District heat is currently more exposed for competition than it has been for several years. Since the mid-1980s, district heat has dominated the heat market, but is now in a tougher competitive situation due to the increasing popularity of heat pumps. This, in combination with energy efficiency, has led to a stagnation of delivered energy. The purpose of the study is to investigate the district heating's current competitive situation in Västerås. This will be investigated based on pricing, performance and paragraphs. In order to get a comprehensive picture of the heat market and to find out what factors customers prioritize, housing companies, house makers and villa owners were interviewed. The study's results show that house owners prioritize delivery reliability, followed by economy and environment in the choice of heating method. Actors' views on pricing were different depending on the preferred heating method, where the different views were primarily about the operating and maintenance costs of heat pumps. In order to analyze pricing the life cycle cost was calculated on the basis of real cases. This was done by creating a calculation model in Excel. The result of pricing shows that district heating was the best option for all cases. However, from a new construction perspective, geothermal heat pump for small houses had similar life cycle cost as district heating, while district heating was superior in price for the larger houses. All cases when a customer had change from district heat to heat pumps were unprofitable due to the switching cost that arises. Performance was evaluated by the environmental impact and delivery reliability of the methods. The consequential life cycle assessment was used when calculating environmental impact. The result showed that the district heating in Västerås has a positive environmental impact because of the social benefits it provides. Heat pumps had a negative impact on the environment in all cases. The delivery reliability was studied through actors' views in combination with scientific research, which resulted in the view that district heating is better. The evaluation of paragraph was limited to Boverket’s building regulations. The competitive situation is currently skewed, where heat pumps have a big advantage as houses can limit their energy efficiency with heat pumps. The future of district heating in Västerås is bright. The challenge is to keep their market domination by maintaining a competitive price as the heat market is facing changes with reduced heat demand and tougher competition. / Fjärrvärmen är idag mer konkurrensutsatt än den har varit på flera år. Sedan mitten av 1980-talet har fjärrvärmen dominerat värmemarknaden, men är nu i en tuffare konkurrenssituation bland annat på grund av den ökande populariteten av värmepumpar. Dessutom har energieffektivisering och tuffare krav lett till en stagnation av levererad värme. Syftet med studien är att undersöka fjärrvärmens nuvarande konkurrenssituation i Västerås. Detta ska undersökas utifrån de tre konkurrensmedlen prissättning, prestanda och paragrafer. För att få en heltäckande bild av värmemarknaden samt att ta reda på vilka faktorer kunder prioriterar i valet av uppvärmningsmetod intervjuades bostadsföretag, hustillverkare och småhusägare. Studiens resultat visar att fastighetsägare prioriterar leveranssäkerhet, följt av ekonomi och miljö i valet av uppvärmningsmetod. Trots att samtliga lyfter fram ekonomi som den avgörande faktorn i valet, berodde det på att leveranssäkerheten antogs vara relativt lika mellan uppvärmningsmetoderna. Miljön har ett visst inflytande, dock så länge det inte innebär en allt för hög ekonomisk kostnad. Aktörers syn på prissättning var olika beroende på föredragen uppvärmningsmetod, där de skilda åsikterna främst gällde värmepumpars drift- och underhållskostnader. För att behandla prissättning opartiskt beräknades livscykelkostnaden för de valda uppvärmningsmetoderna utifrån verkliga fall. Detta gjordes genom att skapa ett beräkningsverktyg i kalkylprogrammet Excel där indata kan varieras. Resultatet av den ekonomiska kartläggningen visar att för samtliga fall var fjärrvärmen billigast. Ur ett nyproduktionsperspektiv hade dock bergvärmepump för småhus i princip samma livscykelkostnad som fjärrvärme, medan för de större fastigheterna var fjärrvärmen relativt överlägsen gällande pris. Samtliga konverterande fall där fastighetsägare bytt uppvärmningsmetod var olönsamma, detta på grund av den konverteringskostnad som uppstår. Konkurrensmedlet prestanda undersöktes genom metodernas miljöpåverkan och leveranssäkerhet. Vid beräkning av miljöpåverkan användes konsekvensperspektivet. Resultatet visade att fjärrvärmen i Västerås har en positiv miljöpåverkan på grund av samhällsnyttan den ger, medan värmepumpar i samtliga fall hade en negativ påverkan. För undersökningen av leveranssäkerhet involverades de två aspekterna driftsäkerhet och enkelhet. Detta gjordes genom att studera aktörers syn i kombination med tidigare forskning, vilket resultera i att fjärrvärme är bättre. Undersökning av paragrafer avgränsades till Boverkets byggregler som sätter kraven för fastigheters energiprestanda. I nuläget är konkurrenssituationen skev, där värmepumpar har en stor fördel då fastigheter kan byggas med sämre energiprestanda med värmepumpar. Fjärrvärmens framtid i Västerås är ljus. Utmaningen är att bibehålla deras stora marknadsandelar genom att upprätthålla ett konkurrenskraftigt pris då värmemarknaden står inför förändringar med minskat värmebehov och tuffare konkurrens.

The society changes rapidly and is heavily dependent on energy. The Energy usage in buildings account for about 40% of total Sweden's energy usage, where energy is used by buildings for electricity, cooling and heating. Therefore, energy is an important issue in today's society from an energy use approach to stop the global warming. In this work, a survey was carried out by an office building in Forsmark Kraftgrupp AB to find out about energy use and create a basis for energy-saving measures. The IDA ICE 4.7.1 program was used to simulate the building's energy use by creating a base model of the building. After that, the base model has been compared with different energy efficiency measures to check where the biggest and least energy saving potentials occur. The result shows that the total energy use in the office building is 198 125 kWh / year. The simulations show that energy efficiency measures could reduce energy use in the building by 81 962 kWh / year, which corresponds to 41.4% of the total energy use. Time control of ventilation systems gives the largest energy savings of 51, 2 kWh / m2, year.

Short term regulation, or hydropeaking, provides useful grid services and can be economically beneficial. However, hydropeaking is also associated with environmental impacts concerning flows and water levels. In the south of Sweden, where the electricity demand is greater than the supply, balance regulation from small hydropower plants can contribute to local grid stability. The objective of this report is to evaluate the possibilities for hydropeaking within Mälarenergi’s hydropower plants, with regards to possible power increase and environmental consequences. The report aims to conclude whether there is potential to optimize the operation of the power plants for production of balancing power. A literature study was conducted, as well as a survey of Mälarenergi’s hydropower plants and regulation dams. To describe potential flow regimes, three scenarios for hydropeaking in Kolbäcksån were created in joint consulation with Mälarenergi. The results show that the total increase in available power will vary from around 5 – 11 MW. It is indicated that the largest environmental impact will occur in the scenario with the greatest difference between base flow and peak flow. It can be concluded that several forms of hydropeaking are possible to utilize in Kolbäcksån. The available balancing power is enough to be able to contribute secondary frequency control for Svenska kraftnät. Flow parameters indicate that environmental and ecological impacts will be relatively mild, although this needs to be investigated further. To complement the findings in this report, an evaluation of the economic conditions for the proposed hydropeaking scenarios is proposed as a future project.

A nursing home for old people is going to be built in Edsbyn, a community in Hälsingland, Sweden. The building needs calculation of energy use to receive a building permit. Seven different indicators in Miljöbyggnad were also examined. Miljöbyggnad is a Swedish environmental certification a building can acquire. In the project some changes in selected parameters of the buildings constructions and installations are examined to see how it affects the need of power to heat and the indoor climate. To obtain answers some simulations in IDA-ICE simulation program have been done together with a literature study. The results show that the building fulfills the requirements of specific energy use and mean value of the U-values that are set in BBR24. The building also fulfills the requirements of the number of primary energy and mean value of the U-values that is set in BBR25. Of the seven indicators in Miljöbyggnad that were examined two received the grade GOLD, three received SILVER and two received BRONZE. When building parameters are varied the results show that the largest difference in heating power is when changing the thickness of insulation and the largest difference in PPD, Predicted Percentage Dissatisfied, is when changing the indoor temperature.

This thesis considers the integration between Savonius wind turbines and photovoltaics to form a hybrid power system. Different integration techniques were studied to find the most suited technique and the necessary components. The hybrid system was then to be compared with a solar panel system of equal sizing to investigate whether it could compete in terms of production and profitability. A model of the hybrid systems was built in MATLAB Simulink to simulate the production of the systems. Simulations used SMHI measurement data over wind speeds, solar radiation and temperature, with data resolution of one hour for 2017. The Swedish electricity trading market was also studied to determine which guidelines and prices that apply when selling electricity to the grid. The investment costs for the systems were estimated to allow economic conclusions to be drawn. The result was that a hybrid system had a higher power delivery to the load but the total production was higher for the solar system. The hybrid system couldn’t compete with the profitability of the solar system in the studied case. Possible reasons for the result was that the wind resources at the tested location wasn’t enough and that the price for wind turbines was high. Conclusions was that the price of the turbines needs to decrease in order to make the hybrid system more competitive. For hybrid systems that contain wind turbines, it is important that the chosen site has good wind resources to take advantage of the potential of the turbines.

The European Union’s goal for year 2020 aims to reduce the greenhouse gases by 20 % compared to the levels of 1990. This goal can be reached by increasing energy efficiency and renewable energy sources by 20 %. In Sweden housing stands for 40 % of the total energy usage and in apartment buildings district heating is the most used way for heating and hot water. In this degree project two apartment buildings, connected by a garage, have been studied to see which solutions would yield a saving in both money and the environment. The building is heated using district heating and is ventilated through mechanical exhaust ventilation. Analyzing the current energy consumption and ventilation rates, two heat pump manufacturers was contacted to see what their systems could save in terms of energy. By recovering heat from the exhaust air with a heat pump the buildings can save both money and have a reduced impact on the environment. Having a demand-controlled ventilation in the garage would not give a large enough saving in energy to be worth the investment. The already scheduled fans have decreased their energy usage by half. However by having a demand-controlled ventilation in the garage it could reduce the harmful heavy metals that get released when cars drive in and out. By simply lowering the temperature in the garage from 15 °C to 10 °C could save about 12 500 sek/year in heating costs. The conclusion to this study is that using a heat pump to recover energy from exhaust air is an investment that will generate financial savings for the cooperative apartment and have a reduced negative impact on the environment.

The world today has large challenges in order to manage a changing climate and the consequences that the climate change has on the environment and human living standards. This climate change is largely affected by the emissions of greenhouse gases, which come from usage of fossil fuels. This is a global problem that will affect the whole world and cause an increase of mean global temperature, which would lead to drastically changes in the living environment for human beings. A large part of the use of fossil fuels is connected to electric energy production. In EU almost half of the electric energy production is based on combustion of fossil fuels like natural gas and coal. These types of energy production need to be phased out and the energy consumption needs to decrease.   With climate change as a background there is a development towards more sustainable households. Companies around the world today invest in developing products that are more environmentally friendly. Household appliance companies develop products that use less water and energy, and a company like ASKO appliances AB tries to equip their machines with a new type of drying system. This new system would mean that less energy is needed for the drying cycle and humid air would not flow out in the kitchen.   The new drying system uses an air channel mounted on the side of a machine where moist hot air passes through the channel. During the passage the hot air will exchange heat with a cold surface inside of the channel. This work is focused on finding an optimal geometry of the air channel that enhances heat transfer between hot air and a cold surface. Installing obstacles inside of the duct could alter the flow pattern, and therefore enhance heat transfer. The work is mostly computer based with simulations performed in software called COMSOL Multiphysics. The software is used to build a 3-D model, where different geometries of obstacles are placed inside of the air channel. Results from simulations are compared with results from experimental trials, thus validating the computer model. Fluid flow simulations are used to investigate the effects of heat transfer for different types of geometries and sizes of obstacles. Parameters like influence angle and obstacle distance are tested.   The study shows results that obstacles inside of an air channel enhance heat transfer between a fluid and a surface. V-shaped obstacles perform the best results in order to enhance heat exchange, this compared with other tested geometries like W-shaped, wave-shaped obstacles and geometry without obstacles.   Different influence angle and distance between obstacles affects heat transfer, the study indicates that influence angle has larger effects on heat transfer than obstacle distance.

A high demand of both electricity and heat exists in Arizona Chemical (a chemical plant dedicated to the distillation of Crude Tall Oil) for production processes. Due to the rising cost of resources and electricity, more and more companies are trying to decrease the energy expenses to increase their competitiveness in a global market, thus increasing their profit. Some companies look at their energy consumption in order to diminish it or to explore the opportunity to generate their own and cheaper energy. In companies where the production of steam already takes place, cogeneration can be a good solution to palliate the cost of the energy used. This study addresses this issue through three actions such as the characterization of the boiler, a better steam flow measurement grid and the generation of electricity. The first one addresses the state of one of the key parts of steam production, the boiler, through the calculation of its efficiency with two different methods (direct and indirect calculation). These methods require some measurements which were provided afterwards by the company supervisor. This will allow the company to identify the weaknesses of the boiler to be able to improve it in the future. The second one aims to improve the knowledge about the steam system. New flow measurement points were suggested after doing an analysis of the current controlled flows to have a better overview outline of the steam use.The third one studies the generation of electricity with a Rankine cycle. The limitations in the characteristics of the steam were identified and different configurations are proposed in accordance to the restrictions identified. An efficiency of 93% is obtained for the boiler with the direct method and 82.3 % for the indirect one. The difference between them can be explained by the use of datafrom different time frames for both methods. The main contributors to the losses are the ones related to the dry flue gas and the hydrogen in the fuel. In the current status only 40% of the steam flows are identified, a number which is expected to raise with the new measurement points. It was not possible to estimate the effect of the new points due to the desire of the company to not disturb the current production. Due to the fuel price the production of steam for only electricity was not profitable and instead the generation of both electricity and heat from the same steam is proposed. This integrated system is now possible to implement due to its low payback time (2.3 years). This solution can generate 758 kW of electricity and provide the company with 6437 MWh of electricity each year. Then, the effect of the variation of different variables over the performance of the cycle were studied: different electricity prices, steam rate production, fuel cost and the state of the condensate recovery were discussed. The variation of both the condensate recovery and fuel cost did not affect the payback time due to their costs being neutralised by the revenues obtained from them. The variation of the electricity prices and steam production affects the payback but due to the high revenue that is expected it does not hamper the good nature of the investment. The generation of electricity is recommended due to the low payback time obtained. The different variations studied in the system did not change the payback time notably and showed that the investment is highly profitable in all the scenarios considered. The use of two smaller turbines instead of the one chosen (with a maximum rated power of 6 MW while only 758 kW is generated with the proposed solution) should be studied since the turbines would work closer to their maximum efficiency.

This report is made as a literature review, focusing on the work done to increase understanding of efficiency in the categories of substations and secondary heating systems, with respect to the deviation from the theoretically possible cooling off in the distribution network as well as the economic benefit that appear. The main purpose of a considerable part of the literature used in this report addresses the issue of identifying individual causes of reduced cooling in district heating systems. These literature resources have been compiled and summarized as part of the report. The technology of district heating is associated with benefits such as better use of the energy in a fuel. This is the case of cogeneration plants where serial generation of electricity and thermal energy increases efficiency compared with the parallel generation where heat is generated locally and electricity is generated centrally. Serial generation thus allows for lower primary energy demand. Another benefit from combustion in units with higher capacity installed is that a higher control of emission with environmental impact is permitted. Additionally local environment change drastically when a few large supply units replace a large number of local supply units. It has also been shown that district heating can reduce greenhouse gas emissions in a cost efficient way. Thus being a part of the energy system to achieve the EU climate goals In Sweden, district heating is developed to a high degree. In connection with decreasing focus on expansion, the focus on maintenance and optimization and how district heating should look like in the future increases. In conjunction with lower heat demand from new and renovated buildings distribution cost will increase. For district heating to maintain competitiveness a development in distribution technology that move toward the next generation of distribution technology is necessary. Average temperatures today in Swedish district heating systems are for supply water 86 ° C and for return water 47 ° C. In the future temperature levels could decrease to current with temperatures down against 55 ° C supply temperature and 25-20 ° C return temperature. The latter system temperature levels moves towards the ideal possible. It is possible to distinguish four generations of district heating distribution technology. The differences between generations are essentially depending on temperature levels but also depend on state of matter. The first generation district heating used high-temperature steam for heat transfer and then the newer distribution technologies resulted in lower temperatures and change of phase, from gas to liquid. The third generation of district heating distribution technology meant lower temperature than the second generation, and likewise the fourth generation will have a lower temperature level than the third-generation distribution technology for district heating. The development is driven by the benefits of lower temperature levels. One of the more appealing benefits of lower supply temperature is the possibility to use low exergy heat, resulting in reduced need of primary energy. The potential heat sources where increased heat supply with lower system temperatures becomes available can be seen in the four next bullets. Waste heat Geothermal heat Solar heat Heat pump Other advantages obtained with lower temperature levels in heat distribution are. Lower distribution losses Higher electrical power efficiency in CHP Increased efficiency in flue gas condensation Increased capacity in the distribution network Reduced need for pump power in the distribution network Lower risk of serious scalding Increased capacity in heat storage Ability to use other materials for distribution at lower cost There seem to be a consensus in the literature that lower temperature levels in district heating systems are a desirable change. The reason for this is likely that there are mostly advantages of lower temperature levels. The drawbacks of lower temperature levels are negligible which make the risk of investment low.

This report is the result of a master’s thesis project which covers the cooling system in Volvo Cars’ fuel cell test vehicle. The purpose is to investigate if the existing cooling system in the fuel cell test vehicle works with the current fuel cell system of the vehicle, in terms of sufficient heat rejection and thus sustaining acceptable temperature levels for the fuel cell system. The project also aims to investigate if it is possible to implement a more powerful fuel cell system in the vehicle and keep the existing cooling system, with only a few necessary modifications. If improvements in the cooling system are needed, the goal is to suggest improvements on how a suitable cooling system can be accomplished. This was carried out by modeling the cooling system in the simulation software GT-Suite. Then both steady state and transient simulations were performed. It was found that the cooling system is capable of providing sufficient heat rejection for the current fuel cell system, even at demanding driving conditions up to ambient temperatures of at least 45°C. Further, for the more powerful fuel cell system the cooling system can only sustain sufficient heat rejection for less demanding driving conditions, hence it was concluded that improvements were needed. The following improvements are suggested: Increase air mass flow rate through the radiator, increase pump performance and remove the heat exchanger in the cooling system. If these improvements were combined it was found that the cooling system could sustain sufficient heat rejection, for the more powerful fuel cell system, up to the ambient temperature of 32°C.