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AbstractDecarbonising the energy system requires high shares of variable renewable generation and sector coupling like power to heat. In addition to heat supply, heat pumps can be used in future energy systems to provide flexibility to the electricity system by using the thermal storage potential of the building stock and buffer tanks to shift electricity demand to hours of high renewable electricity production. Bridging the gap between two methodological approaches, we coupled a detailed building technology operation model and the open-source energy system model Balmorel to evaluate the flexibility potential that decentral heat pumps can provide to the electricity system. Austria in the year 2030 serves as an example of a 100% renewable-based electricity system (at an annual national balance). Results show that system benefits from heat pump flexibility are relatively limited in extent and concentrated on short-term flexibility. Flexible heat pumps reduce system cost, CO2 emissions, and photovoltaics and wind curtailment in all scenarios. The amount of electricity shifted in the assessed standard flexibility scenario is 194 GWhel and accounts for about 20% of the available flexible heat pump electricity demand. A comparison of different modelling approaches and a deterministic sensitivity analysis of key input parameters complement the modelling. The most important input parameters impacting heat pump flexibility are the flexible capacity (determined by installed capacity and share of control), shifting time limitations, and cost assumptions for the flexibility provided. Heat pump flexibility contributes more to increasing low residual loads (up to 22% in the assessed scenarios) than decreasing residual load peaks. Wind power integration benefits more from heat pump flexibility than photovoltaics because of the temporal correlation between heat demand and wind generation.

Blockchain is described as having endless theoretical potential. In reality however, it is hard toestablish how blockchain can be utilized and what opportunities blockchain may create. Theunclear future of blockchain constitutes a challenge for many companies. Many large incumbentsare uncertain of how to implement blockchain technology in their organization and are anxiousabout the consequences of the new technology. The purpose of this exploratory study is to evaluateblockchain applications for a district heating company in Stockholm to understand favorable areas,necessary criteria for successful implementation and how blockchain could enable new businessopportunities in the district heating market. To be able to reach the purpose of the thesis aliterature study and an empirical study were performed. The literature study is in the form of anextensive investigation about the areas of blockchain and district heating. The empirical studyincludes 17 interviews, both internal interviews with employees at Stockholm Exergi and externalinterviews conducted with professionals with knowledge about blockchain, district heating and theenergy sector. Furthermore, two workshops, in collaboration with Stockholm Exergi, wereperformed at the end of the thesis to evaluate and prioritize the developed blockchain applications.This thesis proposes 32 blockchain applications within 10 areas in the district heating industry.The applications are categorized after their potential, in three categories; green for the blockchainapplications that are valuable to investigate further, orange for the applications that potentiallycould be interesting to investigate further, and red for the applications that are not interesting toinvestigate further. Some applications focus on solving inefficiencies within district heating andsome on exploiting the benefits of blockchain. Eight applications are categorized with greenprioritization, and thus presented in more detail. To take into account that blockchain probablywill have a greater impact in the future, a future scenario was developed and used in the situationalanalysis for the applications. Furthermore, a framework was developed with the aim to be a toolfor a district heating company to utilize while considering if a blockchain implementation wouldbe beneficial, and if so, in what way. The framework is focused on district heating companies butcan be utilized by other actors as well.Our recommendation for a district heating company in Stockholm is to wait one or two yearswhile staying updated. Especially important for the companies are to stay updated on whether newblockchain standardizations will emerge in the energy sector. However, if a district heatingcompany want to initialize a blockchain project we advise the companies to start a pilot projectthat does not affect the current business model but has the potential to be scaled. Since theblockchain technology enhances collaboration, it is important to consider which partners shouldbe included and how the application can create value for all involved parties. However, due to theuncertainty of the technology, companies need to be well aware of that assumed created value maynot be reached as expected. Furthermore, district heating companies also need to bear in mindthat other parameters, for example additional technologies, policies or infrastructure systems, maybe necessary to implement in order to create value from a blockchain solution. Blockchain beskrivs ofta som något med ändlös teoretisk potential. I verkligheten är det dock svårtatt fastställa hur blockchain kan användas och vilka möjligheter blockchain kan skapa. Den osäkraframtiden för blockchain är en utmaning för många företag att förhålla sig till. Inte minst för storaetablerade företag då blockchain kan användas för att decentralisera en centraliseradmarknadsstruktur. Syftet med denna undersökande studie är att utvärdera blockchainapplikationerför ett fjärrvärmeföretag i Stockholm, för att förstå gynnsamma områden,nödvändiga kriterier vid genomförande och hur blockchain skulle kunna möjliggöra nyaaffärsmöjligheter på fjärrvärmemarknaden. För att uppfylla uppsatsens syfte genomfördes enlitteraturstudie och en empirisk studie. Inom litteraturstudien genomfördes en omfattandeundersökning av blockchain och fjärrvärme. Den empiriska studien bestod av 17 intervjuer, bådeinterna intervjuer med anställda från Stockholm Exergi och externa intervjuer med experter inomblockchain, fjärrvärme och energisektorn. Vidare genomfördes under slutfasen två workshops isamarbete med Stockholm Exergi, för att utvärdera och prioritera de skapade blockchainapplikationerna.Rapporten presenterar 32 blockchain-applikationer inom 10 olika områden inomfjärrvärmeindustrin. Applikationerna är kategoriserade efter sin potential i tre grupper, grön för deapplikationer som kan vara fördelaktiga för ett fjärrvärmeföretag och bör fortsätta undersökas,orange för de applikationer som sannolikt inte skulle vara fördelaktiga och röd för de applikationersom inte är intressanta för ett fjärrvärmeföretag att fortsätta undersöka. Vissa applikationerfokuserar på att lösa de ineffektiviteter som finns för fjärrvärme och vissa på att utnyttja fördelarnamed blockchain. Det åtta applikationer med grön prioritering presenteras mer detaljerat. Ettframtida scenario togs fram för att ta hänsyn till att blockchain sannolikt kommer att ha störrepåverkan i framtiden. Detta används som hjälpmedel när situationsanalysen för applikationernagenomförs. Dessutom utvecklades ett ramverk som har som syfte att vara ett verktyg för ettfjärrvärmeföretag att utnyttja när en blockchain implementering övervägs. Ramverket är inriktatpå fjärrvärmeföretag men kan även användas av andra aktörer.Vår rekommendation till ett fjärrvärmeföretag i Stockholm är att vänta ett eller två år, samtidigtsom de håller sig uppdaterade om marknadsförändringar för blockchain. Särskilt viktigt för ettfjärrvärmeföretag är att hålla sig uppdaterad om huruvida nya blockchain-standardiseringar uppstårinom energisektorn. Om ett fjärrvärmeföretag vill initiera ett blockchain-projekt, rekommenderarvi att starta med ett pilotprojekt som inte påverkar den nuvarande affärsmodellen, men harpotential att skalas. Eftersom blockchain-teknologin möjliggör samarbete är det viktigt attöverväga vilka partners som kan ingå i lösningen och hur applikationen kan skapa värde för allaberörda parter. Företag måste emellertid vara väl medvetna om att det förväntade värdet kanskeinte uppnås på grund av teknologins osäkerhet. Dessutom måste företagen också överväga attandra parametrar, till exempel andra teknologier, politik eller infrastruktur, är nödvändiga, för atten blockchain implementering ska skapa värde.

Abstract Socio-technical transformations towards low-carbon energy systems are on the way in developed countries. Conversely, developing countries tend to be locked in fossil fuels and foster coal-based energy structures, emphasizing reliable and cost-effective energy provision and sidelining environmental concerns. In this study, we identified and analysed the predominant factors related to coal-based power generation in Bangladesh. We applied a mixed-method approach, initially conducting a systematic literature review and, subsequently, semi-structured expert interviews to identify and validate relevant factors. We then assessed their relative importance using an Analytical Hierarchy Process based on expert judgments. The results of this assessment reveal that socio-economic aspects and environmental issues scored highest, while technological aspects and sector regulations were considered to be less relevant for large-scale coal power implementation. We conclude that future energy policies created in Bangladesh will need to use appropriate legal instruments and address issues such as human displacement and resettlement, low levels of public acceptance, health hazards and environmental pollution. Participative policy frameworks should be deployed in coal plant projects, and active monitoring systems are necessary to reduce the negative consequences associated with increased electrification and energy consumption. To address foreseeable structural challenges, it furthermore will be crucial to explore sustainable alternatives.

This article examines land-use, market and welfare implications of lignocellulosic bioethanol production in Hawaii to satisfy 10% and 20% of the State's gasoline demand in line with the State's ethanol blending mandate and Alternative Fuels Standard (AFS). A static computable general equilibrium (CGE) model is used to evaluate four alternative support mechanisms for bioethanol. Namely: (i) a federal blending tax credit, (ii) a long-term purchase contract, (iii) a state production subsidy financed by a lump-sum tax and (iv) a state production subsidy financed by an ad valorem gasoline tax. We find that because Hawaii-produced bioethanol is relatively costly, all scenarios are welfare reducing for Hawaii residents: estimated between -0.14% and -0.32%. Unsurprisingly, Hawaii.s economy and its residents fair best under the federal blending tax credit scenario, with a positive impact to gross state product of $49 million. Otherwise, impacts to gross state product are negative (up to -$63 million). We additionally find that Hawaii-based bioethanol is not likely to offer substantial greenhouse gas emissions savings in comparison to imported biofuel, and as such the policy cost per tonne of emissions displaced ranges between $130 to $2,100/tonne of CO2e. The policies serve to increase the value of agricultural lands, where we estimate that the value of pasture land could increase as much as 150% in the 20% AFS scenario.

New transparent optodes for life-time based microscopic imaging of O₂ were developed by spin-coating a μm-thin layer of a highly luminescent cyclometalated iridium(III) coumarin complex in polystyrene onto glass cover slips. Compared to similar thin-film O₂ optodes based on a ruthenium(II) polypyridyl complex or a platinum(II) porphyrin, the new planar sensors have i) higher brightness allowing for much shorter exposure times and thus higher time resolution, ii) more homogeneous and smaller pixel to pixel variation over the sensor area resulting in less noisy O₂ images, and iii) a lower temperature dependency simplifying calibration procedures. We used the new optodes for microscopic imaging of the spatio-temporal O₂ dynamics at the base of heterotrophic biofilms in combination with confocal imaging of bacterial biomass and biofilm structure. This allowed us to directly link biomass distribution to O₂ distribution under both steady state and non-steady state conditions. We demonstrate that the O₂ dynamics in biofilms is governed by a complex interaction between biomass distribution, mass transfer and flow that cannot be directly inferred from structural information on biomass distribution alone.

Abstract. Flooding in the Amazon basin is frequently attributed to modes of large-scale climate variability, but little attention is paid to how these modes influence the timing and duration of floods despite their importance to early warning systems and the significant impacts that these flood characteristics can have on communities. In this study, river discharge data from the Global Flood Awareness System (GloFAS 2.1) and observed data at 58 gauging stations are used to examine whether positive or negative phases of several Pacific and Atlantic indices significantly alter the characteristics of river flows throughout the Amazon basin (1979–2015). Results show significant changes in both flood magnitude and duration, particularly in the north-eastern Amazon for negative El Niño–Southern Oscillation (ENSO) phases when the sea surface temperature (SST) anomaly is positioned in the central tropical Pacific. This response is not identified for the eastern Pacific index, highlighting how the response can differ between ENSO types. Although flood magnitude and duration were found to be highly correlated, the impacts of large-scale climate variability on these characteristics are non-linear; some increases in annual flood maxima coincide with decreases in flood duration. The impact of flood timing, however, does not follow any notable pattern for all indices analysed. Finally, observed and simulated changes are found to be much more highly correlated for negative ENSO phases compared to the positive phase, meaning that GloFAS struggles to accurately simulate the differences in flood characteristics between El Niño and neutral years. These results have important implications for both the social and physical sectors working towards the improvement of early warning action systems for floods.

AbstractBioenergy projects can lead to direct and indirect land use change (LUC), which can substantially affect greenhouse gas balances with both beneficial and adverse outcomes for bioenergy's contribution to climate change mitigation. The causes behind LUC are multiple, complex, interlinked, and change over time. This makes quantification uncertain and sensitive to many factors that can develop in different directions—including land use productivity, trade patterns, prices and elasticities, and use of by‐products associated with biofuels production. Quantifications reported so far vary substantially and do not support the ranking of bioenergy options with regard to LUC and associated emissions. There are however several options for mitigating these emissions, which can be implemented despite the uncertainties. Long‐rotation forest management is associated with carbon emissions and sequestration that are not in temporal balance with each other and this leads to mitigation trade‐offs between biomass extraction for energy use and the alternative to leave the biomass in the forest. Bioenergy's contribution to climate change mitigation needs to reflect a balance between near‐term targets and the long‐term objective to hold the increase in global temperature below 2°C (Copenhagen Accord). Although emissions from LUC can be significant in some circumstances, the reality of such emissions is not sufficient reason to exclude bioenergy from the list of worthwhile technologies for climate change mitigation. Policy measures to minimize the negative impacts of LUC should be based on a holistic perspective recognizing the multiple drivers and effects of LUC.This article is categorized under: Bioenergy > Economics and Policy Bioenergy > Climate and Environment

This paper investigates battery preheating before fast charging, for a battery electric vehicle (BEV) driving in a cold climate. To prevent the battery from performance degradation at low temperatures, a thermal management (TM) system has been considered, including a high-voltage coolant heater (HVCH) for the battery and cabin compartment heating. Accordingly, an optimal control problem (OCP) has been formulated in the form of a nonlinear program (NLP), aiming at minimising the total energy consumption of the battery. The main focus here is to develop a computationally efficient approach, mimicking the optimal preheating behavior without a noticeable increase in the total energy consumption. The proposed algorithm is simple enough to be implemented in a low-level electronic control unit of the vehicle, by eliminating the need for solving the full NLP in the cost of only 1Wh increase in the total energy consumption.