Ocean Thermal Energy Conversion, OTEC, is a sustainable energy conversion technology that is not yet commercialized. OTEC is a technology that utilizes the temperature difference in oceans between the warm surface water and the cold water at 1 000 m depth to run a Rankine Cycle. This technology can produce electricity and provide synergies like fresh water, air conditioning and aquaculture. A simulation program for three alternative OTEC systems has been created in order to decide which OTEC system is most profitable; closed, open or hybrid system. In this simulation a production cost analysis is performed in order to investigate and decide which one of the three systems that has the lowest production cost. The production cost analysis also analyzes if the profitability is affected by the size of the facility. After these analyzes, the most profitable of the three different OTEC-systems is expanded by an installation of Solar collectors in order to see if the thermal efficiency is improved. The result shows that the most profitable system varies with the size of the facility.

Akademiska hus is a real estate company that specializes in providing Swedish universities with housing facilities for educational and research purposes. The company strives to reduce its use of energy by 40% between the years 2000 and 2025. The aim of this thesis is to determine which measures can be taken to reduce the need of purchased energy in a building that is used by theSwedishUniversityof Agricultural Sciences inUppsala.In order to determine the results of various changes to the building envelope and ventilation system, the building was modelled in the computer simulation program VIP-Energy. Other proposed changes to make the use of energy more efficient concerned water use and lighting. The need of purchased energy can also be reduced by producing electricity or heat on site, using solar energy.Results show that economically viable measures include upgrading windows and faucets, adjusting control systems for ventilation and lighting, and installing roof mounted solar panels for power production.

Finnhamn is a small group of islands in the Stockholm archipelago. At Stora Jolpan, the biggest island, there is a hostel. The main building was built in 1915 and is called Utsikten. The purpose of this project is to on behalf of the Archipelago Foundation (Skärgårdsstiftelsen) find alternative systems that can replace the existing heating system of Utsikten (an oil-fired boiler and electricity heaters) to a system with renewable energy. The alternative system that this project focuses on is a system of Solar collectors combined with a wood chip boiler.

The purpose of the house which is the basis of this report is to be able present itself on the market as a relatively cheap and at the same time a climate friendly choice. The house is supposed to be able to be built anywhere in Sweden and the rest of Scandinavia in a short period of time. This puts demand on what kind of heating system the house can have, since not all places have the geographic advantage of being able to use geothermal or district heating. Therefore the heating system choices will only include those that are not limited by their geographic location. The house will be built in modules which only require the groundwork to be done before the house can be erected. In this report "System solutions for plus or passive-housing" a comprehensive literature search has been conducted as well as a number of calculations.

The study aims to investigate the feasibility of small-scale electricity production with solar electricity systems, also known as PV (photovoltaic) systems, in Australia. Due to the global warming, sustainable energy has in recent years become an increasingly important issue, both internationally and in Australia. With one of the largest dependencies on fossil energy sources in the world, the country's abundant solar radiation is a possible solution to this issue.Both the technical and the economic feasibility of small-scale PV systems were investigated. On the technological side, the electricity generation, distribution and consumption systems were studied. On the economical side, the parameters that drive the profitability of a PV investment were investigated.

A passive house in Norra Djurgårdsstaden drawn by Tengbom Arkitekter is going to be built. A shaft for airing is needed for a few apartments in the house.The airing shaft is designed for a few two room apartments in the house, which are not able to achieve satisfactory airing, as their outer walls are facing a single direction. The other apartments on the same floor are corner apartments. These apartments do not have the same difficulty with airing since they have their outer walls in different directions, with different pressures at the facades. The airflow in the airing shaft is supposed to be driven only by natural forces, by the sun. The purpose of natural driven forces is to achieve low energy consumption for the house.In this thesis, a design of the shaft for airing has been developed.Initially an open shaft for all apartments was analyzed.

The awareness regarding environmental issues is increasing and as a result a large number of products are eco-labeled. This enables the consumers to make enlightened environmental decisions when purchasing products. Eco-labeling is no longer for products only, but also for services like hotels. It?s difficult to determine what it actually means to eco-label a hotel and what kind of benefits it includes.

Abstract In order to make the modern agriculture less dependent on non-renewable external inputs, it has to rely more on ecosystem services. The agricultural system produce not only food, fiber and fuel, it also generates other ecosystem services such as e.g. photosynthesis, recycling of nutrients, influencing local microclimate, pollination, biological control and detoxification of noxious chemicals. This study is an attempt to get a better understanding about the interaction among different ecosystem services and different habitats capacity to generate them. An evaluation of eight different methods is done. The ecosystem services studied are the ability to absorb solar energy, biomass production, botanical diversity, decomposition and natural predation of aphids.

The housing sector of today represents for almost 40% of the energy consumption, an energy consumption of which the major part consists of non-renewable energy sources. This is not sustainable and utilization of new energy-efficient technologies in buildings can be a step in the right direction, towards a sustainable energy society.This report has been made on behalf of and in cooperation with Älvstranden Utveckling AB in Gothenburg to examine how future energy-efficient technologies can affect the energy demand in energy-efficient multi-dwelling buildings.The report is based on Älvstrandens passive house, Hamnhuset, a house whose energy consumption is far below the BBR's requirements. The report looks at the opportunities for improvement within windows, insulation, solar energy technologies, as well as white goods. Computer simulations are then made to apply the selected technologies into a reference building. Technologies are selected from an energy efficient perspective and no account has been taken of other aspects such as the economy.

The purpose of the project has been to work out recommendations that reduce the energy-related costs and environmental impact of HPW Fresh & Dry Ltd., a fruit drying factory in Ghana. The factory produces electricity with diesel and biogas but also purchases electricity from the national electricity company. Heat for the drying process is produced from biogas, kerosene and solar panels. In the project the energy system was analyzed by measuring production and consumption of heat and electricity. The project results show that the factory can become self-sufficient on heat if the available energy is used more efficient. The production units for both electricity and heat have low efficiencies.

This thesis concerns to investigate renovations of existing buildings aiming at enabling energy efficiency, from a conservation and restoration perspective. This includes performing case studies of three projects in the Gothenburg area where renovations has been done and an analysis of directives raised by the EU and later implemented by the Swedish National Board of Housing, Building and Planning, Boverket. In addition to these, regulations enforced by the Swedish law, related to the topic, have been considered.The investigated projects in this case were the housing cooperative Välten in Brämaregården, the Solar Buildings in Järnbrott and Gårdsten as well as Katjas Gata 119 at Backa Röd. In order to measure and compare the results of these projects a comparison between the pre- and post-restoration energy consumption have been performed. To capture additional perspectives the grading system Operation Kungsörn has been applied.Regarding the comparison of energy consumption the renovation of Katjas Gata 119 was found preferable but showed in my view lacking attention to the cultural heritage of the area.

The interest in small-scale electricity in Sweden has increased strongly in recent years. The interest is noticeable both among politicians to increase the share of renewables in the energy mix, and among electricity consumers to partially replace purchased electricity with self-produced. This has resulted in a significant increase of electricity production in low voltage grids in recent years, and the trend appears to continue in the coming years. The majority of the new production plants are solar cells, followed by wind turbines, and it is also in these the greatest efforts are made in this paper.Distributed generation is often seen as something positive since it will contribute to reduced transmission losses and reduced voltage drop in the networks, and that it increases the share of electricity from renewable sources. In cases where the grids are not strong enough, or in other ways not adapted to manage the installed production, power quality may be adversely affected.

A Monte Carlo simulation of the ELECTRA reactor using (U,Zr)N fuel and a liquid lithium coolant is performed using the Serpent simulation code. The results show a reactor with a total reactivity coefficient of the coolant, fuel and material expansion that is strongly negative. These properties make the ELECTRA reactor a good candidate for a safe space reactor that could be used for propulsion of manned and unmanned space vehicles to Mars and other parts of our solar system..

This bachelor thesis aims at investigate how a specified house can optimize its energy consumption.Today the house often stands for the major part of the energy consumption in a consumers? life,whereas an energy optimization creates economic as well as environmental advantages. It is importantto make old houses more energy efficient, but putting high energy demands on new houses could beargued to be more important. The installations functions as both the heart and brain in a house, thusmaking it important to energy optimize these. Since the background describes the importance ofenergy efficiency and optimization in a house, the focus area of this report will be an investigation ofdifferent types of heating systems in order to be able to choose the one most suited for the house.Aspects considered when choosing the heating system was how economic the system is both inservice- and investment costs and how environmental and operational friendly the system is.Through literature reviews there were sufficient information gathered that served as a foundation whencomparing and choosing between the four systems - district heating, pellet-fired boiler, geothermalheating and solar heating.

The interest in small-scale electricity in Sweden has increased strongly in recent years. The interest is noticeable both among politicians to increase the share of renewables in the energy mix, and among electricity consumers to partially replace purchased electricity with self-produced. This has resulted in a significant increase of electricity production in low voltage grids in recent years, and the trend appears to continue in the coming years. The majority of the new production plants are solar cells, followed by wind turbines, and it is also in these the greatest efforts are made in this paper.Distributed generation is often seen as something positive since it will contribute to reduced transmission losses and reduced voltage drop in the networks, and that it increases the share of electricity from renewable sources. In cases where the grids are not strong enough, or in other ways not adapted to manage the installed production, power quality may be adversely affected.