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As more countries progress towards renewable energy, intermittency in the power system is causing an unreliable power supply. Flexibility solutions from prosumers, which both consume and produce electricity, is one solution to provide stability to the power system. Households with both PV and energy storage are studied for this purpose in this thesis where the following flexibility services for both a household and the electricity grid of Sweden are studied: Increasing PV self-consumption, peak shaving, energy arbitrage at the day-ahead electricity market and providing the frequency regulation reserves FCR-N, FCR-D, aFRR and mFRR. Each house is assumed to have a 10 kW PV capacity and a battery capacity of 7.68 kWh. The services are studied in the software HOMER Grid and are modelled in different scales to see how the load in different aggregated levels affect the services. The case studies are a single family house, an overloaded transformer, an energy community and on a national scale. For the aggregated case studies, the potential capacity for PV will be based on the existing Swedish policies and the number of energy storages will be inspired by one the leading countries in Europe in energy storage installations, Germany. The results showed that for a single household the self-consumption and self-sufficiency increased the most with an addition of a battery. The battery was most efficient in peak shaving and reducing the overall electricity cost when the electricity fee targeted both the electricity consumption during peak hours and the monthly peaks. With this price scheme, the payback time of the battery and PV system is around 14 years. However, when the electricity fee is only targeting the electricity consumption during peak hours, the results showed that the monthly electricity demand peaks actually increase with an addition of a battery. For the aggregated case studies, it showed that decentralized batteries are not as effective in decreasing the electricity demand peaks if the peak lasts more than a few hours. On a national scale the results show that 20% of the aggregated batteries capacity is sufficient to provide around 70-100% of each of the frequency reserves individually. The highest savings are gained for the households when both the primary frequency reserves, FCR-N and FCR-D, are provided by the aggregated batteries together with increasing the PV self-consumption, peak shaving and energy arbitrage. The battery payback time is then reduced to 11 years. Based on a sensitivity analysis, the costs that affects the battery payback the most are the investment cost and the power fee. / I takt med att fler länder använder sig mer av förnybar energi, ökar opålitligheten i kraftsystemet på grund av förnybar energis intermittenta natur. Flexibilitetslösningar från konsumenter som kan både producera och konsumera el är en lösning för att förse stabilitet till kraftsystemet. Hushåll med både PV och batteri studeras för detta ändamål i detta examensarbetet där följande flexibilitetstjänster för både hushållet och elnätet studeras: Öka egenkonsumtionen av solel, kapning av effekttoppar, energiarbitrage samt tillhandahålla frekvensregleringens reserver FCR-N, FCR-D, aFRR och mFRR. Varje hus antas ha en 10 kW installerad kapacitet för PV och 7.68 kWh för batteriet. Tjänsterna studeras i programmet HOMER Grid och modelleras i olika skalor för att undersöka hur elkonsumtionen i aggregerade nivåer påverkar dessa tjänster. Fallstudierna är ett enskilt hus, en överbelastad transformator, en samling av hus samt i nationell skala. För de aggregerade fallstudierna kommer den potentiella kapaciteten för PV baseras på Energimyndighetens målbild för produktion av solel och antalet batterier är inspirerade av ett av de ledande länderna i Europa inom energiinstallationer, Tyskland. Resultaten visar att för ett enskilt hushåll ökar egenförbrukningen och självförsörjningen som mest med både batteri och PV. Batteriet var mest effektiv med att minska effekttopparna och den totala elkostnaden när eltariffen innehöll både effekttariffen och tidstariffen. PV systemet med batteriet hade då en återbetalningstid på 14 år. Med endast tidstariffer visar resultatet att de månatliga effekttopparna ökar med tilläggen av batteriet. För de aggregerade fallstudierna visar resultatet att decentraliserade batterier inte är lika effektiva att minska effekttopparna om de varar mer än några timmar. På nationell skala visar resultaten att 20% av den sammanlagda batterikapaciteten är tillräcklig för att förse cirka 70–100% av varje frekvensreserv. Den högsta besparingen för hushållen för den nationella fallstudien fås när både av de primära frekvensreserverna, FCR-N och FCR-D tillhandahålls av de aggregerade batterierna, tillsammans med tjänsterna för att öka PV-konsumtionen, kapning av effekttopparna och energiarbitrage. Batteriets återbetalningstid reduceras då till 11 år. Känslighetsanalysen visar att de kostnader som påverkar batteriets återbetalning mest är investeringskostnaden och effekttariffen.

Eritrea is experiencing difficulties as a result of its low rate of electricity, together with its expanding population and the significance of green energy in today's world. Due to poor infrastructure and capacity, Asmara's electricity grid is well known for being unreliable, with frequent power outages and load shedding. Due to its location in an area with high solar irradiance, Asmara has a lot of potential for PV. Using a reference hotel building that is based on a case study of a current construction project in the capital Asmara, this thesis has chosen to analyze if implementing PV systems with storage can produce sustainable electricity for residential homes in Asmara. Through a study visit to the current construction project, a load profile is designed. The reference hotel building's 96 apartments had an average daily energy consumption of 1828 kWh and a peak power demand of 207 kW based on the designed load profile. The PV system results showed that none of the PV systems was feasible or economical to implement on the reference hotel building. The PV-hydrogen system required less inverter capacity than the PV-battery system, however the PV-battery system was less expensive and needed less installed PV capacity. The COE for the PV-battery and PV-hydrogen systems was 580 respectively 226 times bigger than Eritrea's existing COE, which is not feasible from an economic standpoint. Additionally, both systems' installed PV capacities were greater than the maximum possible capacity on the reference hotel building.

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The aim of this Master Thesis is to find the most suitable amount of photovoltaic (PV) panels to sustain an off-grid thermal energy storage (TES) system and to compare a maximum power point tracker (MPPT) with a pulse width modulator (PWM) in order to analyze which one of them that best suits the system. The purpose is to provide feedback on the design of the electrical part of the system in order to make it suitable for testing in a school in an Uganda refugee camp. This is done by developing a simulation model and by performing an economical analysis of the system. Additionally, visits to the considered refugee camps are done. The results are based on data from the camps and interviews at the Physics department at Makerere University and consider the number of meals cooked by the TES as well as economical profitability and payback time. The recommended amount of PV panels is nine and the recommended controller is an MPPT. The simulation shows that the system reaches a point where an increasing number of panels doesn't increase the number of cooked meals by much. The economic analysis shows that this small increase is not enough to make up for the extra costs of adding more PV panels. Having a lower cost, PWM is preferred in the early years by the economic analysis. However, having a low efficiency, it is less superior to the MPPT. The payback time and revenue are better for the MPPT in the investigated cases. It is important to consider that the model doesn't show reality to a full extent. Experiments are made where it is found that the model is inaccurate on an hourly level but can be considered valid over longer periods of time. When choosing the results, a trade-off is made between maximizing the revenue or shortening the payback time of the TES system. Considering rough circumstances and the uncertain future of the camps existence, short payback time is chosen. This results in nine panels being the optimum amount. However, if the aim is to maximize revenue, twelve panels are better than nine. The price of firewood is a factor of uncertainty which this study relays a lot on and it's thereby important to consider when reading the results. Suggestions for future studies are to investigate the price development of firewood further or to test the use of stones in the thermal storage tank to decrease costs. Additionally, possible utilization of surplus produced energy from the system could be investigated in order to find extra benefits from the installation.

Green ammonia production has been an important topic that is being researched during the last decades due to the increasing demand and to cut down CO2 emissions. One of the promising pathways to achieve green chemical energy synthesis is the Photoelectrochemical (PEC) approach. To realize low-cost and scalable green ammonia production, the direct integration of solar photovoltaic modules and catalysts as a Photovoltaic-Electrochemical (PV-EC) system is highly suitable. In this study, Molybdenum Carbide(Mo2C) decorated with different metal nanoparticles (Pt, Pd, Ru) is being investigated as a potential nitrate reduction (NO3RR) to ammonia. Here various metal-decorated M o2C was successfully synthesized by the chemical reduction method. The metal-decorated M o2C is characterized by Transmission Electron Microscopy(TEM), Raman Spectroscopy, and X-ray diffraction(XRD) analysis and confirmed the formation. Initially, electrocatalytic NO3RR was carried out, and Pt decorated Mo2C was found to demonstrate high Faradic efficiency and NH3 of 30% and 4400 μg/h/cm2. Next, PV-EC was carried out, and a stable solar-powered NO3RR was carried out with Pt-M o2C and Si PV module. The proposed system delivers a yield of 600 ug/h/cm2 and a Faradic Efficiency of 7% .

The growing popularity of photovoltaic (PV) generation systems leads to an increase in the number of residential and commercial grid-tied PV systems that interconnect to the distribution circuit. This affects the characteristics of the distribution circuit; for example, the assumption that the voltage profile of a radial line decreases down-stream becomes invalid because of the addition of the PV system on the line. This poses new challenges when setting the parameters of voltage regulating devices. Add to that the fact that PV systems are intermittent, especially on cloudy days, which make the line even more difficult to regulate, and the number of switching occurrences of the regulating devices increases, thus accelerating wear-and-tear to the utility’s equipment. The objective of this thesis is to develop an index which qualitatively indicates the impact of PV system(s) on operation, efficiency, reliability, and lifetime of voltage regulation equipment. Tests on the proposed index will be performed on several cases including circuits containing state-of-the art methods that integrate PV systems with minimum impact to utility equipment. Investigation of methods to further mitigate equipment wear by selecting the best interconnect point on the circuit will also be conducted to test the proposed index. The development and validation of the proposed index will entail power system modeling and simulation of distributed generation using PSCAD. The proposed index resulted from this study will provide a useful tool to allow utility companies pick the optimum locations for distributed generation to minimize their negative impact on the distribution lines as well as to determine the need for extra mitigation equipment.

This research investigates the demographic and local government permit characteristics of communities with high levels of solar adoption in the San Diego Region. Utilizing a statistical model, this research illustrates which communities have been able to benefit from the current solar incentive programs in a robust market with an abundant solar resource. In San Diego, zip codes with large proportions of people over 65 have the highest correlation with high levels of residential solar adoption. This potentially illustrates that the life changes associated with retiring, including accumulated wealth, stable homeownership, and a fixed income, make residential solar systems accessible and appealing. Moving forward solar policy should expand to better facilitate installations for renters, sharing between neighbors, and clear pathways to retrofit older homes.

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