
Open this publication in new window or tab >>A non-linear gray-box model of buildings connected to district heating systems
2022 (English)In: Energy Proceedings, 2022Conference paper, Oral presentation only (Refereed)
Abstract [en]

Traditional building automation controllers are having low performance in dealing with non-linear phenomena. In recent years, model predictive control (MPC) has become a notable control algorithm for building automation system capable of handling non-linear processes. Performance of model-based controllers, such as MPC, is depending on reasonably accurate process models. For a building using baseboard radiator heater, a non-linear model is a more reliable representation of heat distribution system. Therefore, this study aims to present a non-linear gray-box model for a residential building connected to the local district heating network that is equipped with radiator heat emitters. The model is supposed to forecast the indoor air temperature as well as the radiator secondary return temperature. The model is validated using measurements collected from a building in Västerås, Sweden. In addition to a better accuracy, another motivation behind using a non-linear heating circuit model is to enhance its generalization performance. With the added benefits of accuracy and generalization, this model is expected to extend practical MPC implementation for such buildings.

Keywords
District heating, Non-linear model, Gray-box modeling, Forecasting
National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-60984 (URN)
Conference
ICAE 2022
Available from: 2022-11-23 Created: 2022-11-23 Last updated: 2022-11-29Bibliographically approved
Vadiee, A. (2022). Chapter 7 - Solar heating and cooling applications in agriculture and food processing systems. In: Solar Energy Advancements in Agriculture and Food Production Systems: (pp. 237-270). Elsevier
Open this publication in new window or tab >>Chapter 7 - Solar heating and cooling applications in agriculture and food processing systems
2022 (English)In: Solar Energy Advancements in Agriculture and Food Production Systems, Elsevier, 2022, p. 237-270Chapter in book (Other academic)
Abstract [en]

The agricultural and food processing industries are considered key sectors aligned with sustainable development goals, as they play an important role in sustainable rural development. About 30% of global energy is used in these sectors, particularly thermal energy in both heating and cooling applications. Research considers solar energy technologies to be promising ways to increase system flexibility and lead to climate mitigation impacts. Different types of solar heating and cooling systems can supply a wide range of desired operating temperatures for various applications in agricultural and food processing systems. The main applications of solar thermal energy systems in the agricultural and food processing industries are solar air heaters for drying and dehydration processes, solar water heaters for both heat and food processing systems, solar cooking systems, solar heating and cooling systems for maintaining greenhouse climate, and solar-powered cooling systems for both food processing and space cooling. Furthermore, some innovative active and passive integrated solar systems such as the solar-blind concept remain underdeveloped. Further advances in solar energy integration systems in the agricultural and food processing industries will lead to considerable climate mitigation impacts as well as more resilient energy management in this sector.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Solar water heatingair coolingsolar air heatingfood processingthermo-economic assessment
National Category
Energy Engineering Environmental Sciences related to Agriculture and Land-use
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-60983 (URN)10.1016/B978-0-323-89866-9.00001-8 (DOI)2-s2.0-85142723013 (Scopus ID)978-0-323-89866-9 (ISBN)
Available from: 2022-11-23 Created: 2022-11-23 Last updated: 2023-04-12Bibliographically approved
Jalilzadehazhari, E., Vadiee, A. & Johansson, J. (2021). Subsidies required for installing renewable energy supply systems considering variations in future climate conditions. Journal of Building Engineering, 35, 101999-101999, Article ID 101999.
Open this publication in new window or tab >>Subsidies required for installing renewable energy supply systems considering variations in future climate conditions
2021 (English)In: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 35, p. 101999-101999, article id 101999Article in journal (Refereed) Published
Abstract [en]

Improving the energy performance of detached houses is expected to play an important role in achieving energy and climate targets in Sweden. The majority of detached houses require energy renovations due to technical deteriorations in heating, ventilation, and air conditioning systems approaching the ends of their lives. Renewable energy supply system implementation leads to total energy use reduction. No previous studies provided information regarding how possible climate futures could affect subsidies required to implement these systems. This study compared the performance of an air-to-water heat pump (ASHP), a ground-source heat pump (GSHP), and an integrated system of a ground-source heat pump and photovoltaic solar panels (GSHP-PV) in reducing the total energy use of a detached house, which was initially supplied by an electric boiler. The performances of the supply systems were analysed in regard to three different climate scenarios, following the Special Report of Emissions Scenarios, A2 storyline. The effects of three different interest rates and two different lifetimes on subsidies were also investigated for all three energy supply systems. The GSHP-PV system was the most efficient system, as it secured 97%–100% of the total energy consumption, followed by GSHP and AWHP. The analyses of the results showed that variations in future climate conditions changed the subsidies required to install the supply systems. Furthermore, the results showed that changes in lifetime had greater impact on subsidies than interest rate growth.

National Category
Energy Engineering
Identifiers
urn:nbn:se:mdh:diva-60982 (URN)10.1016/j.jobe.2020.101999 (DOI)000618177600003 ()2-s2.0-85097052750 (Scopus ID)
Funder
InterregInterreg
Available from: 2022-11-23 Created: 2022-11-23 Last updated: 2023-05-10Bibliographically approved
Stridh, B., Campana, P. E., Sandra, A., Thomas, C., Tomas, L., Nordlander, E. & Vadiee, A. (2020). Förbättrad beräkning av solelproduktion i Sverige.
Open this publication in new window or tab >>Förbättrad beräkning av solelproduktion i Sverige
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2020 (Swedish)Report (Other academic)
Abstract [sv]

Nordligt läge med lägre solstrålning än exempelvis södra Europa och förhållande­vis lågt elpris gör att noggranna förutsägelser av energiutbyte från solcellsanlägg­ningar är av stor vikt när man gör investeringskalkyler i Sverige. Noggrannare beräkningar av förväntad solelproduktion ger mindre ekonomisk osäkerhet, vilket resulterar i en mer resurseffektiv utveckling. Val av meteorologiska data och be­räkningsmetod för kalkyler av solelproduktion är därför av stor vikt.

En fråga är därför vilket simuleringsprogram för solelproduktion som är bäst att använda i Sverige. OptiCE, Polysun, PVsyst och PV*SOL med programmens meteo­rologiska databaser visade sig här vara relativt likvärdiga för Stockholm, Norrköping och Visby. Överensstämmelsen är relativt god med de uppmätta vär­dena för solelproduktion under 2019, med skillnader på mindre än ±5%. Men de ger alla 13%-15% för höga värden för Kiruna. PVGIS med databas ERA5 ger lite större avvikelser för Stockholm, Norrköping och Visby än ovan nämnda program men ger ett värde nära det uppmätta under 2019 i Kiruna. SAM och PVGIS med databaserna SARAH eller COSMO ger större avvikelser än ovan nämnda pro­gram. Då SARAH i en jämförande studie hade bäst nog­grannhet är det tänkbart att beräkningarna i PVGIS skulle kunna förbättras genom att välja SARAH i kombi­nation med ett lägre värde än grundinställningen 14% för system­förluster.

Den största osäkerheten vid uppskattning av solcellssystems elproduktion kommer från solstrålningsdata. Genom att förbättra solstrålningsdata och göra dem allmänt tillgängliga hjälps investerare att fatta beslut med minskad osäkerhet. Det finns behov av en branschstandard för solstrålningsdata i Sverige. En vidareutveckling av STRÅNG-modellen för solstrålningsdata är önskvärd. Ett standardförfarande hur man beräknar inverkan av skuggning skulle vara värdefullt, då skuggning vid sidan om val av solstrålningsdatabaser kan ha en stor inverkan på utbytet av solel.

Solstrålningsklimatet kan förändras över tid, vilket man kan se i upp­mätt solstrål­ning för Sverige. I framtiden kan även pågående klimatföränd­ring ha betydelse för solinstrålning och därmed solenergiproduktion. Data för solstrålning, vind, tempe­ratur och albedo­ från klimatscenarion för två tids­perioder (2030-2065 och 2066-2095) användes för att uppskatta hur solel­produktionen kan komma att påverkas. Resultatet pekar på att solelproduktionen minskar något men att förändringen endast är statistiskt signifikant i det scenario som representerar fortsatt höga kol­dioxidutsläpp och då endast för norra Sverige under den senare tidsperioden. Sett över hela landet beräknas förändringen för denna period hamna mellan -9% (10:e percentilen) och -2% (90:e percentilen) med medelvärde på ca -6%.

De kartor för Sverige för optimerade lutningar, solstrålning och solelproduktion som tagits fram med den utvecklade modellen OptiCE är ett verktyg för att bättre förstå, utforma och förbättra installationer av solcellssystem i Sverige.

Bland de undersökta modellerna för uppdelning av global horisontell solstrålning i diffus och direkt strålning för att ta fram egna solstrålningsdata för användning i simuleringsprogram är slutsatsen att för timvärden är Engerer2 eller Paulescu och Blaga lämpliga val. För 1-minutvärden visar Yang2 bäst pre­standa.

Abstract [en]

Northern location with lower solar radiation than southern Europe and relatively low electricity prices means that accurate predictions of energy yield from photovoltaic (PV) systems are of great importance when making investment calculations in Sweden. More accurate calculations of expected PV yield result in less economic uncertainty, which results in a more resource-efficient development. The choice of meteorological data and calculation method for PV yield is therefore of great importance

One question is which simulation program for PV yield is best to use in Sweden. OptiCE, Polysun, PVsyst and PV*SOL using the programs meteorological databases are relatively equivalent in this work for Stockholm, Norrköping and Visby. The agreement is relatively good with the measured values ​​for PV yield in 2019, with differences of less than ±5%. But they all give 13%-15% too high values ​​for Kiruna. PVGIS with database ERA5 gives slightly larger deviations for Stockholm, Norrköping and Visby than the above-mentioned programs but gives a value close to the measured in 2019 in Kiruna. SAM and PVGIS with the databases SARAH or COSMO give larger deviations than the above-mentioned programs. As SARAH in a comparative study had best accuracy, it is conceivable that PVGIS calculations could be improved by choosing SARAH in combination with a lower value than the default setting of 14% for system losses.

The greatest uncertainty in estimating solar cell systems electricity production comes from solar radiation data. By improving solar radiation data and making it publicly available, investors are helped to make decisions with reduced uncertainty. There is a need for an industry standard for solar radiation data in Sweden. A further development of the STRÅNG model for solar radiation data is desirable. A standard procedure for calculating the effect of shading would also be valuable, as shading can have a major impact on PV yield.

Data for solar radiation, wind, temperature and albedo from the climate scenario for two periods (2030-2065 and 2066-2095) were used to estimate how solar production may be affected in a future climate. The results indicate that PV yield is declining somewhat, but that the change is only statistically significant in the scenario that represents continued high carbon dioxide emissions and then only for northern Sweden during the recent period. Across the country, the change for this period is estimated to be between -9% (10th percentile) and -2% (90th percentile) with an average value of about -6%.

The maps for Sweden for optimized slopes, solar radiation and solar production produced with the developed model OptiCE are a tool for better understanding, designing and improving installations of PV systems in Sweden.

Among the models examined for the decomposition of global horizontal solar radiation into diffuse and direct radiation to produce own solar radiation data for use in simulation programs, the conclusion is that for hourly values ​​Engerer2 or Paulescu and Blaga are suitable choices. Of the models studied for 1-minute values, Yang2 shows the best performance.

Keywords
Photovoltaics, solar irradiance, diffuse, trend, simulation, yield, Solceller, solstrålning, diffus, trend, simulering, utbyte
National Category
Physical Sciences
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-53184 (URN)
Projects
Förbättrad beräkning av solelproduktion i Sverige
Funder
Swedish Energy Agency, 44657-1
Available from: 2021-01-25 Created: 2021-01-25 Last updated: 2022-11-09
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9426-4792

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