A wireless sensor network is designed to monitor events and report this information to a central location, or sink node. The information is required to efficiently travel through the network. It is the job of the routing protocol to officiate this process. With transmissions consuming the majority of the energy available to a sensor node, it becomes important to limit their usage while still maintaining reliable communication with the sink node. The aim of the research covered in this dissertation was to adapt the flat and hierarchical architectures to create a new hybrid that draws on current protocol theories. The designed and developed protocol, Hybrid Energy Efficient Routing (HEER) protocol, builds upon the initial groundwork laid out by the previously developed Simple Energy Efficient Routing (SEER) protocol designed by C.J. Leuschner. Another aspect of the work was to focus on the current lack of credibility that is present in the WSN research community. The validity of SEER was examined and tested and this led to the main focus of this research, ensuring that HEER proves to be valid. The HEER protocol for wireless sensor networks is designed such that it is computationally simple, limits the number of transmissions, employs a cross-layer approach, is reliable, is energy-aware, has limited support for mobile nodes, is energy efficient, and most importantly is credible. Sensor nodes are extremely limited when it comes to their available energy resources. To maximise the node and network lifetimes requires the designed algorithm to be energy aware and as efficient as possible. A cross-layer design approach is followed which allows for the different layers of the OSI model to interact. The HEER protocol limits the number of transmissions that are used for network operation. This is achieved by using a minimal amount of messages for network setup and by selecting the optimal route. Route selection is calculated using hop count, current energy available, energy available on the receiving node, and lastly the energy required to reach the destination node. HEER combines and expands upon the method used by SEER for route selection. Network lifetime for networks of large sizes is increased, mainly due to more efficient routing of messages. The protocol was kept computationally simple and energy efficient, thus maintaining network survivability for as long as possible. / Dissertation (MEng)--University of Pretoria, 2008. / Electrical, Electronic and Computer Engineering / unrestricted

Abstract Recent advances in wireless communications coupled with the widespread of bandwidthhungry and high-power consuming wireless services as well as the rapid penetration of multimedia-enabled smart handheld devices generate a drastic growth in mobile traffic volume. With these trends, the goals of 5G and beyond wireless communications include energy efficiency, low latency, and low service cost from the user’ perspective as well as spectrum efficiency, revenue increasing, and lower capital and operational cost from the network operators’ point of view. This thesis studies the potential of mobile clouds for improving energy, spectral, and cost efficiency towards the primary goals of 5G networks. Mobile clouds define a promising 5G integrated technology which combines the conventional cellular and shortrange networks into a novel and powerful communication architecture. Mobile clouds can be seen as a flexible and efficient platform for cooperative content delivery, cooperation, resource sharing, and social networks. Research work in this thesis is conducted in two main areas, namely fundamental and applied research on mobile clouds. Fundamental research focuses on cloud formation strategies and cloud maintenance mechanisms. In the applied area, the potential of mobile clouds for content distribution is investigated in both licensed and unlicensed bands. For content distribution using unlicensed band, several cooperative strategies are designed and their efficiency is compared to traditional multicast strategy in terms of energy efficiency, content distribution latency, and users’ quality of experience (QoE). In content distribution over licensed band, spectrum sharing and resource allocation algorithms are considered for multi pair and full-duplex device-to-device (D2D) communications, aiming at improving spectral efficiency and network performance as well as quality of service (QoS) provisioning. In addition, a business model is designed to consider how mobile clouds can reduce the cost of users and operators while improving revenue of operators and increasing users’ satisfaction. The results of this thesis show that mobile clouds technology creates a flexible and efficient platform which can efficiently enhance spectral efficiency, significantly improve energy efficiency and network performance while guaranteeing cost efficiency for users and network operators simultaneously. / Tiivistelmä Langattomassa viestinnässä on viime aikoina saavutettu useita edistysaskeleita samalla kun suurta kaistanleveyttä edellyttävien ja paljon tehoa kuluttavien langattomien palveluiden käyttö on yleistynyt ja multimediatoiminnoilla varustetut älylaitteet ovat vallanneet nopeasti markkinoita. Tämän seurauksena mobiililiikenne on lisääntynyt huomattavasti. Näiden suuntausten valossa langattoman 5G-viestinnän ja sitä seuraavien sukupolvien langattoman viestinnän kehitystavoitteita ovat muun muassa seuraavat: käyttäjän näkökulmasta energiatehokkuus, mahdollisimman lyhyet viiveajat ja palvelun käytöstä aiheutuvien kustannusten edullisuus sekä verkko-operaattorin näkökulmasta spektritehokkuus, tulojen kasvattaminen ja aiempaa matalammat pääoma- ja käyttökustannukset. Tässä väitöskirjassa tarkastellaan millaisia mahdollisuuksia mobiilipilvet tarjoavat energia-, spektri- ja kustannustehokkuuden parantamiseen ja siten 5G-verkkojen päätavoitteiden saavuttamiseen. Mobiilipilvi on lupaava osa 5G-teknologiaa, jossa perinteiset solukkoverkot ja lyhyen kantaman verkot yhdistyvät aivan uudenlaiseen ja tehokkaaseen tietoliikennearkkitehtuuriin. Mobiilipilvet voidaan nähdä joustavana ja tehokkaana alustana sisällön yhteisjakelulle, yhteistyölle, resurssien jakamiselle ja toiminnalle sosiaalisissa verkoissa. Tätä väitöskirjaa varten on tehty tutkimusta sekä mobiilipilviä koskevan perustutkimuksen että soveltavan tutkimuksen parissa. Perustutkimuksessa keskitytään tarkastelemaan pilvien muodostamisessa käytettäviä strategioita ja pilvien ylläpidossa käytettäviä mekanismeja. Soveltavan tutkimuksen alueella mobiilipilvien tarjoamia sisällön jakelun mahdollisuuksia tarkastellaan sekä luvanvaraisilla että vapaasti käytettävillä kaistoilla. Vapaasti käytettävillä kaistoilla toteutettavaa jakelua varten työssä kehitetään useita yhteistoimintastrategioita, joiden tehokkuutta verrataan perinteiseen monilähetysstrategiaan energiatehokkuuden, sisällön jakelun viiveiden ja käyttäjien kokemuksen laadun (Quality of Experience, QoE) osalta. Luvanvaraisilla kaistoilla toteutettavan sisällön jakelun osalta tarkastellaan moniparisessa ja samanaikaisessa molemminsuuntaisessa laitteiden välisessä viestinnässä (D2D-kommunikaatiossa) käytettäviä spektrin jakamisen ja resurssien allokoimisen algoritmeja, jotta spektritehokkuutta ja verkon suorituskykyä sekä palvelun laatua (Quality of Service, QoS) pystyttäisiin parantamaan. Tämän lisäksi työssä kehitellään liiketoimintamallia, jonka avulla voidaan pohtia, miten mobiilipilvillä voidaan vähentää käyttäjien ja operaattorien kustannuksia ja samalla kasvattaa operaattorien tuloja ja parantaa käyttäjien tyytyväisyyttä. Tämän työn tulokset osoittavat, että mobiilipilviteknologia on joustava ja tehokas alusta, jolla voidaan lisätä olennaisesti spektritehokkuutta, parantaa merkittävästi energiatehokkuutta ja verkon suorituskykyä sekä taata kustannustehokkuus sekä käyttäjien että verkko-operaattorien näkökulmasta.

Tumble dryers are becoming more and more common in ordinary households as a complement to the washing machine. Tumble dryers offer a fast drying cycle independent on weather conditions and require small space. They do, however, considering the large number of units use a large amount of electricity. The main objective in this thesis is to identify possibilities in order to reach a reduced electricity use for domestic tumble-drying of clothes. This involves an investigation of the condensing tumble dryer in order to point out possible energy efficiency improvements. The purpose of the energy label, which indicates the energy efficiency of the tumble dryer, is also studied, whether it matches the actual laundry habits. Finally, suggestions for technical development of the tumble dryer are made in line with today’s consumer behaviour. The performance of the condensing tumble dryer has been studied using a design of experiments to create a statistical model in Paper I. This model was used to find the best settings for the power supply to the heater, the internal airflow and the external airflow in order to reach a high specific moisture extraction rate (SMER) and a low leakage ratio. A low external airflow and high power supply to the heater gives the highest SMER. To reach the lowest values for the leakage ratio, a low internal airflow should be applied together with a high external airflow. The use of a statistical model gave valuable information of the performance of the existing tumble dryer. For further improving the energy efficiency of the dryer, the amount of leakage and its location was investigated in Paper IV. By studying energy and mass balances from experiments, pressure measurements and modelling, the effects of leakage on the process were evaluated. As the location of the leakage is so important for the energy efficiency, the worst-case scenario where leakage is located between the heater and the drum is used as a start point in the study. It was determined that there is a large leakage of air between the heater and the drum leading to a significant loss in energy recovery. The drying loads used by consumers are getting smaller, often less than 3 kg dry load, while the maximum capacity of the dryers are increasing, up to 7 or 8 kg. In Paper II, tests were made with different loads in order to investigate if the energy label serves its purpose as today’s standard is set at the dryers’ maximum capacity. The results from this study show that the energy efficiency when drying a small load is significantly lower than for a large load. In order to encourage a production of tumble dryers with higher energy efficiency for small loads, where the dryer is most frequently used, the standards for the energy label should be revised. Today, manufacturers do not gain any benefits by improving the performance for partial loads. A mathematical model over a venting tumble dryer was established in Paper III with the aim of testing different control strategies in order to improve the energy efficiency of the tumble dryer for partial loads. The ideas behind the different strategies were to minimize the heat losses during the drying process and to increase the residence time for the air in the drum and thereby increase the moisture content of the air leaving the drum. Using such a control strategy it is possible to reach an improvement of SMER by approximately 4% when drying small loads. In order to reach larger improvements, however, a more extensive product development will be necessary. Finally, the results in this thesis points at the necessity of including not only the technical development of the tumble dryer, but also the policy tools involved and the consumers’ habits in order to reach a reduced electricity use for drying clothes in households.

Reducing energy demand and carbon emissions from the UK housing stock through efficiency improvements is the focus of policy interest. The 2008 UK Climate Change Act set legally binding targets of an 80% reduction in greenhouse gas emissions against a 1990 baseline. The majority of emissions in the residential sector are carbon dioxide emissions arising from energy used for heating homes and water, cooking, lighting and electrical appliances. The sector s contribution to total UK emissions is significant and therefore reducing energy use in homes is an important factor if the UK is to meet its targets. In this research an initial survey of studies of the residential sector has been conducted to review factors considered to influence energy use and related emissions in UK housing. Further review identified energy and climate change policy instruments and structural change in the energy supply sector between 1970 and the present. A subsequent time-line of policy and events describes the changing, historical policy landscape related to energy efficiency improvements in the sector. As a result of these reviews, a need to better understand how householders have responded to technical energy efficiency improvements in housing, and the influence of social and economic factors, was identified as a research gap. In order to model householders historical behaviour Data Envelopment Analysis (DEA) was identified as an innovative approach for this field of research as a potential means to measure sector efficiency in a new way. The analysis has two stages. In the first, DEA is used to measure the relative efficiency with which the UK housing sector has managed its energy use and related emissions to deliver energy services such as space heating and lighting to householders. In the second stage, multiple regressions are used to examine whether the variability over time in the efficiency measure can be explained by policy interventions, energy market developments, and economic and social factors. DEA is a method for modelling the relative performance efficiency with which an observed sample converts measurable inputs to quantitative outputs. In this research, samples consist of annual observations of the UK housing stock, using data largely taken from DECC s UK housing energy fact file. An efficiency frontier of performance enveloping the observed sample points as closely as possible is constructed through DEA mathematical programming. The core of the analysis lies in identifying relevant quantitative input and output measures from available data. A range of measures of comfort and energy service levels to represent energy service outputs, and household energy and emissions data to represent inputs are examined in the analysis. The result is a timeline of efficiency performance that can be related to socio-economic change and the history of policy interventions. The analysis shows that the efficiency of the UK housing stock to manage its energy use and related emissions has not followed the steady upward trend that might have been expected from technical innovation. There is evidence of rebound effects over time, with householders behaviour in response to technical efficiency improvements acting to raise comfort levels rather than lower energy usage. Nevertheless, statistically significant roles can be identified for factors such as income, price and tenure which have implications for policy design and control and lead to a number of policy recommendations.

Data aggregation is an important technique in wireless sensor networks. The data are gathered together by data fusion routines along the routing path, which is called data-centralized routing. We propose a localized, Delay-bounded and Energy-efficient Data Aggregation framework(DEDA) based on the novel concept of DEsired Progress (DEP). This framework works under request-driven networks with realistic MAC layer protocols. It is based on localized minimal spanning tree (LMST) which is an energy-efficient structure. Besides the energy consideration, delay reliability is also considered by means of the DEP. A node’s DEP reflects its desired progress in LMST which should be largely satisfied. Hence, the LMST edges might be replaced by unit disk graph (UDG) edges which can progress further in LMST. The DEP metric is rooted on realistic degree-based delay model so that DEDA increases the delay reliability to a large extent compared to other hop-based algorithms. We also combine our DEDA framework with area coverage and localized connected dominating set algorithms to achieve two more resilient DEDA implementations: A-DEDA and AC-DEDA. The simulation results confirm that our original DEDA and its two enhanced variants save more energy and attain a higher delay reliability ratio than existing protocols.

Multi-radio multi-channel wireless mesh networks (WMNs) have been the focus of numerous research efforts during the past few years. These efforts aimed at extending the utilization of technologies based on the IEEE 802.11 standard in large-scale communities and even for city wide networking. However, mesh nodes in these networks are typically limited in their resources (e.g., bandwidth, power and radio interfaces). Such a limitation has led to an unsatisfactory network performance as well as users dissatisfaction. This dissertation addresses three important performance issues related to WMNs, namely, network performance enhancement, network survivability and green communications. To address the first issue, a novel quality of service (QoS) aware joint channel assignment (CA) and routing algorithm is developed. The proposed algorithm employs both dynamic and static CA techniques and corresponding link schedules that maximize the network throughput and minimize the delay and packet loss ratio. Next, the thesis addresses the problem of network survivability and theoretically analyzes the effects of node failure probabilities on the ability of the remaining network nodes to maintain their connectivity. A tight upper bound on the node failure probabilities needed to maintain full network connectivity on the one hand is first developed. On the other hand, a lower bound, at which the system loses connectivity, is also derived. We show that these bounds are dependent only on the nodes' geometric distribution and density. Based on the premise that failure of nodes in a small area may lead to failure of dependent nodes in other areas due to the quick divergence of traffic in these areas, an efficient node failure backup scheme is presented. The scheme relies on the capacity of the surviving network components in order to find new paths that do not overload the neighbours of the failed node which reduces the probability of generating congestion. Finally, the thesis addresses the problem of realizing energy-efficient WMNs that can operate using renewable energy sources. In these systems, batteries are often used to store and regulate the use of the supplied green energy to transmit the received data at each network router in order to overcome the problem of supply fluctuating of various energy sources. To realize these networks, the behaviour of the residual energy of the battery at a heavily loaded green wireless mesh node with a general traffic arrival and energy charging functions is first analyzed. Based on obtained theoretical results, both an online and an offline QoS aware packet scheduling schemes are proposed to minimize the probability of depleting the battery. Each of the aforementioned contributions is supported with various experimental evaluations to demonstrate the achieved performance enhancements.

In today’s scenario, energy efficiency has become one of the most crucial issues for Data Center Networks (DCN). This paper analyses the energy saving capability of a Data center network using Segment Routing (SR) based model within a Software Defined Network (SDN) architecture. Energy efficiency is measured in terms of number of links turned off and for how long the links remain in sleep mode. Apart from saving the energy by turning off links, our work further efficiently manages the traffic within the available links by using Per-packet based load balancing approach. Aiming to avoid congestion within DCN’s and increase the sleeping time of inactive links. An algorithm for deciding the particular set of links to be turned off within a network is presented. With the introduction of per-packet approach within SR/SDN model, we have successfully saved 21 % of energy within DCN topology. Results show that the proposed Per-packet SR model using Random Packet Spraying (RPS) saves more energy and provides better performance as compared to Per-flow based SR model, which uses Equal Cost Multiple Path (ECMP) for load balancing. But, certain problems also come into picture using per-packet approach, like out of order packets and longer end to end delay. To further solidify the effect of SR in saving energy within DCN and avoid previously introduced problems, we have used per-flow based Flow Reservation approach along with a proposed Flow Scheduling Algorithm. Flow rate of all incoming flows can be deduced using Flow reservation approach, which is further used by Flow Scheduling Algorithm to increase Bandwidth utilization Ratio of links. Ultimately, managing the traffic more efficiently and increasing the sleeping time of links, leading to more energy savings. Results show that, the energy savings are almost similar in per-packet based approach and per-flow based approach with bandwidth reservation. Except, the average sleeping time of links in per-flow based approach with bandwidth reservation decreases less severely as compared to per-packet based approach, as overall traffic load increases.

Ces travaux sont centrés sur l’étude des potentialités d’utilisation de la pervaporation, procédé de séparation par membrane, en couplage avec des procédés de séparation ou de réaction. L’objectif principal est d’évaluer la faisabilité technico-économique, le gain potentiel mais aussi les limites de son application compatible avec une exploitation industrielle. La détermination de ce gain passe par la simulation des procédés qui nécessite une modélisation correcte des processus élémentaires. Une modélisation à plusieurs niveaux est proposée. Elle permet de prendre en compte les différents systèmes d’études : matériaux membranaires et cas d’application et de donner le choix du nombre de paramètres ajustables en fonction des données expérimentales disponibles. Cette démarche a été appliquée à deux applications différentes. Le premier cas correspond à la récupération de butanol à partir de milieu de fermentation. Cette étude a montré des gains sur la productivité de la fermentation par couplage direct du fermenteur avec la pervaporation équipée de membrane hydrophobe. Le second cas correspond à la séparation eau/acide acétique, avec pour objectif la minimisation de la consommation énergétique pour un cahier des charges fixé. Le couplage retenu met en œuvre une étape de distillation suivie d’une étape de pervaporation équipée d’une membrane hydrophile. Les performances de quatre membranes ont été déterminées expérimentalement pour cette application. Enfin, une méthodologie est proposée permettant de déterminer les performances minimales de membrane permettant d’atteindre, en fonction des spécifications du cahier des charges, un gain énergétique par rapport au procédé conventionnel / The potential economical interest of using pervaporation, a membrane separation process, in hybrid processes (with separation or reaction unit) has been investigated. The main objective is to determine benefits and limitations of its use for an industrial application. The determination of the interest is predicted by simulation which requires a good understanding and a good representation of the elementary phenomenon of mass transfer and thermodynamic. A multilevel pervaporation modelling is developed, which takes into account the system variability (membranes and compounds) and allows choosing the number of fitted parameters according to the available experimental data. Two different industrial applications are studied. First, the recuperation of butanol from a fermentation medium is exposed. This case study has shown the gain on fermentation productivity when pervaporation, equipped with hydrophobic membrane, is used in direct coupling with fermenter. Next, the dehydration of acetic acid is studied with the aim of reduction the energy consumption of the conventional process. The configuration which has been selected involves a distillation column followed by a pervaporation module, equipped with a hydrophilic membrane. Performances of four membranes have been experimentally determined by for this application. Finally, a simulation methodology is developed, which can be applied to determine the membrane performances that need to be achieved to replace conventional processes with a hybrid process while respecting industrial specifications

Sedan oljekrisen på 1970-talet har västvärlden strävat efter att hitta energieffektiva     metoder för uppvärmning i fastigheter. I EU står bostadssektorn för ca 40% av det totala energibehovet och den enskilt största delen i människans ekologiska fotavtryck är koldioxidutsläpp, främst via förbränning av fossila bränslen där energisektorn historiskt stått för en stor del av dess utsläpp. Oljan har som uppvärmningsmedel så gott som fasats ut och på ventilationssidan har det de senaste 30 åren hänt fantastiskt mycket där man hela tiden strävar efter att hitta effektivare och miljömässigt hållbara system. Man har så gott som helt lyckats att få bort fossila bränslen som uppvärmningskälla från bostadssektorn och på ventilationssidan har man kommit så långt att man till och med börjar återgå från stora komplexa system till de något enklare systemen som man lyckats optimera  bl.a frånluftsvärmepumpar. Just frånluftsvärmepumpar spås en fortsatt god framtid där effektiviteten på pumparna, det så kallade COP-värdet (coefficient of performance) tros kunna fördubblas. Kv. Bordsgossen är ett flerfamiljsbostadshus i centrala Gävle och består av fem huskroppar fördelade på 53 lägenheter och därutöver kontors- och butikslokaler på bottenplan. Fastigheten som är från 1963 saknar helt energiåtervinning och fastighetsägaren Svedinger Fastigheter vill nu ändra på detta. Denna rapport tar vid där en tidigare energikartläggning slutar och i denna rapport har det undersökts om det finns lönsamhet i frånluftsvärmepump för fastighetens lägenheter, samt lönsamheten i värmeväxlare för fastighetens garage och en värmeväxlare för den butikslokal som inhyser företaget Arkitektkopia. Resultatet visar att det vid uppskattad installationskostnad finns god ekonomi i att installera frånluftsvärmepump i fastigheten samt att installera värmeväxlare för den lokal som inhyser Arkitektkopia och för fastighetens garage. Det som fastighetsägaren måste ta hänsyn till är att den uppskattade installationskostnaden nödvändigtvis inte är korrekt, utan bör ses som en fingervisare. Svedinger Fastigheter bör även hålla ett öga på den eventuella flödestaxa som den lokala fjärrvärmedistributören funderar på att tillämpa, som om den tas i anspråk antas kunna ha stor påverkan på den ekonomiska vinning som finns att hämta i energieffektivisering. Vidare behöver ventilationen i fastigheten injusteras och om fastighetsägaren beslutar att skrida till verket med ett fönsterbyte ska man ha klart för sig att det kommer att påverka fastighetens termiska komfort och energibehov. / Since the oil crisis in the 1970’s the western world has sought to find energy-efficient methods for heating in real estate. In the EU, the housing sector accounts for about 40% of the total energy demand, and the single largest part of man's ecological footprint is carbon dioxide emissions, primarily through the use of fossil fuels in which the energy sector has historically accounted for a large part of its emissions. Oil has in the terms of heating almost entirely been phased out and over the last 30 years the ventilations development has seen a great deal of progress where the market constantly strives for better efficiency and environmentally friendly techniques. The industry has managed to almost at full extent to remove fossil fuels as a source of heating for housing. On the ventilation side, the technique has come so far that systems start returning from large complex systems to the simpler systems that is optimized, for example, exhaust air heat pumps (EHAP). Exhaust air heat pumps are expected have a good future ahead where the efficiency of the pumps, the so-called COP-value (coefficient of performance), is predicted to be doubled.  Kv. Bordsgossen is a multi-family house in central part of the city of Gävle and consists of five houses divided into 53 apartments and on the ground floor consists of offices and retail premises. The property, which dates back to 1963, has no energy recovery and the property owner, Svedinger Fastigheter wants to change this.  This report has investigated whether there is profitability for a exhaust air heat pump in the property's apartments, as well as the profitability of heat exchanger for the property's garage as well as for the premises that accommodate the company Arkitektkopia. The result shows that, at the estimated installation cost, there is a good economy in installing exhaust air heat pump in the property as well as installing heat exchanger in the part  inhabited by Arkitektkopia, and in the facilities garage. What the property owner needs to take into consideration is that the estimated installation costs necessarily isn’t correct, but should be considered  as a direction point. Svedinger Fastigheter also needs to keep an eye on the possible flow rate that the local district heating distributor is considering applying. Should it be applied it is predicted to have a huge impact on the economical earnings in energy efficient technology. Furthermore, the ventilation is in needs of a adjustment and if the property owner decides to move on  with a window change it will affect the property's thermal comfort and energy needs.

In order to reach the European aim for a sustainable growth, the “Triple 20 by 2020”, the energy audit in every sector is one of the keys of the success. In order to carry on with the energetical development, sustainability and future energy efficient systems, the energy efficiency in the industry is one of the most important matters. The Swedish industry uses 147 TWh of energy per year, which represents the 39% of the total final energy use and also the biggest energy user of the three sectors. The food processing industry only uses a 3% of the total Swedish industrial energy use, however this is 4410 GWh per year, what still has high possibilities to reduce the use of energy through different energy efficiency measures.The present study consists on an energy audit of a small-medium industrial bakery in Ockelbo, Sweden, by starting with the compilation of a few energy efficiency measures that are usually carried out on the energy audits. Then those measures have been tried to implement in the bakery in order to reduce the energy use and therefore the costs, which are the principal aims of the study, together with the approach to future energy efficiency ideas. However, the lack of electrical measure equipment has been a big limitation for the study. The method, that has been the guideline for the energy audit, is the Energy management procedure, which is a widely used method on different energy audits. The main measures that have been proposed are regarding the auxiliary processes like lighting and the compressed air system, additionaly, changes regarding the power contract and the installed power of they bakery are presented. Also different future possibilities for the heat recovery are analyzed and discussed like using the waste heat for preheating tap water for the dough processes. Additionally this study contains a wide explanation of the Swedish electrical bills that every company has to pay and probably many of them do not understand.If the presented energy efficiency measures are implemented the electrical energy use can be reduced with at least 23109 kWh per year. In terms of money, the cost savings are at least 57781 SEK per year with an investment of 106300 SEK.