The study sets out to review various literatures concerning photovoltaic/thermal (PVT) modules for the extraction of electricity and heat, it also reviews different PVT collectors as well as their performance. The study provides an understanding of a system that fully supports ecological society by promoting the use of solar modules from a different scope in future global resolutions. Furthermore, it looks into renewable energy in Sweden, solar energy and PVT systems, operational principles of hybrid PVT collectors, PVT applications, PVT market and legal face of PVT in Sweden among others. Among other social benefits, PVT system contributes enormously to energy savings and energy consumption which in turn lowers CO2 emissions. The review shows that PVT modules can provide homes and industries with 100% renewable electricity and heat that is affordable. This paper adopts systematic literature review, as it allows thorough cross-examination of various publications regarding the subject.

<p>Solar electricity is a promising energy technology for the future, and by using reflectors for concentrating solar radiation onto photovoltaic cells, the cost per produced kWh can be significantly reduced. The optical efficiency of a concentrating system determines the fraction of the incident energy that is transferred to the cells and depends on the optical properties of the system components. In this thesis, low-concentrating photovoltaic and photovoltaic-thermal systems with two-dimensional parabolic reflectors were studied and optimised, and a new biaxial model for the incidence angle dependence of the optical efficiency was proposed.</p><p>Concentration of light generally results in high cell temperatures, and the uneven irradiance distribution on cells with parabolic reflectors leads to high local currents and temperatures, which reduce fill-factor and voltage. Cooling the cells by means of water increases the voltage and makes it possible to utilize the thermal energy. The performance of a 4X concentrating photovoltaic-thermal system was evaluated. If operated at 50°C, this system would produce 250 kWh_electrical and 800 kWh_thermal per m² cell area and year. Optical performance can be increased by 20% by using better reflectors and anti-reflectance glazing.</p><p>Low-concentrating photovoltaic systems for façade-integration were studied and optimised for maximum annual electricity production. The optimisation was based on measured short-circuit currents versus solar altitude. Measurements were performed outdoors and in a solar simulator. It was found that the use of 3X parabolic reflectors increases the annual electricity production by more than 40%. High solar reflectance is crucial to system performance but by using a low-angle scattering reflector, the fill-factor and power are increased due to a more even irradiance on the modules.</p><p>Long-term system performance depends on the durability of the components. The optical properties and degradation of reflector materials were assessed using spectrophotometry, angular resolved scatterometry, Fresnel modelling, optical microscopy, and surface profilometry before and after ageing. The degradation of reflectors was found to be strongly dependent on material composition and environmental conditions. Back surface mirrors, all-metal reflectors, and polymer-metal laminates degraded in different ways, and therefore accelerated ageing must be tailored for testing of different types of reflector materials. However, new types of reflector laminates showed a potential for increasing the cost-effectiveness of low-concentrating solar energy systems.</p>

Solar electricity is a promising energy technology for the future, and by using reflectors for concentrating solar radiation onto photovoltaic cells, the cost per produced kWh can be significantly reduced. The optical efficiency of a concentrating system determines the fraction of the incident energy that is transferred to the cells and depends on the optical properties of the system components. In this thesis, low-concentrating photovoltaic and photovoltaic-thermal systems with two-dimensional parabolic reflectors were studied and optimised, and a new biaxial model for the incidence angle dependence of the optical efficiency was proposed. Concentration of light generally results in high cell temperatures, and the uneven irradiance distribution on cells with parabolic reflectors leads to high local currents and temperatures, which reduce fill-factor and voltage. Cooling the cells by means of water increases the voltage and makes it possible to utilize the thermal energy. The performance of a 4X concentrating photovoltaic-thermal system was evaluated. If operated at 50°C, this system would produce 250 kWhelectrical and 800 kWhthermal per m2 cell area and year. Optical performance can be increased by 20% by using better reflectors and anti-reflectance glazing. Low-concentrating photovoltaic systems for façade-integration were studied and optimised for maximum annual electricity production. The optimisation was based on measured short-circuit currents versus solar altitude. Measurements were performed outdoors and in a solar simulator. It was found that the use of 3X parabolic reflectors increases the annual electricity production by more than 40%. High solar reflectance is crucial to system performance but by using a low-angle scattering reflector, the fill-factor and power are increased due to a more even irradiance on the modules. Long-term system performance depends on the durability of the components. The optical properties and degradation of reflector materials were assessed using spectrophotometry, angular resolved scatterometry, Fresnel modelling, optical microscopy, and surface profilometry before and after ageing. The degradation of reflectors was found to be strongly dependent on material composition and environmental conditions. Back surface mirrors, all-metal reflectors, and polymer-metal laminates degraded in different ways, and therefore accelerated ageing must be tailored for testing of different types of reflector materials. However, new types of reflector laminates showed a potential for increasing the cost-effectiveness of low-concentrating solar energy systems.

In Sweden, the residential and industrial energy demand is provided by a significant part of district heating. In a decarbonization plan to reduce the CO2 emissions, the integration of a large-scale solar system in the district heating can be a suitable option. The most used types of collectors are flat plate collectors (FPC), for which efficiency drops at high temperature levels. Parabolic through collectors (PTC) have seen increased interest in later years, due to their higher efficiency at higher temperature levels, which could improve system performance both energetically and economically. A hybrid concept using a combination of FPC and PTC for a solar thermal system has previously been studied for a solar district heating system in Denmark, with the aim to maximize the solar production by operating the solar collectors in the temperature ranges where they excel. The first aim of this thesis was to adapt the hybrid solar system in a district heating system for a Swedish case study and to evaluate if the hybrid optimization studied has similar positive effects in the overall thermal production of the system in Sweden, as it did in Denmark. The second aim of this thesis was to investigate the use of photovoltaic thermal collectors (PVT) instead of FPC for parts of the solar thermal system. With PVT, a single solar collector module allows for simultaneous production of heat and electricity and integration of photovoltaic thermal collectors in the solar assisted district heating could improve the overall performance of the system, both in terms of energy production and economical gain.The study was performed using the simulation tool TRNSYS based on a model developed in a danish case study. It was performed a parametric analysis on the percentage of share of the different types of solar collectors in the total area. The results given from the simulations have been used to carry out an economic evaluation based on the levelized cost of substituted energy, the annual operation and maintenance costs, and the marginal operational cost difference between a conventional district heating system supplied by a boiler only and a solar assisted district heating system. Based on the results found, it has been proved that a greater proportion of parabolic trough collectors in the solar field contribute to a greater production of thermal energy but also to higher expenses in the economy of the project. The best configuration which balanced these two factors was composed by 70 % of flat plate collectors and 30 % of parabolic trough collectors, based on the total area. The integration of photovoltaic thermal has been demonstrated to be not cost-effective for the studied location compared to the optimized ratio of FPC to PTC, mainly due to the high and uncertain price of the new technology. The use of photovoltaic thermal system is not yet widely developed in projects and there are only a few existing projects in operation today. In the future, the development of photovoltaic thermal in solar assisted district heating projects might have a higher realizable economic potential due to the industry learning curve, but more studies will need to be performed on this.

Dans un contexte de lutte contre le réchauffement climatique, le bâtiment est un secteur stratégique du fait de sa forte consommation de chaleur et d’électricité. Le solaire, thermique et photovoltaïque, a de forts atouts pour répondre à cet enjeu avec une compétitivité qui s’accélère. En particulier, le solaire hybride PVT est prometteur avec un double gain : l’extraction de la chaleur sous le module photovoltaïque apporte à la fois un gain de rendement électrique, et un gain de par l’utilisation de cette chaleur pour les besoins du bâtiment. L’état de l’art permet de toucher du doigt la diversité des concepts de solaire hybride, et le PVT plan non survitré à eau a été retenu dans cette thèse. Pour faire face à des problématiques de durabilité et de performance, DualSun a conçu un module hybride avec un échangeur en acier inoxydable directement laminé pendant le process du module photovoltaïque.L’analyse de ces capteurs est faite en Partie I, d’abord avec un modèle 3D de l’échangeur. Ce modèle permet de déterminer des débits minimaux, de quantifier l’intérêt à ne pas isoler les bords du module et de visualiser que la perte de charge pour ce concept est principalement liée aux entrées et sorties du module mais reste tout à fait acceptable. Devant les limitations en termes de périmètre et de temps de calcul de ce modèle 3D, des modèles simplifiés sont proposés et comparés. Les résultats de ces modèles simplifiés corroborent une température de stagnation du concept DualSun de l’ordre de 75°C, ce qui confirme que le design est intrinsèquement résiliant à la surchauffe même en l’absence de besoins. Enfin les performances thermiques sur 9 prototypes avec des variations de composition couche par couche ont confirmé que le modèle est robuste. La puissance thermique(non isolé) est de 758W thermique pour un besoin à 30°C et la puissance photovoltaïque de 250Wc électrique dans des conditions extérieures standards (STC).Une analyse système de ces modules intégrés dans un ensemble complexe est réalisée dans la Partie II. Pour le système dit préchauffage d’eau sanitaire en maison individuelle (CESI), les quatre logiciels PVSyst, PVGis, Polysun, Solo sont comparés au logiciel Trnsys avec les Type 295 et Type 816 qui intègrent les deux modèles simplifiés du module définis dans la partie I. Les modèles physiques de ces logiciels sont cohérents entre eux dans le domaine d’utilisation.Les résultats de ces logiciels utilisés à partir de données statistiques pour la météo et les habitudes de consommation sont comparés à des mesures terrain sur 28 installations CESI hybride chez des particuliers. L’objectif a été de quantifier les erreurs d’estimation des prédictions statistiques par rapport au réel. Si l’écart type sur productible photovoltaïque et les températures maximales atteinte par les modules reliés à l’incertitude sur la météo est faible (environ 10%), l’écart type sur l’estimation du besoin sur la base d’un volume moyen consommé est beaucoup plus forte (de l’ordre de 30%) du fait d’un comportement très irrégulier de consommation chez les particuliers en terme d’heure et de volume de puisage en fonction des jours. Les températures moyennes atteintes au niveau des modules sont supérieures à 45°C pendant la moitié de l’année et permettent un préchauffage effectif du ballon sanitaire. Des couvertures solaires des besoins d’eau chaude de 57-58% sont mesurées près de Lyon.Dans le chauffage d’eau sanitaire collectif en couplage pompe à chaleur (HP+) ou en chauffage piscine (SP), les modèles statistiques permettent une évaluation des productibles du fait d’une stabilité des besoins.En conclusion, le solaire hybride devrait être une technologie clé de la transition énergétique pour les bâtiments dans les années à venir, sa compétitivité avec le vecteur électrique est déjà réelle. La technologie est appelée à évoluer pour réduire ses coûts d’année en année à l’instar du photovoltaïque et renforcer ainsi son positionnement face au gaz. / In the context of the fight against climate change, the building is a strategic sector to address because of its high consumption of heat and electricity. Solar energy, both thermal and photovoltaic, has strong assets to meet this challenge and is becoming more and more cost-competitive. In particular, the PVT hybrid solar is a promising solution with a double advantage: the extraction of heat under the photovoltaic module brings both a gain in electrical efficiency, and a gain by generating heat for the needs of the building. The state of the art demonstrates the diversity of solar hybrid technologies, and this thesis specifically addresses the unglazed flat-plate design with water as the heat transfer fluid. To address sustainability and performance issues, the company DualSun designed a PVT hybrid module with a stainless steel heat exchanger directly laminated during the photovoltaic module process.The analysis of the DualSun collector is done in Part I, first with a 3D model of the exchanger. This model makes it possible to determine minimum flows, to quantify the interest not to insulate the edges of the module and to visualize that the pressure drop for this concept is mainly related to the inlets and outlets of the module but remains acceptable. Given the limitations in terms of scope and calculation time of this 3D model, simplified models are proposed and compared. The results of these simplified models corroborate a stagnation temperature of the DualSun concept of around 75°C, which confirms that the design is intrinsically resilient to overheating even in the absence of hot water consumption. Finally, thermal performance on 9 prototypes with layer-by-layer composition variations confirm that the model is robust. The models demonstrate that the 250Wp non-insulated version of the PVT panel has a thermal power output of 758 Wth for hot water needs at 30°C.A system analysis of these modules integrated in a complex system is carried out in Part II. For the preheating Domestic Hot Water system (DHW), four software programs, PVSyst, PVGis, Polysun, Solo are compared to Trnsys with the Type 295 and Type 816, which integrate the two simplified models of the module defined in the section I. The physical models of these software programs are consistent with each other in the field of use.The results of these software programs used from statistical data for the weather and consumption habits are compared to field measurements on 28 DHW (domestic hot water) hybrid installations in private homes. The objective was to quantify the errors of estimation of the statistical predictions with respect to the reality. While the standard deviation of PV output and maximum temperatures reached by the modules related to the uncertainty on the weather is low (about 10%), the standard deviation of estimated hot water needs based on an average consumption is much higher (about 30%) because of irregular consumption behavior in individuals in terms of time and volume depending on the days. The average temperatures reached at the level of the modules are higher than 45°C during half of the year and allow an effective preheating of the sanitary tank. Solar covering of hot water needs of 57-58% are measured near Lyon.For combined solar and heat pump (HP+) systems in multi-dwelling buildings and for pool heating (SP) systems, statistical models allow a reliable evaluation of the energy production because of stable hot water needs.In conclusion, solar hybrid should be a key technology for the energy transition of buildings in the coming years. PVT technology will evolve to reduce costs from year to year as observed with photovoltaic technology and thus strengthen its cost-competitive position against gas as a heat source for homes and buildings.

In order to reduce emissions from the building sector, which stands for than a fifth of the global energy consumption today, efficient and fossil free heating and cooling systems are of importance. This study investigates the combination of solar photovoltaic thermal collectors and ground source heat pump systems in order to regenerate energy to the ground in combination with free cooling. Research questions investigated was how techno-economically efficient a system with photovoltaic thermal collectors, ground source heat pumps and free cooling in a commercial building is. Moreover, the study evaluates what benefits and challenges such system can have. In addition, Polysun as a modeling tool was evaluated for modeling a system includingthese components. Polysun was used as a model tool to first set up a replication of an existing system in TRNSYS provided by researchers at KTH. The model was then scaled and adjusted with parameters to represent a commercial building using free cooling from Vasakronan, a Swedish property company. Photovoltaic thermal collectors were added to the model of the existing building, with two different configurations, and the heating and cooling demand of the building was varied. The results showed that a configuration with photovoltaic thermal collectors added after the evaporator side of the heat pump generated more energy to the system compared with an installation before the evaporator side of the heat pump. The possibilities of free cooling decreased with increasing number of solar collectors, due to the rise of temperature in the ground. From an economic perspective, photovoltaic thermal collectors are more expensive than photovoltaic modules, since it has an additional cost for the hydraulic system that depends on the building. However, photovoltaic thermal collectors also provide thermal energy that can help balancing borehole systems and reduce the risk for a need of additional drilling. The study performed an uncertainty and sensitivity analysis of the results, showing that the electricity price is the most sensitive parameter to the net present value of investing in photovoltaic thermal collectors. With the electricity price assumed in this study, the net present values were positive for all cases for the given interest rate and lifetime of 25 years. It was also concluded that the modeling tool Polysun has a user friendly interface where energy systems easily can be modeled. In terms of borehole configurations, there is a lack of modeling alternatives which resulted in unexpected temperature rises in the ground for the model. / Byggnadssektorn står idag för mer än en femtedel av den globala energiförbrukningen, där över hälften av energin kommer från fossila bränslen. Därför är det viktigt med effektiva och fossilfria uppvärmnings- och kylsystem för att minska utsläppen, där värmepumpar är ett bra alternativ. Denna studie undersöker kombinationen av termiska solceller och bergvärmepumpssystem i kommersiella fastigheter, med syfte att återladda energi till marken i kombination med frikyla. Syftet var att undersöka hur teknoekonomiskt effektivt ett sådant system är och vilka fördelar samt nackdelar som finns. Dessutom utvärderades modelleringsverktyget Polysun som användes föratt modellera systemen. Arbetet inleddes med att efterlikna ett befintligt system i Polysun från en tidigare studie från KTH som använt modelleringsverktyget TRNSYS. Därefter justerades detta system så att det skulle efterlikna en av Vasakronans byggnader som idag använder bergvärme och frikyla. Tre scenarier konstruerades till basmodellen där samtliga innefattade termiska solceller. Resultaten visade att antalet termiska solceller kunde minska i antal då dessa var kopplade efter förångarsidan av värmepumpen, jämfört med om de är installerade före förångarsidan av värmepumpen. Genom att öka antalet termiska solceller i systemet ökade temperaturen i borrhålen, vilket ledde till en minskad möjlig användning av frikyla. Ur ett ekonomiskt perspektiv är termiska solceller dyrare än solceller som enbart genererar elektricitet, med en extra kostnad för det hydrauliska systemet som även beror på byggnadens utformning. Dock finns det andra fördelar med termiska solceller såsom att de kan hjälpa till att balansera borrhålssystem och minska behovet för att borra ytterligare borrhål. I studien utfördes en osäkerhets- och känslighetsanalys av resultaten, vilken visade att elpriset har stor påverkan på nettonuvärdet av en investering i termiska solceller. Med det elpris som antogs i denna studie var nettovärdet positivt för alla fall med den givna kalkylräntan och livstiden för systemet. Polysun visade sig vara ett modelleringsverktyg med ett användarvänligt gränssnitt där energisystem lätt kan modelleras. När det gäller konfigurationer av borrhål finns det begränsade modelleringsalternativ, där resultaten visade oväntade temperaturstegringar för marken i modellen.

A hybrid photovoltaic/thermal (PVT) collector enables simultaneous electricity and heat production from a single solar module. Integrating PVT collectors with a ground source heat pump (GSHP) improves the seasonal performance of the heating system and prevents from temperature degradation of the ground. However, the integration of PVT and GSHP requires more research, for example, to discover the optimal characteristics of a PVT collector for low operating temperatures and varying weather conditions. Thus, the thermal performance of two commercial unglazed flat-plate PVT collectors was experimentally characterized during low-temperature operation and under dynamic outdoor conditions, including various solar irradiance levels and working fluid flow rates as well as frost formation and condensation on the absorber surface. The thermal performance coefficients were obtained from a simplified version of the ISO 9806:2017 standard steady-state model for solar thermal collectors and used as performance indicators for the tested collectors and for comparison with other PVT collectors found in the literature. During nighttime operation, the PVT collector with a box-channel absorber and the one with a sheet-and-tube absorber have a similar thermal performance, shown as almost the same heat loss coefficients. The effect of flow rate on the heat output of the collectors appears to be negligible when there is no solar irradiance. During humid nights, the heat gains from frost formation and/or condensation on the absorber surface can double the nighttime heat production of the collectors when compared to a dry night with no frost formation or condensation. As the irradiance increases, the box-channel collector starts to outperform the sheet-and-tube collector due to a more effective cooling of the PV module by the box-channel absorber design, which is shown as a higher zero-loss efficiency. The flow rate dependence of the heat output is increased with an increasing irradiance, higher flow rates leading to higher heat outputs. According to the yearly simulations, both tested collectors provide a higher annual heat output under Stockholm weather conditions than the other box-channel and sheet-and-tube collectors available in the Solar Keymark database, when the annual mean fluid temperature is below 7 °C. However, the fin-tube collectors designed for low-temperature heat pump integration outperform the tested collectors on annual basis with mean fluid temperatures below 10 °C. / En solhybrid (PVT) möjliggör samtidig el- och värmeproduktion från en enda solpanel. Att integrera solhybrider med en bergvärmepump förbättrar värmesystemets säsongsprestanda, förhindrar temperatur-nedgång i marken och utgör ett lovande alternativ till luftvärmepumpar. Integrationen av sol-PVT och bergvärmepumpar kräver dock mer forskning, till exempel för att upptäcka de optimala egenskaperna hos en PVT-kollektor, när driftstemperaturerna är låga och väderförhållandena varierar. Därav karakteriserades experimentellt den termiska prestandan hos två kommersiella oglasade PVT-kollektorer under drift vid låg temperatur och under dynamiska utomhusförhållanden, inklusive olika solinstrålningsnivåer och flödes-hastigheter samt frostbildning och kondensation på värmeväxlarens yta. De termiska prestandakoefficienter erhölls från en förenklad version av ISO 9806:2017-standardmodellen för stationärt tillstånd för solfångare och användes som prestandaindikatorer för de testade kollektorerna och för jämförelse med andra PVT-kollektorer som finns i litteraturen. Vid nattdrift har den första PVT-kollektorn med en ”box-channel”-värmeväxlare och den andra kollektorn med en ”sheet-and-tube”-värmeväxlare en liknande termisk prestanda vilket visas av nästan samma värme-förlustkoefficienter. Effekten av massflödet på kollektorernas värmeeffekt verkar vara försumbar, när det finns ingen solinstrålning. Under fuktiga nätter kan värmevinsterna från frostbildning och/eller kondens på värmeväxlarens yta fördubbla kollektorernas värmeproduktion på nattetid jämfört med en torr natt utan frostbildning eller kondens. När instrålningen ökar, börjar ”box-channel”-kollektorn överträffa ”sheet-and-tube”-kollektorn på grund av en mer effektiv kylning av PV-modulen genom den ”box-channel”-värme-växlaren, vilket visas som en högre nollförlusteffektivitet. Värmeeffektens beroende av flödeshastigheten ökar med en ökande solinstrålning: högre flödeshastigheter leder till högre värmeeffekt. Enligt de årliga simuleringarna har de båda testade kollektorerna en högre årlig värmeproduktion under Stockholms väderförhållanden än de andra ”box-channel”- och ”sheet-and-tube”-PVT-kollektorerna, tillgängliga i Solar Keymark -databasen, när den årliga genomsnittliga kylvätsketemperaturen är under 7 °C. Kollektorerna med en ”fin-tube”-värmeväxlare, som är utformade för integration av lågtemperaturvärmepumpar, överträffar dock de testade kollektorerna på årsbasis med genomsnittliga kylvätsketemperaturer under 10 °C.

India is experiencing a bitter challenge in terms of water resources, with the lack of access to safe drinking water being attributed to nearly 200 000 deaths per year. The rural population is especially exposed as groundwater make up 85 % of their drinking water, with widespread contamination being reported. One source of contamination is fluoride, which has been identified in concentrations far beyond the recommended limit from the World Health Organization (WHO), causing severe health problems such as skeletal fluorosis. While India has made significant progress in providing households connections to the grid, electricity access remains unreliable, particularly in rural areas. Membrane distillation (MD) is a thermally driven water purification technology which achieves excellent fluoride reduction rates. Several systems with various combinations of technologies integrated with MD has been researched, where the use of photovoltaic thermal hybrid solar collectors (PVT) and heat pumps (HP) has been receiving increased attention as of late. These two technologies have, to the Author’s best knowledge, never been integrated together for MD, which is the basis of this thesis. With the goal of providing an average of 1000 L of potable water a day, three novel off-grid systems are created using the energy modeling software Polysun with weather data from Balasore, India. Two PVT models and three different HPs identified on the market are considered for the systems. The PVTs differ in terms of glazing, and the HPs have various heating capacities and max water supply temperatures, with one being an air source heat pump (ASHP) and two water source heat pumps (WSHP). One configuration of each combination of PVT and HP is created and optimized in terms of MD modules, battery storage capacity, and feed flowrate, evaluated based on the Key Performance Indicators (KPI) production cost, PVT area, and average daily yield. Furthermore, two different controller strategies are evaluated based on their average daily yield, where one prioritize a high coefficient of performance (COP) for the HP, and the other energy recovery from the MD. The final configurations are thereafter compared based on their production cost. Nine out of the ten final configurations achieve a production cost between 60 - 72 $/m3 after being optimized, which is within the reported range for MD but at the higher end. The larger WSHP achieves the lowest production cost at 60.1 $/m3 paired with the glazed PVT, having a gross area of 323 m2. The glazed PVT performs better than the unglazed for all configurations in terms of both production cost and PVT area. However, the cost of the larger WSHP is based on the $/kW of the smaller WSHP while the two PVTs are assigned an identical $/m2, resulting in the price difference between the products being the determining factor for the actual configuration with the lowest production cost. The lowest PVT area for the final configurations is 294 m2. The required PVT area to reach the production goal is heavily dependent on the amount of MD modules, HP heating capacity and max water supply temperature, and battery storage capacity. Only one configuration achieved a higher yield when energy recovery was prioritized, which supplied 20 % of that system’s thermal energy while not utilizing 61 % of the energy recovery potential. / Indien upplever en bitter utmaning med vattenresurser, där bristande tillgänglighet till säkert dricksvatten är attribuerat nära 200 000 dödsfall per år. Befolkningen på landsbygden är särskilt utsatt då grundvattnet representerar 85 % av deras dricksvatten, som till stor del rapporterats som förorenat. En föroreningskälla är fluorid, vilket har identifierats i koncentrationer långt över den rekommenderade gränsen av World Health Organization (WHO), som leder till allvarliga hälsoeffekter som skelettfluoros. Även fast Indien har gjort stora framsteg inom elnätsanslutningar för hushåll, är elektricitetstillgången opålitligt, speciellt på landsbygden. Membrandestillation (MD) är en värmedriven vattenreningsteknik som uppnår utmärkta reduktionsnivåer av fluorid. Det har forskats om flera system med olika kombinationer av tekniker integrerade med MD, där användningen av hybridsolpaneler (PVT) och värmepumpar (HP) har fått ett ökande intresse på sistone. Dessa två tekniker har, till författarens bästa kännedom, aldrig blivit integrerade tillsammans för MD, vilket är grunden för denna uppsats. Med målet att uppnå en genomsnittlig dricksvattenproduktion på 1000 L per dag, har tre egenartade system skapats i energimodelleringsprogrammet Polysun med väderdata baserad på Balasore, Indien. Två PVT modeller samt tre olika värmepumpar är identifierade på marknaden och implementerade i systemen. PVT modellerna skiljer sig i främst i relation till glasering. Värmepumparna har olika värmekapaciteter samt övre gräns på levererad vattentemperatur, varav en är en luftvärmepump (ASHP) och de två resterande vattenvärmepumpar (WSHP). En konfiguration av varje kombination av PVT och HP skapas och optimeras i relation till MD moduler, batterilagring, och flödeshastighet, som utvärderas med prestandaindikatorerna (KPI) produktionskostnad, PVT yta, samt genomsnittlig dricksvattenproduktion. Två olika kontrollstrategier undersöks även baserat på dricksvattenproduktionen, där en strategi prioriterar en hög prestationskoefficient för HP, och den andra energiåtervinning från MD. De slutliga konfigurationerna jämförs sedan baserat på deras produktionskostnader. Nio av de tio slutliga konfigurationerna uppnår en produktionskostnad mellan 60 - 72 $/m3 efter optimeringen, vilket ligger inom det rapporterade intervallet men på den dyrare sidan. Den större WSHP uppnår den lägsta produktionskostnaden på 60.1 $/m3 i kombination med den glaserade PVT, som omfattar en bruttoarea på 323 m2. Den glaserade PVT presterar bättre än den oglaserad för alla konfiguration sett till produktionskostnad samt PVT area. Dock så är kostnad på den större WSHP baserad på $/kW kostnaden för den mindre WSHP, samt att båda PVT är tilldelade en identisk $/m2 kostnad. Detta leder till att den avgörande faktorn för den faktiska konfigurationen med lägst produktionskostnad är prisskillnaden mellan produkterna. Den lägsta PVT arean för de slutgiltiga konfigurationerna är 294 m2. Den nödvändiga PVT arean för att uppnå produktionsmålet är starkt beroende av mängden MD moduler, batterilagringskapacitet, samt värmekapacitet och övre gräns på levererad vattentemperatur för HP. Endast en konfiguration uppnår en större vattenproduktion när energiåtervinningprioriteras, där 20 % av systemets totala värmeenergi kom från energiåtervinning samtidigt som 61 % av den potentiella energiåtervinningen ej utnyttjas.

The performance of ground-source heat pump (GSHP) systems can be negatively affected over time by soil temperature degradation of boreholes (BH) in heating dominated climates. Land area is scarce in the dense urban environments typical of multi-family houses (MFH) and can lead to accelerated degradation- in tight BH fields. Heat extracted from photovoltaic thermal collectors (PVT) can help with BH regeneration; thus, limiting degradation. Additionally, free cooling (FC) is proposed in this study to tackle the anticipated cooling demandi ncrease in Sweden, while resolving the listed challenges of GSHP systems. A novel multi-source (MS) system integrating FC, PVT and GSHP together shall be investigated in this study. Firstly, implementing FC in a GSHP system for the scenario considered only provided marginal regeneration of the BH in the longterm. Both the SPF4+ and total life cycle cost (TLCC) of an FC+GSHP and GSHPsystem remained virtually constant. Furthermore, operation interference of FC and PVT in the MS system can be mitigated by considering their relative location in the system. In this study, cooling is the priority, thus placing the FC system after the BH field but before the PVT system in the brine loop is recommended. In that case, only 0.56% of the annual cooling is not delivered due to FC operation interference and the PVT thermal yield is decreased on average by 3.52%. By decreasing the BH spacing from 15 to 5 m, a slight SPF4+ increase to 3.22 is possible in a system with FC and 48 PVT collectors. With a sensitivity analysis it was shown that if a 15% decrease is achieved in electricity prices then the TLCC of this system can be lower than the TLCC of 2.13 MSEK for a GSHP system. / Prestandan hos ytjordvärmepump (GSHP) kan påverkas negativt över tid av försämrad marktemperatur i borrhål (BH) i klimat som domineras av uppvärmning. I täta stadsmiljöer med flerfamiljshus (MFH) är markytan knapp, vilket kan leda till accelererad nedbrytning i trånga BH-fält. Värme som utvinns från solfångare (PVT) kan bidra till regenerering av BH, vilket begränsar nedbrytningen. Dessutom föreslås frikyla (FC) i denna studie för att hantera den förväntade ökningen av kylbehovet i Sverige, samtidigt som man löser de listade utmaningarna med GSHP-system. Ett nytt multikällsystem (MS) som integrerar FC, PVT och GSHP tillsammans ska undersökas i denna studie. För det första gav implementeringen av FC i ett GSHP-system för det aktuella scenariot endast marginell regenerering av BH på lång sikt. Både SPF4+ och den totala livscykelkostnaden (TLCC) för ett FC+GSHP och GSHP-system förblev praktiskt taget konstant. Dessutom kan driftstörningar från FC och PVT i MS-systemet minskas genom att ta hänsyn till deras relativa placering i systemet. I denna studie prioriteras kylning, och därför rekommenderas att FC-systemet placeras efter BH-fältet men före PVT-systemet i brineslingan. Endast 0.56% av den årliga kylningen levereras inte på grund av störningar i FC-driften och PVT:s värmeutbyte minskar i genomsnitt med 3.52%. Genom att minska BH-avståndet från 15 till 5 m är en liten ökning av SPF4+ till 3.22 möjlig i ett system med FC och 48 PVT-kollektorer. En känslighetsanalys visade att om elpriserna minskar med 15% kan TLCC för detta system bli lägre än TLCC på 2.13 MSEK för ett GSHP-system.

The thesis work was done as a part of the company's proposal writing work for the Horizon Europe projects, which is the European Union's key funding program for research and innovation with a budget of €95.5 billion. The budget for this project call was €5 million and aimed towards demonstrating the possibilities of Photovoltaic thermal technologies (PVT), which will produce heat and electricity at the same time on agricultural land to combat climate change. The initial stage of the project, which the thesis work corresponds to, consists of the concept of implementing the objectives of the call and demonstrating how it could be achieved by forming a consortium of different companies, allocating the sites, possible applications of the PVT technology, understanding the plants which can grow in the relevant climate conditions under the shading of the panels. There are different companies who participate in the project call and, if they succeed, are liable to demonstrate the objectives of the call under the allocated budget and share the results with the European Union. The thesis work tried to focus on the company's objective for the call, which was to find out the suitable crops to be planted under the integrated PVT greenhouses, details on the weather conditions and applications of heat and electricity on the demonstration sites, i.e., Greece and Portugal. The emphasis was also given to creating a business canvas model and doing the strengths, weaknesses, opportunities, and threats (SWOT) analysis to make a business plan for this project. In this project, an Absolicon X10 PVT collector has been proposed with thermal heat up to 75 ºC and electricity at 230V. The outcomes also showed that each PVT collector integrated into the greenhouse could produce 4.73 MWh/year of thermal energy and can supply 2.2 MWh/year of electrical energy, which can save up to 0.48 tons/year of oil equivalent and avoid 37.6 tons of CO2 emissions during its lifetime of 25 years compared to burning oil. Considering the weather conditions in Greece and Portugal and to make sure the plants do not need much shading, tomatoes, barley and cacao seeds were identified as the potential crops to be planted in the PVT-integrated greenhouses.