The purpose of this thesis is to investigate and clarify the facts surrounding one of Vattenfall's district heating plants; The "solar field" and associated rock cavern in Lyckebo, Storvreta. The plant was built in the '80s by the formerly municipal utility,Uppsalakraftvärme AB, as an experimental building. A ground water filled cavern would serve as seasonal storage of solar heat from an adjacent solar field. Since both the energy company and the facility itself has undergone major changes over the past 30 years, there was a great need to gather facts in order to provide a picture of its current condition and potential for continued use. The thesis investigates the plant's history and problems with the rock cavern losses, and how the operation developed. It also presents the calculations regarding the possibilities of again supplementing the facility with solar energy - which is not the case today - as well as the economic conditions for it. Regarding a re-launch of solar energy, primarily a concentrating solar collector has been studied, as it has the advantages of an integrated control system.

Most of the portable electronic devices use a battery as a primary power source. Nowadays, when the applications are becoming smaller and smaller and more power efficient, the designer needs to concentrate more on reducing power consumption, using secondary power sources and introducing power storage devices. Multiple power source availability and a power storage device on the board will make the applications much more useful and efficient in everyday use. This thesis proposes a power supply unit (PSU) for wireless sensor platforms which is capable of supplying a sensor node with energy from multiple sources, as well as status information from the PSU. Present power storage devices, like electric double-layer capacitors (EDLCs) and batteries, have become more and more common as their characteristics have developed.

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.

The horse is a homeothermic animal and to keep a constant body temperature in winter season is important. Acclimatisation is to provide means for a good thermal insulation consisting of skin, hair, and an outer air layer. The skin covers the horses body and it is composed of three main layers where the top layer of the epidermis consists of dead keratinized cells that are constantly being sheed. The dermis is composed of collagen connective tissue that give the skin its strength. The bottom layer with subcutaneous fat provides a thermal insulation and can be used as an energy reserve in cold weather.

Today the human being see energy as a matter of course but the resources that is used for extract energy is today not enough for the world demand. Of all the energy that is used in Sweden today approximately 40 % goes to the building stock. This number will most likely increase if not necessary actions will be made on the already existing building stock since new houses constantly are built which will be added up on the already existing energy supply. This takes cause of action on the already existing building stocks, to fulfill the demands of the future use of energy that has been set by the authority. At the same time the thermal conditions cannot be influenced by the necessary changes that must be made.

When drivers overnight in the truck lots of electric energy is consumed by heaters, fans, lights and other extra equipment. If the engine is not running, this energy is taken from the lead/acid batteries of the truck which then needs to be recharged during operating hours. The fact that the charge acceptance of the lead/acid batteries is dependent on the temperature makes it hard to fully recharge the batteries at lower temperatures. A negative charge balance can lead to starting problems within a few days use in cold climate.In this thesis work, the effects of different battery charging concept are evaluated on the most common Scania battery (175Ah). A battery model is implemented in Matlab and some simulations of charging are made.

The purpose of this thesis was to make an energy survey and quantify energy flows of individual unit operations associated with the biogas production in Uppsala Vatten och Avfall AB:s biogas plant, located at Kungsängens gård. Moreover, large consumers of energy would be identified and analyzed. The objective of this energy survey was to obtain a detailed understanding of the energy use in the biogas production.The energy survey was divided into two parts: electricity and heat. Each part was treated separately and with somewhat different approach. To estimate the electricity usage during the projcet the rated power of each selected unit operation was noted and multplied with thenmeasured time of usage.

The purpose of this thesis was to make an energy survey and quantify energy flows of individual unit operations associated with the biogas production in Uppsala Vatten och Avfall AB:s biogas plant, located at Kungsängens gård. Moreover, large consumers of energy would be identified and analyzed. The objective of this energy survey was to obtain a detailed understanding of the energy use in the biogas production. The energy survey was divided into two parts: electricity and heat. Each part was treated separately and with somewhat different approach. To estimate the electricity usage during the projcet the rated power of each selected unit operation was noted and multplied with the measured time of usage.

The purpose of this master thesis is to investigate different types of measures for making buildings more energy efficient and to estimate their profitability. The calculations were performed with the building simulation program VIP+ and the evaluation of the profitability with the life cycle cost method. Furthermore, it was examined how losses in the distribution of secondary systems of district heating can be avoided. Options to replace district heating with a local district heating system based on bio-energy have been investigated. The possibilities of achieving more efficient thermal energy consumption and production for the chosen estate were also examined.The object of the study has been a residential estate with 133 detached houses in Uppsala, built in 1974.

Title: Information storage - A growing problem? Authors: Göran Svanhall Pär Truedsson Erik Ponnert Tutor: Bengt Carlsson Problem: Every day companies, regardless of size, produces new information that needs to be stored. In the information society of today, the characteristics of the information changes both in size and complexity. This results in higher demands on which storage solution that suits the company and their field of business. New and more innovating storage solutions enters the market, but are they necessary to smaller companies of development active in the IT society? Questions to Answer: Is data storage a growing problem for companies of development active in the IT society? How do traditional storage solutions manage the information growth of today? How urgent is the need of a new storage solution? Which features are prioritized in the future storage solution? Method: By performing a quantitative survey we delivered an inquiry to several companies, which answers will help us answering our above mentioned questions.

When the Swedish Forestry Act was changed in 1994, brushing of young stands became non mandatory. Since then the annual need for brushing in the country has increased by about 100 000 hectares per year. In later years the price for biomass energy has increased to the same level as pulp wood. The high price on biomass energy and the large areas of stands in the need of brushing has created a new market with its own technical, economical and environmental conditions. There is a development of various techniques to manage the forestry stands with late brushing.

Gunsta is situated about 10 km east of Uppsala. Today there are plans to establish 1000 new households in Gunsta before year 2030. The required energy for heating houses and water would be distributed via a district heating system, which also includes 200 existing residences. The annual required energy, according to this study, would be 16.2 GWh with a maximal peak effect of 6.9 MW. To meet this need, the study suggests a system with heat pumps to upgrade the 31?C water from a 1.8 kilometre deep borehole.

Storage of biomass is often associated with problems such as heat development, dry matter losses and reduction of fuel quality. The rise in temperature can potentially cause a risk of self-ignition in the fuel storage. Moreover, emissions from storage piles can cause health problems in the surrounding. The dry matter losses and reduction of fuel quality can have economical effects. The aim of this thesis project is to develop guidelines on how to store large amount of biomass at Vattenfalls heat and power plants in an optimal way.

Ethanol for automotive purposes is an issue much debated and researchers disagree about the benefits of bioethanol. Converting energy-rich crops into ethanol suitable as motor fuel is a complex process and continuous development and improvements of processes and material used are important steps in the work of developing environmental friendly fuels. Grain is usually preserved by drying which consumes a lot of energy. Alternative storage of high-moisture grain in airtight storage systems reduce the energy required to produce bioethanol and studies have also shown that ethanol yields are increased more than 10% in ethanol fermentations of moist grain compared to dry. Airtight storage is often not perfectly airtight so biocontrol agents are necessary in order to preserve the grain.

This thesis work resulted in a template for how the thermal spray process can be controlled through robot programs. The robots today and their programs need to be replaced, therefore a new structure which can be matched with the new robot systems is needed. The work is limited to only concern structured programming on the new robots on Thermal Spray Centre (TC) with the programming language Rapid. The basic data for the program was retrieved from interviews with concerned personnel at TC, from studies on process parameters for thermal spray and from existing specifications at Volvo Aero Corporation (VAC). The thesis work briefly describes the process thermal spray and the four methods used at VAC.