Today’s society already requires a great connectivity network. This need will only increase in the future, and EDGE data centres are concepts meeting this future need, where the computational power is deployed close to the end user. They are defined, in this thesis, as a concept including different nodes, or data centres, located in proximity connected and participating in the market as one entity. The electricity grid in the Nordics is also a complex system. Many types of interactions with the grid exist and depend on the type of stakeholder. One collection of such interactions is ancillary services, which refer to different types of measures that maintain a reliable grid and electricity system. Electricity consumers within the grid network have the potential to interact and participate in these different functions. In this thesis, the participation of data centres, or EDGE data centres in ancillary services market, is studied. This thesis modelled different scenarios of an EDGE data centre with the grid network. Scenario 1 looked into self-consumption; scenario 2 looked into spot trading; scenario 3 looked into the FCR-N market; scenario 4 looked into the FCR-D markets; and scenario 5 looked into the combination of self-consumption and the FCR-D markets. It is observed from the results that scenario 4 generated the most favourable economic benefits. The results in relation to the price areas (zones in Sweden) were varied for the results. The price area SE4 gave better results for scenarios 1, 2, and 5 as compared to others. The best price area for scenarios 3 and 4 was from the SE1 zone. It is observed from the results that the potential benefit of the different ancillary markets exist and are at times favourable. Hence, there lies a future potential for the participation of EDGE networks in the electricity market thereby generating benefits for the data centres as well as stability for the grid. / Dagens samhälle kräver redan ett bra nätverk för uppkoppling. Detta behov kommer bara att öka i framtiden, och EDGE:s datacenter är koncept som uppfyller detta framtida behov, där datakraften placeras nära slutanvändaren. De definieras i denna avhandling som ett koncept som omfattar olika noder, eller servrar, som är placerade i närheten av varandra och som deltar på marknaden som en enhet. Elnätet i Norden är också ett komplext system. Det finns många olika typer av interaktioner med elnätet som beror på vilken typ av aktör det är fråga om. En samling av sådana interaktioner är stödtjänster, som avser olika typer av åtgärder som upprätthåller ett tillförlitligt nät och elsystem. Elkonsumenter inom elnätet har möjlighet att interagera och delta i dessa olika funktioner. I den här avhandlingen undersöks datacentraler, eller EDGE-datacenter, som deltar. I denna avhandling har olika scenarier för EDGE-datacenter modellerats i förhållande till elnätet. I scenario 1 undersöktes självkonsumtion, i scenario 2 spothandel, i scenario 3 FCR-N-marknaden, i scenario 4 FCR-D-marknader och i scenario 5 en kombination av självkonsumtion och FCR-D-marknader. I korthet gav scenario 4 de mest gynnsamma ekonomiska fördelarna. De potentiella miljöfördelarna diskuteras och kan inte lika lätt kvantifieras. Resultaten i förhållande till prisområdena varierade för resultaten. Prisområde SE4 gav de bästa resultaten för scenario 1 och 2 samt 5. Det bästa prisområdet för scenario 3 och 4 var SE1. Det framgår tydligt av denna avhandling att de potentiella fördelarna med de olika stödmarknaderna finns och att de vid vissa tillfällen är mycket gynnsamma med tanke på de höga lagringskostnaderna. EDGE-nätverkens framtida potentiella deltagande ger positiva resultat i både ekonomiska och miljömässiga termer.

This thesis presents a supervisory hybrid controller for the automatic operation and control of a wind energy conversion and battery storage system. The supervisory hybrid control scheme is based on a radically different approach of modeling and control design, proposed for the subject wind energy conversion and battery storage system. The wind energy conversion unit is composed of a 360kW horizontal axis wind turbine mechanically coupled to an induction generator through a gearbox. The assembly is electrically interfaced to the dc bus through a thyristor-controlled rectifier to enable variable speed operation of the unit. Static capacitor banks have been used to meet reactive power requirements of the unit. A battery storage device is connected to the dc bus through a dc-dc converter to support operation of the wind energy conversion unit during islanded conditions. Islanding is assumed to occur when the tiebreaker to the utility feeder is in open position. The wind energy conversion unit and battery storage system is interfaced to the utility grid at the point of common coupling through a 25km long, 13.8kV feeder using a voltage-sourced converter unit. A bank of static (constant impedance) and dynamic (induction motor) loads is connected to the point of common coupling through a step down transformer. A finite hybrid-automata based model of the wind energy conversion and storage system has been proposed that captures the different operating regimes of the system during grid-connected and in islanded operating modes. The hybrid model of the subject system defines allowable operating states and predefines the transition paths between these operating states. A modular control design approach has been adapted in which the wind energy conversion and storage system has been partitioned along the dc bus into three independent system modules. Traditional control schemes using linear proportional-plus-integral compensators have been used for each system module with suitable modifications where necessary in order to achieve the required steady state and transient performance objectives. A supervisory control layer has been used to combine and configure control schemes of the three system modules to suite the requirements of system operation during any one operating state depicted by the hybrid model of the system. Transition management strategies have been devised and implemented through the supervisory control layer to ensure smooth inter-state transitions and bumpless switching among controllers. It has been concluded based on frequency domain linear analysis and time domain electromagnetic transient simulations that the proposed supervisory hybrid controller is capable of operating the wind energy conversion and storage system in both grid-connected and in islanded modes under changing operating conditions including temporary faults on the utility grid.

This thesis presents a supervisory hybrid controller for the automatic operation and control of a wind energy conversion and battery storage system. The supervisory hybrid control scheme is based on a radically different approach of modeling and control design, proposed for the subject wind energy conversion and battery storage system. The wind energy conversion unit is composed of a 360kW horizontal axis wind turbine mechanically coupled to an induction generator through a gearbox. The assembly is electrically interfaced to the dc bus through a thyristor-controlled rectifier to enable variable speed operation of the unit. Static capacitor banks have been used to meet reactive power requirements of the unit. A battery storage device is connected to the dc bus through a dc-dc converter to support operation of the wind energy conversion unit during islanded conditions. Islanding is assumed to occur when the tiebreaker to the utility feeder is in open position. The wind energy conversion unit and battery storage system is interfaced to the utility grid at the point of common coupling through a 25km long, 13.8kV feeder using a voltage-sourced converter unit. A bank of static (constant impedance) and dynamic (induction motor) loads is connected to the point of common coupling through a step down transformer. A finite hybrid-automata based model of the wind energy conversion and storage system has been proposed that captures the different operating regimes of the system during grid-connected and in islanded operating modes. The hybrid model of the subject system defines allowable operating states and predefines the transition paths between these operating states. A modular control design approach has been adapted in which the wind energy conversion and storage system has been partitioned along the dc bus into three independent system modules. Traditional control schemes using linear proportional-plus-integral compensators have been used for each system module with suitable modifications where necessary in order to achieve the required steady state and transient performance objectives. A supervisory control layer has been used to combine and configure control schemes of the three system modules to suite the requirements of system operation during any one operating state depicted by the hybrid model of the system. Transition management strategies have been devised and implemented through the supervisory control layer to ensure smooth inter-state transitions and bumpless switching among controllers. It has been concluded based on frequency domain linear analysis and time domain electromagnetic transient simulations that the proposed supervisory hybrid controller is capable of operating the wind energy conversion and storage system in both grid-connected and in islanded modes under changing operating conditions including temporary faults on the utility grid.

De senaste åren har en större mängd decentraliserad och variabel energiproduktion tagit plats inom elsystemet, mer specifikt vindkraft och solkraft, och etablering av mer distribuerad produktion kommer att fortsätta i enlighet med mål från nationer och världsorganisationer att fasa ut fossila bränslen och minska på växthusgasutsläpp. I takt med nedläggning av storskaliga kraftverk baserade på fossila bränslen påverkar detta möjligheterna att möta upp elbehovet med den tillgängliga produktionen. Mycket variabel produktion har samtidigt en negativ påverkan på elnätstabiliteten och kan skapa höga effekttoppar. Detta har skapat ett ökat behov av mer flexibilitet på kundsidan för att skapa balans på elnätet. Elektrokemiska batterilager kan lösa många av problemen som uppstår med intermittent förnybar energiproduktion. Batterilager har både utvecklats teknologiskt och minskats i pris avsevärt de senaste tio åren och kostnaderna kommer fortsätta att gå ned. För att batterilager på allvar ska bli intressant behöver aktörer som investerar i denna teknologi veta om det någon gång inom en snar framtid kommer att vara en positiv affär. Syftet med detta arbete har därför varit att undersöka lönsamheten med batterilager i kommersiella fastigheter idag och inom de närmsta 10 åren på den svenska marknaden. Studien har, med hjälp av blandad heltalsprogrammering (MILP) i MATLAB, tagit fram en modell som optimalt schemalägger energiflöden för en fastighet som har ett batterisystem och egen produktion installerat baserat på olika prisbilder. Modellen har i sin tur använts för att beräkna de ekonomiska möjligheterna som erbjuds på Sveriges elmarknad med ett batterisystem i en mängd olika scenarier både vad gäller pris på el, olika effektabonnemang, integration med solpaneler, olika batteristorlekar och systemlivslängd. Resultatet visar att det inte finns någon lönsamhet i att investera i batterier för de undersökta fastigheterna så som Sveriges elmarknad ser ut idag och någon hög lönsamhet kommer inte att ske även om pristrenden på batterier fortsätter nedåt. Ett mindre batterisystem på 28 kWh kan ge, beräknat med internräntan, en positiv avkastning på 1 % år 2020 men ju större batteriet är desto mindre blir avkastningen. Högst avkastningen som kan fås med dagens el- och nätpriser är 4-5 % om en investering görs med 2025-2030 års batteripriser. Om elnätsägarna går mot att endast erbjuda tidsdifferentierade nättariffer året om och det implementeras högre effektavgifter finns det möjligheter att avkastningen kan bli så hög som 15-18 % med 2025-2030 års batteripriser. Arbetet visar också att kapandet av effekttoppar med större batterilager än 28 kWh inte är kostnadseffektivt för de undersökta fastigheterna. / The world has seen a rapid deployment of distributed and time-varying renewable energy systems (RES) within the electricity grids for the past 20 years, especially from wind and solar power. The deployment RES is expected to increase even more as world organizations and nations will continue the phase-out of fossil fuels as the main source of energy for electricity production. As large scale power plants reliant on fossil fuels will shut down it will be harder for the system to balance production and demand. At the same time, time-varying production might have a negative effect on the grid stability which has spurred an increased interest in flexibility on the demand side and a call for technologies and strategies that can create balance on the grid. Energy storage, especially electrochemical battery storage, is seen as a part of a bigger solution to the problems that comes with intermittent energy production. Battery storage has had a fast technological development and a sharp downtrend in pricing the latest ten years and the costs are expected to keep on decreasing. For battery storage to be a serious contender on the electricity market there is a need to understand if and when an investment in this technology might give a positive outcome. The aim of this study has therefore been to analyse the profitability of battery storage within commercial real estate today, and in the oncoming 10-15 years on the Swedish electricity market. The study has, using mixed integer linear programming (MILP) within MATLAB, created a model which optimally schedules power flows for buildings that has a battery system and its own electricity production. The model has in turn been used to evaluate the economical possibilities that exist with a battery system within commercial real estate under various different scenarios that looks into pricing structures on electricity and demand, integration with and without solar panels, different battery sizes and system lifetimes. The results show that there is currently no profitability to invest in a battery system for the specific buildings analysed in this study. While break-even is possible just a couple of years from now, a high profitability will not be reached even with the future downtrend in battery prices under the current electricity market circumstances. A smaller battery system with a capacity of 28 kWh could give an internal rate of return (IRR) of 1 % year 2020. Larger battery systems are generally not cost-effective when compared to smaller battery systems when its primary purpose is utilized for demand reduction. Highest return with today’s electricity and utility pricing is 4-5 % somewhere between 2025 and 2030. However, if the market goes towards exclusively time-of-use billing structures on electricity and higher demand charges, the IRR can reach towards 15-18 % between 2025 and 2030.

The Diploma thesis in theoretical part deals with description of possibilities of accumulations of electricity energy focusing on electrochemical accumulators. Next chapter of theory also describes possible applications of battery storages focusing on costumer. In practical part diploma thesis deals with suggestion of simulation model for battery application peak-shaving. Output of the suggestion represents two case studies based on real data of commercial building consumption. Furthermore, practical part also deals with suggestion of control logic for application peak-shaving which was used for verification of simulation model.

Elnätet är ett komplext och viktigt system som konstruerats som en av de mest imponerande bedrifterna under ingenjörskonstens moderna tid. Det överför elektrisk energi till otaliga byggnader, industrier, skolor och hem. Och alltsammans sker konstant, varje minut av varje dag, året runt.  Grundbulten i systemet är den att en ständig balans måste råda mellan produktion och förbrukning av elektricitet. Vid obalans riskerar nämligen strömavbrott och andra oönskade företeelser att inträffa. Huruvida produktion och förbrukning av elektricitet är i nivå kan beskrivas av elnätets frekvens. Genom att övervaka elnätsfrekvensens beteende fås en överskådlig bild av elnätets status i realtid samtidigt som stödtjänster kan implementeras proaktivt för att motverka eventuella störningar. Tidigare har dessa stödtjänster främst representerats av stora aktörer såsom vattenkraftsanläggningar med enorma förutsättningar för att agera som reglerkraft. I takt med en omställning till en alltmer förnybar energipalett ökar dock behovet av ny reglerkraft. Samtidigt syns ett accelererande av installering av batterilager i bostadsrättsföreningar som energieffektiviserar. Eventuellt finns här en outforskad potential. Möjligen kan batterilager i flerbostadshus utnyttjas för frekvensreglering som en ytterligare balanskraft för elnätet. Projektarbetet syftade till att utreda potentialen kring batteristyrd mFRR-reglering från flerbostadshus. För att utvärdera den eventuella lönsamheten modellerades batteristyrningen i MATLAB. Modellen baserades främst på historiska data för upp- och nedregleringsbud från Nord Pool. I och med kravet på 1 MWh som minsta budstorlek på marknaden gjordes antagandet att vid varje regleringstillfälle reglerar batterilagret i aggregation med andra batterilager som tillsammans täcker den totala kapaciteten på 1 MWh. Modellen fungerar på så sätt att varje uppreglering föranleds av en uppladdning av batterilagret via antingen nedreglering eller spotpriser. Beroende på vilket alternativ som är mest lönsamt. Vidare gjordes antagandet att inga uppregleringsbud sker i två påföljande timmar.  Studiens mest lönsamma resultat genererades då batterilagret modellerades för att anta ett uppregleringsbud per dygn med det extra villkoret att samtliga bud som understiger 300 SEK/MWh förkastas. Vid dessa kriterium erhölls ett positivt årligt resultat om 149 100 kr från 306 battericykler.  Med endast frekvensreglering som användningsområde för batterilagret konkluderade dock studien att, det positiva resultatet till trots, ingen lönsamhet kunde uppnås. Investeringskostnaden är nämligen ännu för hög. Å andra sidan tyder teknologiska framsteg inom batterisektorn på en avtagande kostnadsutveckling. Vid år 2030 väntas nämligen priset för batterilager vara 225 USD/kWh, vilket skulle förbättra resultaten från denna rapport. / The electricity grid is a exceptionally sophisticated and crucial system which was created as one of the most impressive accomplishments in modern engineering. It transmits electrical energy to innumerable buildings, factories, schools and homes. And it can never stop. The system relies on the constant balance between generated and consumed electricity. Should an imbalance occur, it might give rise to power outages or failures in appliances on the grid. Whether or not generated and consumed electricity is at balance is determined by the grid frequency. By surveilling how the grid frequency behaves, an overview of the complete system can be obtained in real time. This is useful when it comes to deciding on whether or not to implement supporting mechanisms to counteract disturbances. The supporting mechanisms were historically represented by large facilities such as water power plants who possess great abilities of regulating the power balance on the grid. With the ongoing switch to renewables the need for more regulating power increases. At the same time installments of battery storage in energy efficient housing can be seen as accelerating. Here might be an untapped potential. What if battery storage in residential properties were utilized for frequency regulation as an additional balancing tool for the grid? The intent with this report was to outline the potential regarding power regulating via battery storages in multifamily residentials. In order to evaluate whether or not any profit could be redeemed, a battery control model was developed in MATLAB. The model was primarily based on historic data for regulating bids from Nord Pool. Since requirements on the market states that the lowest bid needs to be at least 1 MWh, the assumption was made that at every regulating occasion the battery regulates in aggregation with more batteries for a total capacity of 1 MWh. The objective of the model is to charge the battery using either spot price or down-regulating bids. Thereafter, an up-regulating bid is chosen. The assumption was made that no subsequent up-regulating bids were chosen. The most profitable optimization of the model was generated when 1 up-regulating bid was chosen per day with the additional condition that all bids under 300 SEK/MWh were rejected. At these criteria a yearly positive result of 149 100 kr was generated from 306 battery cycles. With frequency regulation as sole application for the battery storage, the study concluded that the model was not profitable. The cost of investment is yet too high. On the other hand, technological improvements will surely amount to declining prices. By year 2030 the price of battery storage may have fallen to 225 USD/kWh, which would improve the results in this study.

The use of lithium-ion batteries is something that is becoming more common in today’s society. They are found in a variety of electronic equipment such as mobile phones, laptops and tools. Several incidents have been reported due to lithium-ion batteries ending up in a state called thermal runaway. This in combination with the increasing demands for environmentally friendly and sustainable energy in the form of e.g. wind turbines and solar panels, can therefore lead to unforeseen consequences. Residual energy from wind or solar power can be stored in an energy storage, often a battery system of several interconnected lithium-ion batteries. In case of an incident in these storages where a large quantity of these batteries is located, there is a risk that an explosion will occur. This further leads to the interest if it’s possible to prevent an explosion with the help of mechanical ventilation.  The purpose of this report has been to investigate the reasons why these batteries are being able to cause an explosion, what gases are emitted in the event of a thermal runaway and how explosive they are. With the results given it’s possible to then perform calculations on ventilation capacity needed to maintain a non-explosive atmosphere. This was carried out through a literature study of currently available research combined with information from various authorities, hand calculations and calculations in Excel.  With the results of the literature study, it can be stated that the battery cell consisting of the cathode material lithium-nickel-manganese-cobalt oxide (NMC) is most reactive. The most common gases emitted from these cells during thermal runaway are hydrogen, carbon monoxide, carbon dioxide, methane, ethylene and ethane. These gases are also the most common gases during thermal runaway when the battery consists of a different cathode material, but the distribution may look different. All of these gases, with the exception of carbon dioxide, are flammable and can contribute to an explosive atmosphere.  Three different scenarios are developed where thermal runaway is assumed to take place at a battery cell inside battery storages of different sizes: two container-based energy storage and one battery storage for home use located in a garage space. In these respective scenarios, a certain number of cells are assumed to be in thermal runaway. The lower flammability limit for the ventilated gas mixture is determined to 8,53% based on the amount of emitted gas and the distribution of it due to thermal runaway. With the knowledge of the lower flammability limit of the emitted gas mixture, as well as other available data from each scenario, the desired capacity for ventilation is calculated at 0,23 m3/s for the two container-based battery storages and at 0,035 m3/s for the battery storage located in the garage space. If this capacity of the ventilation is present when thermal runaway occurs, it means that the concentration of combustible gases should remain below the lower flammability limit. It is worth noting that these calculations were performed to some extent based on assumptions and may therefore be judged more as approximate rather than exact.  The conclusions drawn by the performed calculations are that mechanical ventilation is a potential alternative to ensure that the atmosphere in a battery storage doesn’t become explosive if a thermal runaway occurs in the battery cells.

The interest in hydrogen as an energy carrier is growing. The whole world is investing in development of the technology surrounding hydrogen. In general the research regarding hydrogen focuses on hydrogen as an energy carrier, either for transportation as fuel or for storage and usage at a more profitable time or in times of need. In Sweden most of the current research focus on the transportation sector. This thesis explores the other part, stored hydrogen used at a more profitable time. A biogas-plant outside Uppsala city is used as a case exploring if the investment in hydrogen production and storage in combination with a battery storage is economically feasible. A model of a battery, an electrolyser and a hydrogen storage were created in Simulink where the output is the power flow: optimised towards the highest economic profit. Then, an economic analysis is made to explore the feasibility of the investment. The results show that the investment is not feasible in 2021. If the investment cost of the hydrogen system is reduced by 60%, the maintenance costs are reduced by 20% and the profit is increased by 50% the investment becomes feasible with a payback period of 15,2 years. These changes are reasonable in the coming 10 to 20 years with hydrogen technology developing and an increasingly unstable electric grid allowing for higher compensation for frequency regulating services. / Intresset för vätgas som energibärare växer. Hela världen investerar i forskningen kring vätgas. Oftast inriktar forskningen sig på vätgas som en energibärare med två tydliga huvudfokus: som bränsle för transporter eller för lagring och att använda energin vid ett bättre tillfälle. I Sverige fokuserar den mesta forskningen på transportsektorn. Denna rapport bearbetar den andra delen, att använda vätgas för lagring och utnyttja den vid ett mer lönsamt tillfälle eller vid behovssitutioner, till exempel då elnätet blir instabilt. En biogasanläggning utanför Uppsala används som ett fall för att undersöka om investeringen i vätgasproduktion och lagring i kombination med ett batterilager är ekonomisk lönsamt. En modell av ett batteri, en elektrolysör och ett vätgaslager skapades i Simulink där utparametern är effektflödet optimerad mot ekonomisk lönsamhet. Sen undersöktes systemet ekonomiskt utifrån effektflödet för att undersöka om investeringen var lönsam. Resultatet visade att så inte var fallet: det krävs en sänkt investeringskostnad för vätgassystemet med 60%, de årliga kostnaderna behöver sjunka med 20% och den årliga vinsten behöver öka med 50% för att investeringen ska bli lönsam med en återbetalningstid på 15,2 år. Dessa förändringar kan dock ske inom de kommande 10 till 20 åren då vätgasteknologin fortsätter utvecklas samtidigt som ett allt mer instabilt elnät bidrar till möjligheten för ökad ersättning för frekvensregleringstjänster.

With global climate change as the main driver, there is an increase towards including more variable renewable energy (VRE) sources in the electricity mix. Energy production from utilizing the photovoltaic effect, or PV power, is increasing rapidly and is visioned to cover 5 – 10 % of Sweden’s electricity demand in 2040. In addition to rooftop PV production, large- scale PV production in the form of ground-mounted PV parks is gaining ground. A higher share of VRE in the power system creates new challenges as to uphold the power system stability. For a PV park owner, achieving a preferable economic outcome is also a challenge, as the variable electricity output may not match electricity demand. Therefore, combining a PV park with an energy storage, which can store the PV production energy, is seen as a favorable solution. This way, the variability of the electricity production can be reduced and the stored energy in the battery can be used for services benefitting both the PV park owner and the power grid. This study aims to explore the economic potential of combining a PV park with an energy storage. This is achieved by simulating a lithium-ion (Li-ion) battery storage combined with PV production modeled after a 3.5 MW PV park located in Fyrislund, Uppsala. Five cases with individually differing approaches are simulated, exploring how so-called service stacking can be applied with a battery. The investigated services included in the cases are 1) lowering the cost of connecting the PV park to the power grid, 2) lowering the cost of feeding in energy to the power grid, 3) increasing the revenue of selling electricity on the Nord Pool spot market, 4) increasing the revenue by performing energy arbitrage, 5) increasing the revenue by participating in the primary frequency regulating markets to help stabilize the 50 Hz grid frequency. The cases are evaluated by calculating the net present value (NPV) of the system over 10 years with an annual discount rate of 5 %. Battery capacities ranging from 0.1 MWh/0.1 MW to 8 MWh/2 MW are tested. The system configuration achieving the highest NPV occurs when all services are performed, and a 0.13 MWh/0.1 MW battery is used. This NPV is also higher than the NPV when not including a battery in the system. Conclusions include that the spot price impacts the choice of battery capacity to a high extent and that the battery investment cost motivates using a smaller-sized battery.

Med mikronät åsyftas i denna rapport en sammankoppling av solcellsanläggningar som möjliggör delning av elektrisk energi. Målet med undersökningen var att ta reda på vilka förutsättningar som gör att det är fördelaktigt att bygga mikronät. Detta har gjorts genom att undersöka två tidigare fall där mikronät varit intressant och jämföra slutsatserna från dessa fall med resultaten och slutsatserna från en egen undersökning av Södra Hemlingby där mikronät övervägs. Undersökningen av Södra Hemlingby visar att mikronät i deras fall är lönsamt och att tak som troligtvis inte skulle användas till en enskild solcellsanläggning nu kan komma till användning för solceller. Genom att bygga mikronät skulle mängden inköpt el minska, CO2-utsläpp undvikas och eventuellt skulle en högre nivå av Miljöbyggnad kunna uppnås.  Undersökningen av Södra Hemlingby visar också att ett batteri både kan användas till att reducera effekttoppar och att öka egenanvändningsgraden. Vidare dras slutsatserna att bra förutsättningar för mikronät är vid nybyggnation, när grävarbete kan göras tillsammans med andra grävarbeten, när husen som är tänkta att anslutas står nära varandra, då komponenterna i eventuellt befintligt system är kompatibla med mikronätet och således inte behöver bytas ut, då det finns storanvändare av el i systemet, när elanvändningsprofilerna matchar elproduktionen samt då det finns möjlighet till en ordentlig ökning av egenanvändning. Bäst ekonomi uppnås med en storanvändare som är bra på att ta tillvara på produktionen från solpaneler som har ett högt energiutbyte. / The term microgrid in this report refers to a link-up between solar cell plants which make sharing of electrical energy possible. The aim of this survey was to examinate the pre-requisites that makes building of microgrids meaningful. This has been completed by analyzing two earlier cases where microgrids has been evaluated. The conclusions from these cases have been compared with the results and conclusions from an own made survey of Södra Hemlingby where microgrid is considered. The survey of Södra Hemlingby shows that a microgrid would be a profitable investment and that roofs that probably not would qualify for separate plants now was useful. By building a microgrid the amount of electricity from the power distribution grid would decrease, the carbon dioxide emissions would be avoided, and possibly a higher energy classification for the building would be achieved. The survey of Södra Hemlingby also shows that a battery storage could be used for either power reduction or for increasing the own usage rate. The conclusion about good pre-requisites is drawn to be new housing estate, when ditching could be coordinated with other works, short distances between houses in the system, when the components in a existing system is compatible with a microgrid and dont have to be exchanged, when there is a large consumer of electricity in the system, when the electric consumtion profiles matches the production and when there is room for a large increas in own used electricity. Best economy is reached when large consumer of electricity is utilizing the electricity from panels with a high energy exchange.