Linux is a growing operating system in embedded systems. Today, Linux is not only in heavy servers but also in cell phones, PDAs, cameras and other devices running on battery power. While current technology is more energy efficient, more and more technologies are implemented into a single unit resulting in an overall increase of Power consumption.Low Power consumption is an increasingly important feature of a system today. Lower Power consumption means lower costs, less environmental impact, and longer life for applications that runs on batteries.This work compiles methods to reduce Power consumption of Linux systems. The work includes examining whether the available opportunities are platform-specific or of a more general nature.

This report is an inventory of the street lighting in half of the residential estates owned by Karlstad Bostads AB, a public housing company. The inventory was made to reduce the environmental impact of the street lighting. From the inventory an estimation of the total installed power and the energy consumption was made. The total estimated power of the street lighting was 125 kW and the energy consumption was 500 000 kWh/year with an estimated running time of 4 000 h/year. The dominating source of light was 125 W discharge mercury lamps.

Minimizing Power consumption is a critical part of many embedded design projects. Thechallenge is to limit the Power consumption of the system and at the same time providesatisfactory service to the user. With regards to microprocessors, the main way of limiting powerconsumption during program execution is to adjust the frequency and the voltage at which theprocessor operates.To enable the implementation of real-time scheduling with support for dynamic voltage andfrequency scaling, an exhaustive study of the Freescale i.MX31 embedded microprocessor isperformed. Specifically, the Power consumption relationship to all relevant frequency andvoltage settings is investigated. In addition, to enable frequency and voltage scaling in a real-timeenvironment, a complete timing analysis of proposed voltage and frequency scaling methods isperformed and their suitability for use in real-time systems is evaluated.To integrate voltage and frequency scaling capability into OSE RTOS, a software module hasbeen developed for this operating system.

Today?s wind power plants are only compensated for their reactive Power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Today?s wind power plants are only compensated for their reactive Power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Today?s wind power plants are only compensated for their reactive Power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Today?s wind power plants are only compensated for their reactive Power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

The Swedish energy companies have several different systems for data collection of the energy consumption of their clients. Often computerized remote meter readers are put in practice in order to register the energy consumption of large companies. The majority of household clients, however, are read off by the assistance of manual methods. Household Power consumption is read off once a year. As a result, these clients are not debited for their actual consumption; their invoices during the year are the result of estimations.

Today?s wind power plants are only compensated for their reactive Power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Today?s wind power plants are only compensated for their reactive Power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Several studies indicate that Swedish men consume more meat than women, more frequently appear in advertisements for meat and more often than women handle the grilling of meat. Production of meat is one of the largest contributors to greenhouse-gas emissions and thereby poses a challenge for ecological sustainability. Several Swedish politicians and authorities have argued that reduced meat consumption is necessary to prevent continued global climate change. To understand and change consumption patterns we need to understand the consumer. This essay uses textual analysis to examine how Swedish men through text and images in three cookbooks use preparation and consumption of meat to construct different masculinities.

The Swedish energy companies have several different systems for data collection of the energy consumption of their clients. Often computerized remote meter readers are put in practice in order to register the energy consumption of large companies. The majority of household clients, however, are read off by the assistance of manual methods. Household Power consumption is read off once a year. As a result, these clients are not debited for their actual consumption; their invoices during the year are the result of estimations. At times when the electricity supply system is highly loaded, electricity is more expensive.

In this thesis a number of energy saving methods for a multiplier on algorithmic level are investigated. For the investigation a multiplier is constructed in VHDL, after which the circuit's performance is investigated. A number of techniques for reduced Power consumption are introduced in the circuit and are then evaluated. The conclusions are that all investigated methods, pipelining, interleaving and voltage scaling, should be maximally made use of in order to minimize the Power consumption..

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.

In many clinical applications, it is desirable to transmit sensor information wireless. In earlier research, investigation transmit ECG signal using Bluetooth, was performed. However, when Bluetooth has some drawbacks it is of interest to investigate alternative methods, one such method is ZigBee. Bluetooth has higher data rate speed (1Mbps) than ZigBee (250kbps). However, Bluetooth consumes more power.