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.

The goal of this paper is to provide a model for a sustainable electricity system to an island, in the Pacific Ocean near the equator.The method which has been used is to model supply and demand of electricity in the computer program Stella, through the creation of a dynamic system that balances them against each other. The result from the model will then be used to calculate the electricity price per kWh for the island.The result of the work is that electricity from solar energy is comparable with electricity produced from oil, if the oil pays for all its external costs, and the potential for pumped hydro storage plants is located. It also requires that consumers of electricity can be their own producers to avoid the expenditure of tax and reducing the cost of distribution. But since oil is a finite resource and has had a rising cost in recent years, while solar energy has had a declining cost, perhaps this will be a more competitive solution in the future.

In the spring of 2014 Sweco Systems AB were commissioned to design a ventilation system for a newly built preschool in Linköping. Terms from the client was that it cost efficiency would cope with the energy demands that are placed on the building. The unit chosen was a cross-flow heat exchanger, and this work is to compare it with two other heat exchangers to see if a more energy and cost efficient could have been chosen. The heat exchangers that was chosen for the comparison was a rotating- and a counterflow heat exchanger. Simulations have been made to the different heat exchangers by the manufacturers.

Background The usage of Nutrition supplement in the elderly care is commonly occurring and plays an important role in the intake of nutrition for the elderly. The usage of nutrition supplement is to reduce malnutrition within elderly care. For the elderly it is crucial to keep a healthy diet and to never lose weight. The loss of weight can be very dangerous it could even be fatal for the aged and should therefore be avoided. To have a diet that is rich in energy such as enriched meals prevents the elderly from receiving a shortage of calories since the diet is rich in fat, protein and thus also rich in energy.

Development of a vacuum cleaner nozzle for energy efficient dust pick-up.

The interest for power and energy measurement has greatly raised with todays increasing electricity prices and enviromental awareness. In the search for energy efficient solutions, the measurements are more complex due to increasing of non linear components. Harmonics and non sinusoidal voltages put high demands on sampling and filtering. Meanwhile, the price must be controlled so the customer still will find it interesting to invest in smaller plants. ITT W&WW asks for a robust, heat resistant power meter with compact dimensions to allow mounting inside the casing of a pump.

Detta examensarbete syftar till att utreda vilka av Svenska kyrkans byggnader i Växjö som ska energideklareras samt utföra en energideklaration av en kontorsbyggnad. I energideklarationen ingår det även att ge åtgärdsförslag för olika energibesparingsmöjligheter. En fördjupad studie i nattkylning av stommen har också utförts. Examensarbetet är uppdelat i tre huvuddelar, indelning av byggnader, utförande av energideklaration samt fördjupad studie av nattkyla. I den första delen delas byggnaderna in i grupper utifrån verksamhet och byggnadstyp och därefter utreds om de ska energideklareras.

The company Olofsfors AB manufactures drive belts for forest machinery, known as ECO-Tracks, and abrasion-resistant steel and cutting edges for graders, excavators and tractors, known as Bruxite and SharqEdges. Manufacturing these products requires the steel to be heated and molded, then submerged in water and hardened. The water used in the hardening of steel is pumped to the process from pits below the floor and then pumped back to the pit after it?s been used. Since the temperature of this water rises after being used to harden the steel the temperature of the pumping pit needs to be adjusted to maintain its setpoint of 21°C.

This report is the result of a thesis conducted at the consulting firm Bjerking AB andis the final part of the Bachelor Programme in Construction Engineering at Universityof Uppsala. The work aims to investigate the costs and how the choice of ventilationsystem affects building projects during a long-term period. This report covers costssuch as investment, maintenance and energy but also how they affect residents andbuilders. Building regulations for energy consumption are expected to be tougher;therefore a comparison of two different heat recovery ventilation systems(HRV-system) was made. One system is based on a centrally placed unit that coversthe whole buildings ventilation through vertical shafts.

Life Cycle Cost, often abbreviated as LCC, is a common tool for comparing the total cost of different alternatives, such as heating and cooling methods. Common heating and cooling methods in Sweden are geothermal energy, district heating and district cooling. This report aims to evaluate how different heating and cooling methods differ from each other while being applied on three different types of buildings, using selected LCC-models. Information about the selected LCC-models wasretrieved from each separate model and its website. Reports and agencies were used as sources for information about the heating and cooling methods.

Abstract Background: In 1997 the Kyoto Protocol was signed, it?s an international agreement which is aimed to reduce greenhouse gas emissions. Sweden's goal is to reduce energy using in buildings with 20 percent by 2020 and 50 percent by 2050. This is a comparison with levels from 1995 (Glad, 2006). For Sweden to be able to reach its goals, they need to construct more low-energy buildings (Åhman, Wahlström & Lundblad, 2010).

The Island of Öland has one of the best wind climates for land based wind power in Sweden. An objective for the Island is to become self sufficient using electricity from renewable source of energy such as wind. There is currently 55 MW capacity installed on the Island and it is estimated that grid congestion will occasionally occur if more than 135 MW was installed.The aim of this thesis is to investigate he possibilities for load management by smart charging of electric vehicles, EV. The definition of smart charging is that the charging is done to some extent with an ICT-system, (information and communication technology) that correlates wind electricity generation to the charging of electric vehicles. The purpose is to avoid grid congestions on the sub-sea cable that connects Öland to the mainland because that in turn would curtail wind energy production.

District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.

In cooperate with Asko Cylinda we have developed a new heat system too short the processtime and reduce the energy consume in a dishwasher and still have it too be a class AAA.The environment and quality is important for the company too still be the number one onthe market, If they want too keep that position the product developed of new innovations willbe very important. The systems we have developed are more effective and reduce energy uptoo 25 %. The process time is reduced too less than two hours, from the today two andhalf-hour. The solutions are too heat up the rinse water and the dishwater at the same time,with a new heating system and it make are solutions unique and effective. Its good for thedish and the environment.

Fuel pellets are a refined bio fuel mostly consisting of residues from sawmills and wood industry. At Rindi Västerdala AB's combined bio energy plant in Vansbro fuel pellets are produced, while the waste heat from the process is used for district heating. The pellets are produced from sawdust, wood shavings and dry wood chips that is dried, milled and pressed into small cylindrical rods. The advantage of refining the wood material in this manner is that the energy value is greater per unit volume and unit weight, thereby the cost of transportation per energy unit is reduced. Also, less storage space is needed.Pellet manufacturing is a complex process since many parameters affects the final results.