In this dissertation, three major contributions are presented in a photovoltaic (PV) energy system. Firstly, a three-port grid-forming (GFM) microinverter and a lithium-ion battery pack are integrated at the back of PV panel. As a result, they form an AC-PV energy system module that produces an AC output voltage. The technoeconomic analysis, battery capacity optimization, PV panel size optimization, electrical and thermal model of batteries, battery heat generation model, battery management system and thermal management system are discussed in the AC-PV module by using stochastic analysis and battery test results. Secondly, a three-phase 540 KVA bidirectional inverter and a 1.86 MWh lithium-ion battery energy storage system (BESS) were integrated at the Florida Solar Energy Center (FSEC). A case study is performed for this system by acquiring the energy consumption of the building, the reduced energy consumption, the battery testing, the load shifting, and the peak shaving. The total harmonic distortion (THD) values are also provided. Among eight power management scenarios, the scenarios that include PV panels are satisfied via simulation. However, the scenarios that do not include PV panels are analyzed and presented based on the real-world setting measurements. Thirdly, a modified droop control method is designed for grid-tied and off-grid scenarios. The simulation results are obtained based on three scenarios. The first one is that the voltage and frequency regulation control algorithm is discussed when GFM inverters have the equal power ratings. Then, the load sharing control algorithm is determined based on different GFM inverters' power ratings. The last scenario includes Grid connection. Loads are added and removed from the system to ensure that the frequency and voltage stability is the range of continuous operation. The coupling reactance effect on power sharing is investigated.

Battery Storage Systems (BESS) installed Behind the Meter (BTM) can provide demand management services, reducing electricity costs and enhancing overall electricity system stability. BTM BESS can also imporve self-consumption obtained with distributed generation assets like solar photovoltaics. This study examines the influence on value creation from consumption patterns and utility tariffs. Using Swedish and UK tariffs and a set of consumption profiles, the study determines the optimal BESS configuration and conducts simulations to assess profability through Net Present Value. Comparative analysis reveals the impact of utility tariffs and consumption profiles on profitablility. Projected BESS cost levels for 2030 and 2050 are used to evaluate expected future profitability.  The findings indicate that utility tariff has a stronger influence on BTM BESS profitability than consumption profile. Energy arbitrage creates most of the value, depending more on tariff structure than consumption pattern. However, with higher demand charges, the consumtion profile becomes more important as the relative value of peak shaving increases. Two sensitivity analyses have been performed. The first shows that NPVs are affected by decreased electricity price variability, emphasising the need for accurate long-term price forcasts. The second shows that existing electricity consumption forecasting techniques prove sufficient for effective peak shaving.  In conclusion, this research inderscores the significance of utility tariffs and consumption profiles in determining BTM BESS profitability. Energy arbitrage dominates value creation, while peak shaving gains importance with higher demand charges. Accurate long-term price forecasts are crucial for assessing BTM BESS profitability, and existing consumption forecasting techniques are suitable for peak shaving. / Batterilagring installerad bakom elmätaren kan optimera en fastighets elkonsumtion för att reducera elkostnader samt förbättra stabiliteten i elsystemet som helhet. Den här studien undersöker faktorer som påverkar värdeskapande genom energiarbitrage och peak shaving, inklusive konsumtionsprofiler och eltariffer. Studien undersöker även om det går att uppnål önsamhet under nuvarande och framtida prisnivåer för batterilagring. Studien utgår ifrån svenska och brittiska eltariffer samt fem konsumtionsprofiler, och fastställer den mest optimala konfigurationen av batterilagring genom optimering. Därefter jämförs lönsamheten genom nettonuvärde-analys för att dra slutsatser om hur eltariff och konsumtionsprofil påverkar lönsamhet. Studien visar att lönsamhet för batterilagring bakom mätaren beror mer på eltariff än konsumtionsprofil. Detta eftersom mest värde skapas genom energiarbitrage som är mindre beroende av konsumtionsprofil men direkt beroende av variationer i elpriset. Med högre effektavgifter ökar lönsamhetens beroende av konsumtionsprofilen då det relativa värdet av peak shaving höjs. En känslighetsanalys visar på en stark korrelation mellan värdet av energiarbitrage och variationer i elpriset, vilket visar vikten av långsiktiga prognoser av elprisets volatilitet. Befintliga tekniker för prognostisering av elkonsumtion har tillräcklig noggrannhet för effektivpeak shaving. Sammanfattningsvis visar studien hur eltariff och konsumtionsprofil påverkar lönsamheten för batterilagring installerad bakom elmätaren. Majoriteten av värdet skapas genom energiarbitrage för svenska och brittiska tariffer. Med högre effektavgifter ökar betydelsen av peak shaving. Dessutom betonar studien vikten av långsiktiga prognoser av elprisvolatilitet vid utvärderingen av lönsamheten för investeringar i batterilagring bakom mätaren.

In this report the problem of constructing a bus depot with electrical buses despite the lack of grid capacity, was analyzed. A potential solution is investigated, namely smart control of heat pumps in industries. The possibility of allocating grid capacity to the bus depot by reducing power consumption in heat pumps during peak hours, is taken into consideration. The maximum amount of released capacity in an industrial area is calculated through the controlling of heat pumps. This investigation was made through simulations with a simplified building energy model (lumped capacity model) which was applied to a reference building. After mapping the area Boländerna and the geothermal wells located there, IKEA Uppsala was chosen as the reference building, since a third of the total number of wells were found in that area. To take the whole capacity of Boländerna into account, the model was scaled up to estimate the total, possible reduction of power. The bus depot requires 6 MW nighttime and 4 MW daytime, the total amount of electrical power that could be withdrawn, if all heat pumps were on maximum heat, in the chosen area were 0.75 MW and by controlling the heat pumps during an optimized level, the amount of 142 kW could be made available to the electric grid. 142 kW is not enough cover the need for the bus depot but it could supply the need for a slow charger to one of the buses and is therefore a possible sub-solution to the larger problem.

Diesel engines operating the rig pose the problems of low efficiency and large amount of emissions. In addition the rig power requirements vary a lot with time and ongoing operation. Therefore it is in the best interest of operators to research on alternate drilling energy sources which can make entire drilling process economic and environmentally friendly. One of the major ways to reduce the footprint of drilling operations is to provide more efficient power sources for drilling operations. There are various sources of alternate energy storage/reuse. A quantitative comparison of physical size and economics shows that rigs powered by the electrical grid can provide lower cost operations, emit fewer emissions, are quieter, and have a smaller surface footprint than conventional diesel powered drilling. This thesis describes a study to evaluate the feasibility of adopting technology to reduce the size of the power generating equipment on drilling rigs and to provide ?peak shaving? energy through the new energy generating and energy storage devices such as flywheels. An energy audit was conducted on a new generation light weight Huisman LOC 250 rig drilling in South Texas to gather comprehensive time stamped drilling data. A study of emissions while drilling operation was also conducted during the audit. The data was analyzed using MATLAB and compared to a theoretical energy audit. The study showed that it is possible to remove peaks of rig power requirement by a flywheel kinetic energy recovery and storage (KERS) system and that linking to the electrical grid would supply sufficient power to operate the rig normally. Both the link to the grid and the KERS system would fit within a standard ISO container. A cost benefit analysis of the containerized system to transfer grid power to a rig, coupled with the KERS indicated that such a design had the potential to save more than $10,000 per week of drilling operations with significantly lower emissions, quieter operation, and smaller size well pad.

Energy storage systems is very useful to use in solar panel systems to save money, but also tobe more environment-friendly. The project was given by the solar energy companyPerpetuum Automobile (PPAM) and the project is for their customer, the condominiumcompound Ekoxen. The task is to make a energy regulation for Ekoxen's energy storage sothey can save more money. The energy storage primary task is to shave the top-peaks of theconsumption for Ekoxen. Which means that the battery will supply the household instead forthe three-phase grid. This will make the electric bill for Ekoxen cheaper. Thesimulation/analysis of the energy regulation is done in a spreadsheet tool, where one partworks as a Time-of-Use program and the other work as a modbus feature. Time-of-Use is aweb-based program for PV systems with battery storage, where time-periods can be set toaffect the battery behavior. The modbus feature simulates a system where an algorithm can beimplemented. The results will show that the time-periods for charging the battery with theTime-of-Use program needs to be changed two times per year. One time for the summermonths and a second time for the rest of the months. The results will also show that themodbus feature is better on peak shaving than the time-of-use program.

In this study, an examination regarding what benefits an aggregatedpopulation of Battery Energy Storage Systems (BESSs) could result incompared to when the individual units in the population are being usedseparately has been executed. The increased flexibility and reducedsafety margins as results of the aggregation was also examined. Thestudy was executed on behalf of the smart energy service companyCheckWatt AB and the study furthermore rests upon results of earlierperformed master theses on behalf of the company. By investigating previous work and studies through a literature study,the enabling of anumerical study was done. The numerical study wasbased on a simple model of a Virtual Power Plant (VPP) where severalBESSs are smartly controlled in order to be used for both local peakshaving and as common providers of the frequency reserve FrequencyContainment Reserve - Normal (FCR-N). The study involved the formation of a numerical model which simulated cases of both aggregated and non-aggregated populations of up to 45 load profile units, this in order for advantages and differences to be distinguished. The data used inthe simulations was received mainly from the CheckWatt AB andconsisted of photovoltaic (PV) electricity production and load data of 45 customers of the company. A sensibility analysis of the numericalstudy was also performed, which showed that the studied model andsystem were quite stable. The results of the simulations of the case of the study proved thatthere are some advantages connected to aggregation of several BESSs,and that the aggregation enabled an added value and a higher level offlexibility within the system. The safety margins connected todelivery of FCR-N could be reduced when aggregating several BESS,while a more extensive study is requested regarding safety marginsconnected to peak shaving. The study’s results further showed that anaggregator can be used as a sustainable and flexible solution forbalancing the electrical grid in the transition to a sustainableenergy system allowing a higher penetration of intermittentenergy sources.

The increasing demand for renewable energy sources to meet climate targets and reduce carbon emissions poses challenges to the power grid due to their intermittent nature. One potential solution to maintain grid stability is by implementing Hybrid Energy Systems (HESs) that incorporate a Battery Energy Storage System (BESS). To achieve the most favorable outcome in terms of both technical feasibility and profitability of a BESS, it is essential to employ models for simulating and optimizing the control of system components. This thesis focuses on the analysis of energy and revenue streams in a HES consisting of a BESS, photovoltaics (PVs), and an energy load including a fast charging station for electric vehicles (EVs). The objective is to optimize the system based on revenue generation by comparing the control techniques of peak shaving, energy arbitrage, and the integration of ancillary services within the Swedish energy market. The research questions explore the optimal utilization of the BESS and assess the impact of the different control techniques. A model is created in Python with the package CasADi where data from an ongoing installation of a HES in southern Sweden is combined with data from literature research. The model includes an objective function that minimizes the total cost of power from the grid based on the day-ahead price, battery degradation, and monthly peak power.  To answer the research questions, four different scenarios are simulated. The first scenario is a base for comparison, the second one focuses on peak shaving and energy arbitrage, the third on participation in the ancillary service FCR-D upwards regulation, and the last one is a combination of peak shaving, energy arbitrage, and the ancillary service FCR-D. The results show that the remuneration from the ancillary service FCR-D is comparably much higher than the revenues generated from peak shaving and energy arbitrage, providing more than 500% of revenue compared to the same system but without a BESS. The scenario with peak shaving and energy arbitrage shows an increase in revenue of 29% but with more cycling of the battery which could cause losses in performance in the long term. To validate the results, sensitivity analyses are conducted by evaluating weighting in the objective function, implementing Model Predictive Control (MPC), and reviewing price variations.  In conclusion, efficient control techniques can enhance system performance, minimize losses, and ensure optimal utilization of different energy sources, leading to improved feasibility and profitability. The optimal usage of a BESS involves finding a balance between maximizing revenue generation and minimizing battery degradation. This can be achieved through control strategies that optimize the charging and discharging patterns of the BESS based on electricity price signals, demand patterns, and battery health considerations.

District heating is considered an environmentally friendly, efficient and cost-effective way of providingheat to buildings but even so, the industry will be facing several challenges in the upcoming years. Acombination of higher operating costs, growing demand, competition from alternative heatingtechnologies, national and international climate and energy goals and the need for transparency towardscustomers places high requirements on many thermal energy suppliers. One path to try to meet many ofthe demands is to introduce heat load control in the shape of thermal inertia in buildings as a short-termthermal energy storage. Several pilot tests have been performed in the matter but no study regardinglarge scale implementation and effects on the network has been performed. Adding to this, severaldifferent thermal energy suppliers are developing similar technologies alongside each other but there iscurrently no documentation on different approaches on the matter.Stockholm Exergi, a thermal energy supplier in Stockholm, have just started a project regarding heatload control and wanted deeper understanding in the matter. The overall purpose of this thesis hastherefore been to evaluate how heat load control could be performed successfully by Stockholm Exergito continue to promote competitive and sustainable delivery of district heat. This was done throughanalysis of other heat load control projects which resulted in eight key performance indicators. Thesewere; revenue, costs, fuel mix, greenhouse gas emissions, customer satisfaction, energy demand,available capacity and peak load. The key performance indicators were used to evaluate one ongoingtest run of heat load control performed by Stockholm Exergi to determine the profitability of theapproach. The test consisted of a control period of three hours in four buildings. The base of the studyconsists of a literature study and interviews performed both internally and externally.From the data analysis it was concluded that the energy savings due to heat load control were between13-19% for the individual buildings. The average total energy saving compared the entire day was 15.8%and the average total energy saving during the control period was 57.3%. It could also be concluded thatthe average total available capacity for all four buildings due to heat load control was 410 kWhcorresponding to 20.34Wh/m2 floor area.With the current price agreements, it was found that customers could save 0.145% on their monthly billdue to this reduction. For Stockholm Exergi, cost savings took the shape of avoided fuel costs and thetotal average cost savings were during the control period 0.072% with heat pumps as marginalproduction. Due to lack of data it was not possible to calculate other costs. The avoided GHG emissionsdue to the reduction in generation was 3.4 kg CO2-equivalents. During the control, the indoortemperature was reduced by a maximum of 0.587⁰C but no residents in the test buildings complainedabout bad indoor conditions.It was concluded that the current method and process for heat load control at Stockholm Exergi showsimilar results as other heat load control projects. Even though it is too soon to know for certain, it wasalso found that it has the potential to be economically, socially and ecologically successful in large scale.The thesis also concluded a list of recommendations for the future development of the heat load controlproject within Stockholm Exergi that would contribute to increase the probability of a successfulimplementation.Lastly, it was found that Stockholm Exergi is in the forefront of the development of heat load controlon large scale and are therefore in a position of trial and error where caution is paramount. / Fjärrvärme anses vara ett miljövänligt, effektivt och ekonomiskt lönsamt sätt att tillhandahålla värmetill byggnader men fjärrvärmeindustrin kommer ändå att stå inför flera utmaningar under de kommandeåren. En kombination av högre driftskostnader, ökad efterfrågan, konkurrens från alternativauppvärmningstekniker, nationella och internationella klimat- och energimål samt behovet av öppenhetgentemot slutanvändarna ställer höga krav på många fjärrvärmeleverantörer. Ett sätt att försöka mötadessa krav är att införa värmelastkontroll i form av termisk tröghet i byggnader som en kortsiktigvärmeenergilagring i fjärrvärmenätet. Flera pilot tester har gjorts inom området men ingen studierörande storskalig implementering och effekter på nätverket har utförts. Vidare utvecklar flera olikafjärrvärmeleverantörer liknande tekniker parallellt med varandra, men det finns för närvarande ingendokumentation gällande de olika metoderna.Stockholm Exergi, en fjärrvärmeleverantör i Stockholm, har nyligen påbörjat ett projekt inomvärmelastkontroll och har önskat djupare förståelse inom ämnet. Det övergripande syftet med dennaavhandling har därför varit att utvärdera hur kontroll av värmelasten kan genomföras framgångsrikt avStockholms Exergi för att fortsätta främja konkurrenskraftig och hållbar leverans av fjärrvärme.Detta gjordes genom analys av andra projekt rörande värmelastkontroll vilket resulterade i åtta nyckeltal.Dessa var; vinster, kostnader, bränslemix, växthusgasutsläpp, kundnöjdhet, energibehov, tillgängligkapacitet och toppbelastning. Dessa användes för att utvärdera en pågående testkörning avvärmelastkontroll i Stockholms Exergis fjärrvärmenät för att bestämma lönsamheten med metoden.Testkörningen gjordes i fyra byggnader under en kontrollperiod på tre timmar. Avhandlingen hade singrund i en omfattande litteraturstudie och interna samt externa intervjuer.Från dataanalysen drogs slutsatsen att energibesparingen var mellan 13–19% för de enskildabyggnaderna. Den genomsnittliga totala energibesparingen jämfört hela dagen var 15,8% och dengenomsnittliga totala energibesparingen under kontrollperioden var 57,3%. Den genomsnittliga totalatillgängliga kapaciteten på grund av värmelastkontroll blev därigenom 410 kWh vilket motsvarade 20,34Wh/m2 golvyta.Med de nuvarande prisöverenskommelserna konstaterades det att kunderna kunde spara 0,145% på sinmånatliga faktura på grund av denna minskning. För Stockholm Exergi fanns kostnadsbesparingar iform av undvikna bränslekostnader för spetsproduktion. Den genomsnittliga besparingen för undviknabränslekostnader var under kontrollperioden 0,072% med värmepumpar som marginalproduktion. Ingaandra kostnader kunde beräknas på grund av begränsad data. De undvikna växthusgasutsläppen på grundav denna minskning var 3,4 kg CO2-ekvivalenter. Under kontrollen reducerades innertemperaturen somhögst med 0,587 °C men inga boende klagade över försämrade inomhusförhållanden.En slutsats var att den nuvarande metoden och processen för kontroll av värmelasten utförd avStockholms Exergi visar liknande resultat som andra projekt inom samma område. Det kunde ävenfastställas att det har god potential att vara ekonomiskt, socialt och ekologiskt framgångsrikt i stor skalai framtiden. Avhandlingen fastställde också en lista med rekommendationer för den framtidautvecklingen av värmelastkontroll inom Stockholms Exergi. Dessa rekommendationer ska bidra tillökad sannolikhet för en framgångsrik implementering.Slutligen konstaterades det att Stockholms Exergi ligger i spetsen för utvecklingen av värmelastkontrolli stor skala. Detta innebär att de är i en position där det gäller att försiktigt och långsamt prova sig fram.

Due to the increased demand for electricity in recent years and the estimated demand in the future it has become clear that the capacity of the Swedish electrical grid is insufficient, and the grid is not able deliver the amount of power that is demanded by the market. The crucial points in the grid where the grid capacity is insufficient could be several. It could be in the transmission system but also at locations in the distribution system, such as congestion points for residential areas for example. For the grid to be able to meet the new demands large investments are needed to renew electricity grid. This will cost a lot of money and it will take several years before the grid capacity is up to scale. A problem is that the grid must be dimensioned for the highest power peaks that could be expected even though these might occur just a few times every year. As a response to this a new market for flexibility solutions in the grid has arisen. An example of a flexibility solution is a method called peak-shaving. Peak-shaving is a method that levels out the overall load-profile and so on reduces the highest power-peaks. The aim of this thesis was to investigate how integrated power systems with battery storageinstalled in household villas could implement peak-shaving with the purpose of providing a flexibility-service to the grid. The study includes theoretical simulations, as well as practical experiments and performance analyses of installed systems. The study also includes an investigation how the current price model and tax rules create incentives for costumers to provide this flexibility service. Firstly, a theoretical simulation model in MATLAB was developed that could make a virtual simulation of the result from implementation of peak-shaving based on historical data of the power profile of the household. After this, experimental tests were conducted for three households where peak-shaving was implemented. With the data from the experiments the performance and potential deficiency of the installed systems could be analysed. With the recorded data from the experiments and with collected data of the hourly based price for electricity it could be studied what impact peak-shaving has on the costs for the household and so on what incentives the price model and tax rules creates to implement peak-shaving.What could be concluded in the study was that peak-shaving has a good potential to reduce power-peaks and provide flexibility to the grid. The results from the tests showed that the power-peaks were able to be reduced but the power systems did however have some observed deficiencies that reduced their performance. It could also be concluded that the current price model and tax rules often increases the costs when implementing peak-shaving and so on create poor incentives to provide this flexibility service.

The question of finding the optimal size for battery energy storage systems (BESS) to be used for energy arbitrage and peak shaving has gained more and more interest in recent years. This is due to the increase in variability of electricity prices caused by the increase of renewable but also variable electricity production units in the electricity grid. The problem of finding the optimal size for a BESS is of high complexity. It includes many factors that affect the usefulness and the economic value of a BESS. This study includes a thorough literature study regarding different methods and techniques used for finding optimal size (both capacity and power) for a BESS. From the literature study two meta-heuristic algorithms were found to have been used with success for similar problems. The two algorithms were Genetic algorithm (GA) and Firefly algorithm (FF). These algorithms have in this thesis been tested in a case study optimizing the BESS capacity and power to either maximising the net present value (NPV) of investing in a Li-ion BESS of the LPF type or minimizing the levelized cost of storage (LCOS) for the BESS, with a project lifetime of 10 years. The BESS gains monetary value from energy arbitrage by being a middleman between a large residential house complex seen as the "user" with a predefined hourly electricity load demand and the electricity grid. For the case study a simplified charge and discharge dispatch schedule was implemented for the BESS with the focus of maximising the value of energy arbitrage. The case study was divided into 3 different cases, the base case where no instalment of a BESS was done. Case 2 included the instalment of the BESS whilst case 3 included installing both a BESS and an electrical heater (ELH). The electrical heater in case 3 was implemented to shift a heating load from the user to an electrical load, to save money as well as reduce CO2 emissions from a preinstalled gas heater used in the base case. The results showed that overall GA was a better optimization algorithm for the stated problem, having lower optimization time overall between 60%-70% compared to FF and depending on the case. For case 2, GA achieves the best LCOS with a value of 0.225 e/kWh, being 11.4% lower compared to using FF. Regarding NPV for case 2, FF achieves the best solutions at the lowest possible value in the search space for the capacity and power (i.e., 0.1 kWh for capacity and 0.1 kW for power), with an NPV at -51.5e, showing that for case 2 when optimizing for NPV an investment in a BESS is undesirable. GA finds better solutions for case 3 for both NPV and LCOS at 954,982e and 0.2305 e/kWh respectively, being 35.7% larger and 9.1% lower respectively compared to using FF. For case 3 it was shown that the savings from installing the ELH stands for a large portion of the profits, leading to a positive NPV compared to case 2 when it was not implemented. Finally, it was found that the GA can be a useful tool for finding optimal power and capacity for BESS instalments, compared to FF that got stuck at local optimums. However, it was seen that the charge and discharge dispatch schedule play an important role regarding the effectiveness of installing a BESS. As for some cases the BESS was only used 17% of all hours during a year (case 2, when optimizing for NPV). Therefore, further research is of interest into the schedule function and its role regarding finding the optimal BESS size. / Frågan angående hur man hittar den optimal storleken på en energilagringsenhet av batteritypen (BESS) som skall användas för energiarbitrage samt "peak shaving" har fått mer och mer uppmärksamhet de senaste åren. Detta sker på grund av en ökning av variabiliteten av elpriser, vilket i sig delvis kommer från ett ökat installerande av förnyelsebar, men då också variabla energiproduktionsenheter till elnätet. Problemet med att hitta den optimala storleken för en BESS är på grund av komplexitet i frågan. Det innehåller många faktorer som påverkar effektiviteten samt det ekonomiska värdet av en BESS. Denna avhandling innehåller en litteraturstudie om olika tekniker och metoder som används för att hitta den optimal lösningen för optimal storlek (kapacitet och kraft) på en BESS. Från litteraturstudien hittades två meta-heuristiska algoritmer som använts med succés på liknande problem. De två algoritmerna var "Genetic algorithm" (GA) och "Firefly algorithm (FF). Dessa algoritmer har i denna avhandling blivit testade i en fallstudie för att optimera kapacitet och kraft för en BESS genom att antingen maximera nettonuvärdet (NPV) som fås av att investera i en Li-ion BESS av typen LPF eller att minimera "levelized cost of storage" (LCOE) för en BESS med en livstid på 10 år. Detta genom att man får monetärt värde från att använda en BESS för energiarbitrage genom att vara en mellanhand mellan ett stort bostadskomplex som ses vara en "användare" med ett förbestämt elanvändningsmönster och elnätet. För fallstudien användes en simpel metodologi för laddnings- och urladdninsgschema för att maximera energiarbitrage. Fallstudien delades upp i tre olika fall, ett basfall där ingen installation av en BESS gjordes. I fall 2 installerades bara en BESS medans för fall 3 installerades både en BESS samt en elektrisk värmare (ELH) för att omvandla användarens termiska energianvändning till mer elektrisk energianvändning. Genom detta kan monetära besparingar göras samt reducera mängden CO2 utsläpp som annars hade kommit från en redan installerade gasvärmare, i basfallet.  Resultatet visade att totalt sätt var GA en bättre optimeringsalgoritm för det specifika problemet, med lägre optimeringstid på 60%-70% jämfört med FF och beroende på fall. För fall 2 hittar GA det lägsta värdet på LCOS på 0.225 e/kWh, och var då 11.4% lägre jämfört med FF. Angående NPV för fall 2 hittar FF den bästa lösningen på det minsta möjliga värdet på kraft och kapacitet i sökutrymmet (det vill säga 0.1 kWh för kapacitet och 0.1 kW för kraft), med ett NPV värde på -51.5e, vilket visar att för fall 2 när man optimerar för NPV så finns ingen ekonomisk vinning av att investera i en BESS. GA hittar den bästa lösningen för fall 3, både för NPV och LCOS på 954,982e och 0.2305 e/kWh respektivt, vilket är 35.7% större och 9.1% lägre respektivt jämfört när man använder FF. För fall 3 visade resultaten att besparingarna från att installera en ELH stod för den större delen av alla vinster, vilket ledde till positiva värden för NPV. Slutligen visade resultaten att GA kan vara ett användbart verktyg för att hitta den optimala lösningen för storleken på en BESS, jämfört med FF som fastande på lokal optimala lösningar. Dock kunde resultaten också visa att laddnings- och urladdninsgschemat använt i fallstudien spelade en viktig roll angående effektiviteten med att installera en BESS. I vissa fall så användes BESS:en så lite som 17% av alla timmar på ett år (fall 2, optimering av NPV). Därför är det ett stort intresse att göra fortsatt forskning på andra laddnings- och urladdninsgscheman och dess roll med att hitta en optimal storlek på en BESS.