In this thesis different methods of energy storage are evaluated for use in multifamily residential buildings in order to increase the self-consumption of self-generated photovoltaic electricity. The computational software MATLAB was used to simulate and study five different energy systems applied on two case studies. The five energy systems are; one reference system consisting of photovoltaics, one system with photovoltaics and a hydrogen storage system, and three systems consisting of photovoltaics and batteries using different management strategies. The different systems were compared based on their effect on the buildings self-consumption ratio and grid interaction as well as system costs and profitability. The battery systems successfully increased the self-consumption ratio and decreased grid interaction. Assuming a favourable development of market conditions, all systems containing batteries were paid back. The battery system that could reduce high consumption peaks during the entire year was the most profitable system as the buildings fixed grid fees could be lowered. The hydrogen storage system increased the self-consumption ratio to a small degree, as much of the electricity was lost in the conversion processes. Also, the components of the hydrogen system are very costly and the investment could therefore not be paid back within the 30 year life-time. Photovoltaics can be used to decrease variable electricity costs while energy storage can be used to decrease both variable and fixed electricity costs. The results suggest that focusing on handling power peaks and leveling grid interaction is more valuable than focusing on increasing self-consumption in multifamily residential buildings. The value of energy storage systems in multifamily residential buildings has been discussed with respect to technology development and changes in market conditions, the conclusion being that the value will most likely increase within the next decade and onward. It is believed that local energy storage systems have an important role to play in a power system with an increasing amount of renewable and intermittent power sources.

This thesis aims first to investigate whether solar panels on the container can provide the process of desalination with energy at the desired location, as well as to dimension a photovoltaic system and battery storage that can run the facility off-grid. Then investigate whether solar cells can be an effective energy solution for Millennium Desalination Device (MDD). The results of this study show that the most annual solar production from containers is 11 510 kWh in Gobabeb, Namibia with a modular efficiency of 22,8 %, which corresponds to 8,2 % operating time per year and is the longest operating time that can be obtained from the all three scenarios. This means that with existing technology and only solar panels on the container, desalination plant is impossible to drive all year round off-grid. The installed power for driving 100 % operating time for one year is 141 kW in Gobabeb and 270 kW in Visby, the corresponding module surface will be lowest 618 m2 and 1184 m2 with modular efficiency of 22,8 %, but there are no additional spaces for all equipment like MDD, solar cells and battery in the container. If the operating time drops to 50 %, the installed power will be 71 kW in Gobabeb, the corresponding module surface will be lowest 415 m2 and battery storage capacity will be at least 160 kWh. Net volume with all equipment will be less than the volume of the container. The cost will be at least 0.2 Swedish kronor per liter of pure water produced with a life of 25 year for solar modules. Usage fee per liter of pure water is 0.03 Swedish kronor based on Gotland’s water and wastewater agency and it means MDD is not a cost-effective solution for Gotland at nowadays. But costs may fall in the future with the price reduction of solar cells and batteries. For water shortage areas, this can be a valuable way to solve the water crisis, but it also depends mostly on the area’s water price.

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

Decarbonisation of different energy sectors of society is becoming a pressing issue globally withnumerous legislations and objectives being set to decarbonise electrical grids worldwide. Somehave already been met; however, islanded grids still heavily rely on fossil fuels to meet their electrical demand due to the weakness of their grid and limited available space forcing them to use space-efficient technologies such as diesel generators. This is the case of Fuerteventura in the Canary Islands (Spain) which produces 80-90% of its electricity from fossil fuels. This study will analyse the feasibility of decarbonising the electrical grid of Fuerteventura using a decentralised grid system with wind, solar, and battery storage to achieve 100% renewable generation. To select the best hybrid energy system for the case study, a 9-step methodology has been presented and followed in which both descriptive (qualitative) and quantitative data have been used to provide the background knowledge of the study and the inputs for the analysis which is done using the microgrids optimisation model HOMER. The analysis aims to understand the grid and renewable resources on the island to later develop the different scenarios to be reviewed. The three different scenarios, wind-battery, solar-battery, and wind-solar-battery were modelled and simulated using the latest HOMER software. Results showed reduced LCOE and capital costs in the wind-solar-battery scenario compared to the wind-battery and solar-battery scenarios due to increased use of wind and lower capacity of installed batteries needed. Space availability was shown to be a problem for the scenarios using wind as the turbines would occupy 5% of the islands surface. Environmental and visual impacts would also be noticeable under the wind-battery and wind-solar-battery scenarios as the entire island is a Biosphere Nature Reserve and is a well-known touristic destination for natural virgin beaches. Additionally, the results showed that all 3 scenarios had excess electricity values above 50% of the total electrical production and still experienced some capacity shortages. To solve this, diversification of the generation and storage facilities, implementation of DSM (Demand side management) and V2G (Vehicle-to-grid), and interconnection of the islands is proposed with the latter being the most realistic solution. The study concludes the wind-solar-battery is the most technological and economically feasible solution although several issues need to be addressed for a similar project to be implemented on a real island.

This bachelor thesis aims to investigate household electricity supply and demand during a crisis. Both quantitative and qualitative aspects of crisis preparedness and household electricity demand are considered. In this thesis, the subject is studied by conducting simulations of electricity consumption as well as retrieving theoretical framework and concepts from literature and interviews. Emphasis will be on how the cost of a lithium-ion battery storage, that supplies households with electricity during power outages, is affected by households’ behavioural patterns regarding electricity use. To estimate household electricity demand, data are utilized from a stochastic model which simulates household members electricity usage patterns. Three different scenarios are modelled, representing varying household electricity reliance, across different lengths of power outages. The first scenario illustrates households’ normal electricity demand. The second scenario represents a changed behaviour pattern leading to a reduced electricity demand. The third and last scenario concerns a case where households with adequate crisis preparedness are taken into account, resulting in a linearly scaled down electricity demand. Gaps in the distribution of responsibility between municipalities and households concerning crisis preparedness are brought up and discussed. The thesis highlights households with unique needs that risk not getting the support needed from the municipality in case of a crisis. The result shows that meeting the electricity demand for Knivsta urban area during a power outage by utilizing a battery storage would be very costly for the municipality. Despite the cost reduction from decreased electricity consumption, large investments are still required. A battery storage system on that scale might not be the only nor most optimal solution for crisis preparedness. Instead, opportunities are found by challenging prevailing norms of constant electricity supply and increased resilience among households. Lastly, possible solutions less costly for the municipality are presented.

The rapid development of the lithium-ion battery industry is currently driving down sys-tem costs as a result of maturing processes. Decreasing system costs enables additional revenue streams and applications, provided through li-ion battery storage, to be ex-plored. EAM Solar, a Norwegian solar utility company with operational solar power plants across the globe, seeks to build and operate a solar power plant (SPP) in the Dutch region of Leeuwarden. This thesis investigates whether an SPP with an installed capacity of 16.1MW, can be economically profitable when utilizing li-ion battery energy storage systems (BESS) for arbitrage and time-shift of subsidized solar power in order to avoid large(r) grid-connection costs while accepting grid transmission limits. Literature, environment parameters and estimates from the industry was combined with financial data from the client and collaborators, such as a battery manufacturer, to create viable and realistic economic evaluations.The literature study provided information for relevant parameters such as the life cycle of a battery, which enabled a realistic modeling procedure regarding cyclic and calendric degradation, charge/discharge behavior, end of life terms and overall efficiencies. It was modelled quantitatively in Stella Architect and Microsoft Excel to obtain economical and financial indicators, such as Net Present Value (NPV) & Internal Rate of Return (IRR), to subsequently provide recommendations on whether to make the investment.Results show worse economic outcomes for li-ion BESS investments compared to the original investment of a stand-alone SPP, even when arbitrage was implemented as a cost recovery mechanism and with a smaller grid-connection cost. Furthermore, it is shown that a stand-alone BESS only used for arbitrage is unlikely to become profitable in the foreseeable future at this location or in a similar market mainly due to large in-vestment costs combined with substantial fees associated with access to the day-ahead electricity auction in the Netherlands, EPEX Spot NL. It is also shown that in spite of the lower grid connection for a SPP combined with a li-ion BESS, a 20-25% decrease in battery investment cost is required for the investment to yield similar rate of returns as a stand-alone SPP investment. The model developed in this thesis can be considered to be a tool for evaluating similar systems in the future with minor modifications, espe-cially as the market- and technology environment evolves. / Den snabba utvecklingen utav litium-jonindustrin för batteritillverkning har kraftigt dri-vit ner systemkostnader som ett resultat av mer mogna processer. Sjunkande systemkost-nader möjliggör upptäckande av både nya intäktskällor och användningsområden för li-tium-jonbatteri. EAM Solar, ett norskt solkraftföretag som äger ett flertal solkraftverk världen över, är just i planeringsstadiet för att bygga och underhålla ett nytt kraftverk i den nederländska staden Leeuwarden. Denna uppsats undersöker om ett solkraftverk med en kapacitet på 16.1 MW kan vara lönsamt tillsammans med ett batterisystem som ska användas för att lagra el när överföringsgränsen är nådd, samt för arbitragehandel. Förhoppningen från klientens sida var att den mindre nätanslutning kunde användas tillsammans med ett batterisystem för undvika vissa investeringskostnader. Litteratur, lokala parametrar och kalkyler från industrin kombinerades med finansiella data från klienten och samarbetspartners som batteritillverkare för att skapa trovärdiga och real-istiska resultat.Litteraturstudien gav information om relevanta parametrar såsom livscykeln för ett bat-teri, vilket möjliggjorde en realistisk modelleringsprocedur gällande cyklisk och tidsan-passad degradering, laddning- och urladdningsbeteende, slutvillkor för användning och generella effektiviteter. Modellen modellerades sedan kvantitativt i Stella Architect och i Microsoft Excel för att få fram finansiella indikatorer vilka gav en rekommendation om en investering skulle göras eller ej.Resultaten visade sämre ekonomiska resultat för litium-jonbatteri kombinerat med ett solkraftverk jämfört med endast ett solkraftverk för sig själv, detta även om både ar-bitrage och lagring av överskottselektricitet används för att öka intäkterna kombinerat med en liten anslutning till det nationella nätet. Utöver detta visar det sig att ett batte-risystem som endast används för arbitragehandel är långt ifrån lönsamt för sig själv, och detta lär inte ändras under den närmaste tiden, i alla fall inte på en marknad som den nederländska. Anledningarna till detta är alltför höga investeringskostnader kombinerat med relativt höga avgifter för att ens få handla på den nederländska elmarknaden, EPEK Spot NL. För att nå lika resultat för ett solkraftverk med eller utan batterisystem krävs det, i det bästa fallet, en minskad investeringskostnad på 20-25%. Det ska dock nämnas att det krävs en mindre nätanslutning om ett batterisystem används, vilket är anled-ningen till att de finansiella resultaten är relativt lika, utan detta skulle alla system med batteripaket ge betydligt sämre värde. När uträkningar gjordes på batterisystem som endast används för arbitragehandel gav dem negativa ekonomiska resultat i samtliga fall, oberoende av batteristorlek. Det är dock viktigt att notera att modellen som skapades för denna uppsats är enkel att använda i framtiden. När parametrar ändras är det simpelt att justera modellen för att undersöka precis samma fall i framtiden.

The increasing share of renewable energy especially wind energy leads to increased share of unpredictable and varying energy into the grid. This leads to congestion in the grid which ultimately results in wind curtailment. In Germany in 2015 alone more than 4000 GWh of wind energy was curtailed. On the other hand, off grid energy requirements for event industry especially concerts and festivals, rely heavily on diesel generators to fulfill their power requirements. This thesis investigates a unique use case for the mobile storage application. The batteries are used to utilize the curtailed wind energy for off-grid applications like festivals and concerts in Germany. The batteries are charged at the wind farm during the duration of curtailment and once they are fully charged, the batteries are transported to the location of concert or an event to provide clean energy. The batteries or storage system used for this case have a capacity of 1.5 MWh and the whole system is constructed in a standard shipping container to allow convenient transportation. According to the findings of this study, the proposed use case can lead to a significant CO2 emission reduction, a single storage system could save up to about 8.4 million kg of CO2, at the events and festivals. Furthermore, it could help in renewable energy integration by providing clean wind energy, that is otherwise curtailed, to festivals and concerts. This study identifies a wind farm with most curtailed energy in Germany with total curtailment duration accounting for about 32% of the time in the year 2017. The technical model, simulated in MATALB/Simulink, successfully charged the battery storage system without any bottleneck. The levelized cost of storage was found to be in comparison with the levelized cost of diesel generators. A single storage system has an ability save up to 8.4 million kg of CO2 emissions. The study further proposes policy suggestions to promote such innovative use case. / Den ökande andelen förnybar energi, särskilt vindenergi, leder en till ökad andel av oförutsägbar intermittent energi till elnätet. Detta leder tidvis till en överbelastning på elnätet, vilket resulterar i att vindkraftverkens elproduktion måste begränsas. Endast i Tyskland under 2015 begränsades 4000 GWh av vindenergi. Samtidigt används diesel generatorer i off-grid områden för att bedriva mässor, marknader, festivaler och liknande arrangemang. Den här rapporten undersöker ett specifikt fall för mobila lagringsmöjligheter. Batterier kan användas för att nyttja den begränsade vindenergin för offgrid evenemang som festivaler och konserter i Tyskland. Batterierna laddas i vindkraftsparker vid hög tillgång till vindenergi och transporteras sedan till ett evenemang för att försörjas med förnybar energi. Batterierna eller lagringsmediet som används för detta fall har en kapacitet på 1,5 MWh och systemet är paketerad i en fraktcontainer för enkel transport. Enligt resultaten från denna studie kan det föreslagna användningsfallet leda till en betydande minskning av koldioxidutsläppen, ett enda lagringssystem skulle kunna spara upp till cirka 8,4 miljoner kg CO2 vid evenemang och festivaler. Dessutom skulle det kunna bidra till integration av förnybar energi genom att tillhandahålla ren vindkraft, som annars begränsas, till festivaler och konserter. Denna studie identifierar en vindkraftspark med den mest begränsade energin i Tyskland med total kapacitetsvaraktighet som står för cirka 32% av tiden under 2017. Den tekniska modellen, simulerad i MATALB / Simulink, laddade batterilagringssystemet framgångsrikt utan flaskhals. De nivåiserade lagringskostnaderna visade sig vara i jämförelse med de nivåiserade kostnaderna för dieselgeneratorer. Ett enda lagringssystem kan spara upp till 8,4 miljoner kg koldioxidutsläpp. Studien föreslår vidare policyförslag för att främja ett sådant innovativt fall.

One feature that is hoped for in the smart grid is the participation of energy prosumers in a power market through demand response program. In this work, we consider a third-party virtual power plant (VPP) that has “real-time” control over a number of prosumers’ storage units within an envisaged free market. Typically, a VPP with domestic energy storage will involve a bidirectional flow of energy, where energy can either flow from the grid to the prosumers’ battery or from the prosumers’ battery to the grid. Such a system requires prices to be set correctly in order to meet the market objectives of all the VPP stakeholders (VPP Aggregator, prosumers, and grid). Previous work has shown how VPPs could operate, and the benefits of using energy storage, coupled with pricing, in terms of reducing energy cost for stakeholders and providing the grid with its required load shape. The published work either assumes prices or costs or then optimises for least cost within the grid parameters i.e. losses, voltage limits, etc. However, the setting of prices in such a way that energy can be traded among VPP stakeholders that satisfies all stakeholders’ objectives has not been fully explored in the literature, particularly with real-time VPP aggregators. In this thesis, we present novel strategies for evaluating and setting the prices of a community VPP with domestic storage based on the bidirectional flow of energy through the VPP aggregator between the grid and the prosumers that mutually meet all VPP stakeholders’ objectives. This showed that depending on pricing and the VPP objectives, demand-side management could be attractive. However, the effect on the grid in terms of the load was not what was desired. A new performance index called the “Cumulative Performance Index” CPI is proposed to measure the VPP’s performance. Using the CPI, it was possible to compare and contrast between the VPP technical performance and its business case for stakeholders. Optimizing with respect to the grid’s requirement for DSM from the VPP, it was possible to achieve a CPI of 100%. This work was implemented using a novel approach on a genetic algorithm platform. / Niger Delta Development Commission of Nigeria

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.

Energimarknaden förändras till följd av den alltmer aktuella klimatfrågan. En ökad efterfrågeflexibilitet är en förutsättning för omställningen till förnyelsebara energikällor. Energilagring i batterier ses som en nyckellösning i framtidens elförsörjning. Ett alternativ är implementering av batterilager i byggnader hos slutkonsumenten. Uppsatsen undersöker vilka incitament som finns för en bostadsrättsförening att investera i batterilager. Resultaten visar att ekonomiska aspekter är avgörande för beslutet. Potential till minskade elkostnader samt investeringsstöd är möjligheter som värderas högst. Även hållbarhetsaspekter och miljöperspektiv ger incitament. Störst hinder för investeringen i batterilager är brist på utrymme i byggnaderna. / The energy market is changing due to the current climate issue. Increased demand flexibility is a prerequisite for the transition to renewable energy sources. Energy storage in batteries is seen as a key solution in the ectricity supply of the future. An alterantive is the implementation of battery storage in buildings at the end consumer. The thesis examines the incentives for a Swedish tentant-owner association to invest in battery storage. The results show that financial aspects are crucial for the decision. Potential for reduced electricity costs and investment support are opportunities that are highly valued. Sustainability aspects and environmental perspectives also provide incentives. The biggest obstacle to the investment in battery storage is the lack of space in the buildings.