The present environmental concerns and the rising human requirement for solutions with better comfort and lower costs have resulted in an increased awareness for the energy use in the built environment. Technical advances in building structural systems and materials, heating and other comfort-providing systems and controlling strategies all lead to the integration of building technology with the function of buildings and the aesthetics. Therefore, in the process of improving the performance of energy systems and increasing the energy efficiency, integrated system approaches are of high importance. Performing the necessary energy analysis before any construction-installation occurs can help designers and decision makers reach guided solutions. Hence, a broad range of calculation tools for evaluating the operation of energy systems and the controls in buildings have been developed the latest years with different levels of complexity and angles of focus. However, research and development regarding holistic energy system designs and techniques are in their infancy. The standard tactic has been to isolate system parts, study them as stand-alone sub-systems and focus on optimising components or processes of a complex function. In the present study, it is demonstrated the necessity for uniting energy engineers, architects, installers and technicians regarding decision making upon the energy use for heating, ventilation and air-conditioning (HVAC) in the built environment. Systems approach has been employed for studying the research issue that is presented in the current thesis. An extended part of this treatise has been devoted to systems thinking in practice. The thesis demonstrates systematic methods of modelling and analysing certain, integrated, domestic, HVAC applications. The reference system boundaries enclose the building as a construction and as a dynamic function, a comfort-providing system based on a heat pump, a low-temperature hydronic heat distribution system and controls in a residential application. Obviously, these are not the only components met in a hydronic heating system. Numerous pieces of equipment, as piping, circulating pumps, expansion tanks, zone valves, relief valves and other essential elements are needed to make a safe and functional heating system. However, this study focuses on the analysis of the chosen reference system. Several models have been developed in the computational tools of TRNSYS and EES. These tools have been employed because they allow co-solving, hence the integrated system as well as the interaction between the different parts of the system can be studied. The foremost result of this study is that approaching the system as a whole provides a better picture of the operation of every system component and the interaction between them. Explanations are given for the parameters that have a significant impact on the system’s performance. The thesis shows the importance of factors that are not easy to predict, as well as the difference in the building’s behaviour under fast changing thermal loads when the incorporated thermal mass is altered. Finally, implementing sophisticated controls for reducing the energy costs without compromising thermal comfort is vital. / QC 20101008

Thermal energy storage (TES) is an advanced technology for storing thermal energy that can mitigate environmental impacts and facilitate more efficient and clean energy systems. Thermochemical TES is an emerging method with the potential for high energy density storage. Where space is limited, therefore, thermochemical TES has the highest potential to achieve the required compact TES. Principles of thermochemical TES are presented and thermochemical TES is critically assessed and compared with other TES types. The integration of TES systems with heating, ventilating and air conditioning (HVAC) applications is examined and reviewed accounting for various factors, and recent advances are discussed. Thermodynamics assessments are presented for general closed and open thermochemical TES systems. Exergy and energy analyses are applied to assess and compare the efficiencies of the overall thermochemical TES cycle and its charging, storing and discharging processes. Examples using experimental data are presented to illustrate the analyses. Some important factors related to design concepts of thermochemical TES systems are considered and preliminary design conditions for them are investigated. Parametric studies are carried out for the thermochemical storage systems to investigate the effects of selected parameters on the efficiency and behavior of thermochemical storage systems. / UOIT

Wireless sensor networks (WSNs) have recently achieved a great deal of attention due to its numerous attractive applications in many different fields. Sensors and WSNs possesses a number of special characteristics that make them very promising in many applications, but also put on them lots of constraints that make issues in sensor network particularly difficult. These issues may include topology control, routing, coverage, security, and data management. In this thesis, we focus our attention on the coverage problem. Firstly, we define the Sensor Energy-efficient Scheduling for k-coverage (SESK) problem. We then solve it by proposing a novel, completely localized and distributed scheduling approach, naming Distributed Energy-efficient Scheduling for k-coverage (DESK) such that the energy consumption among all the sensors is balanced, and the network lifetime is maximized while still satisfying the k-coverage requirement. Finally, in related work section we conduct an extensive survey of the existing work in literature that focuses on with the coverage problem.

Energy efficiency of IT infrastructures has been a well-discussed research topic for several decades. The resulting approaches include hardware optimizations, resource management in operating systems, network protocols, and many more. The approach the authors present in this chapter is a self-optimization technique for IT infrastructures, which takes hard- and software components as well as users of software applications into account. It is able to ensure minimal energy consumption for a user request along with a set of non-functional requirements (e.g., the refresh rate of a data extraction tool). To optimize the ratio between utility of end users and the cost in terms of energy consumption, the system needs inherent variability leading to differentiated energy profiles and mechanisms to reconfigure the system at runtime. The authors present their approach called Energy Auto-Tuning (EAT) comprised of these mechanisms and an architecture which automatically tunes the energy efficiency of IT systems.

Energy efficiency is gaining more and more importance, since well-known ecological reasons lead to rising energy costs. In consequence, energy consumption is now also an important economical criterion. Energy consumption of single hardware resources has been thoroughly optimized for years. Now software becomes the major target of energy optimization. In this paper we introduce an approach called energy auto tuning(EAT), which optimizes energy efficiency of software systems running on multiple resources. The optimization of more than one resource leads to higher energy savings, because communication costs can be taken into account. E.g., if two components run on the same resource, the communication costs are likely to be less, compared to be running on different resources. The best results can be achieved in heterogeneous environments as different resource characteristics enlarge the synergy effects gainable by our optimization technique. EAT software systems derive all possible distributions of themselves on a given set of hardware resources and reconfigure themselves to achieve the lowest energy consumption possible at any time. In this paper we describe our software architecture to implement EAT.

Optimal operation of plants is becoming more important due to increasing competition and small and changing profit margins for many products. One major reason has been the realization by industry that potentially large savings can be achieved by improving processes. Growth rates and profitability are much lower now, and international competition has increased greatly. The industry is faced with a need to manufacture quality products, while minimizing production costs and complying with a variety of safety and environmental regulations. As industry is confronted with the challenge of moving toward a clearer and more sustainable path of production, new technologies are needed to achieve industrial requirements. In this research, a new methodology is proposed to integrate so-called new technologies into existing processes. Research shows that the new technologies must be carefully selected and adopted to match the complex requirements of an existing process. The new proposed methodology is based on four major steps. If the improvement in the process is not sufficient to meet business needs, new technologies can be considered. Application of a new technology is always perceived as a potential threat; therefore, financial risk assessment and reliability risk analysis help alleviate risk of investment. An industrial case study from the literature was selected to implement and validate the new methodology. The case study is a planning problem to plan the layout or design of a fleet of generating stations owned and operated by the electric utility company, Ontario Power Generation (OPG). The impact of new technology integration on the performance of a power grid consisting of a variety of power generation plants was evaluated. The reduction in carbon emissions is projected to be accomplished through a combination of fuel switching, fuel balancing and switching to new technologies: carbon capture and sequestration. The fuel-balancing technique is used to decrease carbon emissions by adjusting the operation of the fleet of existing electricity-generating stations; the technique of fuel-switching involves switching from carbon-intensive fuels to less carbon-intensive fuels, for instance, switching from coal to natural gas; carbon capture and sequestration are applied to meet carbon emission reduction requirements. Existing power plants with existing technologies consist of fossil fuel stations, nuclear stations, hydroelectric stations, wind power stations, pulverized coal stations and a natural gas combined cycle, while hypothesized power plants with new technologies include solar stations, wind power stations, pulverized coal stations, a natural gas combined cycle and an integrated gasification combined cycle with and without capture and sequestration. The proposed methodology includes financial risk management in the framework of a two stage stochastic programme for energy planning under uncertainty: demands and fuel price. A deterministic mixed integer linear programming formulation is extended to a two-stage stochastic programming model in order to take into account random parameters, which have discrete and finite probabilistic distributions. Thus, the expected value of the total costs of power generation is minimized, while the objective of carbon emission reduction is achieved. Furthermore, conditional value at risk (CVaR), a most preferable risk measure in the financial risk management, is incorporated within the framework of two-stage mixed integer programming. The mathematical formulation, which is called mean-risk model, is applied for the purpose of minimizing expected value. The process is formulated as a mixed integer linear programming model, implemented in GAMS (General Algebraic Modeling System) and solved using the CPLEX algorithm, a commercial solver embedded in GAMS. The computational results demonstrate the effectiveness of the proposed new methodology. The optimization model is applied to an existing Ontario Power Generation (OPG) fleet. Four planning scenarios are considered: a base load demand, a 1.0% growth rate in demand, a 5.0% growth rate in demand, a 10% growth rate in demand and a 20% growth rate in demand. A sensitivity analysis study is accomplished in order to investigate the effect of parameter uncertainties, such as uncertain factors on coal price and natural gas price. The optimization results demonstrate how to achieve the carbon emission mitigation goal with and without new technologies, while minimizing costs affects the configuration of the OPG fleet in terms of generation mix, capacity mix and optimal configuration. The selected new technologies are assessed in order to determine the risks of investment. Electricity costs with new technologies are lower than with the existing technologies. 60% CO2 reduction can be achieved at 20% growth in base load demand with new technologies. The total cost of electricity increases as we increase CO2 reduction or increase electricity demand. However, there is no significant change in CO2 reduction cost when CO2 reduction increases with new technologies. Total cost of electricity increases when fuel price increases. The total cost of electricity increases with financial risk management in order to lower the risk. Therefore, more electricity is produced for the industry to be on the safe side.

Energy Director is a control and measuring system for energy consumption and is part of the product portfolio of E.ON AG for more efficient use of energy, offered to business customers. As of today, the system has only one parameter of control, namely power, and the objective of this essay has been to investigate whether other ones could be added. The emphasis is on the environmental perspective, which is why carbon dioxide has served as an example for this parameter in question. Parallel with the study of Energy Director electricity on the margin, calculations of carbon dioxide equivalents and also the Swedish trade of electricity have all been highlighted. Results indicate that when reductions in energy are made it is endorsed to omit from electricity on the margin rather than some mean distributed electricity, under certain conditions, and in addition the calculations of the reductions should be modified regarding the efficiency of the power stations fuelled by lignite and bituminous coal. Sweden practices trade with the Nordic countries as well as Poland and Germany. Import and export represents essential factors in the discussion of electricity on the margin but they can nonetheless today be included in calculations concerning savings in emission of carbon dioxide. The development of Energy Director is suggested to follow a model that includes the total emissions of carbon dioxide at each installation. Contributions are descended from local sources at the site, which are continuously measured, and from the energy that is obtained, where the equivalent amount of carbon dioxide has to be theoretically estimated. The total carbon dioxide limit control is then accomplished by means of controlling the obtained energy. / EnergiDirigent är ett styr- och mätsystem som ingår i E.ON:s produktsortiment för effektivare energianvändning. I dagsläget har systemet en styrparameter, uttagen effekt, och syftet med detta arbete har varit att undersöka om ytterligare styrparametrar kan infogas. Fokus för arbetet har varit att undersöka vilken potential EnergiDirigent har att bli miljövänlig. Styrparameter som tjänat som exempel för utredning har varit koldioxid. Marginalel, det svenska elutbytet samt beräkning av koldioxidekvivalenter har behandlats parallellt med arbetet med EnergiDirigent. Arbetsgången har varit teoretisk med litteraturstudier, studiebesök och intervjuer. Resultat visar att vid en miljövärdering av el är det befogat att utgå ifrån marginalel vid besparingar, dock under vissa villkor, och att beräkningarna av besparingarna bör modifieras genom att verkningsgraden för kolkraftverk revideras. Sverige bedriver mycket handel med Norden samt Polen och Tyskland varför de har inkluderats i handelssystemet. Import och export är viktiga faktorer i behandling av marginalel men resurser saknas idag för att implementera faktorerna på ett adekvat sätt i besparingsuträkningar. Utvecklingen av EnergiDirigent bör följa en modell som inkluderar det totala utsläppet av koldioxid vid varje installation. Bidrag till det totala utsläppet kommer ifrån lokala källor hos installationen, som hela tiden mäts, samt från den mängd energi som införskaffas, där motsvarande mängd koldioxid uppskattas teoretiskt. En styrgräns sätts på de totala utsläppen och följs sedan genom styrning på den inkommande energin.

A large proportion of the energy consumption is in the building industry and a large part goes to heating our homes and premises. In the developing countries' development now threatens the large consumption of energy in our earth's climate. It is in the West world that we must be good role models in terms of energy efficiency. One solution to reduce energy consumption for heating of buildings may be to continue to build low energy houses and passive houses, but it is also about rebuilding the buildings that currently have high energy consumption such as the old Million program Houses. These buildings will be standing many years and their energy consumption will not diminish over time by itself and energy prices will certainly not diminish in the future. This report will touch on the subject mainly new construction, how to build an energy efficient building, but a smaller portion will touch on the subject rebuilding, particularly the solutions that can fit into economic terms.   Calculations have been done to link the concepts of Umean of a building and its energy consumption. This was done by calculations using an Excel document created in connection with this thesis.   The buildings and architectural solutions addressed in this report will focus on apartment buildings where the partner of this thesis is Eskilstuna Municipal Building. Eskilstuna Municipality Property manages buildings and premises to Eskilstuna Municipality, but also owns their own house with rental apartments.

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. Målet med denna indelning av byggnader är att Svenska kyrkan ska få vetskap om vilka av deras byggnader som berörs av lagen om energideklarationer. I andra delen görs en energideklaration för en kontorsbyggnad. Det visar sig att det finns en hel del energibesparande åtgärder som kan göras i kontorsbyggnaden. En del av åtgärderna är endast enkla åtgärder som inte kräver något större ingrepp i byggnaden för att utföras. I den tredje delen genomförs en fördjupad studie i nattkylning av stommen i byggnader, där tung och lätt stomme jämförs gentemot varandra. För att utföra jämförelsen används simuleringsprogrammet IDA Klimat och Energi. Resultatet av simuleringen visar ingen besparing av energi till följd av nattkylning av stommen i den simulerade byggnaden, vilket leder fram till en parameterdiskussion om hur olika parametrar påverkar lönsamheten vid nattkyla. / This diploma work aims to investigate which of the Swedish church’s buildings in Växjö that needs to be energy declared and also to perform an energy declaration of an office building. In the energy declaration there’s also included measures for various energy-saving potential. An in-depth study of night-cooling of the framework has also been performed. This diploma work is divided into three main parts, classification of buildings, carrying out the energy declaration and a depth study of night-cooling of the building’s framework. In the first part buildings where divided into different groups on the basis of activities and type of building and then investigated whether to be energy declaration or not. The objective of this classification of buildings is that the Swedish church will know which of their buildings that’s affected by the law concerning energy declarations. The second part is an energy declaration of an office building. It turns out that there are a lot of energy-saving measures that can be done in the office building. Some of them are only simple measures that don’t require any major interference in the building to be performed. In the third part is carried out an in-depth study of night-cooling of buildings’ frameworks, where heavy and light frames are compared against each other. In order to carry out the comparison the simulation program IDA Climate and Energy was used. The results of the simulation shows no saving of energy as a result of night-cooling of the building frame in the simulated building, which leads to a parameter discussion on how various parameters affecting the profitability of night-cooling.

In June 2006 the Swedish government decided that the use of energy in buildings should be reduced by 20 percent until 2020, compared to the level of energy used in 1995. To contribute to this goal, the real estate company “Eskilstuna Kommunfastigheter AB”, set up own goals for their buildings. In 2009, the goal for schools was to have a maximum energy use of 118 kWh/m2year for heating and hot water. The school “Hållsta skola”, just south of Eskilstuna, exceeds the limit since it used 270 kWh in 2008. The school is heated by oil burners, which is not desirable since oil is a fossil fuel. The aim of this study was to identify cost effective measures for decreased energy use for heating and hot water in the school, and to find alternatives to the oil burners. The school was built between 1963 and 1975 and consists of two buildings. The insulation in the roof, walls, windows and floor is poor and the ventilation is mainly performed without heat recovery. Measures including insulation of the roof, new windows, heat recovery in the ventilation system and more effective water taps were studied with Life Cycle Cost analysis (LCC) and Pay-off analysis. The energy use with and without the new performance was calculated with the building simulation program VIP+. If all of the economically favorable measures are carried out the total energy use would decrease to 167 kWh/m2year. One of the alternatives to oil burners that were suggested is heat pumps. The two types of heat pumps studied, ground source or air source, were both found to be profitable, although the ground source heat pump would be slightly more profitable. In the calculations it was considered that an electric boiler would back up the heat pumps during cold days. With heat pumps, the energy bought for heating and hot water would be about 55 kWh/m2year, which is well below the goal of maximum 118 kWh/m2year.