<p>This dissertation examines the impact of the expansion of renewable technology at both national and local level, through distinct essays. At the national level, the first paper analyzes the effects of economic and distributional impacts of climate mitigation policy, in the context of a developing country, to understand the interactions between the energy system and the macroeconomic environment. In the case of the local level, the second paper uses synthetic control method, to estimate the effect at the county level of utility scale wind in the development indicators for two counties in the U.S. </p> <p>The first paper assesses the economic and distributional impacts of Nicaragua’s commitments to limit future greenhouse gas emissions in the context of the Paris Agreement, known as the Nationally Determined Contributions (NDCs). The analysis relies on two distinct models. The first is a top-down approach based on a single-country computable general equilibrium (CGE) model, known as the Mitigation, Adaptation and New Technologies Applied General Equilibrium (MANAGE) Model. The second is a bottom-up approach based on the Open-Source energy Modeling System (OSeMOSYS), which is technology rich energy model. The combined model is calibrated to an updated social accounting matrix for Nicaragua, which disaggregates households into 20 representative types: 10 rural and 10 urban households. For the household disaggregation we have used information from the 2014 Living Standards Measurement Study (LSMS) for Nicaragua. Our analysis focuses on the distributional impacts of meeting the NDCs as well as additional scenarios—in a dynamic framework as the MANAGE model is a (recursive) dynamic model. The results show that a carbon tax has greatest potential for reduction in emissions, with modest impact in macro variables. An expansion of the renewable sources in the electricity matrix also leads to significant reduction in emissions. Only a carbon tax achieves a reduction in emissions consistent with keeping global warming below 2°C. Nicaragua’s NDC alone would not achieve the target and mitigation instruments are needed. An expansion of generation from renewable sources, does not lead to a scenario consistent with a 2°C pathway. </p> <p>The second paper measures the impact of wind generation on county level outcomes through the use of the Synthetic Control Method (SCM). SCM avoids the pitfalls of other methods such as input-output models and project level case studies that do not provide county level estimates. We find that the local per capita income effect of utility wind scale is 6 percent (translate into an increase of $1,511 in per capita income for 2019) for Benton County and 8 percent for White county in Indiana (an increase of $2,100 in per capita income for 2019). The per capita income effect measures the average impact, which includes the gains in rents from capital, land, and labor from wind power in these counties. Moreover, we find that most of the rents from wind power accrue to the owners of capital and labor. Even assuming the lowest projections of electricity prices and the highest reasonable cost we still find a 10 percent minimum rate of return to capital for both Benton and White counties’ wind power generators. Furthermore, we find that there are excess rents that could be taxed and redistributed at the county, state, or federal level without disincentivizing investment in wind power.</p>

Die wechselhafte Energiebereitstellung für drahtlose Sensorknoten durch Solarzellen stellt das Energiemanagement dieser Systeme vor große Herausforderungen. Bedingt durch saisonale und kurzfristige Effekte treten kontinuierlich Schwankungen in der Eingangsleistung auf, gleichzeitig soll jedoch eine zuverlässige und konstante Systemfunktion realisiert werden. Um dies miteinander zu vereinbaren, wird ein Modell zur Beschreibung der erwarteten Eingangsleistung aufgestellt, mit welchem der planmäßige Energieverlauf bestimmt werden kann. Dieser kann wiederum mit der realen Eingangsleistung verglichen werden, um den tatsächlichen energetischen Zustand des Sensorknotens zu bestimmen. Daraus lassen sich beispielsweise Entscheidungskriterien für die Steuerung der Energieverteilung oder Betriebszustände ableiten. Im Rahmen der Arbeit werden die physikalischen Hintergründe zur Modellierung der eingehenden Sonnenenergie beschrieben, der Stand der Technik zur Modellierung aufgezeigt und ein Modell als Basis für die weiteren Untersuchungen ausgewählt. Dieses wird auf die stark limitierte Hardware von drahtlosen Sensorknoten angepasst. Die Herausforderungen liegen dabei hauptsächlich in der geringen verfügbaren Rechenleistung, wenig Datenspeicher im System und dem Ziel, möglichst wenig Energie für die Berechnung zu verbrauchen. Im Ergebnis zeigt sich, dass ein angepasstes Modell auf drahtlosen Sensorsystemen umgesetzt werden kann und trotz der starken Limitierungen lauffähig ist. Es wird eine deutliche Verbesserung in der Verteilung der Energie über den Tag ermöglicht, wodurch sich trotz wechselhafter Quelle eine konstante Systemfunktion ergibt. Nebenher wird die Zuverlässigkeit und Ausfallsicherheit erhöht und Überdimensionierungen in Energiespeicher und Solarzelle können verringert werden. Das modellbasierte Energiemanagement stellt somit einen wichtigen Baustein für eine gesicherte Energieversorgung drahtloser Sensorsysteme dar. / The volatile energy supply by solar cells for wireless sensor nodes causes vast challenges for the energy management of such systems. Conditioned by seasonal and short time effects, the incoming power continuously varies. Simultaneously a reliable and constant function of the system has to be realized. To reconcile this, a model for the expected incoming solar power has been derived, which enables the estimation of the planned energy curve. This curve can be compared with the real progression of incoming power measured in parallel, to determine the current state of energy of a sensor node. This comparison is used to derive decision criteria for the control of the energy distribution or operating conditions. Within this work, the physical backgrounds for the modelling of the incoming solar energy and the state of the art of modelling solar power are described. A model is chosen as basis for further investigations and adapted to the limited hardware of wireless sensor nodes. The main challenges are the reduced processing power, few data memory in the system and the objective to consume as few energy as possible for the calculation. The results show that an adapted model can be implemented on wireless sensor systems and that it is executable despite the heavy limitations. This enables a distinct improvement of the distribution of energy across the day, which results in a constant systems function, despite the varying incoming power. At the same time the reliability and failure safety are being improved and the oversizing of the solar cell and the storage elements can be reduced. Therefore the model based energy management is an important component for a stable power supply of wireless sensor systems.

Since many buildings in Canada were built prior to the advent of national and provincial energy codes and standards, quantifying building envelope thermal performance in existing buildings is an important step in identifying retrofit opportunities. Due to the lack of building codes or standards for existing buildings in Canada, development of a rapid and robust quantitative approach to evaluate and rank buildings for vertical envelope retrofits is required. Hence, this dissertation sought to develop quantitative approaches to evaluate existing building envelope thermal performance in Canada and beyond. Following current professional practices, in Chapter 1, a comprehensive study was conducted on 49 campus buildings at the University of Victoria (UVic) to evaluate potential energy savings from vertical envelope retrofits, and to further validate those savings through more detailed energy models and parametric analyses for a subset of buildings. To this end, the thermal performance of a building envelope was quantified based on its heat loss coefficient (UA), obtained from multiplying its surface area (A) by its thermal transmittance (U-value). Heat loss calculations were used as a metric to inform envelope rehabilitation prioritization, while considering other data such as age and physical condition in parallel. Archetype energy models for selected buildings were used to evaluate the impacts of envelope retrofits on energy and GHG savings. The outcomes of this study allowed the University to weigh the benefits of improved energy performance from envelope retrofits against associated capital cost expenditures. Also, the implemented methodology and studied parameters unveiled a new horizon in evaluating the thermal performance of existing building envelopes in Canada, where a building code for existing buildings has not yet been established. Considering the economic findings of the envelope retrofits studied, it was concluded that in the absence of an existing building energy code, the University would likely require additional incentives, such as higher utility costs, higher carbon taxes, or qualifying for utility incentive programs to justify improving existing building envelope performance on the basis of energy only. The strength of the proposed methodology in Chapter 1 was in its balance of effort and ultimate decision-making utility, where reasonable thermal bridging approximations based on simulation models for existing buildings can yield data accurate enough to inform a ranking exercise on a large breadth of subject buildings. However, since numerical models do not consider degradation of building materials, real moisture content, and errors associated with manufacturing and installation, actual building envelope thermal performance differs from 3D simulation models. To study this limitation, in-situ thermal assessments of building envelopes were performed to quantify their actual thermal performances. To this end, Chapters 2 to 4 of this dissertation attempted to determine the viability of an external infrared thermography (IRT) survey technique for quantification of heat losses through the opaque building envelope, and also explores its potential application in identifying and comparing sources of air leakage. The experiments were performed on wood-framed wall assemblies commonly used in Canada due to growing interest among designers, builders, and governments to encourage the use of wood as a building material. In these studies, (Chapter 2 to Chapter 4), thermal transmittances (U-values) of wall assemblies were estimated with external IRT and compared with 3D computer simulations. Furthermore, the impact of the accuracy of U-values estimated with IRT on the deviation of energy simulation outputs with metered data was examined. Finally, a novel relative quantitative infrared index (IRI) was proposed as a means to facilitate rapid evaluation and subsequent ranking of building envelope thermal performance. From the experiments in Chapters 2 & 3, it was found that the U-values obtained with IRT were comparable with simulated values suggesting IRT can be a reliable tool for estimating the thermal performance of wood-framed wall assemblies. Results also demonstrated that thermal imaging artefacts including nonlinear characteristics of infrared (IR) camera focal array, a.k.a. non-uniformity corrections (NUC) and vignetting could have a substantial influence on the accuracy of results, in particular energy model outputs. This limitation was resolved by introducing a practical approach where thermal images were taken from different incident angle. Overall, IRI was found to be a reliable metric for relative quantitative comparison of building envelope thermal performance regardless of boundary conditions. Moreover, outcomes of the IRT air leakage study in Chapter 4 indicated that combined qualitative and quantitative IRT approaches could potentially be implemented by practitioners to identify sources of air leakage and thermal bridges in buildings and compare their relative severity. Since blower door testing is gradually being introduced as a building code requirement to measure building envelope airtightness in an increasing number of Canadian jurisdictions, performing IRT simultaneously is potentially valuable exercise in this context. Ultimately, the methodologies outlined in Chapters 2 to 4 can help decision-makers to characterize building envelope retrofits from a performance perspective, and potentially serve as a basis for governments to develop policies to improve existing building energy performance. The methodologies in Chapters 2 to 4 prompted opportunities to utilize the emergent technology of small unmanned aerial vehicles (UAVs) equipped with an infrared camera for quick thermal assessments of building envelopes. The last chapter of this dissertation, Chapter 5, outlines advantages and limitations of aerial IRT (UAV-IRT) surveys compared to conventional stationary IRT. Furthermore, a set of best practices for UAV-IRT were presented to minimize dynamic measurement uncertainty. It was concluded that with the current IR camera technology, aerial surveys for quantitative thermal assessment of building envelope are not as accurate as with conventional infrared thermography; further investigations by manufacturers and researchers are recommended. / Graduate

<p>With increasing concerns about the global warming effects of HFC refrigerants, low-GWP refrigerants and non-vapor compression heat pumps are investigated as potential mid- and long-term replacements for current vapor compression heat pump systems that rely on high-GWP refrigerants. To address the need for more environmentally friendly space cooling and heating, and water heating solutions. the U.S. Department of Energy (DOE) Office of Energy Efficiency & Renewable Energy (EERE) is supporting the development of smarter, more efficient, and affordable heat pumping systems operating with low- or near-zero GWP refrigerants through different programs including the Energy, Emissions, and Equity (E3) Initiative. In addition, the Emerging Technologies (ET) Program within the Building Technologies Office (BTO) emphasized the research and development efforts needed to support new technologies that could reduce energy usage in residential and commercial buildings by 50\% over the next decades. In the literature, limited studies were found that systematically investigated different combinations of conventional and emerging space conditioning and water heating technologies while accounting for real building loads, different climate zones, utility structures, and current state-of-the-art equipment. Existing literature primarily focused on thermodynamic performance evaluations at fixed boundary conditions. In addition, separate sensible latent cooling (SSLC) and other novel cooling and dehumidification systems (e.g., membrane-based systems) can significantly reduce the electricity usage for space conditioning. To compare the performance of conventional and emerging technologies several figures-of-merit such as the second law efficiency, are often used. However, limitations exist in previous studies to define the thermodynamic reversible limits and second law efficiency for cooling and dehumidification systems.</p><p>This study developed a comprehensive modeling framework to evaluate both current state-of-the-art vapor compression systems and emerging HVAC\&R technologies in real-world scenarios. The platform will be used to assess potential energy savings, scalability issues, and the effectiveness of combined technologies for different buildings, climate conditions, and utility structures.</p><p>To compare HVAC technologies, a new physics-based definition for the reversible limit and the second law efficiencies for cooling and dehumidification systems with air recirculation has been developed. The new framework is then extended to define a novel performance metric, the seasonal second law efficiency, to form a universal benchmark for assessing various cooling and dehumidification systems. Five cooling and dehumidification systems including magnetocaloric cooling, solid desiccant dehumidification, and membrane dehumidification are evaluated using this benchmark. Steady-state thermodynamic models are constructed for each system. Second law efficiency for each system under various outdoor temperatures and indoor sensible heat ratios (SHR) are calculated. The annual electricity usage of the five systems is used to justify the seasonal second law efficiency definition. The results show that compared to conventional vapor compression systems with mechanical dehumidification, the membrane-based AMX-R cycle can reduce annual electricity use by 12.2%-22.2% and increase the seasonal second law efficiency by 36%.</p><p>The advancements of nine not-in-kind (defined as non-vapor compression systems, solid-state, and chemical-based systems) technologies, i.e. magnetocaloric, thermoelectric, elastocaloric, electrocaloric, membrane-based, Vuilleumier, sorption, chemical looping, and desiccant, were reviewed in detail and compared with the state-of-the-art vapor compression systems. Suitable figures-of-merit were defined to compare the different technologies from a thermodynamic standpoint as well as technology readiness level. As a result of the thorough literature review, a roadmap was created to track the development of emerging HVAC&R technologies and future developments. More importantly, the roadmap enabled the identification of several case studies to evaluate potential energy savings both for space conditioning and water heating. Techno-economic studies for eight HVAC configurations for space heating, cooling, and water heating were conducted for a realistic building scenario under various climate conditions. Different combinations of advanced equipment such as heat pump water heater (HPWH), ground-source heat pumps (GSHP), cold-climate heat pumps (CCHP), and membrane-heat pumps were compared with traditional vapor compression heat pumps and gas furnaces. A building model was developed in EnergyPlus and validated with historical data from the DC Nanogrid House at the Purdue University campus. A total of eleven climate zones were considered, and both local weather conditions and utility pricing were implemented in the simulations. Moreover, future SEER2/HSPF2 equipment ratings and E3 Initiative targets were also included in the analyses.</p><p>The initial simulation results provided climate-based equipment selection guidelines and quantitative techno-economic assessments. For instance, CCHPs with two-stage compression in heating mode save 10%-20% in annual heating cost compared with single-stage VCHPs in Climate Zone 4A, 4C, 5A, 5B, 6A, and 6B. Membrane evaporative air-conditioners could provide cooling cost savings in places where is a significant cooling load, such as Zone 1A, 2A, 2B, 3A, 3C, 4A, 5A, and 6A. Gas furnaces should only be used in cold places where the electricity price per kWh to gas price ratio is higher than 3. GSHP has the lowest HVAC annual energy cost in six out of eleven climate zones in the U.S. Dual fuel heat pumps are not always the most economical option but yield better average cost savings among the eleven locations. HPWHs should be recommended in areas where the electricity price to gas price ratio is below 3. </p><p>The developed simulation framework will be instrumental to continue in-depth investigations of current and next-generation heat pump technologies. The ultimate goal of this research is to provide future guidelines on the selection of building-specific and climate-specific equipment solutions that will enable energy savings and future decarbonization strategies (e.g., geospatially-resolved simulations).</p>

In 2019, 770 million people worldwide lived without electricity. As many as 490 million people could be electrified with 210,000 mini-grids by 2030. Obtaining information for decision-making is crucial to determine the viability of such a project. Currently, it is a major challenge for mini-grid developers to gather this information at the speed and scale necessary to make effective investment choices. Village Data Analytics (VIDA) is a decision-making tool used for mini-grid project planning and site selection. This paper presents a method to estimate the cost of a mini-grid distribution network on a site-by-site basis. This method can estimate the total demand, potential connections, distribution infrastructure components and corresponding costs for each site. The model can make predictions for 50 sites within two hours so the tool is especially useful for preliminary estimates in the planning phase. A more detailed study of the individual sites is recommended. Comparison with a benchmark has shown that on-site conditions often reveal activities that can only be captured by a survey. However, collecting on-site data is time-consuming and costly. Therefore, GIS and modelling tools can serve as a good approximation of the on-ground reality and are relevant to accelerate planning and support timely decision-making. / 2019 levde 770 miljoner människor världen över utan elektricitet. Så många som 490 miljoner människor skulle kunna elektrifieras med 210 000 mininät till 2030. Att få information för beslutsfattande är avgörande för att avgöra om ett sådant projekt är lönsamt. För närvarande är det en stor utmaning för utvecklare av mininät att samla in denna information i den hastighet och skala som krävs för att göra effektiva investeringsval. Village Data Analytics (VIDA) är ett beslutsfattande verktyg som används för projektering av mininät och platsval. Det här dokumentet presenterar en metod för att uppskatta kostnaden för ett distributionsnät för mininät på plats för plats. Denna metod kan uppskatta den totala efterfrågan, potentiella anslutningar, komponenter för distribution sinfrastruktur och motsvarande kostnader för varje plats. Modellen kan göra förutsägelser för 50 platser inom två timmar, så verktyget är särskilt användbart för preliminära uppskattningar i planeringsfasen. En mer detaljerad studie av de enskilda platserna rekommenderas. Jämförelse med ett riktmärke har visat att förhållanden på plats ofta avslöjar aktiviteter som bara kan fångas genom en undersökning. Men att samla in data på plats är tidskrävande och kostsamt. Därför kan GIS- och modelleringsverktyg fungera som en bra approximation av verkligheten på marken och är relevanta för att påskynda planering och stödja beslutsfattande i rätt tid.

The potential of hydrogen as a clean energy carrier is hotly debated, but it promises to significantly contribute to a sustainable energy future. Hydrogen can replace fossil fuels in carbon-intensive industries, heavy transport and aviation, and support a renewable energysystem by acting as energy storage to balance intermittent supply. With increasing investment, high demand projections and the promise of hydrogen to reduce carbon emissions, it is becoming increasingly important to include hydrogen in energy models. While some studies include hydrogen in their energy models, they don’t comprehensively analyse the effects of uncertainty, which is significant in the hydrogen sector. This thesis addresses this gap by developing a Nordic energy model that includes hydrogen supply and storage using OSeMOSYS, based on the European OSeMBE model. In addition to a scenario analysis, a global sensitivity analysis is performed to identify the most influential uncertainties and key interactions between the hydrogen and electricity sectors. The study identifies hydrogen demand and carbon pricing as key uncertain drivers of change, affecting system costs and emissions levels. Uncertainty about the efficiency of carbon capture and the potential for biomass technology with carbon capture and storage also significantly impact emissions. While the share of renewables is projected to be robust, the technologies used for hydrogen production are susceptible to uncertainties. Steam reforming dominates in the absence of a strong carbon price. Electricity and hydrogen from biomass can provide negative emissions and have the potential to play an important role in decarbonisation. However, biomass availability is limited and policy support like carbon pricing is needed to make these technologies competitive in the market. A key link between the electricity and the hydrogen system is electrolysers. However, while cheaper electricity makes electrolysers more attractive, the cost and performance of hydrogen production technologies, such as steam reforming or biomass gasification, are more relevant in determining which hydrogen technologies will dominate. Hydrogen storage and fuel cells aren’t used in the study, except in small amounts for some of the runs in the sensitivity analysis. However, this may change with a specified time-dependent hydrogen demand or a finer time representation in the model. The thesis shows that uncertainties around hydrogen have a much larger impact on emissions than uncertainties around the electricity system. Hydrogen technologies are in close competition, with steam reforming difficult to displace. While in the Nordic countries, the advance of renewables in electricity generation seems unstoppable, the hydrogen sector needs public policy support to become an ally in decarbonisation rather than a burden. / Vätgasens potential som en ren energibärare är omdiskuterad, men den kan bidra avsevärt till en hållbar energiframtid. Vätgas kan ersätta fossila bränslen i koldioxidintensiva industrier, tunga transporter och luftfart, och stödja ett förnybart energisystem genom att fungera som energilagring för att balansera intermittenta leveranser. Med ökande investeringar, prognoser om hög efterfrågan och löftet om att vätgas kan minska koldioxidutsläppen blir det allt viktigare att inkludera vätgas i energimodeller. Vissa studier inkluderar vätgas i sina energimodeller, men de analyserar inte effekterna av osäkerhet på ett heltäckande sätt, vilket är betydande inom vätgassektorn. Den här avhandlingen adresserar detta gap genom att utveckla en nordisk energimodell som inkluderar vätgasförsörjning och lagring med hjälp av OSeMOSYS, baserat på den europeiska OSeMBE-modellen. Förutom en scenarioanalys utförs en global känslighetsanalys för att identifiera de mest inflytelserika osäkerheterna och viktiga interaktioner mellan vätgas- och elsektorerna. Studien identifierar efterfrågan på vätgas och prissättningen på koldioxid som viktiga osäkra drivkrafter för förändring, vilket påverkar systemkostnader och utsläppsnivåer. Osäkerheten kring koldioxidavskiljningens effektivitet och potentialen för biomassateknik med koldioxidavskiljning och lagring påverkar också utsläppen avsevärt. Även om andelen förnybara energikällor förväntas vara robust, är de tekniker som används för vätgasproduktion känsliga för osäkerheter. Ångreformering dominerar i avsaknad av ett starkt koldioxidpris. Elektricitet och vätgas från biomassa kan ge negativa utsläpp och har potential att spela enviktig roll i utfasningen av fossila bränslen. Tillgången på biomassa är dock begränsad och politiskt stöd i form av t.ex. koldioxidpriser behövs för att göra dessa tekniker konkurrenskraftiga på marknaden. En viktig länk mellan el- och vätgassystemet är elektrolysörer. Men även om billigare el gör elektrolysörer mer attraktiva, är kostnaden och prestandan för vätgasproduktionstekniker såsom ångreformering eller förgasning av biomassa mer relevanta för att avgöra vilka vätgastekniker som kommer att dominera. Vätgaslagring och bränsleceller används inte i studien, förutom i små mängder för några av körningarna i känslighetsanalysen. Detta kan dock förändras med en specificerad tidsberoende vätgasefterfrågan eller en finare tidsrepresentation i modellen. Avhandlingen visar att osäkerheter kring vätgas har en mycket större inverkan på utsläppen än osäkerheter kring elsystemet. Vätgasteknikerna konkurrerar nära varandra, men ångreformering är svår att ersätta. I de nordiska länderna verkar framstegen för förnybara energikällor inom elproduktion vara ostoppbara, men vätgassektorn behöver offentligt politiskt stöd för att bli en allierad i utfasningen av fossila bränslen snarare än en börda.

<p>Predmet istraživanja načelno se odnosi na razmatranje koncepta dvostrukih ventilisanih fasada (DVF) i njihov uticaj na energetsku efikasnost objekta. Ovaj koncept predstavlja jedan od primera adaptivnih fasada. Plan istraživanja zasnovan je na eksperimentalnom radu (na realnom objektu) i na numeričkim simulacijama modela objekta. Rezultati eksperimentalnog dela istraživanja pokazuju na koji način zavise termičke osobine objekta sa DVF od trenutnih meteorolo&scaron;kih uslova. Takođe, ovi rezultati poslužili su za fino pode&scaron;avanje modela i za postizanje &scaron;to vernije slike realnog objekta. Kriterijum prihvatljivosti, kada je model potvrđen, definisani su sa preporučenim statističkim indikatorima. Na taj način, formiran model u daljoj analizi je kori&scaron;ćen za definisanje sezonskih operativnih strategija. Rezultati simulacija za sve predložene operativne strategije, ocenjuju kakav je njihov uticaj na potro&scaron;nju energije za grejanje i klimatizaciju posmatranog objekta. Poređenjem sa modelima objekta sa tradicionalnom fasadom, pokazana je opravdanost primene koncepta DVF u klimatskim uslovima Beograda.</p> / <p>Research generally refers to the consideration of the concept of a double skin facades (DSF) and their impact on energy efficiency of the building. This concept is an example of adaptive facades. The research plan is based on experimental work and on the numerical model simulation. The results of experimental research works show how energy characteristics of the object with the DSF depend of current meteorological conditions. Also, these results were used to fine-tune the model to achieve as closely as possible the real presentation of the real building. The criterion of eligibility, when the model is verified, are defined with the recommended statistical indicators. Validated model in further analysis is used to define seasonal operational strategies. The simulation results for all proposed operational strategies, assess what is their impact on the building energy consumption for heating and air-conditioning. Compared to the models with a traditional facade, analysis show justification for the application of the concept of DSF in the climatic conditions of Belgrade.</p>

The increasing share of renewable energies in the power sector influences the economic viability of investments in new conventional power plants. Many studies have investigated these issues by considering power plant operation or the long-term development of the power plant fleet. However, power plant decommissioning, investment and operation are intrinsically linked. This doctoral thesis therefore presents a modelling framework for an integrated consideration of power plant decommissioning, investment and operation. In a case study focusing on Germany, the effects of the integration of renewable energies on power plant decommissioning, investment and operation are evaluated in the context of different assumptions regarding the remaining lifetime of nuclear power plants. With regard to the use of nuclear power, a phase-out scenario and a scenario with lifetime extension of nuclear power plants (by on average 12 years) are considered. The results show that static decommissioning (i.e. considering fixed technical lifetimes) underestimates the capacity available in the power sector in the scenario without lifetime extension since retrofit measures (versus decommissioning) are not taken into account. In contrast, capacity available in the case of nuclear lifetime extension is overestimated since mothballing (versus regular operation) is not considered. If the impact on decommissioning decisions of profit margins accrued during power plant operation are considered (“dynamic decommissioning”), the electricity price reduction effect due to a lifetime extension is reduced by more than half in comparison to static decommissioning. Scarcity situations do not differ significantly between the scenarios with and without lifetime extension with dynamic decommissioning; in contrast, there is a significantly higher need for imports without lifetime extension with static decommissioning. The case study demonstrates that further system flexibility is needed for the integration of renewable energies. It can be further concluded that the share of flexible power plants is higher with the phase-out of nuclear power plants. With regard to the decommissioning dynamics, the phase-out can be considered as beneficial for the economic viability of fossil power plants. Furthermore, the phase-out does not, overall, lead to environmental disadvantages in the medium term, but may be beneficial in the long run since lock-in effects are avoided. Further research is required with regard to the consideration of future flexibility options and a new market design. / Der steigende Anteil erneuerbarer Energien beeinflusst die Wirtschaftlichkeit von Investitionen in neue konventionelle Kraftwerke. Zahlreiche Studien haben diese Aspekte in Bezug auf den Kraftwerksbetrieb oder die langfristige Entwicklung des Kraftwerksparks untersucht. Stilllegungen, Investitionen und Betrieb im Kraftwerkspark bedingen jedoch einander. Aus diesem Grund wird in dieser Doktorarbeit ein Modellierungsansatz für eine integrierte Betrachtung von Kraftwerksstilllegung, -investition und -betrieb vorgestellt. In einer Fallstudie für Deutschland werden die Auswirkungen einer Integration erneuerbarer Energien auf Kraftwerksstilllegung, -investition und -betrieb im Zusammenhang mit unterschiedlichen Annahmen über die Restlaufzeit von Kernkraftwerken untersucht. Bezogen auf die Nutzung der Kernenergie wird hierbei ein Ausstiegsszenario sowie ein Laufzeitverlängerungsszenario (Verlän-gerung der Laufzeit um durchschnittlich 12 Jahre) betrachtet. Die Ergebnisse zeigen, dass die statische Stilllegung (d.h. die Betrachtung fester technischer Lebensdauern) im Fall eines Verzichts auf die Laufzeitverlängerung die im Kraftwerkspark verfügbare Leistung unterschätzt, da Retrofit-Maßnahmen (im Vergleich zur Stilllegung) nicht berücksichtigt werden. Die verfügbare Leistung im Falle einer Laufzeitverlängerung wird dagegen überschätzt, da die Möglichkeit der Kaltreserve (im Vergleich zum regulären Betrieb) vernachlässigt wird. Werden die Rückwirkungen der im Betrieb erwirtschaftbaren Deckungsbeiträge auf Stilllegungsentscheidungen (“dynamische Stilllegung”) betrachtet, so wird der strompreissenkende Effekt durch die Laufzeitverlängerung im Vergleich zur statischen Stilllegung mehr als halbiert. Knappheitssitutationen unterscheiden sich nicht wesentlich mit und ohne Laufzeitverlängerung im Fall der dynamischen Stilllegung, während bei statischer Stilllegung ohne Laufzeitzeitverlängerung ein deutlich größerer Importbedarf besteht. Die Fallstudie zeigt, dass weitere Systemflexibilitäten für die Integration erneuerbarer Energien benötigt werden. Der Anteil flexibler Kraftwerke ist größer im Fall des Kernenergieausstiegs. Der Kernenergieausstieg wirkt sich in Bezug auf die Stilllegungsdynamik positiv auf die Wirtschaftlichkeit fossiler Kraftwerke aus. Insgesamt führt der Kernenergieausstieg zu keinen mittelfristig nachteiligen Umwelteffekten, er kann sich jedoch langfristig positiv auswirken, da Lock-in-Effekte vermieden werden. Es besteht weiterer Forschungsbedarf in Bezug auf die Berücksichtigung künftiger Flexibilitätsoptionen und ein neues Marktdesign.

The UK’s decarbonisation strategy to increasingly electrify heating and transport will change the demand requirement on the electricity system. Additionally, under a climate change future, it is projected that the decarbonised grid will need to be able to operate under higher average temperatures in the UK, increasing the need for comfort cooling during summer and leading to additional electricity demand. These new demands will result in greater variation between minimum and peak demand as well as a significant increase in overall demand. Concurrently, supply-side decarbonisation programmes may lead to more intermittent renewables such as wind, PV, tidal and wave, elevating variability in electricity generation. Coupled with the anticipated higher variation in demand this brings on several challenges in operating the electricity grid. In order to characterise these challenges this research develops a bespoke electricity dispatch model which builds on hourly models of demand and generation. The hourly demand profiles are based on a high electrification of heating, transport and cooling coupled with future temperatures premised on the UKCP09 high emission scenario climate projections. The demand profiles show a significant increase in peak demand by 2050 reaching 194 GW, mainly due to summer cooling loads which contribute 70% of the demand. The cumulative CO2 emissions budgets of the GB power sector that are consistent with avoiding global climate change to 2°C are used to develop two low carbon generation scenarios distinguished by the amount of intermittent renewable generation technologies. The dispatch model tests the capability of generation scenarios with the use of hourly generation models in meeting future demand profiles out to 2050.The outputs from dispatch model indicate that there are shortages and excesses of generation relative to demand from 2030 onwards. The variability analysis outlines low and high generation periods from intermittent technologies along with the pace at which intermittent generation increases or decreases within an hour. The characterisation of variability analysis reveals the type of reserve capacity or smart solutions that are required to maintain the security of electricity supply. The solutions that could address the challenges quantified from the model outputs in operating a decarbonised GB electricity grid are explored using expert interviews. The analysis of the stakeholder interviews suggests smart grid solutions that include technologies as well as changes in operational procedures in order to enhance the operational resilience of the grid. Active Network Management through monitoring and control, demand management, storage systems and interconnectors are proposed to address challenges arising from varying demand and generation variability.

Li-ion batteries have demonstrated to be a very flexible source with energystorage capability. Due to their scalability and wide range of power and energydensities, they are suitable for several applications. Li-ion storage cantherefore provide different services, the remuneration of which depends onthe electricity market of the country. In this work, two different case studiesof combination of Li-ion batteries with large-scale renewable power plantshave been investigated: batteries with solar PV in India and with wind powerin Sweden. Simulation models have been developed to assess the operationand profitability potential of different services in these two case studies. Themodels have been built using control algorithms, linear optimization (LP) andstochastic programming techniques. The results show that the use of batteriesfor solar power output smoothing under a power purchase agreement canbe a profitable business case in India. Moreover, batteries providing primaryfrequency regulation (FCR-N) in Sweden show to have a positive economicvalue. System breakeven costs to make the stacking of wind power productionimbalance compensation and FCR-N services profitable have been found,which based on conservative price expectations should be achieved by 2022. / Li-ion batterier har visat sig vara en mycket effektiv källa för lagring av energi.Tack vare deras skalbarhet och det breda utbudet av kraft och energidensiteterhar de flera användningsområden. Li-ion batterier kan därför användas föratt tillhandahålla olika typer av tjänster vars ekonomiska ersättning beror avlandets elmarknad. Detta arbete undersöker två fallstudier av Li-ion batterieri kombination med storskaliga kraftverk som drivs av förnybara energikällor:batterier i kombination med solkraft i Indien och vindkraft i Sverige. Simuleringsmodellerhar utvecklats för att undersöka driften och lönsamhetspotentialenför olika tjänster i de två fallstudierna. Modellerna baserar sig påkontrollalgoritmer, linjär optimering och stokastisk programmeringsteknik.Resultaten visar att användningen av batterier för utjämning av solenergi enligtett kraftköpavtal kan vara lönsamma i Indien. Dessutom har användningenav batterier för primärreglering (FCR-N) visat sig ha ett positivt ekonomisktvärde i Sverige. Breakeven kostnaderna för att göra kombinationen av vindkraftsproduktionensbalanskompensering och FCR-N tjänster lönsamma harhittats, vilket ska uppnås senast år 2022 baserat på en konservativ prisprognos.