| 1. |
- Abas, Naeem, et al.
(författare)
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Dynamic simulation of solar water heating system using supercritical CO2 as mediating fluid under sub-zero temperature conditions
- 2019
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Ingår i: Applied Thermal Engineering. - Oxford, UK : Pergamon Press. - 1359-4311 .- 1873-5606. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- CO2 is becoming increasingly important as a mediating fluid, and simulation studies are indispensable for corresponding developments. In this study, a simulation-based performance investigation of a solar water heating system using CO2 as a mediating fluid under sub-zero temperature condition is performed using the TRNSYS (R) software. The maximum performance is achieved at a solar savings fraction of 0.83 during July. The as lowest solar savingss fraction of 0.41 is obtained during December. The annual heat production of the proposed system under Fargo climate is estimated to be about 2545 kWh. An evacuated glass tube solar collector is designed, fabricated and tested for various climate conditions. Moreover, a detailed comparison of the system's performance at sub/supercritical and supercritical pressures shows that the annual heat transfer efficiency of the modeled system is 10% higher at supercritical pressure than at sub/supercritical pressures. This result can be attributd to the strong convection flow of CO2 caused by density inhomogeneities, especially in the near critical region. This condition resuls in high heat transfer rates.
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| 2. |
- Acuña, G. J., et al.
(författare)
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Teaching about complementarity - proposal of classes for university students - including exercises
- 2022
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Ingår i: Complementarity of Variable Renewable Energy Sources. - : Elsevier. - 9780323855273 - 9780323855280 ; , s. 687-713
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The idea behind this chapter is to provide teachers and students with material that can be used while studying renewable energy sources with special attention paid to their complementary characteristics. The questions and exercises included below refer to chapters presented in the book. In case of any questions, we provide the readers with contact details to chapters corresponding authors who would be happy in assisting you in case of any queries.
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| 3. |
- Akel Hasan, A., et al.
(författare)
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A review of solar thermal cooling technologies in selected Middle East and North African countries
- 2022
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Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 54
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Tidskriftsartikel (refereegranskat)abstract
- Cooling loads are a substantial part of the total electricity demands of countries in the Middle East and North Africa (MENA). Fortunately, because of its warm and sunny climate, the MENA region is naturally suited to solar cooling technologies. This article summarizes the most recent research and developments in solar thermal cooling technologies. The working principles and a general literature survey of solar thermal cooling technologies including absorption, adsorption, and desiccant is presented. This is followed by a summary of the literature specific to the MENA region, along with a survey of the prototypes and commercial installation of solar cooling across the MENA region. Based on this review, pilot solar cooling projects in the region are around 1180 kWc, which are split between space conditioning and industrial refrigeration applications. Most of the pilot projects are of absorption cooling type using an ammonia–water binary cycle and parabolic trough solar collectors. However, a few adsorption cooling systems are employed with a water–silica working pair and flat plate collectors. Finally, desiccant cooling systems are still in their infancy, as research and experimental systems in educational institutes.
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| 4. |
- Aqachmar, Z., et al.
(författare)
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Electrification of Africa through CPV installations in small-scale industrial applications : Energetic, economic, and environmental analysis
- 2022
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Ingår i: Renewable energy. - : Elsevier Ltd. - 0960-1481 .- 1879-0682. ; 197, s. 723-746
-
Tidskriftsartikel (refereegranskat)abstract
- This paper aims to evaluate the energetic, economic, and environmental performances of small-scale concentrated photovoltaics (CPV) power systems under 107 African climatic and financial zones with different energy mixes. The proposed concept focuses on small-scale installations for small- or medium-scale industrial premises as such devices are involved in the international strategy about micro-grids. Yearly average electric productions, capacity factors, economic and environmental considerations, and sensitivity were all analysed. The mathematical methodology for calculating the power of a concentrated triple-junction solar cell, the annual energy conversion of a CPV plant, the costs, and the CO2 mitigation were assessed. The parametric study shows that the capacity factor becomes highest for a cell area of 5.5 cm2 or if the concentration ratio reaches the value of 2400. Furthermore, LCOE is lowest for Errachidia in Morocco with 15.88 c$/kWh followed by Fada in Chad with 16.82 c$/kWh, while it is highest in Wad Hajm in Sudan as 5.23 × 1016 c$/kWh. Moreover, South Africa allows the highest reduction of indirect CO2 emissions. Furthermore, energy produced is greatest in Errachidia in Morocco (606.27 GWh), Tiaret in Tunisia (601.11 GWh), and Upington in South Africa (598.11 GWh). Results are shown on innovative GIS maps of Africa. © 2022 Elsevier Ltd
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| 5. |
- Bellone, Yuri, et al.
(författare)
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Simulation-Based Decision Support for Agrivoltaic Systems
- 2024
-
Ingår i: Applied Energy. - : ELSEVIER SCI LTD. - 0306-2619 .- 1872-9118. ; 369
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a framework to compare the performances of different agrivoltaic systems, or agriphotovoltaic systems, in a range of environments was developed and tested. A set of key performance indicators derived from simulations was combined in a multi criteria decision analysis approach. The agriphotovoltaic systems were then ranked based on their similarity to the optimal solution for a specific environment. Main key performance indicators were crop ratio, energy conversion per hectare, specific energy yield, water use efficiency, and initial capital expenditure. Four agriphotovoltaics, namely vertical, interspace mono -axial, overhead mono -axial, and an overhead bi-axial, with five pitch width for each agriphotovoltaic and cultivated with processing tomato, were modelled across five sites (from the North to the South of Italy) during a ten-year period. The different scenarios were simulated in Scilab, in which a radiation model and GECROS crop model were coded. Global irradiation distribution beneath modules, and thus crop yield, were more homogeneous in vertical and overhead mono -axial than in the other agriphotovoltaic. Processing tomato demonstrated high adaptability to shading and yield was marginally affected in most of the agriphotovoltaic system alternatives. Vertical and overhead mono -axial accounted for the least yield reduction when the same pitch is compared. Overall, overhead mono -axial APV with 6 m pitch ranked first in each site when a 0.7 crop ratio threshold was considered. This framework could serve as a valuable tool for assessing the performance of different solution of agriphotovoltaics systems and their compliance with national regulation, and economic and technical targets.
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| 6. |
- Benavente Araoz, Fabian Andres, 1985-, et al.
(författare)
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Evaluation of the battery lifetime impact on PV systems techno-economic design
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Battery cycle life is a determining factor to enable the sustainability and reliability of off-grid photovoltaic (PV)/battery systems installed in rural communities. External circumstances such as remote localization and disperse distribution of communities, make the replacement and/or maintenance of battery systems with short cycle life rather difficult. Using experimental data of capacity retention from lithium-ion commercial batteries, we calculate the optimized loss of power supply probability (LPSP) and life cycle cost (LCC) for three applications operating in three locations of Bolivia. PV power and battery capacity design are estimated through optimization under the influence of suppressed demand. Optimization results show favorable LCCs when the location offers high solar irradiance in general. Suppressed demand has a marked impact on LPSP for cases where battery cycle life is limited due to aging. This is more evident for the household case, where the seasonal effect on the solar irradiance profile is considered. For the school and health center applications, a uniform load profile has positive impacts on the resulting LCC values.
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| 7. |
- Benavente Araoz, Fabian Andres, et al.
(författare)
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Photovoltaic/battery system sizing for rural electrification in Bolivia : Considering the suppressed demand effect
- 2019
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 235, s. 519-528
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Tidskriftsartikel (refereegranskat)abstract
- Rural electrification programs usually do not consider the impact that the increment of demand has on the reliability of off-grid photovoltaic (PV)/battery systems. Based on meteorological data and electricity consumption profiles from the highlands of Bolivian Altiplano, this paper presents a modelling and simulation framework for analysing the performance and reliability of such systems. Reliability, as loss of power supply probability (LPSP), and cost were calculated using simulated PV power output and battery state of charge profiles. The effect of increasing the suppressed demand (SD) by 20% and 50% was studied to determine how reliable and resilient the system designs are. Simulations were performed for three rural application scenarios: a household, a school, and a health centre. Results for the household and school scenarios indicate that, to overcome the SD effect, it is more cost-effective to increase the PV power rather than to increase the battery capacity. However, with an increased PV-size, the battery ageing rate would be higher since the cycles are performed at high state of charge (SOC). For the health centre application, on the other hand, an increase in battery capacity prevents the risk of electricity blackouts while increasing the energy reliability of the system. These results provide important insights for the application design of off-grid PV-battery systems in rural electrification projects, enabling a more efficient and reliable source of electricity.
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| 8. |
- Benavente-Araoz, Fabian, et al.
(författare)
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Loss-of-load probability analysis for optimization of small off-grid PV-battery systems in Bolivia
- 2017
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Ingår i: Proceedings of the 9th International Conference on Applied Energy. - : Elsevier. ; 142, s. 3715-3720
-
Konferensbidrag (refereegranskat)abstract
- This study evaluates the use of energy storage technologies coupled to renewable energy sources in rural electrification as a way to address the energy access challenge. Characteristic energy demanding applications will differently affect the operating conditions for off-grid renewable energy systems. This paper discusses and evaluates simulated photovoltaic power output and battery state of charge profiles, using estimated climate data and electricity load profiles for the Altiplanic highland location of Patacamaya in Bolivia to determine the loss of load probability as optimization parameter. Simulations are performed for three rural applications: household, school, and health center. Increase in battery size prevents risk of electricity blackouts while increasing the energy reliability of the system. Moreover, increase of PV module size leads to energy excess conditions for the system reducing its efficiency. The results obtained here are important for the application of off-grid PV-battery systems design in rural electrification projects, as an efficient and reliable source of electricity.
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| 9. |
- Bouzidi, B., et al.
(författare)
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Optimization of photovoltaic water pumping systems for date palm irrigation in the Saharan regions of Algeria : increasing economic viability with multiple-crop irrigation
- 2021
-
Ingår i: Energy, Ecology and Environment. - : Joint Center on Global Change and Earth System Science of the University of Maryland and Beijing Normal University. - 2363-7692 .- 2363-8338. ; 6:4, s. 316-343
-
Tidskriftsartikel (refereegranskat)abstract
- The Saharan regions of Algeria, which represent almost 90% of the total area of the country, have severe energy problems due to insufficient or lack of energy access. The sustainable development of those areas must aim at securing and increasing primary production, especially in the agricultural and pastoral sectors. The production itself depends on the supply of water available at great depths. However, the potential volumes of water pumped by photovoltaic water pumping systems are generally greater than the annual requirements for crop irrigation. In this study, we optimized the photovoltaic array, the storage tank and efficient use of the water produced by the pumping system for the irrigation of one hectare palm grove. This excess water produced was reduced by a judicious association by planting other crops (tomato, wheat and sweet pepper). The utilization rate has been improved from 56% to 86%, on the one hand. On the other hand, the impact of the yield and the prices on the economic viability was studied. The project is economically viable for a price per kg of date of 500.00 DA and a yield varying from 20 to 50 kg/tree, and the payback period varies from 3.34 to 1.22 years. The project is not economically viable for a price per kg of date of 100.00 DA/kg for a yield less than or equal to 30 kg/tree. A sensitivity analysis has shown that the photovoltaic water pumping system becomes more competitive than conventional diesel water pumping systems for diesel price beyond 53.98 DA/l (0.38 €). The results are very encouraging for the wide use of photovoltaic water pumping systems for multiple-crop irrigation in the Saharan regions.
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| 10. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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100% renewable wastewater treatment plants : Techno-economic assessment using a modelling and optimization approach
- 2021
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Ingår i: Energy Conversion and Management. - : Elsevier Ltd. - 0196-8904 .- 1879-2227. ; 239
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Tidskriftsartikel (refereegranskat)abstract
- Renewable energies are being given increasing attention worldwide, as they are able to reduce the dependence on depletable fossil fuels. At the same time, wastewater treatment is known to be a significantly energy-intensive sector, which could potentially exploit renewable energies conversion in different forms. This study investigated the feasibility to design high renewable share wastewater treatment plants through dynamic simulations and optimization, aiming to move towards greener and energy-wise wastewater remediation processes. The main aim of the work was achieved by integrating photovoltaic systems with wind turbines, multi-energy storage technologies, i.e., batteries and hydrogen systems, and reverse osmosis tertiary treatment to absorb the power production surpluses. It was supposed that, in the newly proposed scenario, most of the plant electricity need would be covered by renewable energy. The optimization problem was multi-objective and found the trade-off solutions between minimizing the net present cost and maximizing the renewable share. In the first part of the study, the model was developed and applied to a medium-scale Italian municipal wastewater treatment plant. Model generalization was successively accomplished by applying the model to different locations and plant scales across the world. For all the investigated scenarios and cases, the optimal system integration was to design a renewable and storage system with a renewable share of 70%, corresponding to the lowest net present cost. The developed model is highly flexible and can be applied to other relevant case studies, boosting for a more sustainable wastewater treatment sector, enhancing at the same time local renewable energy conversion.
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| 11. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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A gridded optimization model for photovoltaic applications
- 2020
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Ingår i: Solar Energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0038-092X .- 1471-1257. ; 202, s. 465-484
-
Tidskriftsartikel (refereegranskat)abstract
- This study aims to develop a gridded optimization model for studying photovoltaic applications in Nordic countries. The model uses the spatial and temporal data generated by the mesoscale models STRANG and MESAN developed by the Swedish Meteorological and Hydrological Institute. The model is developed based on the comparison between five irradiance databases, three decomposition models, two transposition models, and two photovoltaic models. Several techno-economic and environmental aspects of photovoltaic systems and photovoltaic systems integrated with batteries are investigated from a spatial perspective. CM SAF SARAH-2, Engerer2, and Perez1990 have shown the best performances among the irradiance databases, and decomposition and transposition models, respectively. STRANG resulted in the second-best irradiance database to be used in Sweden for photovoltaic applications when comparing hourly global horizontal irradiance with weather station data. The developed model can be employed for carrying out further detailed gridded techno-economic assessments of photovoltaic applications and energy systems in general in Nordic countries. The model structure is generic and can be applied to every gridded climatological database worldwide.
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| 12. |
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| 13. |
- Campana, Pietro Elia, et al.
(författare)
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An economic analysis of photovoltaic water pumping irrigation systems
- 2016
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 13:8, s. 831-839
-
Tidskriftsartikel (refereegranskat)abstract
- Irrigation using the photovoltaic water pumping (PVWP) systems represents a sustainable and attractive solution, which can combat Chinese grassland desertification and promote a sustainable development of the agricultural sector. This paper investigates the economics of PVWP systems taking into consideration the effects of the key components on the initial capital cost (ICC), life cycle cost (LCC), and revenues. Sensitivity analyses are conducted regarding the crop yield and price, cost of photovoltaic modules, and system components included in the ICC. Results show that the cost of the PVWP system is the most sensitive parameter affecting the ICC under the assumptions made, especially the cost of the PV modules; whereas, the crop production and price affect the net present value (NPV) and payback period (PBP) clearly. The PVWP has surplus power output when the crop water demand is low or it is non-irrigation season. The potential benefit from selling the surplus electricity is also discussed. In addition, the indirect benefits of carbon sequestration and CO2 emission reduction by applying PVWP systems are addressed in this paper.
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| 14. |
- Campana, Pietro Elia, et al.
(författare)
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An open-source optimization tool for solar home systems : A case study in Namibia
- 2016
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 130:15, s. 106-118
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Tidskriftsartikel (refereegranskat)abstract
- Solar home systems (SHSs) represent a viable technical solution for providing electricity to households and improving standard of living conditions in areas not reached by the national grid or local grids. For this reason, several rural electrification programmes in developing countries, including Namibia, have been relying on SHSs to electrify rural off-grid communities. However, the limited technical know-how of service providers, often resulting in over- or under-sized SHSs, is an issue that has to be solved to avoid dissatisfaction of SHSs’ users. The solution presented here is to develop an open-source software that service providers can use to optimally design SHSs components based on the specific electricity requirements of the end-user. The aim of this study is to develop and validate an optimization model written in MS Excel-VBA which calculates the optimal SHSs components capacities guaranteeing the minimum costs and the maximum system reliability. The results obtained with the developed tool showed good agreement with a commercial software and a computational code used in research activities. When applying the developed optimization tool to existing systems, the results identified that several components were incorrectly sized. The tool has thus the potentials of improving future SHSs installations, contributing to increasing satisfaction of end-users.
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| 15. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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An Open-source Platform for Simulation and Optimization of Clean Energy Technologies
- 2017
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Ingår i: 8th International Conference on Applied Energy, ICAE 2016; Beijing; China; 8 October 2016 through 11 October 2016. - : Elsevier. ; 105, s. 946-952
-
Konferensbidrag (refereegranskat)abstract
- This paper is to describe an open-source code for optimization of clean energy technologies. The model covers the whole chain of energy systems including mainly 6 areas: renewable energies, clean energy conversion technologies, mitigation technologies, intelligent energy uses, energy storage, and sustainability. Originally developed for optimization of renewable water pumping systems for irrigation, the open-source model is written in Matlab® and performs simulation, optimization, and design of hybrid power systems for off-grid and on-grid applications. The model uses genetic algorithm (GA) as optimization technique to find the best mix among power sources, storage systems, and back-up sources to minimize life cycle cost, and renewable power system reliability.
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| 16. |
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| 17. |
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| 18. |
- Campana, Pietro Elia, et al.
(författare)
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Dynamic modelling of a PV pumping system with special consideration on water demand
- 2013
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 112:SI, s. 635-645
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Tidskriftsartikel (refereegranskat)abstract
- The exploitation of solar energy in remote areas through photovoltaic (PV) systems is an attractive solution for water pumping for irrigation systems. The design of a photovoltaic water pumping system (PVWPS) strictly depends on the estimation of the crop water requirements and land use since the water demand varies during the watering season and the solar irradiation changes time by time. It is of significance to conduct dynamic simulations in order to achieve the successful and optimal design. The aim of this paper is to develop a dynamic modelling tool for the design of a of photovoltaic water pumping system by combining the models of the water demand, the solar PV power and the pumping system, which can be used to validate the design procedure in terms of matching between water demand and water supply. Both alternate current (AC) and direct current (DC) pumps and both fixed and two-axis tracking PV array were analyzed. The tool has been applied in a case study. Results show that it has the ability to do rapid design and optimization of PV water pumping system by reducing the power peak and selecting the proper devices from both technical and economic viewpoints. Among the different alternatives considered in this study, the AC fixed system represented the best cost effective solution.
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| 19. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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Economic analysis of photovoltaic water pumping irrigation systems
- 2013
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Konferensbidrag (refereegranskat)abstract
- Irrigation through photovoltaic water pumping (PVWP) system represents one of sustainable and attractivesolutions regarding the problems related to the Chinese grassland desertification. This paper is to investigatethe economics of PVWP systems taking in consideration of the key parameters affecting the sizing, and furtherthe initial capital cost (ICC), the life cycle cost (LCC) and revenues. In particular photovoltaic (PV) modules cost,availability of the well and of the irrigation system, designing water-head, irrigated area and related waterdemand, fuel price and grass production are investigated for the sensitivity analysis. The possibility ofcombining water pumping with electricity production for maximizing benefits is also discussed. Both PVWP anddiesel water pumping (DWP) systems are compared in terms of ICC and LCC. LCC, sensitivity, break-even point(BEP), net present value (NPV) and payback period (PBP) analyses are used to compare and evaluate theeconomic feasibility of the different alternatives investigated. The results show that the availability of the welland the depth of the ground water resources are the most sensitive parameters affecting the initial capitalcosts whereas the grass production and incentives affect mainly the NPV and PBP. The co-benefits for carbonmitigation and carbon credit trading through implementing photovoltaic water pumping system for the Chinesegrassland are also addressed in this paper.
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| 20. |
- Campana, Pietro Elia, et al.
(författare)
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Economic optimization of photovoltaic water pumping systems for irrigation
- 2015
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 95, s. 32-41
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Tidskriftsartikel (refereegranskat)abstract
- Photovoltaic water pumping technology is considered as a sustainable and economical solution to provide water for irrigation, which can halt grassland degradation and promote farmland conservation in China. The appropriate design and operation significantly depend on the available solar irradiation, crop water demand, water resources and the corresponding benefit from the crop sale. In this work, a novel optimization procedure is proposed, which takes into consideration not only the availability of ground-water resources and the effect of water supply on crop yield, but also the investment cost of photovoltaic water pumping system and the revenue from crop sale. A simulation model, which combines the dynamics of photovoltaic water pumping system, groundwater level, water supply, crop water demand and crop yield, is employed during the optimization. To prove the effectiveness of the new optimization approach, it has been applied to an existing photovoltaic water pumping system. Results show that the optimal configuration can guarantee continuous operations and lead to a substantial reduction of photovoltaic array size and consequently of the investment capital cost and the payback period. Sensitivity studies have been conducted to investigate the impacts of the prices of photovoltaic modules and forage on the optimization. Results show that the water resource is a determinant factor.
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| 21. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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Evaluation of the first agrivoltaic system in Sweden
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Photovoltaic (PV) systems in Sweden have primarily been seen as an energy efficiency measure to reduce the amount of purchased electricity for buildings, both residential and commercial. Only recently utility-scale solar systems have begun to increase their share of the solar market to support national energy and emissions targets. Due to the economies of scale, conventional ground-mounted PV (CGMPV) installations represent the best solution for producing electricity at the lowest specific initial investment costs. This relatively new solar market segment, with large-scale ground-mounted solar farms on agricultural land, has faced several challenges with the permitting process. Agricultural land that is suitable for cultivation is of "national importance" according to the Swedish Environmental Code. Cultivable agricultural land may be exploited for other purposes on a permanent basis only if it is necessary to satisfy essential societal interests and there is no other possible land to use within the area in question. Traditionally, ground-mounted solar farms have increased competition for land resources for food production and drawn criticism in the so-called "food-versus-fuel (electricity)" debate over whether agricultural land should be used for electricity generation or food production. Agrivoltaic (APV) systems represent an intelligent solution to avoid land use competition by combining arable farming and electricity production on the same agricultural land. The main objective of this project was to study how APV systems perform from an energy, agricultural and economic perspective compared to CGMPV systems and agriculture production. The project aimed to highlight advantages and disadvantages of APV systems at northern latitudes with an energy-food-water perspective. The aim was pursued by establishing an APV test site, the first APV system in Sweden, monitoring its performance both from an energy and agricultural point of view, and developing new techno-economic models. Data from the APV test site were used to better understand how APV systems at northern latitudes affect: 1) the efficiency of the solar modules; 2) crop productivity, and 3) the financial return for ground-based solar PV systems. The first agrivoltaic system in Sweden has been built on a permanent ley grass field, at Kärrbo Prästgård, Västerås, and research activities have been carried out on the ley grass during 2021 and 2022. As in previous research studies in other countries, we defined three sub-fields: 1) a sub-field is covered only by the ley grass (reference area), 2) a sub-field is a CGMPV system 11.8 kWp solar PV system with two rows of solar modules with a 30° tilt and 3) the last subfield is a 22.8 kWp APV system with three rows of vertically mounted solar modules, with ley grass between the modules. This field set-up allowed for comparisons between practices (agriculture and electricity generation) and technologies (CGMPV systems versus APV systems). The calculated specific electricity production during a typical meteorological year for the APV system and the CGMPV system was 1,067 kWh/kWp/year and 1,116 kWh/kWp/year, respectively. Nevertheless, the APV system tends to have higher efficiency than the CGMPV systems due to the solar irradiation patterns on the solar cell surfaces and wind cooling of the PV modules. The main results of the project in terms of shadow effects on the ley grass showed that the APV system did not significantly affect the productivity of the forage grass in 2021-2022. There was no statistically significant difference between the yield of the samples taken in the APV system and the reference area. Even so, the yield per hectare is reduced by approximatively 10%, when the distance between the vertically mounted solar modules is 10 meters, due to the area under the solar modules that cannot be mechanically harvested. The measurements performed at the test site allowed us to validate the earlier developed model for both electricity production and the effects of shading on crop production. Having a model to assess crop yields under APV systems is of utmost importance to be able to pre-assess the system's effects on food production, which is one of the main goals of APV system regulations worldwide. From an economic perspective, APV systems cannot compete with CGMPV systems due to lower electricity production per hectare, lower density of the solar modules per hectare, and higher investment costs per hectare. Nevertheless, APV systems can be the solution to overcome the legal obstacles that prohibit or hinder the use of agricultural land for electricity generation with PV systems.
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| 22. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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Experimental results, integrated model validation, and economic aspects of agrivoltaic systems at northern latitudes
- 2024
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 437
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Tidskriftsartikel (refereegranskat)abstract
- Agrivoltaic systems, which allow the coexistence of crop and electricity production on the same land, are an integrated water–energy–food nexus solution that allows the simultaneous attainment of conflicting Sustainable Development Goals. This study aims to analyse experimental results on the responses of ley grass yield and quality to shadings in the first agrivoltaic system in Sweden. It also aims to validate an integrated modelling platform for assessing agrivoltaic systems' performances before installation. An economic analysis is carried out to compare the profitability of agrivoltaic versus conventional ground-mounted photovoltaic systems and, using a Monte Carlo Analysis, to identify the parameters that most affect the profitability. Despite the agrivoltaic systems’ supporting structures and photovoltaic modules producing an average ∼25% reduction in photosynthetically active radiation at ground level, no statistically significant difference was observed between the yield of the samples under the agrivoltaic system compared to the yield of the samples in the reference area. The agrivoltaic system attained land equivalent ratios of 1.27 and 1.39 in 2021 and 2022, respectively. The validation results of the integrated modelling platform show that the sub-model concerning the crop yield response to shading conditions tends to underestimate ∼7% the actual average crop yield under the agrivoltaic system. The results of the economic analysis show that, from a net present value perspective, agrivoltaic systems have a profitability that is ∼30 times higher than a conventional crop rotation in Sweden.
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| 23. |
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| 24. |
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| 25. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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Li-ion batteries for peak shaving, price arbitrage, and photovoltaic self-consumption in commercial buildings : A Monte Carlo Analysis
- 2021
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 234
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates the benefits of introducing Li-ion batteries as energy storage unit in the commercial sector by considering a representative building with a photovoltaic system. Only the costs and revenues related to the installation and operation of the battery are considered in this study. The operational strategy of the battery consists in balancing the following processes through day-ahead forecasts for both electricity consumption and photovoltaic production: shaving a targeted peak, performing price arbitrage, and increasing photovoltaic selfconsumption. By reviewing the electricity price cost for commercial buildings from several companies around the world, a general electricity price structure is defined. Afterwards, a Monte Carlo Analysis is applied for three locations with different solar irradiation levels to study the impact of climate, electricity price components, and other seven sensitive parameters on the economic viability of Li-ion batteries. The Monte Carlo Analysis shows that the most sensitive parameters for the net present value are the battery capacity, the battery price, and the component of the electricity price that relates to the peak power consumption. For Stockholm, one of the investigated locations, the corresponding Pearson correlation coefficients are -0.67, -0.66, and 0.19 for the case were no photovoltaic system is installed. For the considered battery operational strategies, the current investment and annual operation costs for the Li-ion battery always lead to negative net present values independently of the location. Battery prices lower than 250 US$/kWh start to manifest positive net present values when combining peak shaving, price arbitrage, and photovoltaic self-consumption. However, the integration of a photovoltaic system leads to a reduced economic viability of the battery by reducing the revenues generated by the battery while performing peak shaving.
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| 26. |
- Campana, Pietro Elia, et al.
(författare)
-
Managing agricultural drought in Sweden using a novel spatially-explicit model from the perspective of water-food-energy nexus
- 2018
-
Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 197, s. 1382-1393
-
Tidskriftsartikel (refereegranskat)abstract
- Using a multi-disciplinary approach, this paper integrated spatial analysis with agricultural and energy system modelling to assess the impacts of drought on crop water demand, water availability, crop yield, and electricity requirements for irrigation. This was done by a novel spatially-explicit and integrated water-food-energy nexus model, using the spatial climatic data generated by the mesoscale MESAN and STRANG models. In this study, the model was applied to quantify the effects of drought on the Swedish irrigation sector in 2013, a typical drought year, for a specific crop. The results show that drought can severely affect the crop yield if irrigation is not applied, with a peak yield reduction of 18 t/ha, about 50 % loss as compared to the potential yield in irrigated conditions. Accordingly, the water and energy requirements for irrigation to halt the negative drought effects and maintain high yields are significant, with the peaks up to 350 mm and 700 kWh per hectare. The developed model can be used to provide near real-time guidelines for a comprehensive drought management system. The model also has significant potentials for applications in precision agriculture, especially using high-resolution satellite data.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Campana, Pietro Elia, et al.
(författare)
-
Optimal grassland locations for sustainable photovoltaic water pumping systems in China
- 2015
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Ingår i: CLEAN, EFFICIENT AND AFFORDABLE ENERGY FOR A SUSTAINABLE FUTURE. - : Elsevier. ; 75, s. 301-307
-
Konferensbidrag (refereegranskat)abstract
- Grassland is of strategic importance for food security of China because of the high number of livestock raised in those areas. Grassland degradation due to climate change and overgrazing is thus regarded as severe environmental and economic threat for a sustainable future development of China. Photovoltaic water pumping (PVWP) systems for irrigation can play an important role for the conservation of grassland areas, halting degradation, improving its productivity and farmers' income and living conditions. The aim of this paper is to identify the technically suitable grassland areas for the implementation of PVWP systems by assessing spatial data on land cover and slope, precipitation, potential evapotranspiration and water stress index. Furthermore, the optimal locations for installing PVWP systems have been assessed using a spatially explicit renewable energy systems optimization model based on the minimization of the cost of the whole supply chain. The results indicate that the PVWP-supported grassland areas show high potential in terms of improving forage productivity to contribute to supplying the local demand. Nevertheless, the optimal areas are highly sensitive to several environmental and economic parameters such as ground water depth, forage water requirements, forage price and CO2 emission costs. These parameters need to be carefully considered in the planning process to meet the forage yield potentials. (C) 2015 The Authors. Published by Elsevier Ltd.
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| 32. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
-
Optimisation of vertically mounted agrivoltaic systems
- 2021
-
Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 325
-
Tidskriftsartikel (refereegranskat)abstract
- Agrivoltaic systems represent a key technology for reaching sustainable development goals, by reducing the competition of land used for food versus land used for electricity. Moreover, agrivoltaic systems are at the centre of the nexus between electricity production, crop production, and irrigation water savings. In this study, an optimisation model for vertically mounted agrivoltaic systems with bifacial photovoltaic modules is developed. The model combines three main sub-models: solar radiation and shadings, photovoltaics, and crop yield. Validation of the sub-models is performed showing good agreement with measured data and commercial software. The optimisation model is set as multi objective to explore the trade-offs between competing agrivoltaic key performance indicators. Oats and potatoes are used as reference crops in this study. The results show that the row distance between bifacial photovoltaic module structures significantly affects the photosynthetically active radiation distribution. The resulting crop yield of oats and potato is reduced by about 50% as row distance decreases from 20 m to 5 m. The implementation of an agrivoltaic system for the investigated crops at the chosen location shows a land equivalent ratio above 1.2, which justifies the use of the technology for reaching national sustainability goals.
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| 33. |
- Campana, Pietro Elia, et al.
(författare)
-
Optimization and assessment of floating and floating-tracking PV systems integrated in on- and off-grid hybrid energy systems
- 2019
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Ingår i: Solar Energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0038-092X .- 1471-1257. ; 177, s. 782-795
-
Tidskriftsartikel (refereegranskat)abstract
- Considering the targets of Thailand in terms of renewable energy exploitation and decarbonization of the shrimp farming sector, this work evaluates several scenarios for optimal integration of hybrid renewable energy systems into a representative shrimp farm. In particular, floating and floating-tracking PV systems are considered as alternatives for the exploitation of solar energy to meet the shrimp farm electricity demand. By developing a dynamic techno-economic simulation and optimization model, the following renewable energy systems have been evaluated: PV and wind based hybrid energy systems, off-grid and on-grid PV based hybrid energy systems, ground mounted and floating PV based hybrid energy systems, and floating and floating-tracking PV based hybrid energy systems. From a water-energy nexus viewpoint, floating PV systems have shown significant impacts on the reduction of evaporation losses, even if the energy savings for water pumping are moderate due to the low hydraulic head. Nevertheless, the study on the synergies between water for food and power production has highlighted that the integration of floating PV represents a key solution for reducing the environmental impacts of shrimp farming. For the selected location, the results have shown that PV systems represent the best renewable solution to be integrated into a hybrid energy system due to the abundance of solar energy resources as compared to the moderate wind resources. The integration of PV systems in off-grid configurations allows to reach high renewable reliabilities up to 40% by reducing the levelized cost of electricity. Higher renewable reliabilities can only be achieved by integrating energy storage solutions but leading to higher levelized cost of electricity. Although the floating-tracking PV systems show higher investment costs as compared to the reference floating PV systems, both solutions show similar competiveness for reliabilities up to 45% due to the higher electricity production of the floating-tracking PV systems. The higher electricity production from the floating-tracking PV systems leads to a better competitiveness for reliabilities higher than 90% due to lower capacity requirements for the storage systems.
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| 34. |
- Campana, Pietro Elia, et al.
(författare)
-
Optimization of a residential district with special consideration on energy and water reliability
- 2017
-
Ingår i: Applied Energy. - : ELSEVIER SCI LTD. - 0306-2619 .- 1872-9118. ; 194, s. 751-764
-
Tidskriftsartikel (refereegranskat)abstract
- Many cities around the world have reached a critical situation when it comes to energy and water supply, threatening the urban sustainable development. From an engineering and architecture perspective it is mandatory to design cities taking into account energy and water issues to achieve high living and sustainability standards. The aim of this paper is to develop an optimization model for the planning of residential urban districts with special consideration of renewables and water harvesting integration. The optimization model is multi-objective which uses a genetic algorithm to minimize the system life cycle costs, and maximize renewables and water harvesting reliability through dynamic simulations. The developed model can be used for spatial optimization design of new urban districts. It can also be employed for analyzing the performances of existing urban districts under an energy-water-economic viewpoint. The optimization results show that the reliability of the hybrid renewables based power system can vary between 40 and 95% depending on the scenarios considered regarding the built environment area and on the cases concerning the overall electric load. The levelized cost of electricity vary between 0.096 and 0.212 $/kW h. The maximum water harvesting system reliability vary between 30% and 100% depending on the built environment area distribution. For reliabilities below 20% the levelized cost of water is kept below 1 $/m(3) making competitive with the network water tariff.
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| 35. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
-
Photovoltaic water pumping systems for irrigation : Principles and advances
- 2022
-
Ingår i: Solar Energy Advancements in Agriculture and Food Production Systems. - : Elsevier BV. - 9780323898669 - 9780323886253 ; , s. 113-157
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Agriculture is one of the most water- and energy-intensive sectors of the economy, consuming about 70% of global freshwater withdrawals. Access to clean and affordable water for irrigation is an essential step towards guaranteeing water and food security, improving incomes and living standards, decarbonizing an energy-intensive sector and attaining the United Nations Sustainable Development Goals (SDGs), in particular SDGs 2 (Zero Hunger), 6 (Clean Water and Sanitation), 7 (Affordable and Clean Energy), and 13 (Climate Action). Ensuring access to water for irrigation, as well as for other agricultural (i.e., livestock watering), domestic, and industrial purposes is a global challenge, and it is more challenging in remote areas where the grid connection is often not available. Solar-powered pumping systems represent a renewable solution for the decarbonization of the irrigation sector worldwide. While solar water pumping systems were used in the past to supply water for irrigation, livestock, and domestic purposes only in remote locations without access to the electric grid, the drastic drop in photovoltaic (PV) modules prices has made the technology also competitive for on-grid applications. This chapter reviews the configurations of solar water pumping systems for irrigation, highlighting the water–food–energy nexus aspects and recent advances, reviewing case studies, and analyzing the economics and current and future challenges.
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| 36. |
- Campana, Pietro Elia, et al.
(författare)
-
PV water pumping for irrigation equipped with a novel control system for water savings
- 2014
-
Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; , s. 949-952
-
Konferensbidrag (refereegranskat)abstract
- Typically, PV water pumping (PVWP) systems for irrigation are normally designed based on the worst conditions, such as high water demand and low solar irradiation. Therefore, the installed PVWP systems become oversized in most of time. Since the conventional control systems don't optimize the water supply, the water losses are increased. To remedy the problems related to the operation of the oversized systems, a novel control system is proposed. The control unit interacts between water demand and water supply in order to pump only the amount required by crops. Moreover, the novel control system substitutes the conventional protection approach with a method based on the ground water resources availability and response. The novel control system represents an innovative solution for water savings in PV watering applications.
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| 37. |
- Campana, Pietro Elia, 1984-
(författare)
-
PV water pumping systems for agricultural applications
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Grassland and farmland degradation is considered as one of the worst environmental and economic threats for China. The degradation process negatively affects food and water security, economy, society and climate changes.Photovoltaic water pumping (PVWP) technology for irrigation is an innovative and sustainable solution to curb the grassland degradation. At the same time it can promote the conservation of farmland, especially in remote areas of China. The combination of PVWP technology with water saving irrigation techniques and sustainable management of the groundwater resources can lead to several benefits. These include enhancing grassland productivity, halting wind and rainfall erosion, providing higher incomes and better living conditions for farmers. This doctoral thesis aims to bridge the current knowledge gaps, optimize system implementation and prevent system failures. This work represents thus a step forward to solve the current and future nexus between energy, water and food security in China, using PVWP technology for irrigation.Models for the dynamic simulations of PVWP systems, irrigation water requirements (IWR) and crop response to water have been presented and integrated. Field measurements at a pilot PVWP system in Inner Mongolia have been conducted to analyse the reliability of the models adopted. A revision of the traditional design approaches and a new optimization procedure based on a genetic algorithm (GA) have been proposed to guarantee the match between IWR and water supply, to minimize the system failures and to maximize crop productivity and thus the PVWP system profitability and effectiveness.Several economic analyses have been conducted to establish the most cost effective solution for irrigation and to evaluate the project profitability. The possible benefits generated by the PVWP system implementation have been highlighted, as well as the effects of the most sensitive parameters, such as forage price and incentives. The results show that PVWP system represents the best technical and economic solution to provide water for irrigation in the remote areas compared to other traditional water pumping technologies. The environmental benefits have been also addressed, evaluating the CO2 emissions saving achievable from the PVWP system operation. The assessment of the feasible and optimal areas for implementing PVWP systems in China has been conducted using spatial analysis and an optimization tool for the entire supply chain of forage production. The results show that the potentials of PVWP systems in China are large. Nevertheless, the feasible and optimal locations are extremely sensitive to several environmental and economic parameters such as forage IWR, groundwater depth, and CO2 credits that need to be carefully taken into account in the planning process. Although this doctoral thesis has used China as case study, PVWP technology can be applied for irrigation purposes all over the world both for off- and on-grid applications leading to several economic and environmental benefits.
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| 38. |
- Campana, Pietro Elia, 1984-
(författare)
-
PV water pumping systems for grassland and farmland conservation
- 2013
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Grassland degradation is considered as one of the worst environmental and economic problems in China because of the negative impacts on water and food security. The application of the photovoltaic water pumping (PVWP) technology for irrigation is an innovative and sustainable solution to curb the progress of grassland desertification and to promote the conservation of farmland in remote areas. The combination of PVWP with water saving irrigation techniques and the sustainable management of the water resources enhances the grass productivity enabling to halt wind and rainfall erosion and to provide higher incomes and better living conditions for farmers. PVWP systems have been used for more than 40 years especially for drinking purposes, livestock watering and irrigation in small-medium size applications. Nevertheless, several knowledge gaps still exist and system failures still occur, which are mainly bounded to the system design procedure and optimization. The technical and economic feasibilities related to the system implementation, especially effectiveness and profitability, need to be addressed. Moreover, irrigation in remote areas constrained by availability of water resources has to be investigated for a better understanding of PVWP system integration with the environment and for optimization purposes. This thesis is to bridge the current knowledge gaps, optimize system implementation and prevent system failures Validation of the models adopted and optimization of the system on the basis of solar energy resources and exploitable groundwater has been performed for a pilot PVWP system in Inner Mongolia. The match between the water supplied through the pumping system and the grass water demand has been studied, and the effects of pumping on the available resources and the crop productivity have been evaluated. The economic analyses have also been conducted in order to establish the most cost effective solution to provide water for irrigation and to evaluate the project profitability. In addition, the CO2 emission reductions by using PV technology have been assessed as well. It was found that the proper designed PVWP system represents the best technical and economic solution to provide water for irrigation in the remote areas compared to other water pumping technologies, such as diesel water pumping and wind power water pumping due to the high positive net present values and short payback periods.
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| 39. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
-
Renewable energies in the context of the water-food-energy nexus
- 2022
-
Ingår i: Complementarity of Variable Renewable Energy Sources. - : Elsevier. - 9780323855273 - 9780323855280 ; , s. 571-614
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The water-food-energy nexus approach was identified by the 2008 World Economic Forum as a key concept and methodology for studying and optimizing the important links among energy, water, and food. Energy, water, and food are basic human needs and are threatened by megatrends such as climate change and population growth. Renewable energies play an important role in the energy-water nexus because their water footprint, except for hydropower and bioenergy, is extremely low as compared to conventional fossil-based energy systems, especially for solar power and wind power conversion systems. Solar power and wind power systems reduce pressure on water resources by allowing for better water management, especially when it comes to conflicts between water for energy versus water for food. Renewable energies also represent a key pathway for combating climate change. This chapter introduces the concept of the water-food-energy nexus and its complex interrelationships and gives particular attention to renewable energies. Subsequently, several water-food-energy nexus aspects related to applications of renewable energies are investigated more deeply, with reference to practical examples. Particular attention will be given to floating photovoltaic systems, photovoltaic water-pumping systems, and agrivoltaics. The chapter concludes with the competition of land for energy versus land for food and on the role of the nexus in renewable-based wastewater systems.
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| 40. |
- Campana, Pietro Elia, et al.
(författare)
-
Spatial optimization of residential urban district - Energy and water perspectives
- 2016
-
Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 88, s. 38-43, s. 38-43
-
Tidskriftsartikel (refereegranskat)abstract
- Many cities around the world have reached a critical situation when it comes to energy and water supply, threatening the urban sustainable development. The aim of this paper is to develop a spatial optimization model for the planning of residential urban districts with special consideration of renewables and water harvesting integration. In particular, the paper analyses the optimal configuration of built environment area, PV area, wind turbines number and relative occupation area, battery and water harvester storage capacities, as a function of electricity and water prices. The optimization model is multi-objective which uses a genetic algorithm to minimize the system life cycle costs, and maximize renewables and water harvesting reliability. The developed model can be used for spatial optimization design of new urban districts. It can also be employed for analyzing the performances of existing urban districts under an energy-water-economic viewpoint. Assuming a built environment area equal to 75% of the total available area, the results show that the reliability of the renewables and water harvesting system cannot exceed the 6475 and 2500 hours/year, respectively. The life cycle costs of integrating renewables and water harvesting into residential districts are mainly sensitive to the battery system specific costs since most of the highest renewables reliabilities are guaranteed through the energy storage system.
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| 41. |
- Campana, Pietro Elia, et al.
(författare)
-
Suitable and optimal locations for implementing photovoltaic water pumping systems for grassland irrigation in China
- 2017
-
Ingår i: APPLIED ENERGY. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 185, s. 1879-1889
-
Tidskriftsartikel (refereegranskat)abstract
- Grassland plays a key role for the food security of China because of the large number of livestock raised in those areas. Thus, grassland degradation due to climate change and overgrazing is considered as one of the most severe environmental and economic threat for the future sustainable development of China. Photovoltaic water pumping systems for irrigation can play a fundamental role for the conservation of grassland areas. This paper investigates the geospatial distribution of the technically suitable grassland locations for the implementation of photovoltaic water pumping systems. The technically suitable grassland areas were taken as starting point to assess the optimal locations. The assessment of the optimal locations was conducted using a spatially explicit optimization model of renewable energy systems based on the cost minimization of the whole forage supply chain. The results indicate that the photovoltaic water pumping systems provide high potential for improving forage productivity, contributing to meet the local demand. The optimal areas are highly sensitive to several environmental and economic parameters such as increased forage potential yield, forage management costs, forage water requirements, ground water depth, forage price and CO2 price. Most of the optimal areas are selected when the market forage price ranges from 300 to 500 $/tonne DM, indicating that the forage produced using PVWP technology for irrigation is already competitive compared to the imported forage.
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| 42. |
- Campana, Pietro Elia, et al.
(författare)
-
Techno-economic feasibility of the irrigation system for the grassland and farmland conservation in China : Photovoltaic vs. wind power water pumping
- 2015
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 103, s. 311-320
-
Tidskriftsartikel (refereegranskat)abstract
- Photovoltaic water pumping (PVWP) and wind power water pumping (WPWP) systems for irrigation represent innovative solutions for the restoration of degraded grassland and the conservation of farmland in remote areas of China. The present work systematically compares the technical and economic suitability of such systems, providing a general approach for the design and selection of the suitable technology for irrigation purposes. The model calculates the PVWP and WPWP systems sizes based on irrigation water requirement (IWR), solar irradiation and wind speed. Based on the lowest PVWP and WPWP systems components costs, WPWP systems can compete with PVWP systems only at high wind speed and low solar irradiation values. Nevertheless, taking into account the average specific costs both for PVWP and WPWP systems, it can be concluded that the most cost-effective solution for irrigation is site specific. According to the dynamic simulations, it has also been found that the PVWP systems present better performances in terms of matching between IWR and water supply compared to the WPWP systems. The mismatch between IWR and pumped water resulted in a reduction of crop yield. Therefore, the dynamic simulations of the crop yield are essential for economic assessment and technology selection. (C) 2015 Elsevier Ltd. All rights reserved.
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| 43. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
-
Towards an operational irrigation management system for Sweden with a water–food–energy nexus perspective
- 2022
-
Ingår i: Agricultural Water Management. - : Elsevier B.V.. - 0378-3774 .- 1873-2283. ; 271
-
Tidskriftsartikel (refereegranskat)abstract
- The 2018 drought in Sweden prompted questions about climate-adaptation and -mitigation measures – especially in the agricultural sector, which suffered the most. This study applies a water–food–energy nexus modelling framework to evaluate drought impacts on irrigation and agriculture in Sweden using 2018 and 2019 as case studies. A previous water–food–energy nexus model was updated to facilitate an investigation of the benefits of data-driven irrigation scheduling as compared to existing irrigation guidelines. Moreover, the benefits of assimilating earth observation data in the crop model have been explored. The assimilation of leaf area index data from the Copernicus Global Land Service improves the crop yield estimation as compared to default crop model parameters. The results show that the irrigation water productivities of the proposed model are measurably improved compared to conventional and static irrigation guidelines for both 2018 and 2019. This is mostly due to the advantage of the proposed model in providing evapotranspiration in cultural condition (ETc)-driven guidelines by using spatially explicit data generated by mesoscale models from the Swedish Meteorological and Hydrological Institute. During the drought year 2018, the developed model showed no irrigation water savings as compared to irrigation scenarios based on conventional irrigation guidelines. Nevertheless, the crop yield increase from the proposed irrigation management system varied between 10% and 60% as compared to conventional irrigation scenarios. During a normal year, the proposed irrigation management system leads to significant water savings as compared to conventional irrigation guidelines. The modelling results show that temperature stress during the 2018 drought also played a key role in reducing crop yields, with yield reductions of up to 30%. From a water–food–energy nexus, this motivates the implementation of new technologies to reduce water and temperature stress to mitigate likely negative effects of climate change and extremes. By using an open-source package for Google Earth®, a demonstrator of cost-effective visualization platform is developed for helping farmers, and water- and energy-management agencies to better understand the connections between water and energy use, and food production. This can be significant, especially during the occurrence of extreme events, but also to adapt to the negative effects on agricultural production of climate changes.
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| 44. |
- Ceran, Bartosz, et al.
(författare)
-
PV systems integrated with commercial buildings for local and national peak load shaving in Poland
- 2021
-
Ingår i: Journal of Cleaner Production. - : ELSEVIER SCI LTD. - 0959-6526 .- 1879-1786. ; 322
-
Tidskriftsartikel (refereegranskat)abstract
- A reduction of demand for electrical power in peak periods, commonly called peak shaving, is beneficial for customers from the economic point of view. However, it is also of considerable importance for the National Power System operation in terms of grid stability. This research focuses on the issue of nationwide potential of peak shaving by PV installations in office buildings in Poland. It is assumed that this sector can play a significant role in decreasing the demand for peak power on a large scale. The modelling of office building load was conducted with the use of an Artificial Neural Network. The study took into consideration different tilt and orientation configurations of PV modules as well as their degradation. The impact of peak shaving on the National Power System was assessed on the basis of the monthly peak load balancing factor. The influence of PV installations on grid infrastructure was estimated based on changes in transformer lifetime. The research showed that the optimum PV capacity for an average office building was approximately 600-800 kW(p) with a south orientation and tilt angle of 30 degrees. The highest peak shaving capacity on the country level is observed for PV systems with a south-east orientation. 273.75 MWp in PV capacity reduces the maximum national load by 200 MW in May. The analysed PV system producing electricity for self-consumption, can prolong the lifetime of the overloaded transformer connected to the office building by up to 36%.
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| 45. |
- Chen, Silan, et al.
(författare)
-
Interaction relationship between urban domestic energy consumption and water use - a case study of Beijing and Shanghai
- 2016
-
Ingår i: Water Policy. - : IWA Publishing. - 1366-7017 .- 1996-9759. ; 18:3, s. 670-684
-
Tidskriftsartikel (refereegranskat)abstract
- Energy consumption and water use are inextricably linked. Combining research on energy consumption and water use in an urban context provides a scientific basis for the integrated planning of energy and water supply systems. Domestic energy and water are among the most consumed resources in urban environments. Furthermore, domestic resources represent an increasing proportion of the total resources consumed. This paper explores four key indicators of urban energy consumption (UEC) and water use in Beijing and Shanghai for the period of 2000 to 2011. Using correlation analysis, this study establishes the intrinsic relationship between UEC and water use. It also offers an analysis of the consumption trends of these two resources as well as their interactive relationship. The results show that urban domestic energy consumption (UDEC) and water use have a significant linear correlation: UDEC is positively correlated with water use, and the correlation coefficients of Beijing and Shanghai are 0.81 and 0.97, respectively. In Beijing, urban domestic energy and water use per capita are negatively correlated, with the high correlation coefficient of 0.93. In Shanghai, urban domestic energy and water use per capita are positively correlated, with the correlation coefficient of 0.90.
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| 46. |
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| 47. |
|
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| 48. |
- Daraei, Mahsa, 1991-, et al.
(författare)
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Impacts of integrating pyrolysis with existing CHP plants and onsite renewable-based hydrogen supply on the system flexibility
- 2021
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 43
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The share of renewable energy sources in the primary energy use is increasing worldwide. Given the intermittency of the energy supply from renewables, it is important to increase flexibility in the system to respond to the imbalances between energy demand and supply. Several flexibility options such as power storage and energy integration are currently in use, mostly at small scales. The increased energy supply from renewables and the flexibility solutions can influence the production planning of existing thermal energy conversion plants. In this study, integration of energy technologies including a hydrotreated pyrolysis oil production integrated with existing CHP plants is investigated as a flexibility solution. The system interacts with potential power generation from rooftop PV systems integrated with power-to-hydrogen storage. A cost-optimization model is developed using MILP method. The study focuses on the system flexibility and operational strategy of the existing CHP plants considering market trends, climate changes, and future energy developments with increased penetration of heat pumps and electric vehicles but less fossil fuels use. The results indicate that the suggested integrated system can increase the local energy supply by 33 GWh. Moreover, the power-to-hydrogen storage and onsite hydrogen use can increase the share of renewables in energy supply by 6%. Optimization of the developed scenarios for future energy-related changes indicates that the market trends could significantly reduce the performance of the system by 21% but increase the penetration of renewables in the system by 8%. Overall, scenario analysis shows the potential of using such a polygeneration system for flexible energy supply including existing CHP plants.
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| 49. |
- Daraei, Mahsa, 1991-, et al.
(författare)
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Power-to-hydrogen storage integrated with rooftop photovoltaic systems and combined heat and power plants
- 2020
-
Ingår i: Applied Energy. - Oxford : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 276
-
Tidskriftsartikel (refereegranskat)abstract
- The growing share of intermittent renewable energy sources for power generation indicates an increasing demand for flexibility in the energy system. Energy storage technologies ensure a balance between demand and supply and increase the system flexibility. This study investigates increased application of renewable energy resources at a regional scale. Power-to-gas storage that interacts with a large-scale rooftop photovoltaic system is added to a regional energy system dominated by combined heat and power plants. The study addresses the influence of the storage system on the production planning of the combined heat and power plants and the system flexibility. The system is modeled and the product costs are optimized using the Mixed Integer Linear Programming method, as well as considering the effects on CO2 emissions and power import into the regional system. The optimization model is investigated by developing different scenarios for the capacity and cost of the storage system. The results indicate that the proposed storage system increases the system flexibility and can reduce power imports and the marginal emissions by around 53%, compared with the current energy system. There is a potential to convert a large amount of excess power to hydrogen and store it in the system. However, because of low efficiency, a fuel cell cannot significantly contribute to power regeneration from the stored hydrogen. Therefore, for about 70% of the year, the power is imported to the optimized system to compensate the power shortfalls rather than to use the fuel cell.
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| 50. |
- Daraei, Mahsa, 1991-
(författare)
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Production Planning of CHP plants in transition towards energy systems with high share of renewables
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The global energy system is undergoing a transformative change towards renewable energies. The share of Renewable Energy Sources (RES) and bioenergy in the world’s primary energy use has increased in the recent years. Based on the EU Roadmap 2050 energy plan, the share of renewables in final energy use in Europe will reach at least 55%, a 45% increase from its share today.Due to the intermittent energy supply from renewables, their high penetration in energy systems can jeopardize the system flexibility, in terms of the balance between energy demand and supply. Lack of system flexibility could cause energy curtailments, increase system costs, or make renewables unreliable sources of energy. Moreover, the expansion of the renewable energy supply could influence the operational strategy of existing energy systems like Combined Heat and Power (CHP) plants. Therefore, the current study focuses on increasing system flexibility of a CHP-dominated regional energy system with increased renewable power supply. Two flexibility options, including a polygeneration strategy and large-scale energy storage using power-to-gas technology, were modelled. The system is then optimized using a Mixed Integer Linear Programming (MILP) method to investigate the production planning of CHP plants in a renewable-based energy system with higher level of flexibility. Different technical and market factors could influence the results of the optimization model, and thereby system flexibility. Thus, the study is carried out under various scenarios for better understanding of the future challenges regarding energy supply, market prices, and climate change.The investigation provides an increased knowledge of production planning for the existing CHP plants with increased interaction with renewables. Based on the overall observations of this thesis, the proposed power storage system contributes to the increased system flexibility. However, the study suggests polygeneration and integration strategy as the optimal pathway to increase RES penetration and to support system flexibility, considering future energy developments and changes in energy demand and supply.
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