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  • 1.
    Akbari, Keramatollah
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Impact of Radon Ventilation on Indoor Air Quality and Building Energy saving2009Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Industrial living is caused much people do live and work in closed and confined places; offices and residential buildings. This is why in this new world more fresh air which is generally provided by forced ventilation plays a vital role in living of human being. Furthermore because of many different indoor pollutants, like radon and artificial pollutants, the amount of fresh air and in turn the energy consumption has increased. This energy consumption related to ventilation has reached up to about 30 percent of energy used of building section. So making interaction between indoor air quality (IAQ) and optimization of energy saving is a necessary work.  Radon as a natural pollutant is occurred in environment and in many countries threatens people health whereas is called the second causes of cancer. For reducing radon concentration in residential building at the acceptable level forced ventilation is used usually. Ventilation can improve IAQ but in the other side would increase the energy consumption in building sector and just now the contribution of ventilation exceeds up 50 percent of building sector's share. The aim of this thesis is to study the impact of ventilation on indoor radon by using Computational Fluid Dynamics (CFD) to achieve indoor air quality and energy efficiency. Application of CFD as a new technology, because of its cost and time savings, and on the other side, of its flexibility and precision is  increasingly grown and can be used as a very important and valuable tool for the prediction and measurement of radon distribution in a ventilated building . Currently, measurement techniques and proposed standards and regulations of indoor pollutants and ventilation, particularly related to indoor radon cannot be able to provide a secure, safe and energy efficient indoor climate. This is why the indoor airflow distribution is very complex and with changing building geometry and operation condition, the treatment of air flow pattern, substantially would be changed, whereas the rules are usually independent of the buildings features. Furthermore, the indoor standards and regulations are based on average amount of pollutants in a room, whereas the pollutant distributions aren't identical and are varied throughout the room. Then the current techniques aren't so exactly valuable and acceptable.

    From different methods which is privilege to control pollutants, ventilation method is applicable in existing buildings. Designing effective ventilation can reduce radon concentration to very level low with regarding energy conservation remarks.

     

    This thesis presents results from simulation studies on ventilation and radon mitigation in residential buildings, in view points of indoor air quality and energy savings. The CFD technique is applied to predict, visualize and calculate of mixture radon-air flow. The distribution of indoor radon concentration, air velocity and room temperature also have considered together for achieving indoor air quality and energy saving. The results are also compared with the experimental data and related previous works.

     

    It was found that with increasing ventilation rate, the radon concentration is decreased, but the location of ventilation system is also important. From the simulation results, it is observed that within the ventilated room, there are some zones, which are good for living and somewhere is more polluted. The traditional radon detectors basically show the average value of radon content in 1m­3 of air. That is why detector measuring is not exact and safe.

     

    Simulation results proved that floor heat can be supported ventilation effect and speed up the mixture movement. Floor heating reinforces the buoyancy effect, which is useful to reduce radon content in the floor (seating area) and then lower ventilation rate can be applied.

  • 2.
    Akbari, Keramatollah
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Simulation of Indoor Radon and Energy Recovery Ventilation Systems in Residential Buildings2015Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This study aims to investigate the effects of ventilation rate, indoor air temperature, humidity and using a heat recovery ventilation system on indoor radon concentration and distribution.

    Methods employed include energy dynamic and computational fluid dynamics simulation, experimental measurement and analytical investigations. Experimental investigations primarily utilize a continuous radon meter and a detached house equipped with a recovery heat exchanger unit.

    The results of the dynamic simulation show that the heat recovery unit is cost-effective for the cold Swedish climate and an energy saving of about 30 kWh per  floor area per year is possible, while it can be also used to lower radon level.

    The numerical results showed that ventilation rate and ventilation location have significant impacts on both radon content and distribution, whereas indoor air temperature only has a small effect on radon level and distribution and humidity has no impact on radon level but has a small impact on its distribution.

  • 3.
    Al Hamrani, Emad
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Gibrael, Nemir
    Mälardalen University, School of Business, Society and Engineering.
    Fast determination of fuel/feedstock material properties and composition: By Near infrared (NIR) spectroscopy2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 4.
    Amanatidou, Rebeka
    Mälardalen University, School of Sustainable Development of Society and Technology.
    CFD Measurements of the Cooling Air in a DC-Motor2008Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

     

    The cooling system of a DC-motor is examined in this thesis. A change of direction of the cooling air is desired to prevent the generated coal dust from entering into the windings of the machine. Ultimately this will have a negative effect on the cooling in the machine and the loss of cooling needs to be compensated through other ways. The purpose of this thesis is to work for an improved operational safety and performance of the DC-motor and to make it more competitive in the market. By modelling the interior geometry of the machine and defining the boundaries in the software programs Gambit and FLUENT respectively, the motion and the heat transfer of the airflow could be simulated. The simulation results would give us an understanding of the flow pattern which later could be used to develop design modifications on the cooling system of a DC-motor. In this thesis the main focus lies on creating a simulation model with a sufficiently fine mesh size.

  • 5.
    Andersson, Anna
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Carlsson, Eva-Sara
    Mälardalen University, School of Business, Society and Engineering.
    Structures in Underground Facilities: Analysis of a Concrete Column’s Capacity toWithstand Extraordinary Fire Loads2012Report (Other academic)
    Abstract [en]

    This report presents a Master of Science in Engineering work, carried out at Mälardalen’sUniversity within the research project METRO. The aim for this work was to determineif a concrete column placed close to the tracks at a subway station can withstand theeffect and temperature of a fire in a burning train comparable to the effects and temperaturesthat showed at the full scale test carried out within the METRO project. A literature review was made before a following case study. The results from thiswork show that the column is negligible affected by the fire.

  • 6.
    Andersson, Daniel
    Mälardalen University, School of Business, Society and Engineering.
    Energiuppföljning av verkligt energibehov kontra beräknat för Hälleborgsäldreboende: Sveriges modernaste äldreboende2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In order to reach the 20/20 goals (meaning 20% lower energy consumption until 2020) the energy requirements on buildings must get tougher and tougher. The city of Västerås has from year 2011 set its own energy requirements on all sold estates to 60 kWh/(m2,year). When the city needed to build the new Hälleborgs elderly care center, their aim was to reach this limited energy consumption. Soon, during the planning stage, they changed this requirement to 70 kWh/(m2,year) weighted energy. The reason for this was because they were using two heating systems, one was a electric heat pump and the second was district heating.

    Because of higher average age in the society, the need for more elderly care centers arise even in Västerås. In the spring 2015 Hälleborgs elderly care center was completed and occupied. 2 year after the building was complete, the contractor has to do an energy monitoring and see if the goal 70 kWh/m2 is reached.

    In this bachelor thesis all information will be tested and the aim is to try to make a energy monitoring and figure out what needs to be done to be able to performe the energy monitoring 2017.

    During the work the biggest problem has been to get the right information. The system that should keep all the measured data (Momentum) was found not to have the connection to the building. When we try to pick the data by hand from the building it was not complete.

    So the conclusion is that the building is not ready to energy monitoring jet. This is because the building needs more time to be stable and adjust the technical systems. It also needs more points of energy measurments and flowmeters in order to get the heating water consumption.

    In the electric system first the net owners energy meter is installed, then the building has own meters at each electric central to separate customers consumption from building consumption. When groups of energy is summarized, it is just half of the net owners consumption. This is because some of the energy in the building is not registered. One of the electric energy’s that not is registered is the commercial kitchen, but the difference is to big that it need to be evaluated what’s missed.

  • 7. Andersson, Henny
    et al.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lindmark, Johan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Jansson, Joakim
    Mälardalen University, School of Business, Society and Engineering.
    Suhonen, Anssi
    Savonia University of Applied Sciences, University of Eastern Finland, Finland.
    Jääskeläinen, Ari
    Savonia University of Applied Sciences, University of Eastern Finland, Finland.
    Reijonen, Tero
    Laatikainen, Reino
    Heitto, Anneli
    Hakalehto, Elias
    TECHNICAL REPORT ON PILOT A TESTS IN SWEDEN2015Report (Refereed)
  • 8.
    Andersson, Oskar
    Mälardalen University, School of Business, Society and Engineering.
    Avskiljning av inert material från avfallsbränsle: En fältstudie av förbättrad RDF-produktion på bränsleberedningen i Västerås2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Energy recovery of waste got huge potential of decreasing the greenhouse gas emissions in the world. Combustion in fluidized bed boilers gives high resource efficiency but demands a comminuted fuel with low content of inert (non-combustible) materials, a so called refuse derived fuel (RDF).  A well-functioning separation process as part of the RDF-production allows efficient combustion as well as efficient treatment of the separated materials. The purpose of this degree project is to investigate what factors that influences on the separation of inert material from waste for combustion in a fluidized bed boiler and how the separation can be improved. This is investigated through a field study of a fuel-preparation plant in Sweden. The separation process has been examined visually and by experiments based on sampling and manual sorting of waste fractions. The results show five factors that are assumed to influence on the sorting. Three of them are suggested to be solved by simple constructions. One factor that shows to have a great impact is the input waste to the process which is varying to a large extent. A measure that is suggested to give improved separation is a recurrent check of the RDF quality and the reject quality. Combined with information about the input waste this should be basis for recurrent adjustments of the plant to achieve a more stable quality of the separation output. Another measure that is suggested is to decrease the size of the material flow through the production line. This is suggested since the size of the flow is assumed to have an important impact on the separation. The decrease can be achieved by more evenly distribute the production over time and over the production lines. This will though require a more active planning of the production and minimization of production stops. As part of the work a new wind sifter has also been tested.  The wind sifter show good potential of improving the separation if it would be installed to create a two-step wind sifting. However, since the investment of a new wind sifter implies a high investment, a study of the costs and saving potential is required before the investment can be suggested as a measure. 

  • 9. Andrén, Lars
    et al.
    Persson, Tomas
    Högskolan Dalarna, Energi och miljöteknik.
    Lennermo, Gunnar
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Handbok för kombinerade sol- och biovärmesystem: Teknik - System - Ekonomi2012Report (Other academic)
    Abstract [sv]

    Handboken beskriver olika solfångarkonstruktioner och solvärmekretsens ingående komponenter och ger en grundlig inblick i ackumulatortankens konstruktion och funktion. I boken finns förslag på systemutformning, olika tekniska lösningar och hur systemen bör styras och regleras. Handboken beskriver i första hand utformning-lösning-styrning av kombinationen sol- och pelletsvärme, men tar även upp solvärme i kombination med vedpannor, värmedrivna vitvaror och värmepumpar. Värmesystem med vattenburen värme är utmärkta att kombinera med solvärme, men det är i de flesta fall enklare att få till bra lösningar vid nyinstallation, än vid komplettering av befintlig anläggning. När solvärme och pelletsvärme ska kombineras finns det många alternativ till systemutformning. Det är viktigt att vattenburna pelletssystem utformas korrekt och kombineras på rätt sätt med solvärme för att komforten ska bli hög och elanvändningen låg. Vattenmantlade pelletskaminer med ett vattenburet värmesystem är extra intressant i kombination med solvärme. När eldningen upphör i samband med att värmebehovet avtar kan solvärmen ta över. En generell slutsats är att konventionella svenska pelletspannor med inbyggd varmvattenberedning inte är lämpliga i kombination med solvärmesystem. Den typen av bränslepannor ger komplicerade systemlösningar, höga värmeförluster och det är svårt att åstadkomma en tillräckligt bra temperaturskiktning i ackumulatortanken om varmvattenberedning sker i pannan. Solvärme för varmvattenberedning kan vara ett enkelt och bra komplement till pelletskaminer som genererar varmluft. För solvärmesystem är det viktigt att kraftig temperaturskiktning erhålls när värmelagret laddas ur. Det betyder att ackumulatortankens (eller varmvattenberedarens) nedre vattenvolym ska kylas ner till temperaturer som ligger nära ingående kallvattentemperatur. Ackumulatortankens mellersta del bör kylas till samma temperatur som radiatorreturen. Vid design av solfångarkretsen måste överhettning och stagnation kunna klaras utan risk för glykolnedbrytning eller andra skador på värmebärare eller rörkrets (och andra komponenter i kretsen). Partiell förångning minskar risken för att glykolen skadas då solfångaren når höga stagnationstemperaturer. Solfångarens glykolblandning tillåts koka (förångas) på ett kontrollerat sätt så att endast ånga blir kvar i solfångaren. Vätskevolymen i solfångaren samlas upp i ett större expansionskärl och systemet återfylls när vätskan kondenserar. Dränerande solfångarsystem med enbart vatten är ett möjligt alternativ till konventionella solfångare. De kräver en större noggrannhet vid installationen, så att sönderfrysning undviks. Dränerande systemlösningar är relativt ovanliga i Sverige. Om solfångaren under senhöst-vinter-tidig vår kan arbeta med att förvärma kallvatten från 10 till 20 ºC erhålls en betydligt bättre verkningsgrad på solfångaren (och framför allt ökar värmeutbytet då drifttimmarna ökar väsentligt) än om radiatorreturen (som i bästa fall ligger på temperaturnivån 30 - 40 ºC) ska förvärmas. Därför bör radiatorreturen placeras en bra bit upp från botten i ackumulatortanken och tappvarmvattnet ska förvärmas i en slinga som börjar i tankens botten. Om det finns ett VVC-system måste systemet anslutas på ett speciellt sätt så att ackumulatortankens temperaturskiktning inte störs. En viktig parameter vid ackumulatortankens utformning är att värmeförlusterna hålls låga. Det är viktigt för att klara tappvarmvattenlasten med solvärme under mulna perioder sommartid (men också för att hålla energianvändningen låg). I moderna hus, där ackumulatortanken i regel placeras i bostaden, blir det en komfortfråga att undvika övertemperaturer i det rum där värmelagret placeras. En bra standard på isoleringen (med minimerade värmeförluster) kräver att det finns ett lufttätt skikt över hela isoleringen som dessutom sluter tätt mot röranslutningar. Ofrivillig självcirkulation i anslutande kretsar som kan kyla av och blanda om ackumulatortankens vattenvolym, bör förhindras med backventiler och nedböjning av rören i isolerskiktet eller direkt utanför tanken.

  • 10.
    Arul, A.J.
    et al.
    Indira Gandhi Ctr. for Atom. Res., Kalapakkam, India.
    Chandran, Kumar
    AERB-Safety Research Institute, Kalpakkam 603 102, India.
    Marimuthu, S.
    Indira Gandhi Ctr. for Atom. Res., Kalapakkam, India.
    Singh, O.P.
    Indira Gandhi Ctr. for Atom. Res., Kalapakkam, India.
    The power law character of off-site power failures2003In: Annals of Nuclear Energy, ISSN 0306-4549, Vol. 30, no 14, 1401-1408 p.Article in journal (Refereed)
    Abstract [en]

    A study on the behavior of off-site AC power failure recovery times at three nuclear plant sites is presented. It is shown, that power law is appropriate for the representation of failure frequency–duration correlation function of off-site power failure events, based on simple assumptions about component failure and repair rates. It is also found that the annual maxima of power failure duration follow Frechet distribution, which is a type II asymptotic distribution, strengthening our assumption of power law for the parent distribution. The extreme value distributions obtained are used for extrapolation beyond the region of observation.

  • 11.
    Arul, A.J
    et al.
    Indira Gandhi Centre for Atomic Research, Kalpakkam, India.
    Chandran, Senthil Kumar
    AERB-Safety Research Institute, IGCAR Campus, Kalpakkam, India.
    Athmalingam, S.
    Indira Gandhi Centre for Atomic Research, Kalpakkam, India .
    Singh, O.P.
    Atomic Energy Regulatory Board, Niyamak Bhavan, Anushaktinagar, Mumbai, India .
    Suryaprakasa Rao, K.
    Department of Industrial Engineering, Anna University, Chennai, India .
    Reliability analysis of safety grade decay heat removal system of Indian prototype fast breeder reactor2006In: Annals of Nuclear Energy, ISSN 0306-4549, Vol. 33, no 2, 180-188 p.Article in journal (Refereed)
    Abstract [en]

    The 500MW Indian pool type Prototype Fast Breeder Reactor (PFBR), is provided with two independent and diverse Decay Heat Removal (DHR) systems viz., Operating Grade Decay Heat Removal System (OGDHRS) and Safety Grade Decay Heat Removal System (SGDHRS). OGDHRS utilizes the secondary sodium loops and Steam–Water System with special decay heat removal condensers for DHR function. The unreliability of this system is of the order of 0.1–0.01. The safety requirements of the present generation of fast reactors are very high, and specifically for DHR function the failure frequency should be less than 1E-7/ry. Therefore, a passive SGDHR system using four completely independent thermo-siphon loops in natural convection mode is provided to ensure adequate core cooling for all Design Basis Events. The very high reliability requirement for DHR function is achieved mainly with the help of SGDHRS. This paper presents the reliability analysis of SGDHR system. Analysis is performed by Fault Tree method using "CRAFT" software developed at Indira Gandhi Centre for Atomic Research. This software has special features for compact representation and CCF analysis of high redundancy safety systems encountered in nuclear reactors. Common Cause Failures (CCF) are evaluated by beta-factor method. The reliability target for SGDHRS arrived from DHR reliability requirement and the ultimate number of demands per year (7/y) on SGDHRS is that the failure frequency should be <=1.4E-8/de. Since it is found from the analysis that the unreliability of SGDHRS with identical loops is 5.2E-6/de and dominated by leak rates of components like AHX, DHX and sodium dump and isolation valves, options with diversity measures in important components were studied. The failure probability of SGDHRS for a design consisting of 2 types of diverse loops (Diverse AHX, DHX and sodium dump and isolation valves) is 2.1E-8/de, which practically meets the reliability requirement.

  • 12.
    Aslanidou, Ioanna
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. University of Oxford, Oxford, United Kingdom.
    Rosic, Budimir
    University of Oxford, Oxford, United Kingdom.
    Aerothermal performance of shielded vane design2017In: Journal of turbomachinery, ISSN 0889-504X, E-ISSN 1528-8900, Vol. 139, no 11, 111003Article in journal (Refereed)
    Abstract [en]

    This paper presents an experimental investigation of the concept of using the combustor transition duct wall to shield the nozzle guide vane leading edge. The new vane is tested in a high-speed experimental facility, demonstrating the improved aerodynamic and thermal performance of the shielded vane. The new design is shown to have a lower average total pressure loss than the original vane, and the heat transfer on the vane surface is overall reduced. The peak heat transfer on the vane leading edge-endwall junction is moved further upstream, to a region that can be effectively cooled as shown in previously published numerical studies. Experimental results under engine-representative inlet conditions showed that the better performance of the shielded vane is maintained under a variety of inlet conditions. 

  • 13.
    Aslanidou, Ioanna
    et al.
    Cranfield University, United Kingdom.
    Zachos, Pavlos K.
    Cranfield University, United Kingdom.
    Pachidis, Vassilios
    Cranfield University, United Kingdom.
    Singh, Riti
    Cranfield University, United Kingdom.
    A physically enhanced method for sub-idle compressor map generation and representation2010In: Proceedings of the ASME Turbo Expo, Glasgow, United Kingdom, 2010Conference paper (Refereed)
  • 14.
    Avelin, Anders
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Process Modeling of Combustion and Digesters for On-line Applications2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The use of biomass has increased in recent years due to the efforts to reduce the high emissions of greenhouse gases, primarily carbon dioxide from combustion of fossil fuels. At the same time industrial processes have become more complex because of increased production rates and profitability requirements. A higher degree of automation is needed when the processes are too complex to be handled manually. There is a need to find modeling strategies that can automatically handle the challenges that the conversion of biomass in an industrial process entails, such as operational changes, decreasing component and overall system efficiency, drifting sensors, etc. The objective of this thesis is to develop a methodology for on-line applications in industrial processes. Dynamic process models have been developed for continuous digesters and boilers. Process models have been evaluated for their use in continuous industrial process. Applications that have been studied are monitoring and diagnostics, advanced control and decision support. The process models are designed for on-line simulations. The results shows that the use of mathematical simulation models can improve the use of both process data and process understanding, to achieve improved diagnostics, advanced control and process optimization. In the two examples of industrial processes covered in this thesis, we can see that similar types of models can be used for completely different types of processes, such as pulp digesters and boilers. It also demonstrates the ability to combine soft sensors and hard sensors with physical models to take the information to a higher level of utilization.

  • 15.
    Avelin, Anders
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Skvaril, Jan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Aulin, Robert
    Swedish University of Agricultural Sciences, Sweden.
    Odlare, Monica
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Forest biomass for bioenergy production – comparison of different forest species2014In: / [ed] J. Yan, 2014Conference paper (Refereed)
    Abstract [en]

    Forest biomass is a renewable and sustainable source of energy that can be used for producing electricity, heat, and biofuels. The production of biomass for energy is considered to be an important step in developing sustainable communities and managing greenhouse gas emissions effectively. Biomass properties vary and are commonly associated with plant species. Hence, efficient methods to predict biofuel characteristics will greatly affect the utilization and management of feedstock production. In this paper attempt was made to correlate various chemical characteristics with NIR spectra. Wood chips from various plant species was analyzed for lignin content, heating value, ash content and NIR and the results were evaluated with correlation, PCA and PCR. Initial evaluation showed promising results where chemical components in the wood correlate to NIR spectra. A selection of results will be presented in this paper. Further analysis as well as results from PCA and PCR models will be presented in the full paper version.

  • 16.
    Avelin, Anders
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Widarsson, Björn
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Lilja, Reijo
    VTT, Espoo, Finland.
    Time based data reconciliation and decision support for a CFB boiler2009In: IFAC Proceedings Volumes (IFAC-PapersOnline), 2009 / [ed] Yrjö Majanne, Tampere: Tampere University Press , 2009, 338-343 p.Conference paper (Refereed)
    Abstract [en]

    This paper covers a method for operator decision support, where physical simulation models are used to connect different physical variables to each other. By comparing energy and material balances for a larger process area inconsistencies in single process parts and sensor measurements can be detected, by following the development between single measurements and values predicted from the simulations. This information then can be used as input to e.g. a BN, Bayesian Network, for decision support. The application has been for a CFB boiler at Mälarenergi AB. The simulators have been made in Modelica respectively a more advanced model in APROS.

  • 17.
    Azaza, Maher
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tunis El Manar University, Tunis, Tunisia.
    Tanougast, C.
    Lorraine University, France.
    Fabrizio, E.
    University of Torino, Grugliasco, Italy.
    Mami, A.
    Tunis El Manar University, Tunis, Tunisia .
    Smart greenhouse fuzzy logic based control system enhanced with wireless data monitoring2016In: ISA transactions, ISSN 0019-0578, E-ISSN 1879-2022, Vol. 61, 297-307 p.Article in journal (Refereed)
    Abstract [en]

    Greenhouse climate control is complicated procedure since the number of variables involved on it and which are dependent on each other. This paper presents a contribution to integrate greenhouse inside climate keys parameters, leading to promote a comfortable micro-climate for the plants growth while saving energy and water resources. A smart fuzzy logic based control system was introduced and improved through specific measure to the temperature and humidity correlation. As well, the system control was enhanced with wireless data monitoring platform for data routing and logging, which provides real time data access. The proposed control system was experimentally validated. The efficiency of the system was evaluated showing important energy and water saving.

  • 18.
    Azimoh, C. L.
    et al.
    University of Johannesburg, Department of Quality and Operations Management, Faculty of Engineering and Built Environment, Johannesburg, South Africa.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mbohwa, C.
    University of Johannesburg, Department of Quality and Operations Management, Faculty of Engineering and Built Environment, Johannesburg, South Africa.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Replicability and scalability of mini-grid solution to rural electrification programs in sub-Saharan Africa2017In: Renewable Energy, ISSN 0960-1481, Vol. 106, 222-231 p.Article in journal (Refereed)
    Abstract [en]

    The assessment of off-grid electrification programs in developing countries largely based on mini-grid and solar home system (SHS) has shown that they are faced with low development imparts and sustainability challenges, which has resulted in failure of many projects. This study provides solutions on how to surmount these challenges, leaning on the experience of a hybrid solar-diesel mini-grid at Tsumkwe village in Namibia. It provides analyses of a case study based on empirical evidence from field studies, interviews of representatives of households, public institutions and energy providers. In addition, it investigates the technical challenges and economic impacts of the electrification program. HOMER™ and MATLAB™ models were used in the analysis and investigations. The findings show that despite the challenges, the system has been sustained because it keyed into an existing structure with growth potentials. The progressive tariff system adopted by the government helped to cushion costs and allow low income households in the energy matrix. Adoption of strict maintenance measures, and implementation of energy efficiency measures prior to the commissioning of the program, resulted in the reduction of costs. The success elements identified in this study could be extrapolated in other sub-Saharan African countries if the challenges are properly addressed.

  • 19.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Illuminated but not electrified: An assessment of the impact of Solar Home System on rural households in South Africa2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 155, 354-364 p.Article in journal (Refereed)
    Abstract [en]

    The introduction of the off-grid electrification program in South Africa using the Solar Home System (SHS) was a central component of the government policy aimed at bringing development to un-electrified households. An assessment of the performance of SHS in many countries provided little evidence to support the development impact of the system. The general perception is that the SHS program is wasting government funds and has no hope of achieving the set objectives. Previous scientific reports have concluded that SHS is the most viable technology for bringing about socio-economic development to rural households. Most of these conclusions have been based on one sided arguments and largely on anecdotal evidence. This study provides a pluralistic view of the subject from the perspective of the energy service companies (ESCOs) and the households using the equipment. The development impact of SHS is subjected to scientific analysis by investigating the economic and social dimensions of the program. Additionally, the sustainability of the South African SHS program is assessed by investigating the challenges facing the ESCOs and the households. The study reveals that illumination provided by SHS electricity has profound impact on the livelihoods of rural households. Due to the limited capacity of SHS for productive and thermal use, there are limited direct economic benefits to the households. The associated economic impact is peripheral to the secondary usage of SHS electricity. SHS has improved the productivity of small scale business owners who utilize the light from SHS to do business at night. Irregularities in payment of subsidy funds and energy bills, high operation cost, non-optimal use of SHS, grid encroachment, and lack of customer satisfaction contribute to make the business unsustainable for the ESCOs.

  • 20.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    The burden of shading and location on the sustainability of South African solar home system program2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, 308-313 p.Article in journal (Refereed)
    Abstract [en]

    Most contributions on the issues of sustainability of rural electrification projects have focused on the technology and business models used to drive the projects. The issues of user education and environmental impact on the technology have received little attention, despite the fact that these challenges affect lives of projects after commissioning. The usage pattern of solar home systems (SHS) by most users that placed their solar panels close to obstructing objects, results in shading of the panels, and geographic location of households in the concession areas of the South African SHS program affects the performances of the system. The non-optimal use of SHS is mainly due to lack of user education. Therefore this paper reports on the impact of geographic location and shading of panels on the economics and technical performance of SHS. The study was done by investigating the performance of 75 WP solar panels operated at two sites in South Africa (Upington in Northern Cape Province and Thlatlaganya in Limpopo Province), the performance of an optimized shaded SHS and a non-shaded one was also investigated. The results show that both geographic location and shading compromise the performance of the systems, the energy output of a solar panel located at Upington is increased by 19% and the state of charge of the battery (SOC) increased by 6%, compared to the panel situated at Thlatlaganya village. Also the life span of the battery is increased by about one year. The SOC of the partially shaded SHS is reduced by 22% and loss of power to the load increased by 20%. The geographical location of the SHS concession areas in South Africa and lack of adherence to the manufacturer's installation specification affects the economics of SHS and the energy output vis-a-vis the sustainability of the program due to reduction in life cycle of the batteries. 

  • 21.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    An assessment of unforeseen losses resulting from inappropriate use of solar home systems in South Africa2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 136, 336-346 p.Article in journal (Refereed)
    Abstract [en]

    One of the challenges to the sustainability of the Solar Home System (SHS) electrification program in South Africa is equipment theft. In response to this, communities susceptible to solar panel theft resort to mounting their panels flat on the ground so they can be looked after during the day and taken indoors at night for safe keeping. Other households use their security lights to illuminate their environment and provide security for pole and roof mounted solar panels at night. These actions have consequential effects on the performance of the SHS. Several studies have detected resentment from households regarding the low power quality from these systems. Most scientific contributions on the issue of low power from SHS have focused on the challenges based on the technical designs of the systems. The power losses due to the usage pattern of the system has not received much attention. This study therefore reports on the technical losses as a result of the deviation from the designed and installed specification of the system by the users in order to protect their systems. It also investigates the linkage between the technical and economic losses which affects the sustainability of SHS program. A case study was performed in Thlatlaganya village within Limpopo province in South Africa. Technical analysis using PVSYST solar software revealed that the energy output and performance of the battery is compromised as a result of these practices. Economic analysis indicates that the battery life and the economics of owning and operating SHS are affected negatively. The study recommends solutions to mitigate these losses, and proposes a cost effective way of optimizing the operation of SHS using a Bench-Rack system for mounting solar panels.

  • 22.
    Azimoh, Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering.
    Nehrenheim, Emma
    Mälardalen University, School of Business, Society and Engineering.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering.
    Chowdhury, S.P.
    University of Cape Town.
    Chowdhury, Sunetra
    University of Cape Town.
    Using Renewable Energy Paradigm as a Tool for Sustainable Village Concept (SVC) in Africa2012Conference paper (Refereed)
  • 23.
    Bales, Chris
    et al.
    Högskolan Dalarna, Energi och miljöteknik.
    Nielsen, Christian
    Högskolan Dalarna, Energi och miljöteknik.
    Peréz de la Mora, Nicolás
    SAMPOL Ingeniería y Obras / Palma de Mallorca (Spain).
    Sotnikov, Artem
    Vela Solaris AG, Winterthur (Switzerland).
    Louvet, Yoann
    FSAVE Solartechnik GmbH, Kassel (Germany).
    Bava, Federico
    Technical University of Denmark, Lyngby (Denmark).
    Shantia, Alireza
    University of Innsbruck, Innsbruck (Austria).
    Lennermo, Gunnar
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. WSP, Gothenburg (Sweden).
    Seven Phd Studies on Solar District Heat2014In: Proceedings EuroSun 2014 / ISES Conference Proceedings (2014), ISES , 2014, 652-661 p.Conference paper (Other academic)
    Abstract [en]

    The Solar Heat Integration NEtwork (SHINE) is a European research school in which 13 PhD students in solar thermal technologies are funded by the EU Marie-Curie program. It has five PhD course modules as well as workshops and seminars dedicated to PhD students both within the project as well as outside of it. The SHINE research activities focus on large solar heating systems and new applications: on district heating, industrial processes and new storage systems. The scope of this paper is on systems for district heating for which there are six PhD students, three at universities and two at companies. In addition there is a seventh PhD in a Swedish national research school focused on energy efficiency within district heating networks (Reesbe). The initial work has concentrated on literature studies and on setting up initial models and measurement setups to be used for validation purposes. Some results of these studies are presented in the paper. The PhD students will complete their studies in 2017-18.

  • 24.
    Bartusch, Cajsa
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Visualisering av elanvändning i flerbostadshus: Delrapport inom ELAN Etapp III2011Report (Other academic)
    Abstract [sv]

    Elanvändningen i våra bostäder sker utan närmare eftertanke och reflektion. Återkopplingen avseende hushållens individuella elanvändning är i det avseendet mycket betydelsefull. I dagsläget är dock den förbrukningsinformation som hushållen har tillgång till mycket begränsad, i synnerhet i flerbostadshus. Syftet med projektet Visualisering av elanvändning i flerbostadshus är att utveckla och utvärdera designkoncept för individuell återkoppling till hushåll som bor i lägenhet. Designkoncepten avser en portabel display, en webbaserad statistiktjänst samt grafisk förbrukningsinformation på elräkningen. Det övergripande målet med projektet är en minskad och mer medveten elanvändning i flerbostadshus.

    Utvecklingen omfattar displayens och statistiktjänstens funktioner och gränssnitt samt en ändamålsenlig formgivning av den grafiska återkopplingen på elräkningen. Utvärderingen omfattar de boendes användning och upplevelser av de produkter och tjänster som designkoncepten avser. Projektet genomförs i två etapper, varav den första omfattar utvecklingen av ovan nämnda designkoncept och den andra avser utvärderingen av desamma. Föreliggande rapport avser den första etappen, medan den andra redovisas i samband med slutrapporteringen av projektet.

  • 25.
    Bartusch, Cajsa
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Visualisering av elanvändning i flerbostadshus: Slutrapport inom ELAN Etapp III2011Report (Other academic)
    Abstract [sv]

    Elanvändningen i våra bostäder sker vanligtvis utan närmare eftertanke och reflektion. Återkopplingen avseende hushållens individuella elanvändning är i den meningen mycket betydelsefull. I dagsläget är dock den förbrukningsinformation som hushållen har tillgång till mycket begränsad, i synnerhet i flerbostadshus. Syftet med projektet Visualisering av elanvändning i flerbostadshus har varit att utveckla och utvärdera designkoncept för individuell återkoppling till hushåll som bor i lägenhet. Designkoncepten avser en portabel display, en webbaserad statistiktjänst samt grafisk förbrukningsinformation på elräkningen. Det övergripande målet med projektet har varit att bidra till en mer medveten och därmed effektivare elanvändning i flerbostadshus.Utvecklingen har omfattat displayens och statistiktjänstens funktioner och gränssnitt samt en ändamålsenlig formgivning av den grafiska återkopplingen på elräkningen.

    Utvärderingen har omfattat de boendes användning och upplevelser av de produkter och tjänster som designkoncepten avser. Projektet har genomförts i två etapper, varav den första har omfattat utvecklingen av ovan nämnda designkoncept och den andra har avsett utvärderingen av desamma. Föreliggande rapport avser i första hand den andra etappen, medan resultaten av den första har redovisats i sin helhet i en tidigare delrapport; Elforsk rapport 08:18.

    Den trådlösa displayen tillhandahåller framför allt funktioner med mer eller mindre direkt återkoppling, medan statistiktjänsten och i synnerhet den grafiska förbrukningsinformationen i första hand avser uppföljning av den individuella elanvändningen med längre tidsperspektiv. Både displayen och statistiktjänsten erbjuder även möjligheten att göra jämförelser mellan olika tidsperioder och med liknande hushåll. Traditionella stapeldiagram i kombination med förtydligande färgsymbolik har visat sig vara mycket funktionella och har följaktligen använts i flertalet av designkonceptens gränssnitt. Enkelhet och lättillgänglighet har visat sig vara de viktigaste framgångsfaktorerna i samband med återkoppling till elanvändare.

    Den grafiska förbrukningsinformationen på elräkningen har framstått som viktigast i den bemärkelsen att den utgör den återkoppling som når i särklass flest elkonsumenter. Egenskaperna enkelhet och lättillgänglighet har därför en särskilt avgörande betydelse i det här sammanhanget. Ett förhållandevis avskalat designkoncept har således förordats för ändamålet grafisk förbrukningsinformation på fakturan. Tidsupplösningen motsvarar faktureringsperioderna och grafens staplar representerar med andra ord de faktiska och förväntade månadsförbrukningarna under innevarande år samt i jämförande syfte de faktiska månadsförbrukningarna under föregående år.

    Utvecklingen och utvärderingen av en portabel display har omfattat två olika designkoncept: Interactive Institute’s Energy AWARE Clock och ”Ingenjörsdisplayen”. Namnen härstammar från gränssnittens olika utformningar av förbrukningsinformationen, som i jämförande syfte har varit abstrakt men intuitivt tillgänglig respektive konkret och reell. De användartester som har genomförts i hemmiljö tyder därvidlag på att användarna föredrar en kombination av de båda designkoncepten. För en optimal användning av den här produkten krävs en central placering i hemmet, vilket innebär att yttre egenskaper såsom en tilltalande design har visat sig ha stor betydelse för användarna.Den webbaserade statistiktjänsten, som kallas Energiinfo™, utgör den återkoppling som tillhandahåller flest alternativa tidsupplösningar.

    Förbrukningsinformationen som tillhandahålls på månads- och årsbasis har emellertid visat sig vara bäst lämpade för kontroll och uppföljning av hushållets elanvändning, vilka utgör de vanligaste användningsområdena. Användarnas syften är dock för övrigt högst varierande och möjligheten att anpassa förbrukningsinformationen för deras individuella behov har därför visat sig vara mycket betydelsefull i det här sammanhanget.

    Samtliga designkoncept som studien avser har visat sig vara mer eller mindre ändamålsenliga i den bemärkelsen att de i viss mån bidrar till en ökad medvetenhet om hushållets egen elförbrukning samt ett förändrat beteende i syfte att effektivisera densamma. Inget av designkoncepten har dock framstått som viktigare än det andra i det avseendet, utan den förbrukningsinformation som de olika återkopplingsalternativen tillhandahåller kompletterar snarare varandra. Vidare har inget av designkoncepten visat sig vara idealiskt för uppdelningsåterkoppling, vilket innebär information om hur mycket olika hushållsapparater bidrar till den totala elkonsumtionen och tenderar att vara den förbrukningsinformation som hushållen har störst behov av.

  • 26.
    Bel Fdhila, Rebei
    et al.
    Mälardalen University, School of Business, Society and Engineering. ABB AB, Corporate Research, SE - 721 78, Västerås, Sweden.
    Rahmani, Mohamed Ali
    ABB AB, Corporate Research, SE - 721 78, Västerås, Sweden.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering.
    PREDICTION AND MEASUREMENTS OF THE GAS BUBBLES INDUCED MIXING IN A BIO-REACTOR WATER MODEL2013Conference paper (Other academic)
    Abstract [en]

    Biogas is a fuel gaining increased interest. To be commercially viable the biogas production process needs to be further improved with advanced industrial standards where the technical, economic and environmental aspects are fully considered.

    Understanding fluid dynamics and the microbial reactions in the digestion process is necessary to accurately model and predict the biogas production. In connection with the Swedish company SvenskVäxkraft AB we focus on reactors where part of the produced gas is re-injected at the bottom to generate a strong recirculation with a gas-lift effect with a rising flow in the core. The mixture motion in this type of bio-reactors is entirely induced by the gas.

    Computational fluid dynamics (CFD) is used to study the effect of gas plumes of bubbles in the range smaller than 10mm with a maximum local gas volume fraction lower than 10%. This study shows that considering the appropriate models to account for the added agitation and turbulence by the bubbles improves the prediction of the liquid flow characteristics. Neglecting the induced bubble effect leads to erroneous results where the radial dispersion of the gas concentration, the liquid velocity and the turbulence are significantly underestimated.

    To validate the model we performed local measurements in an experimental facility where a laboratory water-model is equipped with advanced instruments to measure the gas volume fraction as well as the liquid and gas vertical velocities.

    It was found that using the bubble induced turbulence model by Sato et al. [8] with the Tomyami models for the drag and lift forces [3-6], provides predictions in good agreement with the measured quantities.

    This study shows that for such processes where the flow is mainly created by the bubbles presence, the pseudo-turbulence (the turbulence induced by the bubbles) and the bubble size distribution need to be properly considered.

  • 27.
    Berhane, Johanna
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Nor, Hamda
    Mälardalen University, School of Business, Society and Engineering.
    Energieffektivisering och energirelaterade aktiviteter i två sektorer.: En kartläggning av energieffektiviseringsarbeten, drivkrafter och hinder till reducerad energianvändning med perspektiv på företag inom den svenska fastighets- och industrisektorn.2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 28.
    Bhatti, Arslan Iqbal
    Mälardalen University, School of Business, Society and Engineering.
    EVALUATION OF PERFORMANCE OF PV SYSTEMS ON SELECTED BUILDINGS IN VÄSTERÅS2016Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
  • 29.
    Björk, Magnus
    Mälardalen University, School of Business, Society and Engineering.
    COMBINED BOILER WITH TPV2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A TPV-system consists of a hot surface emitting heat radiation on a solar cell with a narrow bandgap.  A unit consisting of a boiler and a TPV-system has been constructed for testing of the performance of TPV cells. The emitter is heated by a fuel consisting of RME-oil. The radiation is collected and concentrated through two reflecting cones formed like a Faberge-egg, with an edge-type optical filter between the cones. The Faberge-egg is treated with electro-polishing in order to obtain a high reflectance of radiation. The edge filter transmits radiation of short wavelengths towards the solar cells and reflects long wavelengths back to the emitter. This increase the temperature of the emitter to prevent the TPV-cells to be overheated. The construction made was working as expected and can be used for further experiments. The performance of the TPV-cells were however very poor because of a low emitter temperature. The main problem was to obtain a good heat transport from the flame to the emitter. It is required that the emitter temperature is considerably increased for justifying a continued work on TPV-systems in combination with boilers.

  • 30.
    Björk, Magnus
    Mälardalen University, School of Business, Society and Engineering.
    ENERGY INVESTIGATION, GÄRTUNA: On the facilities of Astra Zeneca, with suggestions of energy optimizations2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    AstraZeneca is one of the largest biopharmaceutical companies in the world, and one of the facilities they have is located in Gärtuna, Södertälje. The facility itself is very big with a floor area of 560.000m2 and has a complex energy system. Caverion holds a facility management contract at AstraZenca, hence operates some of the energy system. The energy investigation of this thesis is part of the work of Caverion to ensure a sustainable energy system in Gärtuna. The energy investigation will include mapping of the energy distribution, seeking for potential of improvements and carry out suggestions for energy optimizations. The methods used during the investigation was a literature study, interviews with personnel of both Caverion and AstraZenca, study of the energy system and calculations relevant to the field of study.

    The mapping of the energy system includes the heat, steam and cooling distribution. When the mapping of the system was done it was clear that the areas with most potential for improvements were the steam and cooling distribution.The mapping of the steam distribution shows a loss of nearly 46% of the steam at year 2014 and the corresponding cost of about 13,640,000 SEK. Even though the steam distribution showed great potential for improvements, it was found that the work of investigating the system would be too difficult for the scope of the thesis. The cooling distribution however is more accessible and the potential is still high due to low coefficient of performance.

    Two suggestions for energy optimizations were carried out. The first suggestions involves upgraded electric fan motors for some of the cooling towers, and the second suggestion is to modify existing dry coolers in benefit to utilize free cooling during winter period. The fan motor upgrade based on calculations is estimated to result in a yearly energy saving of at least 1526 MWh and a corresponding cost saving of at least 800,000 SEK per year after the pay-off time (9 months). The dry cooler modification based on calculations is estimated to result in a yearly energy saving of 3053 MWh and a yearly cost saving of 2,083,449 SEK after the pay-off period of 5 months.

    The investigation carried out in this thesis is relevant to both Caverion and AstraZeneca as it points out the areas with potential of improvements and also gives suggestions on energy optimizations that will reduce energy consumption and result in energy cost savings.

  • 31.
    Blackman, Corey
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Dalarna University, Falun, Sweden.
    Bales, Chris
    Dalarna University, Falun, Sweden.
    Experimental evaluation of a novel absorption heat pump module for solar cooling applications2015In: Science and Technology for the Built Environment, ISSN 2374-4731, Vol. 21, no 3, 323-331 p.Article in journal (Refereed)
    Abstract [en]

    Given the environmental benefits of utilizing free thermal energy sources, such as waste heat and solar energy for cooling purposes, many developments have come about in thermally driven cooling. However, there are still some barriers to the general commercialization and market penetration of such technologies that are associated with system and installation costs, complexity, and maintenance. In efforts to overcome these limitations, a novel absorption heat pump module has been developed and tested. The module comprises a fully encapsulated sorption tube containing hygroscopic salt sorbent and water as a refrigerant, sealed under vacuum, and within which there are no moving parts. The absorption module consists of two main components, one that alternately functions as an absorber or generator and other that alternates between the roles of evaporator and condenser. The module therefore operates cyclically between a cooling delivery phase and a regeneration phase. Each module has a significant energy storage capacity with cooling delivery phases ranging from 6–10 h in length with temperature lifts between 16◦C and 25◦C. The modules are optimized for integration directly into a solar thermal collector, for roof or fac¸ade installation, for daytime regeneration and night-time cooling delivery. Collector integrated modules would be completely modular maintenance-free absorption heat pumps with similar installation requirements to standard solar thermal collectors. This article describes the test method and performance characteristics of the individual absorption modules. 

  • 32.
    Blackman, Corey
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bales, Chris
    Högskolan Dalarna, Sweden.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Techno-Economic Evaluation of Solar-Assisted Heating and Cooling Systems with Sorption Module Integrated Solar Collectors2015In: INTERNATIONAL CONFERENCE ON SOLAR HEATING AND COOLING FOR BUILDINGS AND INDUSTRY, SHC 2014, 2015, Vol. 70, 409-417 p.Conference paper (Other academic)
  • 33. Blanco, A.
    et al.
    Dahlquist, Erik
    Kappen, J.
    Manninen, J.
    Negro, C.
    Ritala, R.
    Use of modelling and simulation in the pulp and paper industry2006Conference paper (Refereed)
  • 34.
    Boström, Cecilia
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Storleksoptimering av en etanolfabrik för integrering med ENA Energis kraftvärmeverk.: Baserat på en regional energibalans mellan tillgång på etanolbränsle i Enköping kommun och producerad etanol med hjälp av tillgänglig ånga från ENA kraftvärmeverk.2008Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The future of ethanol is depending on good solutions for the production. ENA energy power plant produces electrical power and district heating by heating biofuel. By building an integrated bioenergy plant surplus steam could be used to produce ethanol as fuel to vehicle.

    This would mean that ethanol is produced renewable energy and the energy for the process derives from the surplus of power.  ENA energy, MDH (the University of Mälardalen) and the energy authority has initiated a research project were different bioenergy combinations integrate with existing power plant.  As a part of the project which size an integrated factory should be to gain the best efficiency for the plant was investigated. Consideration will be taken to the cost of the production in order to be competitive to the price of imported ethanol.

     

     

    Etanolens framtid vilar på bra lösningar för framställning.  I ENA energi kraftverk i Enköping produceras el och fjärrvärme genom eldning av biobränsle.  Genom att bygga ett integrerat bioenergikraftverk där skulle man kunna använda överskottsånga till att framställa etanol som fordonsbränsle. Detta skulle innebära att etanolen framställs med ett förnybart bränsle och energin till framställningen kommer från ett överskott på värme.   ENA energi, MDH och energimyndigheten har initierat ett forskningsprojekt där en bioenergiintegrering skall undersökas.  Som del i detta skall här undersökas vilken storlek en integrerad etanolfabrik skall ha för att nå högsta totala verkningsgrad för verket samt om framställningspriset kan konkurrera med importerad etanol.

     

  • 35.
    Budt, M.
    et al.
    Fraunhofer Institute for Environmental Safety, Germany.
    Wolf, D.
    Heliocentris Industry GmbH, Germany.
    Span, R.
    Ruhr-Universität Bochum, Germany.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A review on compressed air energy storage: Basic principles, past milestones and recent developments2016In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 170, 250-268 p.Article in journal (Refereed)
    Abstract [en]

    Over the past decades a variety of different approaches to realize Compressed Air Energy Storage (CAES) have been undertaken. This article gives an overview of present and past approaches by classifying and comparing CAES processes. This classification and comparison is substantiated by a broad historical background on how CAES has evolved over time from its very beginning until its most recent advancements. A broad review on the variety of CAES concepts and compressed air storage (CAS) options is given, evaluating their individual strengths and weaknesses. The concept of exergy is applied to CAES in order to enhance the fundamental understanding of CAES. Furthermore, the importance of accurate fluid property data for the calculation and design of CAES processes is discussed. In a final outlook upcoming R&D challenges are addressed. 

  • 36.
    Budt, M.
    et al.
    Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT, Germany.
    Wolf, D.
    Heliocentris Industry GmbH, R and D Clean Energy Solutions, Germany.
    Span, R.
    Thermodynamics, Ruhr-University Bochum, Germany.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Compressed air energy storage - An option for medium to large scale electricalenergy storage2016In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 88, 698-702 p.Article in journal (Refereed)
    Abstract [en]

    This contribution presents the theoretical background of compressed air energy storage, examples for large scale application of this technology, chances and obstacles for its future development, and areas of research aiming at the development of commercially viable plants in the medium to large scale range.

  • 37.
    Bulut, Mehmet Börühan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    An analysis of the relationship between the energy and buildings sectors in Sweden2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Climate change is one of the global challenges of our time. The energy sector is at the focus of the European efforts to combat climate change as it accounts for 80% of the total greenhouse gas emissions in the European Union. Buildings, on the other hand, represent 40% of the energy use and 33% of the total greenhouse gas emissions in the European Union, giving the buildings sector also a key role in the European climate strategy. There are, at the same time, strong interdependencies between the energy and buildings sectors due to the high amount of energy used by buildings and their rising importance as active components in the future energy systems. These interdependencies do not only influence the investment decisions in the energy and buildings sectors, but also the effectiveness of the European climate strategy. Cooperation between the energy and buildings sectors can create beneficial outcomes for the both sectors as well as the environment. It may also encourage innovation, improve the energy performance of buildings, and help achieve a higher penetration of renewable energy into the energy system.

    This licentiate thesis investigates the relationship between the energy and buildings sector at the inter-company level. Presenting the data collected from interviews and a web survey answered by the energy and buildings sectors in Sweden, this thesis examines the level of cooperation between these two sectors, discusses trust issues between stakeholders, presents the factors that negatively impact cooperation, and provides recommendations for the minimisation of these factors.

    The findings presented in this thesis indicate an insufficient level of cooperation between the energy and buildings sectors in Sweden, to which the following factors have been identified to contribute in a negative a way: district heating monopolies; energy efficiency in buildings; building regulations; self-generation of electricity; and energy use patterns. The emphasis on self-interest by stakeholders within the both sectors appears to create trust issues between stakeholders. Accordingly, shifting the focus from self-gains to mutual gains is deemed necessary to improve the cooperation between the energy and buildings sectors. This, however requires significant changes in current practices and business models. It has been identified that the development of smart energy systems that allow a closer interaction between the energy and buildings sectors through flexible energy supply and use would minimise many of the factors that negatively impact cooperation.

  • 38.
    Bulut, Mehmet Börühan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Building as active elements of energy systems2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Buildings account for approximately 40% of the energy demand and 33% of the total greenhouse gas emissions in the European Union. Accordingly, there are several efforts that target energy efficiency in buildings both at the European and Swedish levels. The role of buildings in climate change mitigation, however, is not limited to energy savings. Buildings are expected to become key elements of the future smart energy systems by supplying and using energy in a more flexible way. Reducing the energy demand in buildings effectively and shifting the role of buildings in energy systems from ‘passive’ consumers to ‘active’ prosumers, however, require close interaction and cooperation between the energy and buildings sectors.

    Based on the data collected from interviews and a web survey, this doctoral thesis investigates the relationship between the energy and buildings sectors in Sweden at the inter-company level, presents key stakeholder views on smart energy features in buildings and investigates the opportunities and barriers for their adoption in Sweden and Hong Kong.

    The results of this thesis suggest a potential for improving the cooperation between the Swedish energy and buildings sectors, which was identified to be influenced by the following factors: district heating monopolies; energy efficiency efforts in the buildings sector; unsuccessful technology-neutrality of the building regulations; self-generation systems in buildings; and energy use patterns. Shifting the focus from self-gains to mutual gains appears crucial to strengthen the inter-sectoral cooperation, as there are several opportunities for achieving mutually beneficial solutions for the two sectors. This would, however, require significant changes in current practices and business models as well as the introduction of new technologies, which would allow for a more flexible energy supply and use. Accordingly, technologies that target flexible energy use in buildings are considered the most important smart energy features in buildings. The current high costs of technologies, such as home automation and smart electrical appliances, however, create the strongest barrier to adoption. Therefore, the introduction of new business and ownership models and the elimination of the institutional and regulatory barriers are crucial to achieve a wide-scale development of smart energy features in buildings. The results from Hong Kong suggest that institutional and regulatory barriers can particularly create strong hinders to the adoption of technologies.

    It is possible to achieve more sustainable energy systems, where buildings are active elements of networks that supply and use energy in a more flexible and ‘smarter’ way. Cooperation between the energy and buildings sectors can play a key role in the adoption of smart energy features in buildings and pave the way for the smart built environment of the future.

  • 39.
    Bulut, Mehmet Börühan
    Mälardalen University, School of Business, Society and Engineering.
    The development of active buildings through renovation – Is it possible?2013Conference paper (Refereed)
    Abstract [en]

    Energy consumption in buildings is an important part of the EU energy policy. Until recently, buildings were considered as passive elements in the electricity network that solely consume electricity. The transformation of the today's grid to a Smart Grid is expected to introduce radical changes to the role of buildings in the energy system. Buildings of today will become an active element in the future electricity network and participate in micro-generation, energy storage, vehicle-to-grid and demand response activities. Sweden constructed a large number of buildings in the 60's and 70's within the so called Million Homes Program, which aimed to provide Swedish citizens with 1 million new living spaces with modern facilities in a 10 years period. Buildings of the program have poor energy efficiencies and are reaching an age where extensive refurbishment emerges as a necessity. Large projects for the renovation of such buildings will be conducted in the future, but there are several barriers to them. Cooperation between building and energy sectors is a necessity for not only refurbishing these buildings to become more energy efficient, but also upgrading them to active buildings. This transformation might require the introduction of new actors and business models to markets.

  • 40. Bulut, Mehmet Börühan
    et al.
    Hills, Peter
    The University of Hong Kong.
    Mah, Daphne
    Baptist University of Hong Kong.
    Stigson, Peter
    Wallin, Fredrik
    A comparative study of key stakeholder views on smart homes in Hong Kong and SwedenArticle in journal (Refereed)
  • 41.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Odlare, Monica
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stigson, Peter
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Buildings in the future energy system: Perspectives of the Swedish energy and buildings sectors on current energy challenges2015In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 107, 254-263 p., Article number 6090Article, review/survey (Refereed)
    Abstract [en]

    Buildings are expected to play a key role in the development and operation of future smart energy systems through real-time energy trade, energy demand flexibility, self-generation of electricity, and energy storage capabilities. Shifting the role of buildings from passive consumers to active players in the energy networks, however, may require closer cooperation between the energy and buildings sectors than there is today. Based on 23 semi-structured interviews and a web survey answered by key stakeholders, this study presents the views of the energy and buildings sectors on the current energy challenges in a comparative approach. Despite conflicting viewpoints on some of the issues, the energy and buildings sectors have similar perspectives on many of the current energy challenges. Reducing CO2 emissions is a shared concern between the energy and buildings sectors that can serve as a departure point for inter-sectoral cooperation for carbon-reducing developments, including the deployment of smart energy systems. The prominent energy challenges were identified to be related to low flexibilities in energy supply and use, which limit mutually beneficial cases, and hence cooperation, between the energy and buildings sectors today.

  • 42.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Buildings as components of smart grids - Perspectives of different stakeholders2014In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, 1630-1633 p.Article in journal (Refereed)
    Abstract [en]

    This paper provides the perceptions of the energy and buildings sectors, municipalities and researchers in Sweden about active buildings that provide smart grid services to their inhabitants. As part of this study, we conducted 23 semi-structured interviews with key stakeholders to present the perspectives of stakeholders that are involved in the development process. Our study shows that there are several barriers to development of active buildings and points out the importance of energy policy mechanisms to support the development. It is necessary to introduce new measures in order to financially encourage the stakeholders and motivate the end-users to invest in smart grid technologies. The elimination of the intersectoral barriers and the promotion of cooperation amongst stakeholders could pave the way for a more efficient and smarter grid.

  • 43.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    The role of buildings in the energy system: Intersectoral barriers to future developments2013In: The role of buildings in the energy system - intersectoral barriers to future developments, 2013Conference paper (Refereed)
    Abstract [en]

    Residential energy consumption has a significant share in the final energy use in Sweden. Despite this relationship, it is hard to say that there is cooperation between the building and energy sectors for energy issues in buildings. In the grid of the future, buildings will no longer be a passive element of the electricity system; instead, they will acquire an active role in the operation of the grid. The cooperation between the building and energy sectors could play a key role for a successful development of smart grid technologies in buildings.In this paper, we describe the Swedish case and analyse the barriers to cooperation between the energy and building companies with the help of interviews with several stakeholders. This study showed that there is a demand for new business models in order to accommodate smart grid developments in buildings. Collective projects and new roles that reduce the power differences and barriers between the two sectors could contribute to the cooperation and support the development of future energy services in buildings.

  • 44.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stigson, Peter
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Cooperation for climate-friendly developments: An analysis of the relationship between the energy and buildings sectors in Sweden2016In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 9, no 2, 353-370 p.Article, review/survey (Refereed)
    Abstract [en]

    Buildings account for more than 40 % of the total energy demand in the European Union (EU). The energy sector is responsible for 80 % of the total greenhouse gas emissions in the EU, of which more than a third are emitted as a result of energy use in buildings. Given these numbers and the large potential for energy savings in buildings, the energy and buildings sectors emerged as key contributors to fulfilling the European climate targets. Effective cooperation between these two key sectors can contribute significantly to the efficacy of the European climate strategy. However, there may be factors that negatively impact the relationship between the energy and buildings sectors and put cooperation in climate-friendly developments at risk. Based on 23 semi-structured interviews and a web survey answered by key stakeholders, this paper provides a snapshot of the current level of cooperation between the energy and buildings sectors in Sweden and identifies factors that impact the interdependencies between the two sectors.

    The findings show that the current business models in energy supply and the regulations in place limit the development of mutually beneficial cases between the energy and buildings sectors. This paper contributes to improved knowledge for policymaking that affects both sectors and highlights issues for further study.

  • 45.
    Bulut, Mehmet
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Odlare, Monica
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stigson, Peter
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Active buildings in smart grids - Exploring the views of the Swedish energy and buildings sectors2016In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 117, 185-198 p.Article in journal (Refereed)
    Abstract [en]

    The development of smart grids is expected to shift the role of buildings in power networks from passive consumers to active players that trade on power markets in real-time and participate in the operation of networks. Although there are several studies that report on consumer views on buildings with smart grid features, there is a gap in the literature about the views of the energy and buildings sectors, two important sectors for the development. This study fills this gap by presenting the views of key stakeholders from the Swedish energy and buildings sectors on the active building concept with the help of interviews and a web survey. The findings indicate that the active building concept is associated more with energy use flexibility than self-generation of electricity. The barriers to development were identified to be primarily financial due to the combination of the current low electricity prices and the high costs of technologies. Business models that reduce the financial burdens and risks related to investments can contribute to the development of smart grid technologies in buildings, which, according to the majority of respondents from the energy and buildings sectors, are to be financed by housing companies and building owners. 

  • 46.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    PV water pumping systems for agricultural applications2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

  • 47.
    Campana, Pietro Elia
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Holmberg, Aksel
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Pettersson, Oscar
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Hangula, A.
    Namibia Energy Institute, Namibia University of Science and Technology, Windhoek, Namibia.
    Araoz, F. B.
    School of Chemical Science & Engineering, KTH Royal Institute of Technology, Teknikringen 42, Stockholm, Sweden.
    Zhang, Y.
    School of Chemical Science & Engineering, KTH Royal Institute of Technology, Teknikringen 42, Stockholm, Sweden.
    Stridh, Bengt
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. ABB AB, Corporate Research, Västerås, Sweden.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. School of Chemical Science & Engineering, KTH Royal Institute of Technology, Teknikringen 42, Stockholm, Sweden.
    An open-source optimization tool for solar home systems: A case study in Namibia2016In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 130, no 15, 106-118 p.Article in journal (Refereed)
    Abstract [en]

    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.

  • 48.
    Campana, Pietro Elia
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Leduc, S.
    IIASA, Laxenburg, Austria.
    Kim, M
    Korea Univ., Seul, Korea.
    Liu, J.
    Beijing Forestry Univ, Peoples R China.
    Kraxner, F.
    IIASA, Laxenburg, Austria.
    McCallum, I.
    IIASA, Laxenburg, Austria.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH Royal Inst Technol, Stockholm.
    Optimal grassland locations for sustainable photovoltaic water pumping systems in China2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, 301-307 p.Article in journal (Refereed)
    Abstract [en]

    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.

  • 49.
    Campana, Pietro Elia
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Leduc, S.
    Int Inst Appl Syst Anal, Laxenburg, Austria..
    Kim, M.
    Korea Univ, South Korea..
    Olsson, A.
    KTH Royal Inst Technol, Stockholm, Sweden..
    Zhang, J.
    Univ Maryland, USA..
    Liu, J.
    Int Inst Appl Syst Anal, Laxenburg, Austria.; South Univ Sci & Technol China, Sch Environm Sci & Engn, Shenzhen 518055, Peoples R China.;Beijing Forestry Univ, Sch Nat Conservat, Peoples R China..
    Kraxner, F.
    Int Inst Appl Syst Anal, Laxenburg, Austria..
    McCallum, I.
    Int Inst Appl Syst Anal, Laxenburg, Austria..
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Suitable and optimal locations for implementing photovoltaic water pumping systems for grassland irrigation in China2017In: APPLIED ENERGY, ISSN 0306-2619, Vol. 185, 1879-1889 p.Article in journal (Refereed)
    Abstract [en]

    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.

  • 50.
    Campana, Pietro Elia
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH Royal Inst Technol, Stockholm, Sweden.
    Techno-economic feasibility of the irrigation system for the grassland and farmland conservation in China: photovoltaic vs. wind power water pumping2015In: Energy Conversion and Management, ISSN 0196-8904, Vol. 103, no 6, 311-320 p.Article in journal (Refereed)
    Abstract [en]

    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.

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