Thesis (Ph.D.)--Lehigh University, 2007. / Adviser: A. R. Marder.

The market for energy production has experienced relevant changes to reach more sustainable characteristics, during the last two decades. In this context, residential photovoltaic (PV) system has gained popularity as a practical and profitable alternative to complement the electric supply from the grid. In the same line, the seasonal and variable nature of PV supply generates an interest in BESS-battery energy storage systems.The aim with this thesis is to investigate HEMS-home energy management system for a residential electricity production using PV and storage in Sweden. HEMS allows residential customer and producer to sell or buy energy to minimize the final electricity bill. The capacityof BESS and the scheduling are optimized by using a proposed algorithm. Results gained indicate that factors such as household electricity demand and allocation during the day, electricity price, and tariff scheme are the critical variables to consider in the design of the BESS system. Optimal battery capacities obtained are within the range of available battery market stock-sizes. However, several of the standard battery capacities of the leading manufacturers are oversized for this case. For Swedish context, a BESS installation cost below 270 €/kWh generates saving on the annual electricity bill of having BESS in comparison with not using BESS. In addition, the daily charge of EV, electric vehicle, was studied to see if a higher demand for household electricity could generate an optimal capacity and higher savings. / Marknaden för energiproduktionhar under de senaste två decenniernagenomgått förändringar för att bli mer hållbar. I detta sammanhang har solcell-system eller photovoltaic, PVför elproduktion i bostäder blivit ett praktiskt och lönsamt alternativ för att komplettera elförsörjning från elnätet. Solcellernas produktion är dock säsongsbetonadoch varierar även över dygnet varför system för lagring av el i batterier s.k. BESS blir intressant.Syftet med denna uppsatsär att undersöka HEMS, ett hushålls system för hantering avel-generering med solcelleroch batterilagring i Sverige. HEMS tillåter bostadskunder och producent att sälja ochköpa elför att minimera den slutliga elräkningen. Kapaciteten för BESSoch schemaläggning optimeras med hjälp av en föreslagen algoritm. De uppnådda resultaten tyder på att faktorer som efterfrågan på hushållsel och fördelning under dagen, elpriset och systemen för taxaär de kritiska variablernaatt beakta vid utformningen av BESS. Optimal batterikapacitet som uppnåtts ligger inom området för, på marknaden, tillgängliga batteristorlekar. Flera av de vanligaste batteriernas kapacitet,hos de ledande tillverkarna,är dock överdimensionerade. För svenska sammanhang genererar en BESS-installationskostnad under 270 € / kWh besparingar på den årliga elräkningen i jämförelse med att inte använda BESS. Som tillägg studerades daglig laddning av en elbil för att se om ett större elbehov kunde generera en mer optimal kapacitet och än större besparinga

Smurfit Kappa Piteå is the largest kraftliner producer in Europe. At the mill they have five different steam producers and one of those is the biomass boiler, which is a steam boiler producing overheated steam at 120 bar and 520C. The purpose of this report is to investigate the possibilities to increase the feedwater temperature from today’s 180C to 210C. The consequences on the system are depending on the temperature in the different process stages and the process temperatures are therefore calculated via a method named The NTU-method which is a suitable method to analyze the heat transfer within an object when the ingoing and outgoing temperature are unknown. The feedwater is preheated with a heat exchanger that is heating the feedwater from 130C to 180C using steam with a pressure of 11 Bar. To increase the temperature to the desired  the approach is to install a complementary feedwater heater that uses steam with a pressure of 27 Bar. The new heater is supposed to heat the feedwater from 180C to 210C while the old heater takes the temperature from 130C to 180C. If the old heat exchanger approaches its end of life span it may have to be replaced with a new one with the same design data. One way to fulfill the required heating is to install one feedwater heater that takes the temperature from 130C to 180C using steam with a pressure of 11 Bar and in the next step install the second feedwater heater that takes the temperature from 180C to 210C using steam with a pressure of 27 Bar. There are two alternatives to installation of complementing high pressure heat exchanger. First alternative A is to install the second feedwater heat exchanger between the economizer and the steam dome. Second alternative B is to install the second feedwater heat exchanger between the already existent heat exchanger and the economizer. The consequence of the installation B is an increased energy loss due to the combustion gases while the consequence of installation A does not involve any increase in energy losses. Therefore, alternative A is wiser. However, whatever alternative that is chosen problem will arise since the temperature margin between the steam dome’s saturation temperature and incoming feedwater temperature needs to be at least 25C. This means that the largest possible pre-warming between the boiler’s workload 50-110% is 21C which not do apply to the whole interval. So, as it seems, the utilization of a second feedwater heat exchanger is not applicable over the whole interval of workloads. The increased feedwater temperature come with other consequences on the system. The whole system will be changed due to the increased temperature and it will affect the details. Some of the pipes must be replaced with new ones that fulfills the restrictions accompanying higher process temperatures. The purpose of the increased feedwater temperature is to increase the mass flow steam to the turbine. From calculations and the extraction-steam-consumption graph the increasing net power outcome from the turbine will increase with about 7.5% due to the increasing feedwater temperature. This will make the turbine produce even more electric energy and generate a bigger income to the factory. The investment cost is in total approximately 25MSEK, including replacing the old feedwater heater with a new one and installing a second feedwater heater. With a payback time of eight years and a life span of ten years it is necessary to question the economic potential of the installation. It provides a hint of the potential of the project. However, one should know that all numbers in this report are estimated from rough calculations.

Climate change is one of the most significant challenges to sustainable development facing the international community. Increased attention has been given by industries and governments from both industrialized and developing countries to reduce greenhouse gas (GHG) emissions through the clean development mechanism (CDM), one of the Kyoto Protocol's (KP) flexible mechanisms. China is the biggest developing country in the world. The energy demands in China are increasing quickly with its rapid economic growth. However, low energy efficiency and coal-dominated energy make China the world's second largest CO2 emitter behind the United States. Sweden, an industrialized country with high-energy efficiency and a good renewable energy system, shows its leadership in international cooperation and competence on the climate change issues. Sweden has already declared its desire to contribute to making KP's CDM work and become an effective instrument in the work on international climate change mitigation. It is of great interest to investigate the possibilities and the potential of GHG emission reduction through CDM. The objective of the work, considering the mitigating greenhouse gases in a global perspective, is to study how to introduce CDM with technology transfer between Sweden and China. This study provides illustrative examples of opportunities and benefits as well as revealing the problems associated with this mechanism. Two research areas, i.e. bioenergy technology and energy efficiency in the steel industry, are studied in this thesis. Regarding bioenergy technology, with consideration of technology status and biomass resource differences between Sweden and China, this study explores the potential and benefits of implementing Swedish advanced bioenergy technologies in China. A case study further shows that it is possible to produce and utilize wood pellets in China by using Swedish technology under CDM. As for the energy efficiency in the steel industry, an optimization model was developed to simulate CO2 emissions. The modeling results show that CO2 could be reduced at a low cost by implementing CDM projects between Swedish and Chinese steel plants. / <p>Godkänd; 2005; 20070108 (haneit)</p>

The energy consumption in Sweden has risen remarkably over the last 40 years and the society is more and more dependent on electricity to maintain socially important functions. Authorities, grid-owners and consumers are increasing their demands for a more secure energy delivery. Skellefteå Kraft is doing continuous investments in this area and its focus is to get the electric grid durable and weather resistant. It is, however, not possible to this is within the same year due to technical- and economic reasons which is why there ́s a need for an effective preventive maintenance solution. Batteries have seen a huge breakthrough thanks to the electric car and increasing demand to store renewable energy. Hopefully batteries are powerful enough to be a viable solution as backup power when a power failure occurs which is what this project have been investigating. This project consists of a literature study regarding the current battery technology that ́s in use today but also the future technologies that are under development and expects to be commercially available within the next 15 years. The project has also done a theoretical set-up to see if today ́s batteries are capable of providing enough power to a normal size house over at least 12 hours while they also are light enough to transport by one or two technicians. This set-up includes two different inverters and four battery alternatives that are compared to each other. The results show that it ́s theoretically possible to use smaller batteries to provide enough power when connected to each other to form a battery bank. It does however require between 20 to 32 batteries to reach enough capacity which also results in weights up to 700 kg and costs up to 500 000 SEK in total. Luckily experts ́ analysis and prognostics are positive and a potential investment in five years might be reasonable. A comparable battery bank in five years might cost 70 % less based on price reductions the past five years and new technology might even reduce weight and costs by 80 % in less than 15 years. If one wants to be prepared for a future investment a future project or degree project would be to do a small-scale prototype to evaluate the batteries real performance in the field.

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This thesis includes an energy survey of a school in Luleå called Benzeliusskolan and was carried out on behalf of the municipality of Luleå. Benzeliusskolan is currently heated with electric radiators and the thesis contains an investment calculation for the installation of a geothermal heating system. Calculations have been made to determine Benzeliusskolans theoretical heat demand. A survey of current electricity usage for heating has also been carried out for cost comparisons.   The result of the thesis is following: • The theoretical heat demand for all buildings is 251 212 kWh per year. Transmission losses amount to 228 257 kWh and heat losses through infiltration amount to 34 646 kWh per year. The heat requirement for ventilation was calculated to 58 995 kWh. Heat input of 70 687 kWh takes place every year from internal heat and solar energy.   • Mapping current consumption resulted in that current usage is 257 952 kWh of electricity for heating and 12 684 kWh of electricity for tap water per year.   • The power requirement for all buildings, including waterborne heating batteries in all ventilation systems, was calculated to 146 kW.   • A proposal for a geothermal heating system with a main central in house B where heat pumps are placed and heat transport to the other buildings, houses A and C, takes place through isolated culverts. The cost has been estimated at approximately 2 200 000 SEK through quotes and standard costs. The cost includes geothermal heat pumps, waterborne heating batteries for ventilation systems, drilling, radiators, installation costs and culverts between the buildings. The cost is based on an internal rate of 2% and an expected life span of 20 years.   • The investment in a geothermal system results in a reduction in electricity consumption for heating and tap water of 68.8%, 186 275 kWh per year. The investment had resulted in a cost saving of approximately 113 000 SEK per year during the estimated 20-year life span of the heat pump. Break-even occurs after about 19 years and 7 months and the total savings after 20 years amount to 52 000 SEK.

In recent years, the University of Skövde (HiS) is carrying an advance research in Virtual Commissioning and Emulation. The main goal of the research is to test and verify the control logic of an industrial system virtually before implementing it in the real industry. Literature shows how higher modeling detail level is needed taking into account aspects such as geometry, kinematic, behavior and interfaces. That makes an interesting branch of research for the university and that is the reason why the university is focusing on creating models in component level, where a complete emulation data model is being expanded. The aim of this thesis is to develop a way of modelling electric, hydraulic and pneumatic connections in order to create independent models that can be connected between them for creating systems. Furthermore, an energetic analysis of the system has been done. In the first part of the thesis, a frame of reference and a literature review has been done in order to learn about the fields that the authors are going to work. After that, the simulation models of different electric, pneumatic and hydraulic components have been created with a method, inspired by the producer/consumer concept, which provides a generic solution that allows energy flow in different domains between components in a simple way. Then, different component simulation models have been connected in order to emulate more complex systems. Once the models are done, there have been some test in order to know if all perform as expected. Finally, a discussion of the failures which have been during the project have been done. The experiments done have shown that the proposed and then implemented system has fulfilled all the objectives, unlocking the next step of the emulation development.

Världen står inför stora utmaningar där energibehovet ständigt ökar i takt med den globala ekonomin. Något de flesta människor idag känner till är kopplingen mellan energianvändning och negativ påverkan av miljö samt klimat. Sveriges industrier står inför stora utmaningar med ständigt växande global marknad. Följder blir tuffare konkurrenssituation för många företag. Konkurrenssituationen medför att företag flyttar sin verksamhet till länder med lägre produktionskostnader. Kostnader vilka i Sverige har ökat väldigt mycket de senaste decennierna. För att stoppa utflyttning av industriverksamhet krävs stora effektiviseringar i industriföretags energianvändning och förändring av attityd gentemot energianvändning. Studien vilken ligger till grund för rapporten utfördes med energikartläggning av en lokal hos ståltillverkaren Ovako Sweden AB i Hofors. Lokalen där energikartläggningen utförts innehåller en process kallad betning. Kartläggningen grundas på data erhållna av ÅF, vilka även har varit samarbetspartners i studien. Väldigt stora mängder energi används i lokalen, närmare bestämt 14 000 MWh. Störst andel energi går till produktionsprocesser i form av ånga och elektricitet. Ånganvändning står för 8 500 MWh medan elektricitetsanvändning uppgår till 4 500 GWh. För ånga kan kostnadsminskning med 60 % implementeras. Elektricitetskostnader kan med föreslagna metoder minskas med uppskattningsvis 14 %. För uppvärmning av lokalen beräknades användningen uppgå till 2 500 MWh. Användning av uppvärmningsenergi kan minskas drastiskt då byggnaden är väldigt dåligt isolerad och använder mycket energi till uppvärmning. Vid införande av samtliga föreslagna åtgärder för uppvärmning sparas totalt 95 % av uppvärmningskostnader

Uppsala municipality has ambitions to reduce greenhouse gas emissions by installing solar power. To do this, the municipality has set a goal to install 30 MWp of solar power by the year 2020, and today 25 MWp has yet to be installed. The objective of this study is to investigate if Uppsala municipality is able to install 25 MWp solar power on municipality owned buildings or if an additional solar park installation is required. This is done through simulations and calculations and results are visualized in QGIS, a geographical information system software. The conclusion of this study is that Uppsala municipality will need a solar park at a magnitude of 0.9 MWp and rooftop installations of 24.1 MWp to reach the goal of 30 MWp. The cost of this installation would be 296 MSEK. The GIS-layers illustrates municipality owned rooftops suitable for solar power installation and module installation proposals. A sensitivity analysis is performed were the type of module is changed, which in turn affects efficiency and module angles. The outcome of the sensitivity analysis is that the type of module and the module efficiency are important parameters that affect the result. Depending on how valuable the land area is, higher module efficiency could be advantageous. Future work could involve an investigation about which type of PV technology that best satisfies Uppsala municipality’s priorities.