This bachelor thesis investigates the implementation of a solar panel and battery storage system in a Swedish church that is intermittently heated focusing on its economic effect and its environmental impact in terms of CO2 emissions. The models are developed to evaluate the costs and CO2 emissions associated with power production, storage, usage and installation of the implemented system. The thesis examines two cases: Case 1, where all the energy is bought from the grid, representing the current energy usage in many churches, and Case 2 which assumes the integration of a solar panel and battery storage system. In terms of economic effects, the thesis reveals that the solar panel and battery storage system results in a negative impact on the church’s costs regarding energy usage. Over a period of 25 years, the church is projected to incur a loss of 956 400 SEK. However, it is worth noting that the direct energy costs when having an implemented solar panel and battery storage system are reduced by 33%, and the sale of surplus solar power generates an income of 1 816 100 SEK. Regarding the environmental impact, the implementation of the solar panel and battery storage system results in increased emissions compared to when only consuming the Swedish electricity mix. This is mainly due to the emissions regarding manufacturing of the solar panel and battery storage system. However, it is visible that the implementation of solely solar panels would lower the system’s total CO2 emissions. The sensitivity analysis demonstrates that replacing the Swedish electricity mix with the EU electricity mix for sold solar energy results in a positive environmental impact. This since the power generated from the solar panels replaces the European electricity mix which has a higher CO2- emission equivalent. This is important to consider since it is impossible to determine which electricity mix the sold PV energy will replace. In conclusion, while the implementation of a solar panel and battery storage system negatively affects the church’s energy costs and leads to increased CO2 emissions in the examined case, there are certain benefits to consider. The reduced energy bought from the grid and lowered direct energy costs, as well as the revenue from selling surplus solar power establishes the potential for the system to provide a positive impact. However, there is a need for advancements in battery technology for this to be a possibility.

This paper presents a mathematical sizing algorithms of a stand alone and grid-connected photovoltaic-battery system for a residential house. The objective is to minimize the total storage capacity with cost of electricity. The proposed methodology is based on a Linear and Non-linear programming involving a real data collected through one year with reference to Hradec Kralove meteorological data and typical load profile in Czech Republic. The algorithm jointly optimizes the sizes of the photovoltaic and the battery systems by adjusting the battery charge and discharge cycles according to the availability of solar resource and a time-of-use tariff structure for electricity. The results show that jointly optimizing the sizing of battery and photovoltaic systems can significantly reduce electricity imports and the cost of electricity for the household. However, the optimal capacity of such photovoltaic battery varies strongly with the electricity consumption profile of the household, and is also affected by electricity and battery prices.

This paper presents a mathematical sizing algorithms of a grid-connected photovoltaic-battery system for a residential house. The objective is to minimize the total storage capacity with cost of electricity. The proposed methodology is based on a Linear and Non-linear programming. We have presents results from a existing PV panel FS-4115-3 for the given climatic conditions and the electricity use profile. Measurements for whole household electricity consumption have been obtained over a period of two months. They were all obtained at one hour interval. The algorithm jointly optimizes the sizes of the photovoltaic and the battery systems by adjusting the battery charge and discharge cycles according to the availability of solar resource and a time-of-use tariff structure for electricity. The results show that jointly optimizing the sizing of battery and photovoltaic systems can significantly reduce electricity imports and the cost of electricity for the household.

This paper examines the possibility of adding a photovoltaic(PV) power station to an already planned wind park in terms of profitability. At this time, southern Sweden’s grid is facing a number of challenges and is hurting economic development. Hybrid parks have showed to be able to tackle some of those challenges. This study has used a two-scaled methodology to analyse which solar PV size is the optimal to be co-located to the wind park of 24MW[Office1] . The results show that the 21MW size is the ideal one. In addition, to complement the findings, an analysis has been conducted to determine which battery size would be the optimal size to be added to the hybrid system. The results showed that a 1MW/1MWh battery storage would be the ideal size, however, it is possible that a 5MW/MWh battery storage might produce better results if peak shaving is included. All the scenarios in this study have been analysed in terms of IRR.

Wind resources are highly intermittent and fluctuant, making wind turbines less reliable and the unstable power output will affect grid stability and security. This paper presents an idea of integrating the solar PV plant and energy storage system into an existing wind project, project Rödene in Gothenburg. The hybrid renewable system, which consists of two or more renewable energy sources, is considered the renewable energy development trend. An economic analysis of a 1.2 MW PV plant, 5 MW lithium-ion battery storage system and 300 kg hydrogen fuel cell storge system are assessed in terms of LCOE and LCOS of plants. The revenue stream is discussed separately, consisting of electricity tariff, ancillary services and energy arbitrage. The results show that both PV plant and energy store systems are unprofitable. When the PV panel cost is reduced more than 30% and the annual production increases at least 30%, the LCOE of the PV plant arrives at the break-even point. Also result shows the hydrogen fuel cell energy storage system is too expensive of commercial use, and the battery energy storage system has a high potential of profitable if the ancillary service in Sweden is well organized in the future

Distributed generators (DGs) with integration of renewable resources (RRs) such as photovoltaic (PV) and wind turbine have been widely considered to reduce the dependency on conventional power generation systems along with enhancement of the quality and sustainability of the power system. Recently, DC microgrid has gained popularity in many real-world applications such as rural electrification due to its simplicity and low power losses. However, the power variability of renewable resources and continuous change in load demand imposes risks of power mismatch in standalone DC systems that increase the chances of stability and reliability issues. Therefore, complementary generation and/or storage systems are coupled with standalone DC microgrid to mitigate the power fluctuations and maintain a power balance in the system. This dissertation presents a power management strategy (PMS) based on model predictive control (MPC) for a standalone DC microgrid. A control scheme for a standalone DC microgrid system with RRs, storage, and load is desired to have the capability of effective power management that maximizes the extraction of energy from renewable generators, minimizes the transients in the system during disturbances, and protects the storage from over/under charging conditions. As a part of the proposed MPC, an optimization problem is formulated to meet the voltage performance in the system with respect to operating conditions and constraints. The proposed PMS uses the ARIMA prediction method to forecast the load and environmental parameters. The predicted parameters are utilized to estimate the future performance of the system by solving the dynamic model of the system, and a cost function is optimized to generate suitable control sequences. This research also presents detailed mathematical models of the considered systems. This dissertation presents an extensive simulation-based analysis of the proposed approach. With the proposed control, maximum utilization of the renewable generators has been achieved, and the DC bus voltage is regulated at nominal value with minimum transients under various load/environmental disturbances. Moreover, the research investigates the proposed MPC based on ARIMA prediction by comparing the performance of different types of prediction methods. The dissertation also measures the effectiveness of the proposed MPC by comparing its performance with a conventional PI controller.

I Sverige läggs stort fokus på omställningen till ett hållbart och klimatneutralt samhälle, där avkarbonisering och elektrifiering av transportsektorn anses avgörande för att minska utsläpp av växthusgaser. En storskalig batteriproduktion i Sverige och i Europa medför nya problem kring hållbarhetsaspekter gällande utvinning av råvara som exempelvis litium, kobolt och nickel. Men även andra problem gällande avfallshanteringen av litiumjonbatterier. Återvinning och återbruk av litiumjonbatterier anses vara en viktig del i strävan mot en cirkulär batteriproduktion. Dock finns svårigheter med implementering av dessa processer på en storskalig marknad gällande ekonomiska, miljömässiga och tekniska aspekter. Syftet med arbetet är att kartlägga för- och nackdelar med återbruk av littiumjonbatterier i kontrast till återvinning av littiumjonbatterier som nått sitt förbruknings- (EoL - End of Life) tillstånd och identifiera viktiga aktörer för marknadsutökning av både återbruk och återvinning av litiumjonbatterier. En litteraturstudie gjordes tillsammans med en intervju med företaget Vattenfall. Genom detta identifierades ekonomiska, tekniska och miljömässiga aspekter gällande återvinning och återbruk av litiumjonbatterier.   Resultatet av rapporten visar att smarta automatiserade dataanalyser (smarta algoritmer som självständigt kan sortera olika typer av batterier, fatta beslut om batteriernas tillstånd och genom användning av sensorer kan mäta och kontrollera temperaturförändringar) krävs för att göra batteriåtervinning och återbruk effektivare, säkrare och mer ekonomiskt lönsamt.  Återbruk av litiumjonbatterier förlänger batteriets livslängd där metaller knyts till batterier under en längre tid och kan hjälpa till att minska flaskhalsproblematiken gällande ohållbar metallutvinning. Återbruk kan vara bättre än återvinning ur miljösynpunkt i exempelvis energilagringsapplikationer kopplade till förnybar energiproduktion. Litiumjonbatteriet står för en stor del av elbilens miljöpåverkan. Återbruk av elbilsbatterier i diverse applikationer kan därför göra att elbilens miljöpåverkan minskar då batteriets miljöpåverkan inte bara knyts till elbilen. Idag anses återvinning mer ekonomiskt lönsam och det finns fler aktörer och ekonomiska incitament för att stärka batteriåtervinning än för batteriåterbruk. / Sweden places a lot of focus on the transition to a sustainable and climate-neutral society, where decarbonisation and electrification of the transport sector are considered crucial to reducing emissions of GHG (greenhouse gas). Large-scale battery production in Sweden and in Europe brings new problems regarding waste management and the demand for raw materials used in the manufacturing of lithium-ion batteries. Recycling and reuse of lithium-ion batteries could be an important part of the effort towards a circular battery production chain. However, there are difficulties in implementing these on a large-scale market when it comes to financial, environmental and technical points of view. The purpose of this report is to map the pros and cons of reusing lithium-ion batteries in contrast to recycling the lithium-ion batteries that have reached their EoL (End of Life) and to identify important actors for both methods. A literature study was made as well as an interview with the company Vattenfall. Through this, economical, technical and environmental aspects regarding recycling and reuse of lithium-ion batteries were identified.  The results of the report show that automated data analysis (smart algorithms that can independently sort different types of batteries) is required to make battery recycling and second-life batteries more efficient, safer and more economically viable. The reuse of lithium-ion batteries has the possibility of extending the battery's lifetime and the metal usage and thereby reducing the bottleneck problem regarding unsustainable metal extraction. Second-life applications of LIBs can be better than recycling from an environmental point of view in, for example, energy storage applications linked to an increase in renewable energy. Reusing electric car batteries in other applications can reduce the electric car's environmental impact from a life cycle perspective. Today, there are more financial incentives to strengthen battery recycling than battery reuse.

蓄電池は携帯機器，電気自動車をはじめ，自然エネルギー有効利用に至るまで広範囲に利用され，その重要性はますます高まっている。これら機器の使用時間や特性は蓄電池の特性に大きく依存することから，電池自体の特性改善に加え，劣化を診断してより効率的に電池を運用することが求められている。本論文は，非線形情報処理を得意とする人工知能を用いた2次電池の劣化診断法を開発し，エネルギーの有効利用に資する技術を確立した。機器動作時の電池電圧・電流波形と電池劣化特性との関連性を，人工知能を用い学習することにより，機器稼働時に電池の劣化を診断することができる。なお，この関連性は非線形で複雑であるが，非線形分析を得意とする人工知能は劣化診断に適している。学習には時間を要するものの，診断は短時間になし得ることから，提案法は稼働時劣化診断に適している。本論文では，この特徴を生かし，電池の等価回路（ECM）を導出し，充電率（SOC），容量維持率（SOH）を推定している。また，本論文では現在産業応用分野で用いられている，リチウムイオン電池，ニッケル水素電池，鉛蓄電池を対象とし，提案法はあらゆる電池使用機器に応用可能である。また，提案法を電池状態監視装置（BMU）や，マイコンなどを用いた組み込みシステムに応用可能とし，実証している。以上のことから，本論文は，新たな蓄電池の劣化診断法の確立し，その有効性を確認している。 / The importance of rechargeable batteries nowadays is increasing from the portable electronic devices and solar energy industry up to the development of new EV models. The rechargeable batteries have a crucial role in the storage system, mostly in mobile applications and transportation, because the period of its usage and the flexibility of the function are determined by the battery. Due to the black box approach of the ANN it is possible to connect the complex physical phenomenon with a specific physical meaning expressed with a nonlinear logic between inputs and output. Using specific input data to relate with the desired output, makes possible to create a pattern connection with input and output. This ability helps to estimate in real time the desired outputs, behaviors, phenomes and at the same time it can be used as a real time diagnosis method. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

Solar energy is resourceful for many purposes, for example, harvesting renewable electricity with photovoltaic (PV) technology. The number of new grid connections of PV is continuously increasing, and the Swedish PV market for residential prosumers is growing. Providing accurate information about PV’s benefits and the installation’s technical details is essential to attract more prosumers to the PV market. One outlet for such information is providers of PV, who are also responsible for the technical details. From a technical perspective, how much of the produced electricity the prosumer can self-consume impacts the profitability of the investment. Higher self-consumption is associated with more savings, and a battery storage system has the potential to increase self-consumption. Two different approaches were used to carry out this thesis. Communication was studied with a qualitative approach, and the technical term self-consumption was analysed quantitatively. A discourse analysis with a pragmatic approach was performed to study what meanings are created when retailers communicate about the two genres within the discourse of PV: the benefits and the technical specifications. Qualitative data used for this part was collected from the websites of PV retailers. The quantitative part involved calculations of self-consumption levels and simulations of a battery storage system in MATLAB using an extensive data set over households with real PV systems. The identified research gap indicates no previous studies on how PV retailers communicate and few studies of self-consumption using data from real systems. The results from the discourse analysis of the benefits showed that some of the central meanings were: “a prosumer's roof is worth money if they can afford the investment”, “PV has a positive environmental impact”, and “adoption of PV is a trend that prosumers should follow”. The central meaning from the analysis of the technical specifications was that “a prosumer does not need to be concerned about the technical aspect of the installation because the company takes care of it”. The results from the quantitative study showed that from the available data, self-consumption was dependent on how the PV system size is matched to the consumption of the household. Depending on the ALR groups, the households had different mean values of self-consumption, whereas the most common group ALR=6 had a mean self-consumption level of 38%. The simulations with battery storage showed that systems with lower initial self-consumption (below 40%) could increase self-consumption faster with increasing battery capacity but could not reach maximum self-consumption values.

Main purpose of the thesis is the creation of a concept a fast-charging station associated with accumulation that uses renewable source. The introduction of the thesis describes a standard that specifies the charge of electric vehicles using direct and alternating current as well. It depicts an overview of using charging connectors. The first part also deals with overview of the technology of renewable sources and exploitation energy storage system for charging station. The second part introduces the theoretical basement for mathematical model of the charging station in Matlab/Simulink. The function of model station is verified by a physical laboratory model. For options verification of the connection station to the distribution net is created simulation of voltage losses in Matlab/Simulink. The thesis shows four 24 hours’ scenarios that have been simulated. According to the assumptions of simulation, the technology of station and connecting component is suggested. Next is the designed energy and financial analysis of the project charging station until 2030.