Thèses sur le sujet « Geoenergia »

Este trabalho tem como objetivo estudar a participação e os interesses brasileiros no processo de integração energética sul americana, com foco nos setores de eletricidade e gás natural, analisando os aspectos políticos, econômicos, sociais e ambientais envolvidos sob a perspectiva daquilo que chamamos de geoenergia humana (termo criado para designar a relação de multicausalidade envolvendo os aspectos sociais, econômicos, ambientais e políticos presente no planejamento energético, e a forma que se distribuem territorialmente os recursos energéticos e possíveis empreendimentos associados a eles). Para isso, é feita, primeiramente, uma discussão sobre a relação entre energia e desenvolvimento socioeconômico, na qual a integração energética faz parte das políticas de desenvolvimento dos Estados. Em seguida, é feita a análise da integração energética sul-americana, relacionando-a ao processo de crescimento econômico da região, baseada na discussão sobre o potencial energético do continente e, em seguida, na revisão histórica do processo de integração energética nessa região onde são identificados os principais projetos e agentes envolvidos. A terceira parte do trabalho se volta para o estudo específico da participação brasileira no processo de integração energética sul americana, o que implica na identificação dos principais projetos que envolvem o Estado brasileiro ou empresas deste país na região e na análise da participação e dos interesses dos principais envolvidos. Por último, é feita a análise dos aspectos socioambientais envolvidos na questão, onde é apresentada a ideia de geoenergia humana e são discutidos conflitos socioambientais presentes neste contexto. Os resultados e as conclusões do trabalho evidenciam a relação direta que existe entre o crescimento econômico dos países e o desenvolvimento dos seus respectivos setores energéticos, o que envolve a comercialização de energia e o processo de integração energética no qual os maiores avanços se deram na União Europeia. Da mesma forma, mostram que nos últimos anos se intensificaram as iniciativas de integração de infraestruturas na América do Sul, bem como os esforços comuns em superar o enfoque bilateral ao qual se restringiam os projetos antigamente, com destaque para a Iniciativa para a Integração da Infraestrutura Regional Sul-Americana (IIRSA) e a União das Nações Sul-Americanas (UNASUL). Neste contexto, é evidente o protagonismo brasileiro, que se dá por meio de políticas de Estado que visam estimular a participação do Banco Nacional do Desenvolvimento Econômico e Social (BNDES) e das empresas nacionais de construção civil. Por último, devem ser destacados os diversos conflitos socioambientais relacionados aos empreendimentos energéticos no continente principalmente na região amazônica e que permitem questionar a concepção de desenvolvimento que está por trás do processo de integração na América do Sul.
This works goal is to study Brazils participation and interests in the process of energetic integration in South America, focusing on electricity and natural gas. It analyses the political, economics, social and environmental aspects involved from the perspective of the human geoenergy (term that refers to the relation between the different variables of the energetic planning that are distributed in space in different ways). In order to do so, the relation between energy and socioeconomical development is analysed, considering the process of energetic integration as intrinsic to the countries development policies. This works discusses the concept of energetic integration, considering the history of disputes between countries because of energy resources, and shows current examples of energy policies in the world. The third part of this work is focused on the specific study of Brazilian participation in the process of energetic integration in South America. This implies in the identification of the main projects that involve Brazil or its companies in the region and in the analysis of the participation and interests of the main parts involved. Finally, an analysis of the socio-environmental aspects involved in the matter is presented. At that point, the idea of human geoenergy is presented and the socio-environmental conflicts within this context are discussed. . The results show a direct relation between the countries economic growth and the development of their energetic sectors, which involves energy commercialization and the process of energetic integration in which the bigger advances happened in the European Union. It is also shown that, in the last years, the initiatives of infrastructure integration in South America were intensified, as were the common efforts to overcome the bilateral approach of the former projects in which the Initiative for the South American Regional Infrastructure Integration (IIRSA) and the Union of the South American Nations (UNASUL) stands out. Within this context, Brazils main role is evident. The countrys policies aim to stimulate the National Bank of Social and Economic Development (BNDES) and the civil construction national companies participation. Finally, the socio-environmental conflicts related to the energy endeavours in the continent, mainly in the Amazon region, that make us question the notion of development behind the South American integration, are put on the spotlight.

Le risorse sotterranee sono essenziali per l’approvvigionamento idrico ed energetico nelle aree urbane. Tuttavia, le attività umane modificano l’assetto naturale del sottosuolo alterandone le condizioni chimico-fisiche, tra cui il regime termico. L'effetto isola di calore nel sottosuolo (SUHI) è stato osservato in diverse città del mondo con temperature da 2 a 8°C più calde rispetto alle aree suburbane, e trend di riscaldamento sono riconducibili al cambiamento climatico e all’urbanizzazione. Infatti, le città ben sviluppate sono anche più colpite a causa della sovrapposizione di fonti di calore antropiche come i seminterrati degli edifici, le superfici asfaltate, i tunnel e gli impianti geotermici. Tale fenomeno ha implicazioni positive (es: maggior efficienza del riscaldamento con geotermia) e negative (es: l'inquinamento termico) sulle acque sotterranee, e l’integrazione di tecniche di monitoraggio e modellazione è fondamentale per quantificare i contributi di calore naturale/antropico in un ambiente complesso e valutarne l'evoluzione futura. Inoltre, gli obiettivi dell'UE sulla mitigazione del cambiamento climatico si concentrano sullo sviluppo di energie rinnovabili per ridurre le emissioni di gas serra. Tra queste, l’energia geotermica superficiale è considerata una valida alternativa ai sistemi di condizionamento tradizionali in quanto è disponibile quasi ovunque ed ha un bassissimo impatto. L'area metropolitana di Milano è una delle regioni maggiormente popolate d'Europa e ha una domanda energetica molto alta. Inoltre, molte attività legate all'urbanizzazione hanno contribuito ad alterarne la superficie e il sottosuolo, ma una valutazione dello stato termico tutt’ora non esiste. Nella prima parte di questo studio, si è stimato il potenziale geotermico a bassa entalpia a scala regionale integrando dati climatici e parametri idrogeologici/termici del sottosuolo. Tramite soluzioni analitiche si è calcolato il potenziale di impianti a circuito chiuso e aperto, considerando: per i primi, i parametri, la temperatura del sottosuolo, e le caratteristiche dello scambiatore, mentre per secondi, l’abbassamento piezometrico e il salto di temperatura ammessi dalla normativa regionale. I risultati sono stati confrontati con gli usi energetici attuali su base comunale, suggerendo la configurazione più favorevole. Nella seconda parte, si dimostra l'estensione dell’isola di calore sotterranea, di intensità fino a 3°C nella città di Milano. L’analisi spazio-temporale dei record di soggiacenza e temperatura ha messo in luce il ruolo dei principali fattori naturali e antropici: il flusso di calore verso l’acquifero è più intenso dove la tavola d’acqua è superficiale e strutture/infrastrutture antropiche sono densamente distribuite. Questo accumulo di calore si riflette in un trend tra +0.1 e +0.4 °C/a che porta fino a +25 MJ/m2/a nel sottosuolo del centro città. Inoltre, sono anche stati osservati gli effetti dell'urbanizzazione sull'abbondanza microbiologica nella falda superficiale. Infine, è stato sviluppato il primo modello numerico (FEM) di flusso e trasporto di calore alla scala urbana, focalizzandosi su (I) la ricostruzione delle eterogeneità del sottosuolo per simulare il trasporto di calore advettivo, (II) una soluzione analitica accoppiata per definire la condizione al contorno termica alla superficie e (III) l'integrazione di molteplici sorgenti di calore naturali/antropiche. Dalla simulazione dello stato attuale emerge che il flusso di calore dagli edifici e dalle infrastrutture/gallerie contribuisce all'85% dell'accumulo di calore annuale (1.4 PJ). Inoltre, il potenziale termico è stato valutato anche numericamente, e si è dimostrato che l’aumento di calore sotterraneo dovuto ai possibili effetti del riscaldamento globale e dell’espansione urbana è ben maggiore rispetto allo sviluppo geotermico che, per questo motivo, dovrebbe essere valorizzato.
Urban areas rely on subsurface resources to produce drinking water and extract low enthalpy geothermal energy. However, atmospheric and subsurface environment modifications by climate change and/or human activities affect the physical-chemical conditions such as the groundwater thermal regime. The subsurface urban heat island (SUHI) effect was documented in several cities worldwide with 2 to 8°C warmer temperatures than in suburban areas and warming trends were linked to global warming and urbanization. Highly developed cities are more impacted due to the superimposition of anthropogenic heat sources (e.g. building basements, asphalted surfaces, tunnels, geothermal installations), and positive (e.g. heating potential) and negative (e.g. thermal pollution) implications for groundwater uses exist. Thus, monitoring and modeling tools are mandatory to disentangle the complex superimposition of positive/negative heat flows from natural/anthropogenic sources and assess the future evolution. Moreover, EU objectives on climate change mitigation are focused on the development of renewable energies to reduce greenhouse gas emissions. Low enthalpy geothermal energy is considered a valid alternative to common heating/cooling techniques as it is available almost everywhere and has a low carbon footprint, especially where thermal energy is supplied by fossil fuels. The Milan city area (MCA) is one of the most densely populated and industrialized regions in Europe and, consequently, has a very high thermal power demand. Moreover, many activities related to urbanization contribute to modify the groundwater environment but their effects on the subsurface thermal status have never been assessed. In the first part of this study, the low enthalpy geothermal potential of the shallow aquifers was assessed at regional scale. Advantageous hydrogeological characteristics (e.g. highly conductive aquifers) were mapped and different analytical solutions used to estimate the thermal potential of ground coupled (GCHP) and groundwater (GWHP) heat pumps. The potential of GCHP was estimated considering subsurface hydraulic/thermal parameters and temperature, climatic data and borehole characteristics. The potential of GWHP was estimated considering the water drawdown and temperature drop allowed by regulation. The results were compared with heat demand rates on a municipal basis and the most profitable configuration was discussed. Successively, the extent and intensity of the SUHI in the MCA was assessed. Natural and anthropogenic controls on groundwater temperatures were revealed analyzing head and temperature records, and the occurrence of an up to 3° C intense SUHI was demonstrated. Vertical heat fluxes to the aquifer are strongly related to the groundwater depth and density of surface structures/infrastructures. This heat accumulation is reflected by a constant warming trend between +0.1 and +0.4 °C/y leading up to a +25 MJ/m2/y heat storage by densely distributed heat sources. Furthermore, the effects of urbanization, SUHI and physical-chemical conditions on the microbiological abundance were assessed by a flow cytometry analysis. Finally, a holistic city-scale fluid flow and heat transport FEM model was developed focusing on (I) the reconstruction of large-scale aquifer heterogeneities to consider the advective dominated heat transport, (II) the definition of the upper thermal boundary by a coupled analytical solution and (III) the integration of natural and human-related fluid/heat sources as transient boundary conditions. A fluid/heat budget analysis revealed the heat flow from buildings, infrastructures and tunnels contributes to 85% of the net annual heat accumulation (1.4 PJ/y). The thermal potential was evaluated numerically, and it was demonstrated that future climate change and city expansion could lead to the highest subsurface warming compared to shallow geothermic development which, for this reason, should be highly supported.

Detta examensarbete utfördes på uppdrag av Umeå Kommun. Uppgiften bestod av att utvärdera dagens användning av en borrhålsbrunn samt undersöka vad som är det optimala användningsområdet för borrhålsbrunnen. Borrhålsbrunnen används i dagsläget för att förvärma samt kyla utomhusluft in till kontorsbyggnaden Kubens ventilationsaggregat. Ventilationens förvärmning består av två delar, en markkanal och ett geoenergibatteri. Viktiga parametrar hos förvärmningen analyserades med hjälp av mätvärden för temperatur och flöde. Resultaten jämfördes därefter med alternativet att använda borrhålsbrunnen tillsammans med en värmepump. Då borrhålsbrunnens kapacitet inte var tillräcklig för att klara byggnadens hela uppvärmningsbehov, undersöktes det hur en värmepump skulle kunna köras i kombination med fjärrvärme. Två driftstrategier, Bas och Kapatoppar, undersöktes. Bas leverar en basproduktion under hela vinterperioden medan Kapatoppar startar vid -6°C för att sänka effekttoppar. Utvärderingen av förvärmningen visade att geoenergibatteriet är mer kompatibelt med ventilationsaggregat av VAV-typ (Variable Air Volume) än vad markkanalen är. Däremot är inte förvärmning i kombination med roterande värmeväxlare ett bra koncept för byggnaden som den används idag. På grund av att förvärmningen är placerad före den roterande värmeväxlaren så är bara 15-20 % av förvärmningseffekterna energibesparande. Detta kombinerat med en optimerad drift av aggregatet sett till tidsstyrning och behovsstyrning av flöde gör att förvärmningen har en liten påverkan både på byggnadens maximala effektbehov och totala energibehov. Att köra värmepump i kombination med fjärrvärme för uppvärmning var ekonomiskt lönsamt främst på grund av att värmepumpen kunde kapa byggnadens effektoppar. Kostnaden för storleken på den abonnerade effekten uppgår idag till drygt 40 % av den totala fjärrvärmekostnaden. Dagens relation mellan el- och fjärrvärmepriser bidrog naturligtvis också till att värmepumpsalternativet var lönsamt. För de undersökta förutsättningarna så blev paybacktiden för en värmepump med den lönsammaste driftstrategin, Bas, 4,4 år.

På grund av den globala uppvärmningen kommer efterfrågan på kyla öka i framtiden och ett alternativ som kan tillgodose användarnas kylbehov men samtidigt sänka byggnadens energiförbrukning är passiv kylning med geoenergi. Furuliden är ett äldre- och gruppboende som tillhör det kommunala bostadsbolaget Allbohus som hyr ut lägenheter och lokaler i Alvesta kommun. Majoriteten av de boende i Furuliden tillhör grupper som är extra känsliga för värme och fastigheten har haft problem med att inomhustemperaturen ibland blivit för varm. Möjligheten att kyla och värma ventilationsluften passivt i Furuliden med hjälp av 8 parallella energibrunnarna som är installerade vid fastigheten har undersökts för ett billigare och ett dyrare alternativ. Detta har gjorts genom beräkningar, programmering samt insamling av offerter. Resultatet visar att energibrunnarna har kapacitet att tillgodose kylbehovet för de båda alternativen.

An office building (sthlm new hus 4) located in the south of Hammarbyhamnen overlooking Hammarbybacken is planned in 2018. Climate control of the office building are via radiators, high-temperature chilled beam and pre-treated supply air. The building is currently being designed for district heating and remote cooling. The study aims to investigate whether borehole thermal energy system (BTES) are a reasonable alternative to provide the office building with heat and cooling, from an environmental- and life cycle cost (LCC) perspective. The aim of the study is to generate an energy requirement for the office building, which is done by construct a model of the building using IDA ICE, a simulation software. The energy requirement is covered by either district heating/-cooling (energy system I) or BTES (energy system II) as the primary energy source. A model of the BTES is constructed in excel based on data from experience input. Life cycle cost analysis are used for economical comparison between the energy systems. The environmental assessment is based on Nordic electricity mix, which controls the impact of the energy systems. Energy system II entails a need for energy support to avoid over dimension the heat pump, which is done by complementing the surplus need through district heating and remote cooling. LCC shows an economic breakpoint at 11-year calculation period, where BTES becomes economically advantageously. Environmentally, energy system II releases 14.3 tonnes of CO2eq compared to energy system II which results in a reduced emission of 47 tonnes of CO2eq based on Nordic electricity mix.

En energieffektiv geoenergianläggning kan åstadkommas genom att välja rätt systemtemperatur. Systemtemperaturerna påverkas av geoenergisystemets delkomponenter. Syftet har varit att genomföra en teknoekonomisk utvärdering av värmesystemets systemtemperatur i geoenergiprojekt. Arbetet påbörjades med en teknisk utvärdering av systemtemperaturen för att undersöka vilka parametrar som har en betydande inverkan på systemtemperaturen. Därefter genomfördes en ekonomisk utvärdering på systemtemperaturen. Den ekonomiska utvärderingen utfördes genom att utvärdera olika systemtemperaturers livscykelkostnad (LCC) i en referensbyggnad. Resultatet visade tydligt att LCC ökar med sänkt framledningstemperatur. Vid systemtemperaturer över grundfallets systemtemperatur som har framledning-/returtemperatur på 40/30 °C, sjönk LCC med 1–2% per grad och vid framledning-/returtemperaturer under 40/30 °C ökade LCC med 6–8% per grad. De faktorer som hade störst inverkan på systemtemperaturen var byggnadens värmebehov, byggnadens utformning och slutapparaternas effektivitet. Dessa faktorer avgör hur låg systemtemperatur som är möjligt att implementera i en byggnad.

I Skattkärr har en konstgräsplan projekterats med uppvärmning för att kunna användas vintertid då snö och kyla sätter stopp för aktiviteter på en ouppvärmd konstgräsplan. I Skattkärr finns inte möjligheten att ansluta anläggningen till ett fjärrvärmenätverk. Tekniken som valts för att värma planen är istället en typ av geoenergi där PVC-rör ligger under konstgräsplanens ytskikt. Intill planen finns totalt 31 borrhål. Ur borrhålen hämtas värmen från berget med kollektorslangar och leds ut till en rörslinga under planen. Till skillnad mot vanlig bergvärme används ingen värmepump. I stället utnyttjas i Skattkärr bergets och markens naturliga värme på uppskattningsvis 7 °C. Det förväntas räcka för att hålla snö och is borta från konstgräsplanen. Sommartid när det inte finns behov av uppvärmning, värms vätskan i rören. Värmen kan vidare lagras i berget till vintersäsongen. Planen kan med andra ord, i princip betraktas som en stor solfångare. Systemets största driftkostnad blir därför dess cirkulationspump. Driften i sig är projekterad att vara intermittent. Det innebär att systemet förväntas stå stilla tills behov av uppvärmning eller kylning finns. Systemet slås sedan av när behovet av uppvärmning eller kylning upphört. Syftet med arbetet är att undersöka hur konstgräsplanen ska värmas och kylas optimalt utan att planen blir obrukbar tack vare dess yttemperatur. Målet med arbetet är att skapa en matematisk modell för systemet som beskriver temperaturen på konstgräsplanens yta. För att studera konstgräsplanens yttemperatur görs en matematisk modell vars uppgift är att dynamiskt analysera energiflöden över tid. Modellen är uppbyggd i programmet Simulink, en del av MATLAB. Modellen av konstgräsplanen består utav flera delberäkningar som i sin tur ger olika energiflöden. Planen betraktas i balansen som en platta på mark med ett värmelager. På så vis kan generaliseringar göras för att underlätta olika beräkningar med ekvationer tillämpade för plattor på mark. Resultatet visar att uppvärmningssystemet har svårt att värma planen till erfordlig temperatur stora delar av vintern. Istället följer planens yttemperatur rådande lufttemperatur likt en ouppvärmd plan. Dessvärre råder okunskap om strömningstillstånd samt vätsketemperatur i systemets rörslinga. Därför krävs vidare arbete för att säkerställa dessa faktorer. På så vis kan värmetillförseln från uppvärmningssystemet, till planens yta säkerställas. Först då kan ett godtyckligt underlag till cirkulationspumpens styrning presenteras.
In Skattkärr has a heated turf field been projected to enable activities during the winter when snow and cold weather put a stop to activities in an unheated turf field. In Skattkärr it’s not possible to connect the system to a district heating network. The technique chosen to heat the field is instead a type of geothermal energy where PVC-pipes are located beneath the artificial turf’s surface. Next to the the field is a total of 31 boreholes located. From those boreholes heat is collected from the mountain and headed out to a coil under the plan. Unlike conventional geothermal, there is no use of a heat-pump. Instead the system in Skattkärr uses the natural heat from the soil, approximately 7 ° C. It is expected to be enough to keep snow and ice away from the artificial turf field. In summer when there is no need of heating, the fluid in the tubes is heated. This heat can later on be stored in the ground for the winter season. The field may, in other words, in principle, be regarded as a solar collector. The system's operating cost is therefore the circulation-pump. The operation itself is projected to be intermittent. This means that the system is expected to stand still until the need for heating or cooling. The system is then turned off when the need for heating or cooling is ceased. The aim of this work is to investigate how an artificial turf field can be heated and cooled optimally without becoming unusable due to its surface temperature. The goal of this work is to create a mathematical model of the system that describes the temperature on the artificial turf's surface. To study the artificial turf field's surface temperature is a mathematical model created, whose mission is to dynamically analyze energy flows over time. The model is built in Simulink, a part of MATLAB. The model of artificial grass field consists of several partial measurement exercises in turn gives different energy flows. The plan considered in the balance as a slab with a heat store. This allows generalizations to be made to facilitate various calculations with equations applied to slabs on ground. The result shows that the heating system has difficulties to heat the field to temperatures demanded during winter. Instead, the surface temperature follows the current air temperature, like an unheated field. Unfortunately, there is lack of knowledge about the flow conditions and fluid temperature in the pipe loop system. Therefore, further work to ensure these factors are needed. Only then can an arbitrary basis for the circulation pump control be presented.

Jernhusen AB är ett fastighetsbolag inom transportbranschen och är framförallt inriktade mot järnvägen. Jernhusen har ett uttalat mål att bidra till ett hållbart samhälle. Som ett steg i detta vill Jernhusen undersöka möjligheterna med att investera i lokalproducerad förnybar energi på deras tågunderhållsdepåer.Denna rapport utreder förutsättningarna och möjligheterna med detta. Det finns idag flera olika förnybara energikällor som kan användas lokalt på depåerna. De bäst lämpade teknikerna för Jernhusens tågunderhållsdepåer är att använda solenergi och geoenergi. Solenergin kan användas för att producera elkraft med solceller och värme med solfångare. Det finns flera olika typer av solceller med den mest kommersiellt använda typen är polykristallina kiselsolceller. Underhållsdepåerna har stora effektbehov, både för el och för värme. Effektbehovet är som störst under vintermånaderna när tågen behöver avisas. Depåerna har stora öppna tak och bangårdar som lämpar sig till att använda både solceller, solfångare och geoenergi. De flesta depåerna är gamla och fastigheterna innehåller markföroreningar, vilka behöver beaktas om ett geoenergisystem ska installeras på fastigheten. Det finns goda förutsättningar för Jernhusen att installera olika system som utnyttjar förnybara energikällor. Om ett solcellssystem skulle installeras på Hagalund enligt Tabell 6-1 är återbetalningstiden för investeringen 15 år. Detta får anses som en god investering då ett solcellssystem kan ha en livslängd på 40 år. Hade en geoenergisystem installerats på Raus enligt Tabell 6-3 blir återbetalningstiden 17 år. Ett solfångarsystem har låg lönsamhet oavsett vilket depå det installeras på. Dock blir både geoenergi och solfångare betydligt mer lönsamma om byggnaden är uppvärmd av direktverkande el eller vid nybyggnationer.
Jernhusen AB is a real estate company within the transportation industry and their business is focused towards the railway. Jernhusen has a stated goal that the company should contribute to a sustainable society. As a step in this goal the company explores the possibilities of investing in locally produced renewable energy systems at their maintenance depots. This report investigates the potential in that kind of investment. There are currently several different renewable energy sources that can be used for locally producing renewable energy at the depots. The most appropriate techniques for Jernhusen to use are solar energy and geothermal energy. Solar energy can be used to produce electric power with solar cells and to produce heat with solar panels. There are several different types of solar cells but the most commonly used are polycrystalline silicon based solar cells.The maintenance depots have large power requirements for both electricity and heat. The power demand is greatest during the winter months when the train needs de-icing. The maintenance depots have large open roofs and rail yards suitable for solar cells, solar panels and geothermal systems. Most of the depots are old constructions and the properties contains a lot of soil pollution that need to be considered if a geothermal energy solution is up for investigation. There are good prospects for Jernhusen to install various systems using renewable energy sources. If a solar cell system were installed at Hagalund according to Table 6-1 the payback period for the investment is 15.1 years. This must be seen as a good investment when the solar cells have a lifespan of 40 years. If a geothermal system were installed at Raus according to Table 6-3 the payback period is 17.2 years. A solar panel system has a low profitability regardless of which depot the system is installed at. However, both the geothermal system and the solar panel system are far more profitable if the building is heated by electricity.

In countries with harsh winter climates extensive winter road maintenance is necessary to achieve traffic accessibility and road safety. These measures have high economic and environmental costs as snow free roads and winter road maintenance in Sweden today is achieved by a combination of mechanical snow clearance and the spreading of salt to prevent ice formation. The salt ends up in the roadside environment and has negative effects on groundwater and vegetation. An alternative to traditional winter road maintenance to obtain non-skid winter roads is the use of hydronic pavement(HP) systems. Existing HP systems in Sweden are powered by district heating which limits the application to urban locations. The goal is to utilize renewable energy sources such as geoenergy which can be used in both rural and urban locations. This thesis suggests Hamnbacken in Visby as a pilot project for a full-scale application of the proposed HP system using surface water source heat.The weather related road surface conditions on Hamnbacken, and the potential of a renewable energysource have been examined in this study and the proposed location has been found favourable for a HP system.
Länder med övervägande kallt vinterklimat är halkbekämpning en nödvändighet för trafikens framkomlighet och säkerhet. Åtgärderna som vidtas för att få snö- och isfria vägar är kostsamma samt har en hög miljöpåverkan, ett vedertagligt exempel är plogning och saltning. Saltet hamnar i slutändan inom vägens omgivande områden och har en negativ påverkan på grundvatten och vegetation. En alternativ lösning till traditionell halkbekämpning är uppvärmda vägar för att uppnå ett halkfritt vinterväglag. Befintliga väguppvärmningssystem i Sverige försörjs av fjärrvärme vilket är en begräsning då tillgången till fjärrvärme finns i anslutning till tätorter. Målet är att utnyttja förnybara energikällor såsom geoenergi som är tillgänglig både i tätorter och på landsbygden. Det här examensarbetet undersöker Hamnbacken i Visby som ett pilotprojekt för en fullskalig implementering av väguppvärmningssystem där sjövärme används som energikälla. Denna studie har undersökt väderrelaterade vägförhållanden på Hamnbacken samt potentialen för användning av sjövärme. Den föreslagna platsens förutsättningar har visat sig vara gynnsamma i detta avseende.

In this thesis proposals for different designs of a borehole thermal energy storage (BTES) have been developed for the building DN-huset in Stockholm, Sweden. To build a BTES results in savings in energy costs by approximately 44 %, i.e. 2 million Swedish crowns annually. Furthermore, a BTES would reduce the annual environmental impact with roughly 75-157 tonnes of CO2 equivalents per year, depending on how the electricity consumption’s environmental impact is estimated. The payback period is about 11 years, including the warm-up period that is necessary before commissioning the BTES. The savings in environmental impact and operating costs are a result of energy being reused. During the summer heat is stored in the bedrock beneath the building for retrieval about half a year later in the winter, when there is a heating demand. In addition to developing proposals for different BTES designs the thesis also examines the influence of certain design parameters, conservative choices and operating conditions.

Inom svensk process- och tillverkningsindustri finns det stora mängder spillvärme som sällan kommer till användning. Att hitta olika tekniska lösningar för att effektivt tillvarata denna spillvärme skapar både nytta ur ett hållbart perspektiv samt ur ett ekonomiskt perspektiv för företaget. I denna rapport presenteras en utarbetad beräkningsmodell i Excel. Beräkningsmodellen används för att uppskatta lönsamheten för anläggning av ett högtemperaturlager i berggrunden. Excel-filen ska kunna användas för företag som en första uppskattning om ett borrhålslager är ett alternativ för tillvaratagande av spillvärme. Utformningen av beräkningsmallen utgick från Xylems högtemperaturlager i Emmaboda. Beräkningsmallen testades på Xylems borrhålslager. Resultatet visar att 2166 MWh/år kan tas ut från lagret, vilket stämmer överens till 83 % med Xylems egna beräkningar. Borrhålslagrets verkningsgrad beräknades till 65 % vilket kan jämföras med de 68 % som Xylem kalkylerat med. Nyckelord: Borrhålslager, UTES-system, BTES-system, HT-BTES-system, geoenergi, spillvärme.

A new Spatial Decision Support System (SDSS) has been designed and developed to address a wide spectrum of semi-structured spatial decision problems. These problems are related to site selection, site ranking and impact assessment. The proposed SDSS is conceptualised as a holistic, informed and impact-based multicriteria decision framework. The system has been developed using the .NET C# programming language and open source geoinformatics technologies such as DotSpatial and SpatiaLite. A combination of existing Multi Criteria Decision Analysis (MCDA) and Artificial Intelligence (AI) techniques, with a few novel variations have been developed and incorporated into the SDSS. The site selection module utilises a theme-based Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC). Two site ranking techniques have been introduced in this research. The first technique is based on the systematic neighbourhood comparison of sites with respect to key indicators. The second technique utilises multivariate ordering capability of the one-dimensional Self-Organizing Maps (SOM) to rank the sites. The site impact assessment module utilises a theme-based Rapid Impact Assessment Matrix (RIAM). A spatial variant of the General Regression Neural Networks (GRNN) with a genetic algorithm for optimisation has been developed for the prediction and regression analysis. A number of other spatial knowledge discovery and geovisual-analytics tools have been provided in the system to facilitate spatial decision making process. An application of the SDSS has been presented to investigate the potential of Coalbed Methane (CBM) development in Wales, UK. Most potential sites have been identified by utilising the site selection and site ranking tools of the developed SDSS. An impact assessment has been carried out on the best sites by using Rapid Impact Assessment Matrix. Further analysis has uncovered the spatial variability expected in the potential impacts of the sites, considering key indicators. The application has demonstrated that the developed system can help the decision makers in providing a balanced regime of social, environmental, public health and economic aspects into the decision making process for engineering interventions. The generic nature of the developed system has extended the concept of Spatial Decision Support System to address a range of spatial decision problems, thereby enhancing the effectiveness of the decision making process. The developed system can be considered as a useful modern governance tool, incorporating the key factors into decision making and providing optimal solutions for the critical questions related to energy security and economic future of the region.

In this master thesis, cooling systems are studied in a modern office building in Umeå during a summer period. The project has been done in collaboration with the municipality of Umeå and aims to analyze the cooling system’s task in the building depending on the various systems that makes up the ventilation system. This was done by examining its operation and determining where improvements could be made. The ventilation system is equipped with two types of geo-energy systems for preheating and cooling the outdoor air, Earth to Heat Exchanger (EAHE) and Borehole Heat Exchange (BHE). The ventilation system also includes a thermal wheel and a heat battery that handles the building’s heating demands. In order to get an idea of how these systems contribute to the ventilation system, cooling effects and temperature relationships for each system were investigated. The study showed that the various systems that make up the ventilation system complement each other well to meet the cooling needs during the summer period. The building’s ventilation system contributed to a total temperature reduction of the outdoor air up to 8 ◦C. The BHE system seems to be the one that contributed most to the cooling system with air temperature reduction of 4 ◦C. However, the system was constantly running and contributed to unnecessary cooling of the incoming air. This could have been avoided by programming the system to switch off at specific outdoor temperatures. The air intake that is a part of the EAHE system contributed to high cooling effects in the morning, which corresponds to large temperature reductions of the outdoor air. A conceivable reason may be due to the material property of the air intake. The air intake that is made of steel is cooled by the cold summer nights and has the ability to preserve the cold. When the ventilation system starts operating in the morning, the outdoor air flows through the cooled air intake and leads to large temperature reductions. Contrary to this, when it is hot outside, the air intake can contribute to large temperature increases. This is a concern because the air intake acts primarily as an air filter for the EAHE system and heating the already hot outdoor air before it reaches the ventilation units is not beneficial. To study this, a model of the air intake was built in COMSOL and simulated. The simulation showed that the air intake heats up significantly and leads to uneven temperature distribution through the surface when the outdoor temperature is 28 ◦C and the sun shines straight on the surface. It was also found that the air temperature inside the air intake is affected by the surface temperature. To see if there is a difference with the temperature distribution, the air intake was then simulated with other material types such as brick, wood and PEX. This resulted in the distribution of temperature through the surface becoming more uniform and the air temperature inside the air intake barely being affected by the surface temperature. Therefore, it is recommended to change the material type of the air intake in order to avoid unintended heating of the outdoor air before it reaches the ventilation unit.

Ice rinks are energy intense industrial applications. A typical single sheet ice rink in Sweden uses about 1000 MWh/season. A state-of-the art ice rink systems can use less than 500 MWh/season, indicating the potential for improvements. According to several investigations CO2 refrigeration system with heat recovery has proven to be energy-efficient and cost-effective solution in ice rinks.To further improve the efficiency, geothermal function may be added feature. The objective of this study is to evaluate the geothermal function from techno-economic perspective for a typical ice rink in Sweden. Modelling of several scenarios has been performed. Obtained results suggest that CO2 refrigeration system with 2-stage heat recovery, if upgraded with geothermal function, can save between 1.7 to 6.8% of energy annually. In the best case, this study suggests the geothermal function would pay back in 16.4 years.
Ishallar är energikrävande industriella applikationer. En typisk ishall i Sverige använder cirka 1000 MWh / säsong. Ett toppmodernt ishallsystem kan använda mindre än 500 MWh / säsong, vilket indikerar stora förbättringsmöjligheter. Enligt flera undersökningar har CO2-kylsystem med värmeåtervinning visat sig vara energieffektivt och kostnadseffektivt i ishallar.För att ytterligare förbättra effektiviteten kan geotermisk funktion läggas till. Syftet med denna studie är att utvärdera den geotermiska funktionen ur ett tekno-ekonomiskt perspektiv för en typisk ishall i Sverige. En modellering av flera scenarier har utförts. Resultaten antyder att CO2-kylsystem med 2-steg värmeåtervinning, om det uppgraderas med geotermisk funktion, kan spara mellan 1,7 och 6,8% energi årligen. I bästa fall antyder denna studie att den geotermiska funktionen skulle betala tillbaka om 16,4 år.

The thermal response of a borehole field is often described by non‐dimensional response factors called gfunctions.The g‐function was firstly generated as a numerical solution based on SBM (Superposition BoreholeModel). An analytical approach, the FLS (Finite Line Source), is also accepted for generating the g‐function. In thiswork the potential to numerically produce g‐functions is studied for circular borehole fields using the commercialsoftware COMSOL. The numerical method is flexible and allows the generation of g‐functions for any boreholefield geometry. The approach is partially validated by comparing the solution for a square borehole field containing36 boreholes (6x6) with g‐functions generated with the FLS approach and with the program EED (Earth EnergyDesigner). The latter is based on Eskilsons SBM, one of the first documents where the concept of g‐functions wasintroduced. Once the approach is validated, the square COMSOL model is compared with a circular geometryborehole field developed by the same method, consisting of 3 concentric rings having 6, 12, and 18 boreholes.Finally the influence on the circular geometry g‐function is studied when connecting the boreholes in radial zoneswith different thermal loads.
Den termiska responsen för ett borrhålsfält beskrivs ofta med den dimensionslösa responsfunktionen kallad gfunktion.Responsfunktionen togs först fram som en numerisk lösning med SBM (Superposition Borehole Model).En analytisk metod, FLS (Finite Line Source) är också accepterad för framtagandet av g‐funktioner. I det här arbetetundersöks förutsättningarna att numeriskt ta fram g‐funktioner för cirkulära borrhålsfält genom att använda detkommersiella simuleringsprogrammet COMSOL Multiphysics. Den numeriska metoden är flexibel och kananvändas för alla typer av borrhålsgeometrier. Metoden att använda COMSOL valideras delvis genom att jämföraresultatet för ett kvadratiskt borrhålsfält innehållande 36 borrhål (6x6) med lösningar framtagna med FLS och meddimensioneringsprogrammet EED (Earth Energy Designer). Det senare har sin grund i Eskilsons SBM, ett av deförsta arbeten där begreppet g‐funktion introducerades. När metoden att använda COMSOL verifierats, jämförsden kvadratiska borrhålsmodellen med en cirkulär borrhålskonfiguration, upprättad med samma metod,innehållande 3 koncentriska ringar om vardera 6, 12, 18 borrhål. Slutligen undersöks hur den termiska responsenpåverkas då borrhålen i ett cirkulärt borrhålsfält kopplas samman och grupperas i radiella zoner med olika termiskalaster.
SEEC Scandinavian Energy Efficiency Co.