<p>The aim of this master thesis project is to make an energy survey for a group</p><p>of apartments and suggestions to change the heating system from electricity to a more</p><p>efficient one. There are in total 73 flats in 21 buildings. All flats are separated in several</p><p>houses from two to five flats in one building. There are two different kinds of flats. One</p><p>with three rooms in one floor, in the following referred to as ‘flat A’ and the other one</p><p>with four rooms in two floors, in the following referred to as ‘flat B’. [1]</p><p>In the area there are also two buildings for the commonalty. In these buildings there are a</p><p>shelter and several common rooms like a storage and a laundry. In our work these two</p><p>buildings are not included because they are used by everyone inside the community and</p><p>we could not obtain exact values for the used electricity and the water consumption. So</p><p>our work is specialised only on the residential houses.</p><p>The first part of this thesis contains the energy balance for the different kinds of flats to</p><p>see how much energy they consume for heating and hot tap water. To get theses values</p><p>we have to analyse the total energy flow into one flat and compare it with the energy</p><p>which is used because of transmission losses, ventilation losses, hot tap water, electricity</p><p>for the household and natural ventilation and infiltration.</p><p>The total energy consumption for flat A is about 19000 kWh per year and in flat B about</p><p>23200 kWh per year. But the electricity which is used and has to be bought is about</p><p>15600 kWh per year in flat A flat and 17600 kWh in flat B. The rest of the energy is from</p><p>so called free heat caused by solar radiation and internal heat generation. [1]</p><p>These numbers for the electricity need in one year create annual costs of about</p><p>20000 SEK in flat A and 22500 SEK in flat B. To reduce these costs it is necessary to</p><p>know where this energy goes and for what it is used.</p><p>The important parts of the energy balance for this thesis are the transmission losses, the</p><p>losses caused by natural ventilation and infiltration and the used energy for hot tap water.</p><p>The losses caused by mechanical ventilation have also a significant value, but they would</p><p>only affect the new heating system if the ventilation system would be connected to the</p><p>new system. And the electricity used in the household for electrical devices can only be</p><p>changed by the consumer himself. The part which is affecting the energy costs for the</p><p>transmission and natural ventilation losses and the hot tap water sums up to 9240 kWh per</p><p>year in flat A and flat B. This causes costs of about 10000 SEK per year.</p><p>To reduce these costs it is necessary to change the actual heating system. In the following</p><p>we analyse the saving potentials with a change to an air-water heat pump or with a</p><p>connection to the local district heating network.</p><p>The costs which can be saved with the installation of a heat pump sum up to about</p><p>7000 SEK per year. The installation costs are about 100000 SEK to 125000 SEK</p><p>depending on the different proposed models. If you consider that the existing electrical</p><p>boiler has to be changed anyway in the next years the investment costs for the</p><p>combination with a heat pump decreases. The payback time is then between 9½ and</p><p>13½ years. With assumed increasing electricity prices of 5 % each year the payback time</p><p>decreases to 8½ to 11 years.</p><p>With a connection of each flat to the local district heating network the energy costs for</p><p>heating and hot tap water decreases to 3200 SEK per year. Although the price per kWh for</p><p>district heating is much lower than for electricity the costs are not decreasing a lot</p><p>because of a high annual fixed fee of 7100 SEK. The saved money per year sums up to</p><p>300 SEK and 1000 SEK depending on the electricity contract. The payback time for this</p><p>alternative is between 50 and up to 160 years.</p><p>An alternative to the exchange of the heating and hot water system is to change the actual</p><p>heat exchanger of the ventilation system. With this measure the energy consumption can</p><p>be reduced with less investment costs. The investment costs for a new heat exchanger are</p><p>about 35000 SEK, including a new exhaust hood from the kitchen outwards to reduce the</p><p>contamination of the filters in the heat exchanger. [1]</p><p>The payback time ranges from 13 years in flat A to 21 years in flat B.</p>

The aim of this master thesis project is to make an energy survey for a group of apartments and suggestions to change the heating system from electricity to a more efficient one. There are in total 73 flats in 21 buildings. All flats are separated in several houses from two to five flats in one building. There are two different kinds of flats. One with three rooms in one floor, in the following referred to as ‘flat A’ and the other one with four rooms in two floors, in the following referred to as ‘flat B’. [1] In the area there are also two buildings for the commonalty. In these buildings there are a shelter and several common rooms like a storage and a laundry. In our work these two buildings are not included because they are used by everyone inside the community and we could not obtain exact values for the used electricity and the water consumption. So our work is specialised only on the residential houses. The first part of this thesis contains the energy balance for the different kinds of flats to see how much energy they consume for heating and hot tap water. To get theses values we have to analyse the total energy flow into one flat and compare it with the energy which is used because of transmission losses, ventilation losses, hot tap water, electricity for the household and natural ventilation and infiltration. The total energy consumption for flat A is about 19000 kWh per year and in flat B about 23200 kWh per year. But the electricity which is used and has to be bought is about 15600 kWh per year in flat A flat and 17600 kWh in flat B. The rest of the energy is from so called free heat caused by solar radiation and internal heat generation. [1] These numbers for the electricity need in one year create annual costs of about 20000 SEK in flat A and 22500 SEK in flat B. To reduce these costs it is necessary to know where this energy goes and for what it is used. The important parts of the energy balance for this thesis are the transmission losses, the losses caused by natural ventilation and infiltration and the used energy for hot tap water. The losses caused by mechanical ventilation have also a significant value, but they would only affect the new heating system if the ventilation system would be connected to the new system. And the electricity used in the household for electrical devices can only be changed by the consumer himself. The part which is affecting the energy costs for the transmission and natural ventilation losses and the hot tap water sums up to 9240 kWh per year in flat A and flat B. This causes costs of about 10000 SEK per year. To reduce these costs it is necessary to change the actual heating system. In the following we analyse the saving potentials with a change to an air-water heat pump or with a connection to the local district heating network. The costs which can be saved with the installation of a heat pump sum up to about 7000 SEK per year. The installation costs are about 100000 SEK to 125000 SEK depending on the different proposed models. If you consider that the existing electrical boiler has to be changed anyway in the next years the investment costs for the combination with a heat pump decreases. The payback time is then between 9½ and 13½ years. With assumed increasing electricity prices of 5 % each year the payback time decreases to 8½ to 11 years. With a connection of each flat to the local district heating network the energy costs for heating and hot tap water decreases to 3200 SEK per year. Although the price per kWh for district heating is much lower than for electricity the costs are not decreasing a lot because of a high annual fixed fee of 7100 SEK. The saved money per year sums up to 300 SEK and 1000 SEK depending on the electricity contract. The payback time for this alternative is between 50 and up to 160 years. An alternative to the exchange of the heating and hot water system is to change the actual heat exchanger of the ventilation system. With this measure the energy consumption can be reduced with less investment costs. The investment costs for a new heat exchanger are about 35000 SEK, including a new exhaust hood from the kitchen outwards to reduce the contamination of the filters in the heat exchanger. [1] The payback time ranges from 13 years in flat A to 21 years in flat B.

This report covers a feasibility study for a wind power project in Sri Lanka. Three potential sites for a wind farm are presented, out of which the Ambewela Cattle Farm is chosen as the most suitable. Limitations of a wind farm at the site, due to properties of the electrical grid and logistical issues, are examined and costs related to installing the wind farm are estimated. The maximum capacity of a wind farm is calculated to 45 MW. The payback period of the wind farm is calculated to 4.4 years. Environmental benefits of the wind farm are estimated in terms of avoided CO2-emissions, which are calculated to 76 000 metric tonnes per year. The study concludes that a wind power project at the chosen site should be technically and financially feasible, if a wind turbine that matches certain logistical criteria can be found.

In industry, energy efficiency reduces system cost and emissions to the environment. Energy audits are carried out in industry to identify measures that would increase energy efficiency. However, the usual case is that low-cost measures are implemented while capital intensive measures receive less attention possibly due to, example, inadequate information available to study risks involved. Decisions support tools have been identified as a means of supporting complex production related investment decision. The aim of this paper is to investigate profitability and potential global CO2 emission reduction of energy conversion investments in a small energy intensive industry by using an optimisation method as a decision support tool. The investments are evaluated using consistent future energy market scenarios with interdependent parameters. An optimisation model is developed with reMIND optimisation tool which is used to optimise the system cost of each scenario. The reduction in system cost and global CO2 emissions of the new investments and results from sensitivity analysis are evaluated to determine the optimal investment solution. In the report, it is established that optimisation methods provide a structured means of studying the risk involved in capital intensive investments. The optimisation results show that investment in a small-scale steam turbine combined heat and power production is a profitable and robust investment. The net reduction of global CO2 emission is substantial compared with the reference system. Furthermore, it is shown that biofuel policies alone may not make cost intensive biofuel investments attractive, further reduction in investment cost is required. The energy savings and global CO2 emission reductions achieved in this study can play an important role in achieving the aims of the European Union to reduce greenhouse gas emissions by 20% and save 20 % of energy by the year 2020.

In industry, energy efficiency reduces operating cost and emissions to the environment whiles enhancing energy security. In order to ensure the sustainability of micro and small scale businesses in a developing country such as Ghana, measures that can ensure energy efficiency are therefore essential for these businesses to have a productive and economical operation that will ensure their sustainability. In this study, the potential of energy efficiency measures for micro and small scale businesses have been examined by performing industrial energy systems analysis on some selected micro and small scale businesses in Kumasi-Ghana through a practical study and administering of questionnaire about their energy consumption. Legislative instruments that are linked with energy use in Ghana were looked into. Some possible energy efficiency measures that could be adopted by these businesses have been analyzed. In this study it is established that energy supply to these businesses is not reliable and it is continuously becoming expensive. In addition, other findings were that value could be added to the processes of these businesses if they incorporate energy efficiency measures in their operations. The main driving force that will encourage these businesses to incorporate energy efficiency measures in their operation is the energy prices increase; therefore, their interest is the measures that could reduce their energy cost rather than the positive impacts that will come to the environment. In doing this renewable energy has the greatest potential in ensuring energy efficiency to these businesses. Finally, it is established that there are no specific legislations on energy use that will bring negative effects to these businesses and this could create enabling environment for private investors of energy efficiency.

Nowadays, due to global warming and the depletion of petroleum reserves, renewable energies have gained special prominence. At the moment, wind energy is the most successful renewable energy resource, and the technology to convert this wind energy into electricity has been very developed. As a consequence, the costs per kWh of generation have decreased and it has become a competitive alternative for conventional fossil-fuel power plants to generate electricity.However, a lot of factors and variables are involved in wind power generation. In the first part of this document, some of this factors like the Betz limit, the classification of wind turbines and its components, and the power curve of a wind turbine are explained.In the second part, the performance of a real wind farm is studied. The wind farm is called Es Milà, and it is located in an island called Minorca, in Spain.Firstly, a description of this wind farm and the energy and electricity in Minorca is made.Then, with meteorological and power data of 2007 a thorough study of its performance is completed. In this study, first of all some meteorological aspects like wind direction, wind velocity and its distribution are discussed.After that, the study focuses on electricity production, looking at the power curve, at the expected and the real production, and trying to explain a little of the reactive power.

<p>Wind tunnel studies of the wake behind a model wind turbine have been made in order to get a better understanding of wake development as well as the possibility to predict the power output from downstream turbines working in the wake of an upstream one. Both two-component hot-wire anemometry as well as particle image velocimetry (PIV) have been used to map the flow field. All three velocity components were measured both for the turbine rotor normal to the oncoming flow as well as with the turbine inclined to the free stream direction (the yaw angle was varied from 0 to 30 degrees). The measurements showed, as expected, a wake rotation in the opposite direction to that of the turbine. A yawed turbine is found to clearly deflect the wake flow to the side showing the potential of controlling the wake position by yawing the turbine. The power output of a yawed turbine was found to vary nearly as the square of the cosine of the yaw angle. The possibility to use active wake control by yawing an upstream turbine was evaluated and was shown to have a potential to increase the power output significantly for certain configurations. An unexpected feature of the flow was that spectra from the time signals showed the appearance of a low frequency fluctuation both in the wake and in the flow outside. This fluctuation was found both with and without free stream turbulence and also with a yawed turbine. The non-dimensional frequency (Strouhal number) was independent of the free-stream velocity and turbulence level but increases with the yaw angle. However the low frequency fluctuations were only observed when the tip speed ratio (or equivalently the drag coefficient) was high. This is in agreement with the idea that the turbine shed structures as a bluff body. It is hypothesized that the observed meandering of wakes in field measurements is due to this shedding.</p>

The work presented in this thesis is the result of the KTH CICERO project “Dynamic Engine Performance” in which the main objective was to develop simple models foremission formation. The demand for such models is increasing, mainly due to the tightening emission legislation for diesel engines which has lead to more complex engines and thereby more laborious development and calibration processes. Simple emission models can be a valuable tool during the development phase, e.g. when used with models for gas exchange - and after-treatment systems, and for precalibration of the engine control settings. Since engines in automotive application typically work under dynamic load, the main prerequisites were that the models should be comprehensive enough to handle the extreme conditions that can occur in engines during load transients but still simple enough to be used for calibration. Two main approaches have been used; one where the combustion and emission formation processes were modeled from the flame front and downstream using equilibrium chemistry. In the other approach, the entire mixing/entrainment process was modeled and emission formation was modeled with kinetic chemistry. Both approaches were found to meet the requirements but had different advantages; the first, simpler approach had shorter calculation time while the latter was more comprehensive and required less tuning. The latter also resulted in a model for heat release rate which can be useful as a stand-alone model and allows the emission models to be used for untested conditions. Another objective in this project was to identify techniques/instruments that can be used for emission measurements during transient operation since these are essential for understanding of emission formation in these conditions and as validation data for the emission models. / QC 20110502

<p></p><p>This report covers a feasibility study for a wind power project in Sri Lanka. Three potential sites for a wind farm are presented, out of which the Ambewela Cattle Farm is chosen as the most suitable. Limitations of a wind farm at the site, due to properties of the electrical grid and logistical issues, are examined and costs related to installing the wind farm are estimated. The maximum capacity of a wind farm is calculated to 45 MW. The payback period of the wind farm is calculated to 4.4 years. Environmental benefits of the wind farm are estimated in terms of avoided CO₂-emissions, which are calculated to 76 000 metric tonnes per year. The study concludes that a wind power project at the chosen site should be technically and financially feasible, if a wind turbine that matches certain logistical criteria can be found.</p><p> </p>

Variable Speed Limits (VSL) are often used to improve traffic conditions on congested motorways. VSL can be implemented as mandatory or advisory. The objective of the thesis isto study in detail the effectiveness of VSL. The focus is on both, design parameters and conditions under which VSL are most effective. The MCS system on the E4 motorway inStockholm is used as a case study. The evaluation was conducted using empirical methods (including aggregate data from microwave sensors and other sources, and disaggregate data from a mobile study), and microscopic traffic simulation. The empirical analysis is based on before and after VSL data, including evaluation of individual measures of performance, and multivariate analysis in the form of the fundamental diagram, and speed-density relationships. The results from the empirical study are mixed with an indication that driver behavior has a strong impact on the effectiveness of the system. The microscopic traffic simulation analysis included the development of a platform for testing VSL and more generally motorway control strategies. The simulation platform was calibrated and validated with the empirical data and includes in addition to VSL, and Automatic Incident Detection (AID) system, the ALINEA ramp metering algorithm. The test-platform allows the testing of different control strategies and various combinations of control strategies, under different scenarios and in a controlled environment. The results from the simulation study indicate that driver compliance is an important factor and VSL performance quickly deteriorates as compliance rate drops. Hence, VSL should be implemented as mandatory instead of advisory. In addition, mandatory VSL can be effective both, under incident and moderately congested conditions. A combined VSL and ramp metering strategy can be most effective in reducing travel time, improving traffic conditions on the motorway. Furthermore, the results indicate that such a strategy also has the least impact on the flows entering the motorway from the ramps. / QC20100630