Nowadays, three-phase induction motors are widely used on industrial and other types of processes. Therefore, accurate knowledge of an induction motor performance is very essential to have an idea of its operation conditions. This study is a sequel of a previous one, where Direct and Soft starting methods of three-phase motors has been simulated and compared. As in the previous study, the theory behind this one is based on representing the real motor by aset of equations and values in Matlab, forming a corresponding idealistic motor in a way where all the physical effects are similar. The motor is started under three different frequencies in the VVVF method using supporting simulation of the current, torque, speed,efficiency and power factor curves. The results of the three starting methods are then discussed and compared.

Solar photovoltaic industry is a hot research field, massive attempts are going on all over the world to increase its productivity in different ways. One of the challenges for solar cells is the light spectrum mismatch losses, which referred to the part of solar spectrum that cannot be utilized to electricity by the conventional cells.

Two ways have been suggested to overcome solar spectrum mismatch losses, the first is multi layered cells (tandem cells) with a different light behavior for each layer, and the second is spectrum conversion which is this researches subject.

Spectral modification or conversion in solar cells industry has been studied and different lab scale models have been introduced. According to nanoscale journal, such technology may be the base of the next generation solar cells, mentioning specifically the use of luminescence down conversion and up conversion techniques to control the light spectrum on the solar cell, these endeavors targets to produce solar cells that is not subjugated to Shockley-Queisser maximum efficiency limit of 31%.

This research aims to draw a map of various ideas introduced to incorporate similar technologies in solar cell products, beside further suggestion to enhance its technical behavior and to push the commercialization of the technology forward. This is expected to reveal clear image about technology’s future development map for the upcoming studies, and to create a motivation for further studies towards a commercial production scale.

The proposed commercialized model will result in enhancing the maximum theoretical efficiency limit to 48% if all spectral mismatch loses have been eliminated. Quantum energy level diagrams have been illustrated to describe each model’s performance under a theoretical light spectrum.

The supply of energy is a key factor in modern societies. As the old fossil sources for energy are dwindling, conflicts arise between competing nations and regions. Fossil energy sources also contribute to the pollution of the environment and emission of greenhouse gases.

With renewable energy sources many of these drawbacks with fossil fuels can be eliminated as the energy will be readily available for all without cost or environmental impact.

Combining the renewable energy sources will be very effective, particularly in commercial areas where lake of electricity is high. The cost of combining onshore wind and solar power plant is affordable. Furthermore there is no power failure or load shedding situation at any times. When it is manufactured in a large scale, cost of this integrated natural resources power generation system is affordable. Moreover there is no power failure or load shedding situation at any times. Therefore, it is the most reliable renewable power or electricity resources with less spending and highly effective production. ref [1].

The thesis work would take planning of offshore renewable plant (Lillgrund) with considering the resources of renewable power. The study would take in account combining the Lillgrund wind farm with solar system and take close look into the advantage and disadvantage of combining the renewable resources together and figure out if such station can work in proper way and provide sufficient power production. The study would take in account the effect of each resource on other resource, also calculations would be done.

The study site is Lillgrund in south of Sweden. The Lillgrund wind farm is the most important offshore wind power plant installed in Sweden with a total capacity of 110 MW, corresponding to 48 turbines. ref [2].

ABSTRACT

This project deals with the search of the most proper offshore foundation to install in the Baltic Sea, in order to reduce costs and environmental impact. A pre-study was performed to define the Baltic Sea conditions and the required knowledge for the following steps. Afterwards, the specifications were set and clarified, and then the concept analysis phase was started. The analysis phase included the description of each one of the current foundations, those which are considered conventional foundations and those which are innovative ones. In order to evaluate these concept foundations, selection methods were used to assess the most relevant features of these foundations which should fulfil the requirements. The concepts ranking was studied and it led to the final results. Two different outcomes were obtained; such as, innovative concepts, which obtained the first position in this report; and conventional concepts, as a second finding. The continuous contact with different experienced professionals of this sector was essential during the whole project, in order to obtain advices, experienced knowledge and feedback.

The major common denominator for future efficient fourth generation district heating systems is lower temperature levels in the distribution networks. Higher efficiencies are then obtained in both heat supply and heat distribution. Heat supply becomes more efficient with respect to combined heat and power, flue gas condensation, heat pumps, geothermal extraction, low temperature excess heat, and heat storage. Heat distribution becomes more efficient from lower distribution losses, less pipe expansion, lower scalding risks, and plastic pipes. The lower temperature levels will be possible since future buildings will have lower temperature demands when requiring lower heat demands. This paper aims at providing seven essential recommendations concerning design and construction strategies for future fourth generation systems. The method used is based on a critical examination of the barriers for lower temperature levels and the origins of high return temperatures in contemporary third generation systems. The two main research questions applied are: Which parts of contemporary system design are undesirable? Which possible improvements are desirable? Key results and the corresponding recommendations include temperature levels for heat distribution, recirculation, metering, supervision, thermal lengths for heat exchangers and heat sinks, hydronic balancing, and legionella. The main conclusion is that it should be possible to construct new fourth generation district heating networks according to these seven essential recommendations presented in this paper.

The shipping industry is facing a major challenge. Current and future emission requirements result in considerably increased operating costs. Studies have shown that it is a large potential to reduce the ship operating costs by energy effectivisation. The focus has naturally been on systems with major energy losses, such as combustion engines, propulsion and hull friction.

A passenger ship like Stena Danica with a big climate controlled accommodation could be expected to have major heat losses. By calculating transmission losses from walls, ceilings, window sections, and the energy losses by ventilation, a general view of how heat losses are distributed has been established. The primary goal is to gather information that could be useful in further energy improvements.

Due to lack of information and deficiently measured data have several assumptions and simplifications been made. Despite this, the calculations can be considered as indicative. The results indicated that about 50 percent of the energy losses occur by ventilation and the remaining consists of transmission losses in windows sections and climate shell, (About 25% each). The focus in the calculations has been to estimate the accommodations heating demand. Energy improvements that reduce the heating demand will reduce the cooling demand as well. This may be a greater incentive for measures as the air conditioning system are powered with higher energy quality; electricity. Besides shore power the electricity is mainly generated by diesel generators. The energy used for heating is mainly produced by waste heat or is supplied by shoreside district heating.

Upgrading the ventilation systems are considered to be the most economic method to reduce the heat losses in the accommodation area. The ship's ventilation systems lack any type of demand control, this causes excessive energy losses as the ventilation demand vary greatly regarding to time of the day and numbers of passengers.

The ship has a large amount of single pane windows that also contributes to large energy losses. To upgrade or replace these are considered to be more economic than to improve the insulation on the rest of the climate shell as it doesn’t affect the interior to the same extent. The latter may be worth considering in case of a major renovation of the vessel.

Applying the new ideas developed by the present study on the current design of WTP can lead to satisfactory results and give flexibility in terms of producing more electrical power during periods of low/medium wind velocity. The innovative ideas and methods included in the present work reveal the features of the future renewable energy designs that could, in the few coming years, revolutionize the field of wind turbine designs worldwide. Also, increase the capacity factor significantly, since the application of these ideas in areas where wind class II and III blows have proven to be very effective. Especially, when compares the result of new ideas with the current wind turbine designs.

Testing the innovative ideas regarding the future wind turbines on a current WTP achieved a good results in increasing electric energy production over the year. For example applies the new ideas on a WTP model Enercon (E-101) will achieve an annual increase around 20% of electric power generation (wind class II, Cp = 36), i.e. when wind speed is ranging from 0-10 m/s (Level C – option 02) the production improved at the highest value, reaching up to +46%. Also, in Level B the generation of electricity witnessed an increase up to 10% when the wind velocity being always between level C with a minimum of 10 meters per second and Level A (Level A is the maximum output value, which is changing from one turbine type to the other). 

This pre-study presents the findings concerning a considerable outlined expansion of the district heating sector within the current EU27 member states until 2050. Heat deliveries are presumed to grow by a factor of 2.1 until 2030 and by a factor of 3.3 until 2050.

The current energy policy context is that the latest energy communication from the European Commission (Energy Roadmap 2050) contains only a very modest growth in the future for district heating systems and additional industrial heat use from industrial CHP plants. A small increase is foreseen for industrial demands, while heat deliveries to the residential and service sectors are expected to decrease. In total, the heat delivered is expected to increase by less than one per cent per year, giving a total increase of 20% until 2030 and of 40% until 2050.

In this prestudy, more ambitious growth rates are assessed for district heating in the EU27 between 2010 and 2050. The chosen methodology in this pre-study contains a combination of hour-by-hour energy modelling of the EU27 energy system and mapping of local conditions, which is essential for district heating analysis. However, the link between these two actions has not been fully utilised in this pre-study due to the limited working time available: The mapping action has only indicated the input to the energy modelling action.

Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible. In these strategies, the role of district heating has never been fully explored system, nor have the benefits of district heating been quantified at the EU level. This study combines the mapping of local heat demands and local heat supplies across the EU27. Using this local knowledge, new district heating potentials are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emission targets by 2050, but at a cheaper price than a scenario which focuses primarily on the implementation of heat savings.

Background and Objective

The evolution of district heating (DH) has gone through three generations since the first introduction of distirct heating. It is characterized by the type of transport media and the network temperature levels: the 1^st generation DH system is steam-based system, the 2^nd generation DH uses high network supply temperature above 100^oC, and the 3^rd generation DH represents the current DH system with medium network supply temperature between 80^oC to 100^oC. Up until now, the 4^th generation DH as the low-temperature district heating (LTDH) is emerging as a new system which is going to replace the existing 3^rd generation DH system. Comparing with the existing DH system, the LTDH reduces the network supply temperature down to consumer required temperature level, thus greatly improves the quality match between the energy supply and the energy demand. Meanwhile, LTDH coupling with reduced network temperature and well-designed DH network can reduce network heat loss by up to 75% comparing with the current system. This makes DH economically competitive comparing with local heat generation units in the areas with low heat density or with low-energy buildings.

The traditional approach to evaluating a DH system often focuses on the production/supply aspect and only afterwards on the final users. The LTDH concept switches the perspective, starting from end-user thermal comfort and a quality match between energy supply and energy consumption, and aiming to find the best and most economical way to satisfy the heat demand through efficient distribution networks and supply systems based on waste heat and RE. The new concept therefore starts by identifying suitable in-house substations for low-energy-demand buildings at low supply temperature, goes back to design efficient and reliable networks, and finally considers environmentally-friendly heat production units.

This report describes the concept of LTDH, collects and discusses successful examples of implementation LTDH in the building heating sector. The objective of this report is to raise awareness and provide insights that will stimulate the research, development and implementation of LTDH systems. It will help to increase public recognition and assist policy makers and energy planners, both at local and governmental level, in promoting cost-effective and environmentally friendly DH systems, and in planning and realizing long-term sustainable urban area development. To this end, the report addresses the following research issues:

1. What are the main advantages of LTDH?

2. What technology options are available for LTDH, and what are the associated challenges to consider?

3. How can the risk of Legionella be mitigated in LTDH?

4. What lessons can be learned from early LTDH projects?

5. What heat distribution costs are associated with LTDH?

The challenges facing low voltage grids are rising as an increasing number of domestic houses transition from fossil fueled heating to electricity based heating. Several environmental goals and visions have the same transition from fossil based power to electricity based power in mind for the transportation sector. One of the most important tools for this transformation is widely regarded to be the electric vehicle. With the demands of the electric vehicle pressuring the power grid, several questions arise regarding the growth of the electric vehicle market and what repercussions it may have on the grid. This paper focuses on a typical low voltage grid in southern Sweden and what effects a growing electric vehicle market may have on it. Through computer-assisted simulations based on several future scenarios regarding the EV market, this paper finds that few modifications and reinforcements are needed on this particular grid within the next 10 to 15 years. After this timeframe the voltage drop becomes a serious concern and should be addressed.

Now a days, there is lot of alternatives available, which provides green and renewable energy. Through these alternatives, the consumer’s demand for energy is being satisfied. It is important to use the available energy in a systematic and efficient way so that there are many benefits. The purpose of this study is to briefly identify the various prospects, problems, and policies for energy efficiency in industries. Basis of purpose on the negative impacts caused due to the increased use of energy consumption in industries. This literature study is based from practical examples of industries, industrial applications and other new technology. As the electric motor system operates most of the industrial processes, the electricity consumption of motors in industries accounts for two thirds of total energy consumption. Influencing energy efficiency in industries provides substantial advantages. Various motor applications such as pumps, fans, air compressors, cooling compressors, variable speed drives is studied for their operation and working conditions. The utilization of energy efficient technologies to a greater extent can perceive savings to the industries. In spite of being aware of potentials of using energy efficient technologies in industries, energy efficient technologies are not widely used. A barrier to energy efficiency is explained as a practice that inhibits the industrial decision of being efficient in terms of energy and finance. The barriers consent with energy efficiency in industries is fair enough to be considered, while compromising energy for temporary prosperity is not upright. Influence of increased energy efficiency in market areas need coordination of all industries and commercial area throughout the country. The coordination between the industries and commercial sectors can be closely achieved by raising energy policies and energy regulations. The energy efficient policies are considered as cognizance for market transformation and this can maintain the industry, the environment, and the energy. The options available for market transformation are enormous. It is suggested to implement the energy efficient policies as energy efficiency is important for sustainable future. By adopting the right policy, at right situation can provide enormous benefits to the process, industry, and nation. A basis of energy efficiency in industrial application can provide potential energy savings for the present and future industrial situation. This can provide a balance between INDUSTRY-ENVIRONMENT-ENERGY.

District heating satisfies about 60% of the heat demand in Swedish buildings. Today, more than two thirds of the heat supply to the district heating systems is based on biomass and waste, and biomass alone accounts for about half of the heat supply. The purpose of this paper is to present the Swedish experiences of introducing and expanding the use of biomass in the district heating systems and to identify the main drivers behind this development. Our five research questions and the corresponding conclusions consider the driving forces from energy policy tools and local initiatives, the biomass prices, the established infrastructures in forestry and district heating, the technology paths for biomass conversion, and finally the future challenge of competing uses of biomass. © 2016 The Authors

District heating is the most common source of heating in Sweden and has played a crucial part in the country’s substantial reductions of carbon dioxide emissions. This recycling technology is ideal in order to use thermal energy as efficiently as possible and makes the goals set for a sustainable future more achievable. The future potential of this technology is therefore huge. Today, a lot of the district heating systems have installed heat storages in order to improve the systems reliability and performance. These heat storages have the potential to be utilized even further in the future by acting as a balancing power for the power grid. However, there is currently no data available regarding the storage capacity available in the district heating systems. This thesis therefore seeks to quantify the installed storage capacity in Swedish district heating systems. The data gathered regarding this can then be utilized in research regarding potential future applications of heat storages, such as balancing the power grid. All collected data regarding heat storage capacity has also been analyzed in an effort to find any correlations between the relative storage capacity and the size, energy sources, customer prices and operational costs of each investigated system. This analysis has concluded that most of the district heating systems in Sweden have installed storage capacity and that it is more commonly used in larger systems. It is also concluded that most of the installed storage capacity is used to counteract daily heat load variations. The heat storages influence district heating systems by reducing their operational costs as well.

The context for this chapter is the current use and typical applications of thermal energy storages within contemporary district heating and cooling systems in the Nordic countries. Examples include a new assessment method, distributed heat storages, and hourly, daily, weekly, and seasonal heat and cold storages. Specific sizes have been estimated for 209 heat storages and 9 cold storages.

Exergy is applied to the Swedish energy supply system for the period 1970–2013. Exergy flow diagrams for the systems of electricity and district heating as well as for the total supply system of energy and material resources for 2012 are presented. The share of renewable use has increased in both electricity and district heat production. The resource use is discussed in four sectors: residential and service, transportation, industry and agriculture. The resource use is also analyzed with respect to exergy efficiency and renewable share. The total exergy input of energy and material resources amounts to about 2700 PJ of which about 530 PJ was used for final consumption in 2012. The results are also compared with similar studies. Even though the share of renewable resource use has increased from 42% in 1980 to 47% in 2012, poor efficiency is still occurring in transportation, space heating, and food production. A strong dependence on fossil and nuclear fuels also implies a serious lack of sustainability. A more exergy efficient technology and a higher renewable energy share are needed in order to become a more sustainable society.

The recent growth of the Chinese district heating sector has been very high. No other country in the world can show the same growth rate during the last decades. The heated building area increased six times between 1995 and 2008. China has also enjoyed strong growth of scientific articles and papers about district heating in recent years. One third of all international scientific journal articles and conference papers about district heating came from Chinese scientists during 2010–2012, while Swedish scientists accounted for one quarter according to the Scopus scientific search engine. It is important to identify the Chinese district heating research to judge the potential for future collaborative research on district heating systems between Sweden/Europe and China. The 205 international publications on district heating by Chinese scientists published until 2013 have been mapped and summarised with respect to demand, supply, technology, market and environment. More diversified heat supply with renewable source was grasping the Chinese interest, since many new systems have been established, having more degrees of freedom when choosing various heat supply and technology options. The Chinese district heating systems were compared with sustainable district heating solutions in Sweden. Both countries would benefit from future research cooperation. © 2015 Elsevier Ltd.

Exergy concept is applied on district heating systems with different network temperature levels in their distribution networks. These district heating systems use a combination of renewables and heat recovery from other primary processes. The aim is to show simplicity and value of using exergy concept when comparing current and future temperature levels. Both the traditional exergy factor and the novel exergy utilisation rate are used in these analyses. Exergy utilisation rate expresses the ratio between the exergy delivered to customer heating systems and the exergy content in heat supply input to the distribution network. The analyses are performed on four different generations of district heating technologies, two national groups of district heating systems in Denmark and Sweden for revealing variations among systems, and two municipal systems for revealing variations within systems. The main conclusions are simplifications can be introduced in order to analyse the network temperature levels, current exergy factors reveal that current temperature levels can be reduced, and that almost two thirds of the exergy content in heat supply input are lost in the heat distribution chain. These conclusion will be vital input in developing the future fourth generation of district heating systems using both renewables and heat recovery. © 2015 Elsevier Ltd.

The World ́s environmental problems have been more widely known and investments in the environment are increasing. A major cause of the environmental problems is the real estate market. The real estate market is about to change. Environmental certifications are beginning to be established on the market and the demand on environmental certifications is starting to grow among the population. The purpose of this report is to describe the market for Green buildings and explain the financial incentives that exist for real estate companies to build and own Green buildings. In this study Green buildings is defined as all commercial buildings that are environmentally certified in accordance with LEED, BREEAM, Green Building and the EU GreenBuilding. The report is based on empirical evidence from several relevant people in the real estate industry. Empirical evidence has been gathered to create a picture of how the market is created. The report will also investigate whether there may be financial incentives for building and owning Green buildings. The content of this report has led to the conclusion that the market for Green buildings has expanded significantly over the past five years and continues to expand. The report has also made the conclusion that it may exist financial incentives for real estate companies to build and own Green buildings. 

The primary aim of this thesis was to use the calculation instrument for the solar energy potential map of Landskrona to simulate several PV systems to a sanitation company. The calculation tool is designed to calculate the profitability and environmental benefits of installing solar panels. The calculation tool was adapted in order to compare cost efficiency, environmental benefit and degree of self-sufficiency and self- consumption for the solutions. The PV system was planned to a company, Landskrona Svalöv Renhållning (LSR).

Furthermore, four different ways to construct the PV system were investigated; flat against the roof, tilted with respect to the roof, tilted with respect to the roof and oriented (azimuth angle), as well as an installation with a string of tilted PV modules together with PV modules mounted flat against the roof. Variation of the system configurations was achieved by changing the parameters tilt and azimuth angle. The capacity was adjusted so that the annual production would be 83 500 kWh for all the studied systems. The different systems were optimized in two ways; first for the most output per module, and secondly for the greatest self-sufficiency in order to minimize the losses of excess production.

PV modules optimally oriented for production per module provides the highest profitability and lowest payback period. The study suggests that photovoltaic systems are a competitive installation for LSR even without subsidies.

The degree of self-consumption was 11 %. Simulation results showed that the degree of self-sufficiency could only be increased marginally by simply changing the orientation of solar cells (with power adapted to maintained production level). There was no significant benefit from tilting the solar cells by 90 ° to increase self-sufficiency in the winter.

The simulations showed that almost all of the produced electricity was used to LSR 's internal load. This high degree of self-consumption showed very little excess electricity was produced. LSR is connected to the medium voltage power grid via two transformers. The surplus production covered only part of the no-load losses in transformers. Surplus electricity could therefore not be sold, but the high self-consumption rate limited this loss of revenue.

The solar electricity from crystalline silicon cells, results in slightly higher greenhouse gas emissions than wind power but much lower than the production mix of electricity available in the market. The self-produced solar electricity contributed to the environment because LSR did not have to buy the contracted wind electricity, which then became available for others.

The study's conclusions are that a PV system is likely to be profitable for LSR. Self-sufficiency would be about 11%, and the self-consumption rate of 98%. The environmental benefit consisted of the contribution of renewable energy in the mix of electricity generation on the market.

Wind power is a massively increasing energy source in the European Union, due to the 2020 goals that 20% of EU:s energy flow has to originate from renewable sources. Big wind turbines produce low frequency noise, which is a growing problem as the rapid technical development leads to larger and larger turbine.

This master thesis aims to examine the frequency distribution of the noise emitted from wind turbines of different sizes with the ultimate goal to establish trends. Using sound recordings from Vestas V27, V42 and V90 turbines, the noise is divided into octave bands using MATLAB to study the amount of low frequency noise. Due to a lack of accessibility to turbine sites, some site observed in the study suffer from a large amount of nearby noise pollution. However, a change in sound level in the region of the 63 to 250 Hz one-third octave bands is shown when comparing the V90 turbine data to the smaller sizes, correlating well with previous research in the field, but more research and measurements are needed to explain the occurrence on a more detailed level.

The ambitious policy in Denmark on having a 100% renewable energy supply in 2050 requires radical changes to the energy systems to avoid an extensive and unsustainable use of biomass resources. Currently, wind power is being expanded and the increasing supply of electricity is slowly pushing the CHP (combined heat and power) plants out of operation, reducing the energy efficiency of the DH (district heating) supply. Here, large heat pumps for district heating is a frequently mentioned solution as a flexible demand for electricity and an energy efficient heat producer. The idea is to make heat pump use a low temperature waste or ambient heat source, but it has so far been very unclear which heat sources are actually available for this purpose.

In this study eight categories of heat sources are analysed for the case of Denmark and included in a detailed spatial analysis where the identified heat sources are put in relation to the district heating areas and the corresponding demands. The analysis shows that potential heat sources are present near almost all district heating areas and that sea water most likely will have to play a substantial role as a heat source in future energy systems in Denmark.

Industrial heat recovery can be used in district heating systems. It is a possibility to make use of heat that is otherwise lost. Increased usage of industrial heat recovery reduces the need for fuel combustion lowering green-house gas (GHG) emissions, such as CO2. Industrial companies can, however, move or close down industrial activities. This is apprehended as a risk and lowers the interest of district heating companies to invest in industrial heat recovery.

In Swedish district heating systems, industrial heat recoveries have been undertaken since 1974. Today, the heat recovery is active in about seventy systems. This leads to the question of how risky it is, for district heating companies, to engage in industrial heat recovery.

Over forty years of operation statistics have been collected and analyzed in order to estimate the risk of industrial heat recovery to district heating companies. Key results show that the risk is not linked to different industrial branches. Recommendations include suggestions to management on how to consider risk and consequence when assessing potential industrial heat recovery investments.

Urban development demands on construction aggregates are set to rise dramatically over the coming years within the Stockholm region and a significant environmental challenge will be associated with the large flows of construction aggregates and excavated materials in and out of future development projects respectively.   Material banks receive construction and demolition waste (CDW), process this waste and supply recycled aggregates to the construction industry helping to reduce the demand on natural construction minerals.  The transportation of these material flows between the material banks and development areas is predominantly by road in the Stockholm region.  With the transport sector responsible for almost one third of green-house-gas (GHG) emissions in Sweden, there is a motivation for investigating the environmental benefits of minimising transportation distances of construction aggregates.  Quantities of CDW in the form of excavated granular soil and rock from future development locations within a case-study area comprising three municipalities; Botkyrka, Huddinge and Haninge, in the south of Stockholm, have been estimated based on their municipal comprehensive plans up to the year 2030.  This has been done with the assistance of an earthworks estimation tool, the ESAR model, developed by Ecoloop AB.  Distances between existing and planned material banks and future development areas together with the estimated material quantities have been combined to approximate total vehicle-kilometres for the transportation of these materials under a business-as-usual scenario up until 2030.  A comparison has been made to an alternative scenario of strategically located material banks within the case-study area, whereby a methodology has been developed within this study to strategically locate material banks utilising GIS software ArcMap together with land availability map layers for siting material banks previously developed under a separate related study.  In comparison to the business-as-usual scenario, one strategically located material bank within the case-study area reduces total material haulage distances of excavated granular soils and rocks from development areas to the material banks by approximately 42% or 3.67 million vehicle-kilometres, equating to a reduction of 3478 tonnes of CO₂e throughout the time horizon of this study.  Another output from the ESAR model is the estimated construction aggregate demand for sub-surface earthworks backfilling activities.  A material flow analysis for the strategically located material bank indicates that the material bank is able to satisfy the sub-surface backfilling construction aggregate demand in the form of recycled aggregates throughout its operation.  Considering the flow of recycled aggregates back to development areas for backfilling earthworks activities, a total combined reduction of 45% or 5.54 million vehicle-kilometres of material haulage distance is achievable, equating to a saving of 5248 tonnes of CO₂e.  Reductions in GHG emissions from strategically located material banks are likely to also be significant beyond the boundaries of this study and warrant further research.

This disquisition aims for the study of turbulence intensity influence over the power performance of different sizes of turbines with the intent to validate a hypothesis. The hypothesis formulated for the analysis is the relationship between the rotor diameter (turbine size) and turbulence intensity. The hypothetical relationship is that the smaller turbines tend to experience more influence on the power performance from the turbulence in comparison with larger ones. For this examination, three different wind turbines of models Vestas V90, V100, V126 were chosen from three Swedish wind farms. The power performance of turbines at various levels of turbulence intensity were analyzed and the power deviation from the mean value due to influence of turbulence were assessed. The power deviation values of different turbines were compared at same level of wind speeds and also the power coefficients at same level of tip speed ratios were compared to validate the hypothesis. It was observed that the hypothesis seemed to appear true as higher influence on power curves were observed on V90 compared to others. Nevertheless, there were some obscene results which might be due to several factors such as influence of variation in hub height, site and inadequacy of data.

With an increasing demand for electrical energy, it is certain that the production will also increase,especially in rapid developing countries like India. Rapid industrialization is carving for more electrical energy, investment and suitable space for its infrastructure. But this development has to be sustainable keeping in mind the increasing global temperature due to pollution.

India is the second largest population in the world and hence produces a lot of waste daily. As of now, most of the waste goes to the landfills and gets burnt there or decomposed, either way releasing greenhouse gases in the process and degrading the environment. The municipal waste management is a challenging process in developing countries because of non-availability of proper infrastructure. There are some methods to manage this waste, such as scientific landfills,Incineration, Biomethanation, Gasification, Pyrolysis and Plasma Arc Gasification.By Gasification the solid waste is converted into synthesis gas which can be used for chemical industries, power generation, transportation and industrial heating etc. This process shrinks the solid waste to slag or ash which can either be used to manufacture eco bricks or can be disposed of on landfill. Thus saving a lot of place from land filling and if used for power generation it does not release any considerable harmful gases into the environment making it a sustainable process and partially renewable source of energy.

This project will estimate the capital requirement and procedure to setup a 1 MW gasification plant in Indian state of Telangana. In the study, the generation, composition, treatment and energy potential of solid waste have been studied. The technologies for waste-to-energy conversion have also been studied and the feasibility comparison of two leading technologies has been done.

Municipal solid waste has seen increasing annual volumes for many decades in contemporary Europe and constitutes, if not properly managed, an environmental problem due to local pollution and greenhouse gas emissions. From an energy perspective, waste is also an alternative fuel for power and heat generation; energy recovery from waste represents an effective measure to reduce landfilling and avoid disposal emissions while simultaneously reducing the equivalent demand for primary energy supply. A key factor for obtaining the full synergetic benefits of this energy recovery is the presence of local heat distribution infrastructures, without which no large-scale recovery and utilisation of excess heat is possible. In this paper, which aims to estimate municipal solid waste volumes available for heat recovery in European district heating systems in 2030, a literature and data review is performed to establish and assess current and future EU (European Union) waste generation and management. Main conclusions are that more heat can be recovered from current Waste-to-Energy facilities operating at low average heat recovery efficiencies, that efficient incineration capacity is geographically concentrated, and that waste available for heat recovery in 2030 is equally determined by total generation volumes by this year as by future EU deployment levels of district heating. © 2015 Elsevier Ltd.

Nowadays the globalization and the economy expansion of the emerging countries demand anincreasing amount of energy. Therefore, energy production as well as the efficiency of energyusage, is essential for future developments of societies. Renewable energies appear as a turnkeysolution that could support the growing demands, and at the same time not being harmful to theenvironment [1]. Within the types of renewable energies, wind energy could be considered asone with large potential.In this paper I present the study of a Swedish wind farm placed in Rockneby.Once the wind turbines were installed and working correctly, a discrepancy between the realenergy obtained and the theoretical energy indicated by the manufacturer was detected. Thestored data in the SCADA system were compared with the values provided by the manufacturerand several analyses were performed. Initially an anomaly in the power residual deviation wasdetected. It was showing an unusual behaviour at high wind speeds. The variation of the airdensity in the wind farm at hub height was considered as a possible reason of the disagreementobserved in the power parameters since the reference density used by the manufacturer was aconstant value calculated in laboratory environment. However, this idea was rejected becausethe power generated in both conditions is similar. The pitch angle was analysed after detectinga significant variations in wind speed measurements made by the anemometer in the turbinenumber three. As a result, it was found a pitch variation in the turbine which seems due to afailure in the anemometer. As a final result, the turbulences were analysed giving as aconclusion that the turbulence intensity were situated around 20%. Therefore, I mainly suggestas a possible explanation of this fact the influence of the turbulence accompanied of a badcalibration or failure in the anemometers.

In Sweden, district heating meets currently above half of the heat demands in buildings. District heating research in Sweden has a long tradition dating back to 1975. The latest research program period included 34 projects and was executed between 2013 and 2017. In this paper, a synthesis is performed on the Swedish research frontier by assessing these recent research projects. The three study purposes was to provide an overview over the executed projects, to identify new research questions, and to identify future challenges to the Swedish district heating industry. The assessment was based on six defined key areas, such as demand, resources, system frameworks, technology, cold supply, and international perspective. The subsequent content analysis was performed from three perspectives: the perspective of energy system transition, the customer perspective, and the sustainability perspective. Final conclusions include the three future challenges for the Swedish district heating industry. These are future strategies to communicate the value of district heating, vision for district heating beyond the transition to fossil free supply, and technology development for efficient use of low temperature heat sources. © 2018 Elsevier Ltd

Rapporten beskriver möjligheterna  att ställa om Sveriges elförsörjning till 100 procent förnybart i tre olika tidsperspektiv, fem, tio eller femton år.

Scenarierna är genomförbara. Kostnaden för elproduktion från nya anläggningar för sol- och vindkraft är redan idag eller kommer snart att vara lägre än kostnader för energi från nya anläggningar för den fossilkraft eller kärnkraft som ska ersättas. Detta gäller i synnerhet om man tar hänsyn till de så kallade externa kostnaderna. Externa kostnader är kostnader för klimatpåverkan, kemiska och radioaktiva rutinutsläpp och stora olyckor som belastar samhället, men som inte betalas direkt av elproducenterna. Framtidens el från förnybar energi kan framställas till lägre kostnad än den vi har för dagens energiförsörjning.

Runt om i världen ökar produktionen av elektricitet från solenergi och Sverige är inget undantag. Här uppnår däremot solelens andel av totala elproduktionen mindre änen promille. I denna rapport har vi därför utvärderathur mycket potentiell takyta som finns att tillgå i Tranemo kommun. För att evaluera detta har det gjorts en fältstudie tillsammans med samarbetspartnern Tranemo kommun där företag och kommunala byggnader undersökts. Därifrån har takytors area, lutning och väderstreckdokumenterats för att med vår egenkonstruerade beräkningsmodell uträknalämpligheten för platsen. I beräkningsmodellen behövs endast treindataför att kunna räkna ut ett ungefärligt värdepå solinstrålningen mot en vinklad yta. Dessaär platsens koordinater samt ytans lutning och vädersträck. För ett mer precist värde är molnighetsgrad nödvändigt för platsen. Vi har dokumentera en yta på 116000m2för solceller vilketkan utgöra 7 % av det årligaelbehovet i Tranemo, men endast en mindre delpå 46000 m2användbar ytaanser vi idag vara lämpliga. Det finns dock mycket mer yta att tillgåeftersom siffrorna endast är baserade påkommunala byggnader och företag.Delämpligaytorna kan bidra med en elproduktion på 6,74 GWh, motsvarande 3 % av Tranemos årliga elanvändning. Som kontrast har Sverige i dagsläget också en potential på ungefär 3 %. Kommunens potential är följaktligen näramedelvärdet för landet, vilket skulle påvisa goda möjligheterför solenergi.

Boken beskriver inledningsvis de grundläggande energiprinciperna samt det tekniska energisystemets organisation och hur detta energisystem relaterar till andra över- och underordnade energisystem. Vidare behandlas mer ingående den energianvändning som det tekniska energisystemet ska tillgodose i byggnader, industrier och transporter. Vidare beskrivs miljöpåverkan, energihistorien och de nuvarande politiska målen för energisystemet kortfattat. Boken avslutas med trettio viktiga slutsatser, fjorton typiska anläggningar för energiomvandling, definitioner av de viktigaste energiglosorna och svaren till bokens 42 övningsuppgifter.

Syftet med denna lärobok är att ge en inledande översikt över den nomenklatur med konventioner, uttryck, storheter, beteckningar och enheter som används inom energitekniken. Man kan därför uppfatta läroboken som en kommenterad glosbok. Inriktning och nivå på läroboken ligger mellan den grundläggande energifysiken och den mer praktiskt tillämpade energitekniken. En viktig grundkunskap för denna bok är gymnasiets fysik- och kemikurser. Med denna bok som grund kommer det bli enklare att förstå efterföljande mer detaljerade energitekniska kurser.

Bokens målgrupp är universitets- och högskolestudenter som har valt en utbildning med energiteknisk inriktning.

This project has been devoted to collection of long time series of national average district heating prices in Europe, since this information is neither collected by the International Energy Agency nor Eurostat.

In all, relatively long time series of district heating prices have been identified in 23 European countries, of which 20 countries are currently members of the European Union. Additional countries were Iceland, Norway, and Switzerland. These annual average prices have been estimated according to three different methods. Data sources have primarily been various national sources as national statistical authorities. Secondarily, various international sources have been used, when national sources could not provide required information.

The outputs from this price collection project consist of long time series of national average district heating prices until 2013 and the corresponding annual revenues and heat sales. In all, 560 annual average national district heating prices have been estimated.

Five main conclusions have been identified concerning European district heating prices:

1. Currently, very little aggregated information is available about district heating prices in various European countries. The purpose with this price collection has been to close this information gap.
2. International energy price analysts have therefore excluded district heating prices from their analyses.
3. Countries with high district heating prices during 2013 were Denmark, Slovak Republic, Germany, Norway, and Sweden.
4. Countries with low district heating prices during 2013 were Iceland, Bulgaria, Switzerland, Hungary, and Poland.
5. Countries with high proportions of district heating costs in the disposable incomes during 2013 were Slovak Republic, Lithuania, Latvia, and Estonia.

Market analyses and further conclusions based on these estimated time series of national district heating prices will be published in another publication. Hence, no explanations for different price levels in various countries have be provided in this report. © 2016 ENERGIFORSK

Information about European space cooling demands is rare, since cooling demands are not properly measured, when electricity is used for operating space cooling devices. Cooling demands are only measured at deliveries from district cooling systems. However, information about cooling demands by location and country is required for planning district cooling systems and modelling national energy systems. In order to solve this cooling information dilemma, space cooling demands have been assessed for European service sector buildings. These estimations were based on cold deliveries from twenty different European district cooling locations in eight countries. Main findings are that (1) the estimated specific cold deliveries are somewhat lower than other estimations based on electricity inputs and assumed performance ratios, (2) aggregated spacecooling demands are presented by country, and (3) an European contour map is presented for average specific space cooling demands for service sector buildings. © 2015 Elsevier Ltd.

More than two thirds of the heat supply to the Swedish district heating systems is nowadays based on biomass and waste resources. These district heating systems provide heat to cover more than half of the heat demands in the Swedish building stock. This paper reveals the development from the original use of fossil fuels in the late 1970s, the introduction of biomass as fuel in the early 1980s, the transition to considerable more renewables during the 1990s, and to the current situation when biomass dominates the heat supply. Our four conclusions consider the established infrastructure in both forestry and district heating, driving forces from energy policy tools and local initiatives, the contradiction between primary energy use of biomass and traditional heat recovery, and finally the future challenge of competitive use of biomass.

District heating is growing rapidly in China as Chinese building areas is expanding fast giving increased heating and cooling demands. This report gives an overview of the current situation for district heating and the research and development in this sector in China. Possibilities for collaboration between Swedish and Chinese researchers and companies in the field of district heating and cooling are also presented.

Electricity-driven air-conditioning is energy-intensive and puts a strain to many grids during hot periods in warm climates. Solar thermal cooling could be an alternative to conventional cooling, using a renewable energy source and supplying the most energy during peak demand periods with insignificant effect to the electric grid.

Office buildings in warm climates have high cooling loads, naturally peaking during daytime because of occupancy and ambient temperature. Thus, office buildings have a seemingly advantageous relationship between the possible supply of solar thermal energy and cooling demand. With this background, solar cooling systems for two office buildings with the same dimensions are investigated, placed in a tropical- and a sub-tropical location.

There are great differences in the design conditions for solar cooling systems in the tropics and the sub-tropics, between the chosen locations Manila and Abu Dhabi more specifically.

Manila has a quite evenly distributed cooling load while Abu Dhabi has a strongly pronounced summer season with very high maximum cooling loads, while the winter temperatures are relatively low. The prior described conditions creates a big difference between loads throughout the year, making a thermal chiller less effective in this aspect. However Abu Dhabi is expected to have an overall smoother- and ultimately a more high performance solar cooling system due to lower humidity, which facilitates the important cooling of the chiller.

Evacuated tube collectors were used at both sites, where the collectors in Manila needs to be larger relative to the chiller cooling capacity, in order to compensate for the irregularity of direct solar radiation.

The electricity price in Abu Dhabi is too low for the solar cooling system to be economically feasible compared to a conventional system, where the net values over 20 years are 163 000 € and 127 000 €, respectively. Manila has on its hand a very high price for electricity, making the 20-year net values for both the solar cooling- and the conventional system approximately 170 000 €.