Sverige har klimatmålet att nå negativa utsläpp av växthusgaser efter 2045 och det har en stor betydelse för att kunna uppnå Parisavtalet. Året 2021 stod bostäder och service för 43 % av den totala slutliga energianvändningen i Sverige och en minskning av den här användningen genom energieffektivisering är ett steg åt rätt riktning. Villa Ehrling byggdes 1982 i Falun och var tidigt ute med unika lösningar. I arbetet kartläggs de olika energieffektiviserande åtgärderna som förekommer i energivillan och energiberäkningar har genomförts över husets energiprestanda och klimatskal. Resultatet jämförs med dagens krav och andra lågenergihus för att avgöra om idéerna i villan kan implementeras än idag på nybyggnationer. Det primära syftet med villan är att utnyttja aktiv och passiv solenergi med vatten-och luftsolfångare samt lagra solenergi i villans stomme. Genom en unik utformning av fasaden med en 70 graders takvinkel, samt en orientering av byggnaden med stora glasspartier åt sydväst, kan värme tillföras från solinstrålningen under stora delar av året men också avskärmas under sommaren då solen står högre på himlen och värmebehovet är lägre. Utöver det har fasaden designats för att minska energiförluster från kall vind från norr med en låg takvinkel på 26 grader och begränsat antal fönsterytor. Villans ventilationssystem förvärmer tilluften genom lagrad värme i marken och återvinner värmen i frånluften. Överskottsvärmen kan lagras i ett stenmagasin under huset bestående av kullersten och tas ut när behovet finns. Ytterligare energieffektiviserande lösningar som förekommer i villan är återanvändandet av spillvärmen i avloppet med en avloppsvärmeväxlare. Resultatet av studien visar att villa Ehrling har en energiprestanda som varierar beroende på beteendet hos boende från omkring 35 % till 75 % lägre än de krav som ställs på nybyggnationer enligt Boverkets byggregler. Det här innebär att villan uppnår en hög energiklassificeringen med betygen A eller B än idag och hamnar i samma klassificering som andra lågenergihus. Byggnaden har en genomsnittlig värmegenomgångskoefficient på 0,314 W/(m2 K) vilket nästan uppfyller det högsta tillåtna värdet på denna koefficient idag. Jämfört med moderna lågenergihus fann den här studien att klimatskalet på villa Ehrling var mycket sämre. Slutsatsen från detta arbete är att trots villa Ehrling byggdes omkring 40 år sedan är det en villa som är mycket relevant än idag, både prestandamässigt och att mycket av husets energieffektiviserande lösningar är vanligt förekommande i nybyggnationer och andra lågenergihus idag. / Sweden has the goal of reaching negative emissions in the year 2045 to be able to reach the Paris agreement. In the year 2021, 43 % of the total energy consumption in Sweden came from housing and service and more efficient buildings is a step in the right direction. Villa Ehrling was built in 1982 in Falun, Sweden, with some interesting concepts. This report will present the concepts of the building and calculations that cover the performance of the house and its envelope. The results are compared with the requirement of how well insulated a house should be when built today. The performance and concepts of Villa Ehrling is also compared with other low-energy buildings to determine if some of Ehrlings concepts are of any use to implement in other buildings. The primary purpose of villa Ehrling is to utilize solar energy actively with air and water solar collectors, and passively by storing heat in building parts. A unique design of the façade, with and an orientation towards southwest with large areas of glass and a roof with an angle of 70 degrees, enables the ability to absorb solar heat during larger parts of the year and block the sun rays during summer when the heat demand is low. The façade contains small areas of glass towards northeast and a low roof angle of 26 degrees to reduce energy losses causes by cold winds.The ventilation system utilizes stored heat in the ground to preheat incoming air. The heat in the outflowing air is also utilized to preheat incoming air. Villa Ehrling has a heat storage made of cobblestone where energy is provided by heated air, and the energy can be extracted when the need occurs. Heat from showers and hot tap water usage is used in a heat exchanger and preheats tap water.The result of the study shows that villa Ehrling has an energy performance that varies depending on the behaviour of residents from about 35 % to 75 % lower than the requirements for new constructions according to the Swedish National Board of Housing, Building and Planning's building regulations. This means that the villa achieves a high energy classification with the grade A or B even today and ends up in the same classification as other low-energy houses. The building has an average heat transfer coefficient of 0.314 W/(m2 K), which almost meets the maximum permissible value of this coefficient today. Compared to modern low-energy houses, this study found that the envelope of villa Ehrling was much worse.The conclusion from this work is that despite villa Ehrling being built about 40 years ago, it is a villa that is very relevant even today, both in terms of the energy performance and that much of the house's energy efficient solutions are common in new buildings and other low-energy houses today.

The electricity sector has traditionally been constructed for large scale generation and distribution from the high-voltage to the low-voltage network. Transition is however underway; intermittent power generation has become less expensive and nuclear power plants are set to close down. A key issue is that intermittent power generation is by definition weather dependent, hence it cannot be planned. Smart grid solutions have the possibility to meet variations in electricity supply and demand and make use of output from intermittent renewable energy through a broad range of products and services, e.g. energy storage and adjustment of electricity production and consumption in strategic times for residential, commercial or industrial end users. Even if the technological solutions exist, these demand side resources have still not been integrated to the market to the extent that is needed. Since they are of such key importance, there is an urgent need to understand the barriers in current market structures as well as to identify opportunities and innovative business models that can bring these resources to the market. An interview study was conducted in order to provide an understanding of the challenges individual companies encounter as they develop business models to integrate their product and service offering into the electricity markets. Additional data was gathered through a literature review of academic papers, market reports and law propositions. The results of the study showed that the business models are currently undergoing stages of 'trial-and-error' to accommodate the specific needs of the electric power system. Actors are trying to prove to the electricity sector that distributed energy resources have a purpose to serve in the electric power system. The actors of these technologies seek to explore various types of value propositions, and sources of income, which to some extent are centered around the sharing of costs and resources with end customers. Furthermore, it would be desirable to align the incentives with the particular distribution network's needs and context to form the basis for the choice of capacity reinforcement. There are clear operational advantages of smart grid technologies, which also reduce profitability related to network capacity. This has to be taken into account and evaluated to encourage cooperation between the parties in the electricity sector. / Elsektorn har traditionellt konstruerats för storskalig produktion och distribution från högspännings- till lågspänningsnätet. En förändring är dock på gång; intermittent kraftproduktion har blivit billigare och kärnkraftverk stängs ner. Ett problem är att intermittent kraftproduktion per definition är väderberoende, så det kan inte planeras. Smarta elnätslösningar gör det möjligt att möta variationer i elförsörjning och efterfrågan, och ta tillvara på produktionen från intermittent förnybar energi genom ett brett utbud av produkter och tjänster, t.ex. energilagring och justering av elproduktion och konsumtion vid strategiska tidpunkter för bostads-, kommersiella eller industriella slutanvändare. Även om de tekniska lösningarna finns, har dessa resurser för efterfrågeflexibilitet ännu inte integrerats i marknaden i den utsträckning som behövs. Eftersom de fyller en viktig funktion är det angeläget att förstå hindren i nuvarande marknadsstrukturer, samt att identifiera möjligheter och innovativa affärsmodeller som kan föra dessa resurser till marknaden. En intervjustudie genomfördes för att förstå de utmaningar som enskilda företag möter när de utvecklar affärsmodeller och integrerar sina produkt- och serviceerbjudanden i elmarknaden. Ytterligare uppgifter samlades in genom en litteraturöversikt av akademiska handlingar, marknadsrapporter och lagförslag. Resultatet av studien visade att affärsmodellerna för närvarande genomgår en fas av 'trial-and-error' för att tillgodose elkraftsystemets specifika behov. Aktörerna försöker bevisa för elsektorn att distribuerade energiresurser har ett syfte att tjäna i elkraftsystemet. De aktörer med dessa teknologier försöker utforska olika typer av värdeerbjudanden och inkomstkällor, som till viss del är inriktade på att dela kostnader och resurser tillsammans med slutanvändarna. Vidare bör incitamenten för det specifika distributionsnätets behov och sammanhang ligga till grund för valet av kapacitetsförstärkning. Det finns tydliga operativa fördelar med smart elnätsteknologi, vilket också minskar lönsamheten relaterat till nätkapacitet. Detta måste beaktas och utvärderas för att uppmuntra samarbeten mellan parterna inom elsektorn.

Buildings account for around 40 percent of the primary energy consumption in Europe and in the United States. They also hold tremendous energy savings potential: 15 to 29 percent by 2020 for the European building stock according to a 2009 study from the European Commission. Verifying and predicting the impact of energy conservation measures in buildings is typically done through energy audits. These audits are costly, time-consuming, and may have high error margins if only limited amounts of data can be collected. The ongoing large-scale roll-out of smart meters and wireless sensor networks in buildings gives us access to unprecedented amounts of data to track energy consumption, environmental factors and building operation. This Thesis explores the possibility of using this data to verify and predict the impact of energy conservation measures, replacing energy audits with analytical software. We look at statistical analysis techniques and optimization algorithms suitable for building two regression models: one that maps environmental (e.g.: outdoor temperature) and operational factors (e.g.: opening hours) to energy consumption in a building, the other that maps building characteristics (e.g.: type of heating system) to regression coefficients obtained from the first model (which are used as energy-efficiency indicators) in a building portfolio. Following guidelines provided in the IPMVP, we then introduce methods for verifying and predicting the savings resulting from the implementation of a conservation measure in a building.

Cooling towers form an important part of chilled water systems and perform the function of rejecting the heat to the atmosphere. These systems are often not operated optimally, and cooling towers being an integral part of the system present a significant area to study and determine possible energy saving measures. Operation of cooling towers in economizer mode in winter and variable frequency drives (VFDs) on cooling tower fans are measures that can provide considerable energy savings. The chilled water system analysis tool (CWSAT) software is developed as a primary screening tool for energy evaluation for chilled water systems and quantifies the energy usage of the various components and typical measures that can be applied to these systems to conserve energy, all while requiring minimum number of inputs to analyze component-wise energy consumption and incurred overall cost. A careful investigation of the current model in CWSAT indicates that the prediction capability of the model at lower wet bulb temperatures and at low fan power is not very accurate. A new model for accurate tower performance prediction is imperative, since economizer operation occurs at low temperatures and most cooling towers come equipped with VFDs. In this thesis, a new model to predict cooling tower performance is created to give a more accurate prediction of energy savings for a tower. Further the economic feasibility of having additional cooling tower capacity to allow for economizer cooling, in light of reduced tower capacity at lower temperatures is investigated.

This research examines variation in average household energy consumption for space heating in municipalities in Massachusetts in order to explore the magnitude of variation among communities and potential causes. A dataset that aggregates natural gas consumption at the municipal level is used for a sample of municipalities in Massachusetts. Based upon this data, a regression model is developed to determine building and household occupancy characteristics that influence household energy consumption. The findings suggest dwelling size, tenure, and age are related to average household energy consumption. Based upon these findings, recommendations are developed for the restructuring of federal and state level energy efficiency programs.

<p>The International Energy Agency (IEA) estimates that residential and commercial buildings consume 40% of global energy and emit 24% of CO2. A building's design parameters and location significantly impact its energy usage. Adjusting the building parameters and features in an optimum way helps to reduce energy usage and to build energy-efficient buildings. Hence, analyzing the impact of influencing factors is critical to reduce building energy usage.</p> <p>Towards this, artificial intelligence applications, such as Explainable Artificial Intelligence (XAI) and machine learning (ML) identified the key building features to reduce building energy. This is done by analyzing the efficiencies of various building features that impact building energy consumption. For this, the relative importance of input features impacting commercial building energy usage is investigated. Also analyzed is the parametric analysis of the impact of input variables on residential building energy usage. Furthermore, the dependencies and relationships between the design variables of residential buildings were examined. Finally, the study analyzed the impact of location features on cooling energy usage in commercial buildings.</p> <p>For the purpose of energy consumption data analysis, three datasets, named the Commercial Building Energy Consumption Survey (CBECS) datasets gathered in 2012 and 2018, University of California Irvine (UCI) energy efficiency dataset, and Commercial Load Data (CLD) were utilized. For this, Python and WEKA were used. Random Forest, Linear Regression, Bayesian Networks, and Logistic Regression predicted energy consumption using datasets. Moreover, statistical tests, such as the Wilcoxon-rank sum test were analyzed for the significant differences between specific datasets. Shapash, a Python library, created the feature important graphs.</p> <p>The results indicated that cooling degree days are the most important feature in predicting cooling load with contribution values 34.29% (2018) and 19.68% (2012). Also, analyzing the impact of building parameters on energy usage indicated that 50% of overall height reduction achieves a reduction of heating load by 64.56% and cooling load by 57.47%. Also, the Wilcoxon-rank sum test indicated that the location of the building also impacts energy consumption with a 0.05 error margin. The proposed analysis is beneficial for real-world applications and energy-efficient building construction.</p>

Amorphous silicon photovoltaic windows intend to not only improve thethermal bridge that windows represent but also to collect energy from theradiation incident on the windows themselves. This kind of windows can beapplied anywhere, however to maximize the benefit these can bring it isrecommended for sun-oriented façades. This research aims to investigate theimpacts that this type of windows can have on the energy performance andthermal comfort of a three-story historical stone building in the cold climateof Sweden using the simulation software IDA ICE. The model used for thesimulations had previously been developed and tested in other researches thatinvolved this same building. This research shows that the yearly energyconsumption for the townhall can be reduced down to 280000 kWh,representing a reduction of 5000 kWh compared to the base model, if theHigh transparency windows are applied, representing a reduction of 1,7%.The use of any of the four proposed windows has shown to increase thepercentage of best comfort hours by at least 5% and lowers the percentage ofunacceptable comfort hours at least by a 10%, even having cases with 0 hoursat this comfort level. The upper level of the South façade would be able toprovide the building with 800 kWh yearly, being the level with the highestenergy collection due to having more windows. Approximately every windowcould collect around 90 kWh yearly, which represents 20% of what a solarpanel of the same area correctly oriented could obtain in the same period oftime. Thus, the amorphous silicon photovoltaic windows do not seem to bethe best change despite offering a very promising thermal comfort. Theeconomical viability of this project is what prevents it from being feasiblesince the energy saving/obtaining characteristics are not of great magnitude.

Denna studie fokuserar på balansgången mellan krav på energieffektivitet och bevarandet avkulturarv i kontexten av kulturhistoriska byggnader. Syftet är att utforska hur förvaltning ochvärdering av dessa byggnader kan påverkas av framtida energikrav, med särskild fokus på depotentiella konsekvenser som detta kan medföra för fastighetsägare, förvaltare och andraintressenter. Studien använder en kombination av en litteraturstudie samt en kvalitativ studiebaserad på semistrukturerade intervjuer med fastighetsägare och fastighetsvärderare. Decentrala fynden visar att det är utmanande att energieffektivisera kulturhistoriska byggnadertill de nivåer som krävs, samt att värderingen av sådana byggnader kräver en särskildskicklighet i att balansera subjektiva preferenser med objektiva kriterier, givet marknadensolika preferenser. Energieffektivisering av kulturhistoriska byggnader kan öka dess marknadsvärde genom attsänka driftskostnader och göra fastigheter mer attraktiva för miljömedvetna investerare.Vidare kan sådana åtgärder vara svåra att implementera utan att kompromissa medbyggnadens kulturella och historiska värde. Värderingen av kulturhistoriska fastigheterkräver därför både teknisk och kulturell expertis, samt en djup förståelse förmarknadsdynamiken. Studien identifierar ett kunskapsgap på marknaden gällande dettarelativt nya problem. Avslutningsvis betonas vikten av att navigera genom dessa komplexafrågor för att bevara vårt kulturella arv samtidigt som vi adresserar dagens utmaningar, såsombehovet av energieffektivitet och hållbarhet. / This study focuses on the trade-off between energy efficiency requirements and thepreservation of cultural heritage in the context of cultural historical buildings. The aim is toexplore how the management and valuation of these buildings may be affected by futureenergy requirements, with a particular focus on the potential consequences this may have forproperty owners, managers and other stakeholders. The study uses a combination of literaturestudy and a qualitative study based on semi-structured interviews with property owners andproperty appraisers. The central findings show that it is challenging to make heritagebuildings energy efficient to the required levels, and that the valuation of such buildingsrequires a special skill in balancing subjective preferences with objective criteria, given thedifferent preferences of the market. Energy efficiency of heritage buildings can increase their commercial value by loweringoperating costs and making properties more attractive to environmentally consciousinvestors. However, such measures can be difficult to implement without compromising thecultural value of the building. The valuation of heritage properties therefore requires bothtechnical and cultural expertise. The study identifies a knowledge gap in the market regardingthis relatively new problem. It concludes by emphasizing the importance of navigatingthrough these complex issues to preserve our cultural heritage while addressing today'schallenges, such as the need for energy efficiency and sustainability.

We are currently facing a global climate crisis, which demands that we decrease our energy consumption and carbon footprint. An essential area of focus is the energy optimization of buildings. Purpose: The objective of this study was to assess the current indoor climate within the office building Vråken in Västerås and investigate different measures for the ventilation system and identify potential energy and cost savings. Method: A literature review was carried out to establish the theoretical foundation and examine previous research in the subject area. The staff's perception of the indoor climate within the office building was evaluated through a survey. Relevant information was collected to understand the building's construction and current ventilation system. Further on, a model of the office building was established in IDA ICE to simulate the two selected ventilation measures. Finally, a life cycle cost calculation compared the profitability of the studied measures. Results: The results indicate that the measures have a minor impact on the indoor climate compared to the reference case. Assessing the changes in the indoor climate is challenging due to multiple climate parameters and the simulation results of this study are considered uncertain. The results show that the energy consumption of ventilation can be reduced by 46 or 51%. This corresponds to an annual energy savings of either 122 or 110 MWh, depending on the chosen measure. The first measure, which involves installing zone dampers on each floor, has an estimated investment cost of 92 531 SEK. The second measure, which entails equipping one of the floors with a separate air handling unit, is estimated to cost 388 650 SEK. The profitability assessment shows that the reduction in the total life cycle cost is 2 683 332 SEK for the first measure and 2 631 543 SEK for the second measure. In total, both measures result in a cost savings of 45 or 44% over a period of 25 years compared to the buildings current ventilation system. Conclusions: The results from this study are influenced by several factors with varying degrees of impact, including the existing ventilation system, building model and the assessment of the indoor climate. Despite this, the results indicates that the studied measures can maintain an acceptable indoor climate and at the same time save both energy and costs for the ventilation in the office building.

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.