In order to ensure a stable power system, a balance between production and consumption at every given moment is necessary. An indication of this balance is the system frequency, which deviates from its nominal value in case of imbalance. With an increasing share of weather dependent energy in the Nordic synchronous system, such as wind power, the need for stabilizing services are becoming even more crucial. Ancillary services are a way of keeping the frequency stabilized, they are provided by different actors in the power system with flexible production or consumption. This contributes to increasing or decreasing the input and output of energy to the system when needed. Ancillary services are procured in separate markets that are structured and designed by the transmission system operator, Svenska kraftnät. This thesis investigates wind power and its potential of providing ancillary services in the Swedish power system. The report presents two different studies which are performed based on two specific wind farms in Sweden. Firstly, the possibility of providing ancillary services by the wind farms alone are considered with emphasis on the economic profitability. A model is used to present a theoretical maximum of income based on historical production and market data from 2022. The second study has an additional aspect of combining the wind farms with a battery energy storage system (BESS), creating a hybrid system, to examine the potential improvement of income for the company. Due to the production being dependent on weather conditions, the BESS can provide additional contribution when needed. The second study is performed using an optimization model in order to optimize the use of the BESS for the simulated period. The results presented an increase of revenues when participating on the ancillary service markets for both studies. The first study showed that down regulating services were the most profitable, this being FCR-D down and aFRR down. With the hybrid system, the profitability was even more significant. It demonstrated a big potential of participating on the FFR market during the summer and FCR-D during winter. Furthermore, the hybrid system also showed an increase in participation on the up-regulating markets. Without the BESS, the windfarm is forced to curtail production toparticipate in the up-regulating markets, which proved to be less profitable than participating on down-regulating markets. The results also give an understanding of the cycling of the BESS and how this affects the results and the BESS lifetime. With coming market development, the conditions on the ancillary service markets is expected to change, the effect of this is considered in a sensitivity analysis. Finally, the studies collectively show the opportunity for wind power to contribute to stabilizing the power system and ensuring the security of energy supply in the Nordicsynchronous system.

The transition to a fossil-free industry is a current topic, and in Swedish industry, energytransition of existing energy systems is promoted to reduce climate impact. Energy transitioninvolves a structural change in the energy system with a focus on energy use and energysupply. To reduce global greenhouse gas emissions, the transition can be achieved throughelectrification and the use of biomass. Currently, sawmills combust significant amounts of biomass to meet the heat demandof industrial wood drying. As the biomass used is a by-product of the sawmills’ otherproduction processes, this combustion is usually considered sustainable and circular. However,some research indicates that increased biomass usage in several industrial sectors can leadto overexploitation of the resource with negative environmental impacts. Despite thesedisagreements, many argue that bio-based residual flows must be utilised efficiently to meetsociety’s future biomass needs. Against this background, it needs to be examined whether sawmills should continue tocombust biomass or whether an energy transition would be more economically and ecologicallysustainable. The aim of this study is to investigate how energy use in the sawmill industrywill change in the future and what potential consequences this change may have. In addition,the possibilities and feasibility of electrifying the drying process in the sawmill industryare investigated. To achieve this purpose, a literature search and an interview study wereconducted. The results from these parts form the basis for a scenario-based quantitativestudy of the consequences of different energy transition cases. The results show that future energy use in the sawmill industry will be affected by severalfactors. One important factor is the price of biomass, which can provide an incentive toelectrify the energy-intensive drying process. However, it can be challenging to make anelectrified drying process profitable, and until then energy efficiency will be prioritised ratherthan biomass replacement. The results also indicate that electrification of the drying processcan reduce the climate impact, assuming that the electricity source is fossil-free. The releasedbiomass can then be used more efficiently than incineration, and the optimal use may be toproduce long-life products. Clear knowledge gaps have been identified regarding the electrification of the drying processand its potential consequences. Since the sawmill industry is not ready for an energytransition today, there is time to fill these gaps and develop the electrifying processes. Furtherinvestigations should be conducted on various aspects of electrified drying through in-depthmodelling and analysis of the sawmill energy system. Additionally, future studies couldinvestigate the extent of the impact of sawmill biomass release on the surrounding energysystem.

In this study, the parameters of population, gross domestic product (GDP), heat price, U-value, and temperature have been used to predict heat consumption for Sweden till 2050. It should be noted that the heat consumption has been considered for multi-family houses. Most multi-family houses (MFH) get their primary heat from district heating (DH). A literature analysis of various models and variables has been conducted to enhance comprehension of forecasting and its process. The majority of earlier research has focused on electricity or energy rather than heat. The aim of this study is to create a model (linear and non-linear) from 1993 to 2019 with a minimum error as possible, and then use the genetic algorithm (GA) and neural network (NN) to predict Sweden's heat consumption till 2050

Backup power is essential to supply important functions in society with electricity in case of a blackout. Today in Sweden most backup generators are based on diesel fuel and seldom used, but they are still associated with bad environmental impact while operating. What if a backup system could be designed to increase its value and at the same time lower the environmental impact? This study has investigated alternative solutions for backup power and applied them on a specific case. A food providing industry with great variations in their load profile (40 - 240 kW) is looking for a backup solution able to supply the industry for 12 h in case of a blackout. The study started off by investigating different techniques and their suitability for providing backup power, such as diesel generators (DG), battery energy storage systems (BESS), micro gas turbines (MGT) and fuel cells (FC). Most suitable to be compared with the traditional diesel solutions in terms of cost, climate and technique was found to be two hybrid systems. The first one a combination of a DG and BESS and the second a combination of a MGT and BESS. The two hybrid systems were primarily dimensioned to a size of 100 kW (DG/MGT) with a 350/350 kWh/kW BESS based on terms and after analyzing the industry's load profile. The two hybrid systems were compared with a 350 kW DG in two aspects over a time frame of 15 years, life cycle costs (LCC) and carbon dioxide emissions. Compared with only DG the result showed a 15% LCC increase and a 26% emission reduction for the hybrid solution with DG + BESS. For MGT + BESS the LCC increase was 30% but the emission reduction was 52%. Included into the LCC analysis is utilization of the BESS for grid services such as peak shaving, arbitrage and grid support which had a major positive economic impact. The LCC results were however sensitive to changes in some parameters such as investment costs and rates. Finally, the study tried to optimize the cost and climate performance of the two hybrid systems. By reducing a few terms, sizing of the systems could be adjusted. This resulted in both hybrid systems being more profitable and climate friendly with a larger DG/MGT and a smaller complementing BESS for peak loads, outperforming the only DG solution.

This thesis examines the possibilities and limitations of connectingoffice buildings to demand response (DR) programs, with emphasis on the effect it has on indoor climate. Heating, ventilation and airconditioning (AC) systems was used as sources to scale power, and thereby contribute with power to capacity markets related to the electrical grid. By simulations performed in MatLab, as well as livetests in one of Vasakronan’s buildings, this work contributes with knowledge of DR in office buildings in the Swedish environment, which to date have been lacking in literature. All systems considered in thisreport has potential to contribute with power to DR programs. Heating and AC systems has greater power saving potential than the ventilation system. However, ventilation also holds potential as a source of power savings and is applicable to a larger portion of the building stock.Indoor air carbon dioxide level is affected to varying degrees depending on the extent of power reduction, where a reduction up to 90 % of ventilation is possible without exceeding approved limits. Reduction of ventilation caused the highest rise in carbon dioxide levels during mid- day and especially during the winter. Flexibility is key for the control system, especially when considering future climate challenges andtrends. DR strategies should include control of all systems both during the active DR time but also when returning to normal activity to reduce the risk of compensation from other systems.

With the growing acceptance of photovoltaic (PV) systems globally including Sweden, an increasing number of PV systems has continually been installed all through Sweden. In this study, a selected residential area in Uppsala Sweden is considered as a possible site for PV system installation. Due to the intermittent nature of this energy source and the disturbances it causes to the grid, there is therefore the need to determine the amount of PV that can be accommodated by the already existing grid without any adverse effect to it. This is known as hosting capacity (HC). The HC signifies the level of risks the network operator as well as customers are willing to take with regard to the stability of the grid network. Many possibilities exist by which this can be done which are well discussed later in this report. However, the deterministic method is used in this work. For an effective determination of the HC, the DIgSILENT Power Factory 2021 is used to simulate a synthetic network assumed to be similar to that of the area studied. A parametric analysis is also done to as certain the impact some network variables would have on the limit of PV systems a grid network can accommodate. The results of the study showed that under 0 % penetration, the grid network is stable and no violations witnessed neither from the network with 800 kVA transformer considered as the main network in this study nor that with 500 kVA used for the parametric studies. However, the loadings on the two transformers varied by about 15 %. Integrating PVs into the grid network introduced some level of instability which increases as the size of the PVs increases. This shows the need to peg the PVs’ size to a certain maximum to be able to have control over the grid network. Customers are allowed to install lower sizes but not more than this maximum. The results also showed that changing the transformer size do not affect the nodal voltages nor the cable loadings in the network provided all other parameters remained the same. The only impact is on the transformer loading, with smaller transformers experiencing higher loading condition. This study serves as a basis to determine the initial range of PV sizes customers are allowed to install in the area studied in Uppsala Sweden.

Ett viktigt steg vid tillverkningen av ett energieffektivt och hållbart trädbränsleär torkning. Torkprocessen är energiintensiv och kan uppgå till så mycket som en fjärdedel av trädbränslets totala produktionskostnad. En både låg och jämnt fördelad fukthalt är en avgörande faktor för bränslets kvalitet och vidare användning. Det i sin tur ställer höga krav på en energieffektiv torkprocess som producerar ett bränsle med önskad kvalitet. För att vidare bidra till forskningen inom torkning av trädbränslen har en laborativ ångtorkanläggning med fast bädd byggts på Karlstads universitet. En tidigare studie har gjorts på torkanläggningen där träflis ångtorkades. I resultatet av studien visade det sig förekomma oönskade fuktvariationer i den torkade flisen till följd av en ojämn flödesbild. Flödesbilden beskriver hur ångflödet sprider sig genom flisbädden och är en viktig faktor för en jämn torkprocess och torkanläggningens effektivitet. Syftet med studien är att effektivisera torkanläggningen genom att förbättra flödesbilden, samt fastställa hur torkanläggningen bör köras för att säkerställa en produktion av ångtorkad flis med en jämnt fördelad fukthalt. Temperaturmätningar på flisbädden gjordes under drift och användes som underlag för att bestämma hur torkanläggningen bör byggas om för en jämnareflödesbild. Den ombyggda torkanläggningen utvärderades med avseende på energianvändning, SMER och slutlig fuktvariation i den torkade flisen. Utifrån torkförsök med olika driftförutsättningar på ångflödets dynamiska tryckstegring, ångtemperatur och bäddhöjd fastställdes ett rekommenderat driftfall. Genom att montera en perforerad plåt framför flödesinloppet till torkkammaren på torkanläggningen kunde torkkammarens uppvärmningstid minskas med 5 minuter. Vidare reducerades energianvändningen med 11%, samtidigt somSMER ökades med 14% i förhållande till före ombyggnation. Fuktvariationeni flisbädden reducerades från 21% till 8%. Rekommenderad drift fastställdes till en dynamisk tryckstegring på 200 Pa, en ångtemperatur på 180˚C och 100mm bäddhöjd. / An important step in the production of an energy-efficient and sustainable wood fuel is drying. The drying process is energy demanding and can amount to as much as a quarter of the wood fuel's total production cost. A both low and evenly distributed moisture content is a decisive factor for the quality of the fuel and its further use. This in turn places high demands on an energy-efficient drying process that produces a fuel of the desired quality. To further contribute to the research in the drying of wood fuels, a laboratory steam drying plant with a fixed bed has been built at Karlstad University. A previous study has been done on the drying plant where wood chips were steam dried. The results of the study showed undesirable moisture variations in the dried wood chips as a result of an uneven flow pattern. The flow pattern describes how the steam flow distributes through the bed of wood chips and is an important factor for an even drying process and the overall efficiency of the drying plant.The purpose of the study is to increase the efficiency of the drying plant by improving the flow pattern, and to determine how to operate the drying plant to assure a production of steam-dried woodchips with an evenly distributed moisture content.Temperature measurements on the wood chip bed were made during dryingexperiments and were used as a basis to determine how to rebuild the drying chamber for a more even flow pattern. The rebuilt drying plant was evaluated regarding energy use, SMER and final moisture variation in the dried woodchips. Based on drying experiments with different operating conditions on the dynamic pressure rise of the steam flow, steam temperature and bed height, a recommended operating case was determined. By placing a perforated plate in front of the flow inlet to the drying chamber of the drying plant, the preheating time of the drying chamber could be reduced by 5 minutes. Furthermore, energy use was reduced by 11%, while SMER was increased by 14% compared to before the rebuild. The moisture variation inthe wood chips was reduced from 21% to 8%. Recommended operation conditions were set at a dynamic pressure rise of 200 Pa, a steam temperature of 180˚C and 100 mm bed height.

I Sverige kommer största delen av producerad el från förnybara källor men solenergin står i dagsläget för ett litet bidrag till den svenska elproduktionen. Energipolitiska mål gör gällande att Sverige ska ha 100% förnybar elproduktion år 2040. I dagsläget är industrisektorn en av huvudkonsumenterna av elektriciteten i Sverige. Industrifastigheter lämpar sig ofta väl för takmonterad solcellsinstallation. Genom energieffektiviseringar och användning av förnybar el kan företag reducera sina elkostnader och sin miljöpåverkan. Överproduktion av el från solcellsanläggning kan dessutom generera inkomster från såld solel. Målet med arbetet var att förse industriföretaget Springwire Sweden AB med jämförande energi-, ekonomi- och miljöanalys för olika investeringsscenarier av solcellsanläggning och/eller LED-belysning för att presentera investeringen med bäst lönsamhet, kortast återbetalningstid samt störst miljöpåverkansreduktion. Föreslagna scenarier undersöktes med avseende på energiflöden, ekonomisk genomförbarhet samt miljöpåverkan och jämfördes med företagets nuläge med hjälp av energikartläggning, kostnads-/intäktsanalys och livscykelanalysmetoder. Med hänsyn till rådande skatteregler för solcellsanläggningar begränsades största enskilda undersökta solcellsanläggning till 500 kWp. Springwire förfogade över två fastigheter vilka båda kunde husera varsin 500 kWp-anläggning på taket och därför undersöktes installation av 500 kWp-anläggning på båda fastigheternas tak (500+500 kWp). De ekonomiska resultaten visade att solcellsanläggningen 500+500 kWp kombinerad med LED-belysning var den mest lönsamma investeringen av de undersökta investeringsfallen under antagna ekonomiska livslängden 30 år. Nettonuvärdet, investeringens lönsamhet, för 500+500 kWp-anläggningen kombinerad med LED-belysning var 10 MSEK. LED-belysning var investeringen med kortast återbetalningstid, 2,5 år. Investeringen 500+500 kWp kombinerad med LED-belysning minskade koldioxidavtrycket för företagets produkter med 24% jämfört med nuläget. Det innebar att miljöpåverkan för varje ton ståltråd minskade med 19,5 kg CO2e vilket med hänsyn till företagets totala ståltrådproduktion per år motsvarade minskning med 80 ton CO2e. Studiens resultat visade att genom att investera i solcellsanläggning och/eller LED-belysning kan industriföretag inom ståltrådproduktion öka sin ekonomiska lönsamhet över tid och samtidigt minska miljöpåverkan från sina produkter. / In Sweden, most of the electricity produced comes from renewable sources, but solar energy still accounts for a small contribution to the Swedish electricity generation. Energy policy goals state that Sweden will have 100% renewable electricity production by 2040. Currently, the industrial sector is one of the main consumers of the electricity in Sweden. Industrial properties and buildings are often well suited for roof-mounted photovoltaic system (PV system) installation. Through energy efficiency improvements and the use of renewable electricity sources, companies can reduce the corresponding energy costs and the environmental impacts. Overproduction of electricity from PV systems can also generate income from sold solar electricity. The aim of this work was to provide the industrial company Springwire Sweden AB with comparative energy, economic and environmental analysis for different scenarios on the investment in PV systems and/or LED-lighting to present the investment with the best profitability, shortest payback period and largest environmental impact reduction. The proposed scenarios were investigated in terms of energy flows, economy feasibility and environmental impacts, and were compared with the current energy sources in the company using energy mapping, cost-benefit analysis and life cycle assessment methods.  Regarding the current tax rules for PV systems, the largest individual investigated PV system is limited to 500 kWp. Springwire has two properties where each building could be host of a 500 kWp plant on the roof and therefore the installation of a 500 kWp PV system on the roof of both properties (500+500 kWp) was investigated. The economic results shows that the PV system 500+500 kWp combined with the LED-lighting is the most profitable investment over the assumed economic lifetime of 30 years between all the proposed scenarios. The net present value was found to be SEK 10 million for the 500+500 kWp PV system combined with LED-lighting. LED-lighting was the investment with the shortest payback period, 2.5 years. The investment of the 500+500 PV system combined with LED-lighting would reduce the carbon footprint of the company's products by 24% relative to the current scenario. It means the climate impact of each ton wire would decrease by 19.5 kg CO2 eq, and considering the total amount of the company production per year, this value would be 80 ton CO2 eq.  The results of the study revealed that by investing on photovoltaic systems and/or LED-lighting, industrial companies on wire production can increase their economic profitability over time while reducing the environmental impact of their products.

Energy efficiency of buildings is becoming more and more common as a step towards decreasing the amount of climate emissions in the world. In the Swedish city Gothenburg, there are many existing buildings that soon faces extensive renovations due to age and therefore they have a lot of potential to, at the same time, improve the energy efficiency. Some of the buildings uses district heating as heating system and therefore this project has included an investigation of how the energy efficiency of a building affects the delivery of the district heating. The project also included an investigation of how energy efficiency of existing buildings affects the planning of the future needs of district heating.By applying energy saving measures on a reference building that can represent all the buildings in an area can the maximal power use at the DVUT be forecasted. The energy savings impact on the building’s energy- and power signatures is also a part of the study. The result of the energy savings measures is then used in an example of Gothenburg´s urban development by applying the results of the reference building on an area called Heden.The project includes a study, a model in VIP-Energy, an economic analysis of the energy savings and the example of the urban development of Heden. The results shows that the suggested measures reduce the primary energy number by 47 % and that the maximal power use reduced by 50 %. For property owners the economic analysis showed that the measures were not enough profitable. On the other hand, did the result, by the example with Heden also showed that Göteborg Energi can profit by reducing the energy use in existing buildings because it reduces the future additional net power.

A method of providing ventilation using impinging jets (IJV) utilizes stratification while delivering air at a high velocity. As a result of this attribute and the simplicity of its terminal construction, IJV offers an advantage over the well-known Displacement Ventilation (DV) system. The corner IJV system was used during this investigation to construct the Computational Fluid Dynamics (CFD) simulation protocol. To verify the suitability of the turbulence model used in the CFD simulation, numerical values derived from several turbulence models were compared to full-scale experiment data. The results of this study demonstrate that turbulent models are the most important factors when using CFD for the study of the velocity field generated by IJVs terminals. A parametric study was conducted after the models were created and verified using the CFD software COMSOL to determine which is the most suitable arrangement for occupants' ventilation and draught avoidance in a square room. Calculations using computational methods were conducted to characterize the rooms' performance under different operating conditions and cross-sections of the air supply terminals. Among the findings of the research is that increasing the cross-section of the supply terminal reduces the sensation of local discomfort, but decreases air velocity speeds. Furthermore, placing the supply terminal on the same side of a room block improves occupant satisfaction, whereas placing the supply terminal on opposite sides enhances ventilation efficiency.