Impacts of shared mobility on vehicle lifetimes and on\ua0the carbon footprint of electric vehicles

Shared cars will likely have larger annual vehicle driving distances than individually owned cars. This may accelerate passenger car retirement. Here we develop a semi-empirical lifetime-driving intensity model using statistics on Swedish vehicle retirement. This semi-empirical model is integrated with a carbon footprint model, which considers future decarbonization pathways. In this work, we show that the carbon footprint depends on the cumulative driving distance, which depends on both driving intensity and calendar aging. Higher driving intensities generally result in lower carbon footprints due to increased cumulative driving distance over the vehicle’s lifetime. Shared cars could decrease the carbon footprint by about 41% in 2050, if one shared vehicle replaces ten individually owned vehicles. However, potential empty travel by autonomous shared vehicles—the additional distance traveled to pick up passengers—may cause carbon footprints to increase. Hence, vehicle\ua0durability and empty travel should be considered when\ua0designing low-carbon car sharing\ua0systems

If Electric Cars Are Good for Reducing Emissions, They Could Be Even Better with Electric Roads

This research investigates carbon footprint impacts for full fleet electrification of Swedish passenger car travel in combination with different charging conditions, including electric road system (ERS) that enables dynamic on-road charging. The research applies a prospective life cycle analysis framework for estimating carbon footprints of vehicles, fuels, and infrastructure. The framework includes vehicle stock turnover modeling of fleet electrification and modeling of optimal battery capacity for different charging conditions based on Swedish real-world driving patterns. All new car sales are assumed to be electric after 2030 following phase-out policies for gasoline and diesel cars. Implementing ERS on selected high-traffic roads could yield significant avoided emissions in battery manufacturing compared to the additional emissions in ERS construction. ERS combined with stationary charging could enable additional reductions in the cumulative carbon footprint of about 12–24 million tons of CO2\ua0over 30 years (2030–2060) compared to an electrified fleet only relying on stationary charging. The range depends on uncertainty in emission abatement in global manufacturing, where the lower is based on Paris Agreement compliance and the higher on current climate policies. A large share of the reduction could be achieved even if only a small share of the cars adopts the optimized battery capacities

Carbon footprint effects of shifting from flights to night trains for Swedish tourism

Changes in travel behaviour are needed to tackle the climate impact associated with long-distance flights, including a switch to sustainable transport modes. In this paper, we analyse scenarios of carbon footprint reduction associated with a switch from flights to night trains for holidays in Europe for the case of Sweden, including outbound, inbound and domestic tourism. We use a prospective lifecycle assessment framework combined with results from a stated preference experiment to determine the impact of future mode shift behaviours. Our results indicate that a mode shift could be triggered by progressive night train policies resulting in (i) fewer transfers and (ii) price levels similar to those of flights. The shifts from flights to night trains could result in 9% lower cumulative carbon footprint in relation to a baseline travel demand scenario for the period 2025–2050. Decarbonization of long-distance travel in line with the Paris Agreement would likely require a combination of many different types of measures including a shift to low-carbon fuels

Consumption based scenarios for Sweden - a basis for discussing new climate targets

Also available in Swedish: \ua0https://research.chalmers.se/publication/52652

Indicate separate contributions of long-lived and short-lived greenhouse gases in emission targets

European Union funding: 821205, 821003, 820829. Wellcome Trust: 205212/Z/16/

Indicate separate contributions of long-lived and short-lived greenhouse gases in emission targets

European Union funding: 821205, 821003, 820829. Wellcome Trust: 205212/Z/16/

Tracking Emissions Reductions and Energy Efficiency in the Steel Industry

The iron and steel industry has become increasingly globalised. Market conditions are also changing and de-carbonisation of production is challenging. The objective of this thesis is to assess how energy efficiency and greenhouse gas emissions reductions can be promoted and effectively monitored in the steel industry. The thesis contributes with analyses based on the Malmquist Productivity Index for a top-down analysis of the energy efficiency of EU Member States’ iron and steel production, and Partial Least Squares regression for bottom-up assessments of different monitoring tools. The thesis also contributes with a scrap availability assessment module to enhance the energy system model ETSAP-TIAM. The first phase of the research showed that future production needs to shift towards innovative low-CO2 technologies even when all available recycled material is fully used. Techniques using carbon capture and storage (CCS) as well as hydrogen-based technologies can be expected to become economically viable under tightened climate policies. The second phase of the research showed that current indicators are insufficient. System boundaries of energy use and emissions data do not align with production statistics. Indicators based on energy use or emissions in relation to production in physical terms may be useful to track specific processes. However, current indicators fail to reflect the companies’ product mix. Enhanced energy and climate indicators that adjust for the product mix provide better estimates while failing to reflect the increasing globalisation. Effective monitoring of industrial transformation will be increasingly important as pressure from climate policy via global CO2-pricing is unlikely in the short term. Current or enhanced indicators do not fully capture industrial transformation and are not recommended. Future research should focus on defining indicators to estimate energy use and emissions along industrial value chains in climate policy contexts.Järn- och stålindustrin har blivit alltmer globaliserad. Marknadsvillkoren förändras samtidigt som utfasningen av fossila bränslen är utmanande. Målet med den här avhandlingen är att bedöma hur energieffektivitet och växthusgasutsläppsminskningar kan främjas och effektivt utvärderas inom stålindustrin. Avhandlingen bidrar med analyser baserade Malmquists produktivitetsindex för att analysera energieffektivitet av EU:s medlemsstaters järn- och stålproduktion, och partiell minsta- kvadrat-regression för att bedöma olika utvärderingsmått. Avhandlingen bidrar även med en modul som bedömer skrottillgång för att förbättra energisystemmodellen ETSAP-TIAM. I en första fas visade forskningen att framtida produktion behöver ställas om mot innovativa teknologier med låga CO2-utsläpp även när allt tillgängligt återvunnet material används fullt ut. Tekniker som använder koldioxidinfångning och -lagring (CCS) samt vätebaserade teknologier kan förväntas bli ekonomiskt försvarbara under åtstramade klimatpolitiska styrmedel. I en andra fas visade forskningen att nuvarande indikatorer är otillräckliga. Systemgränser för energianvändnings- och växthusgasutsläppsdata stämmer inte överens med produktionsstatistik. Indikatorer utifrån energianvändning eller utsläpp i relation till fysisk produktion kan vara användbara för att följa upp specifika processer. Nuvarande indikatorer lyckas dock inte spegla företagens produktmix. Förbättrade energi- och klimatindikatorer som justerar för produktmixen ger bättre uppskattningar, men speglar inte branschens ökande globalisering. Effektiv utvärdering av industriell transformation blir alltmer viktig då påtryckning från klimatpolitiska styrmedel via global CO2-prissättning är kortsiktigt osannolik. Nuvarande eller förbättrade indikatorer fångar inte industriell transformation fullt ut och rekommenderas inte. Framtida forskning bör fokusera på att definiera indikatorer som uppskattar energianvändning och växthusgasutsläpp längs industriella värdekedjor. QC 20170428</p

Optiskt selektiva ytor i lågkoncentrerande PV/T-system

One of the traditional approaches to reduce costs of solar energy is to use inexpensive reflectors to focus the light onto highly efficient solar cells. Several research projects have resulted in designs, where the excess heat is used as solar thermal energy. Unlike a solar thermal system, which has a selective surface to reduce the radiant heat loss, a CPV/T (Concentrating PhotoVoltaic/Thermal) system uses a receiver covered with solar cells with high thermal emittance. This project analyzes whether the heat loss from the receiver can be reduced by covering parts of the receiver surface, not already covered with solar cells, with an optically selective coating. Comparing different methods of applying such a coating and the long-term stability of low cost alternatives are also part of the objectives of this project. To calculate the heat loss reductions of the optically selective surface coating a mathematical model was developed, which takes the thermal emittances and the solar absorptances of the different surfaces into account. Furthermore, a full-size experiment was constructed to verify the theoretical predictions. The coating results in a heat loss reduction of approximately 20 % in such a CPV/T system and one of the companies involved in the study is already changing their design to make use of the results

Tools for Evaluating Energy Efficiency of Steel Production : Lessons from Sweden and Europe

The European Union faces challenges related to climate change, security of energy supply, and competitiveness of European industries. Energy efficiency indicators are required for monitoring and controlling the effectiveness of policies such as the recently endorsed Energy Efficiency Directive. This thesis aims at assessing whether traditionally used energy efficiency indicators capture the development of energy efficiency in the iron and steel sector. The study is based on results from two statistical methods: a top-down, i.e. Malmquist productivity index, and a bottom-up, i.e. partial least squares regression. The specific energy consumption (the indicator representing the sector within the Odyssee energy efficiency index) was scrutinised together with associated indicators based on economic production using the aforementioned statistical methods. The results demonstrated the specific energy consumption does not capture the characteristics of the value chain of steel products. Therefore, it is not sufficient for capturing the energy efficiency of iron and steel industries. Previous studies suggest using indicators based on economic production (e.g. value added) since they represent the value chain to larger degree. However, the value creation process of companies belonging to larger international groups cannot be estimated reliably. Furthermore, the trends of both types of indicators tend to be highly influenced by structural changes, veiling the actual efficiency development. Energy use statistics published by international organisations were also compared for the Swedish case. The results demonstrated that international organisations use different methodologies for allocating energy use statistics between consumption and transformation sectors. The method has significant implications on the trends observed, if based on openly available statistics. This thesis complements previous research by reviewing implications of traditional energy efficiency indicators based on company data, national statistics or openly available statistics and contributes with insights essential for future efforts towards improving energy efficiency indicators for the steel industry.Den europeiska unionen står inför utmaningar relaterade till minskad klimatpåverkan, säkerställd energitillgång samt konkurrenskraften hos europeisk industri. Energieffektiviseringsindikatorer krävs för att övervaka och kontrollera effektiviteten hos energipolicy såsom det nyligen antagna energieffektiviseringsdirektivet. Den här avhandlingen syftar till att bedöma om traditionellt använda energieffektiviserings-indikatorer fångar järn- och stålsektorns utveckling inom energi-effektivitet. Studien är baserad på resultat från två statistiska metoder: en top-down-metod, Malmquists produktivitetsindex, och en bottom-up-metod, partiella minsta kvadratmetoden. Den specifika energikonsumtionen – indikatorn som representerar sektorn i Odyssees energieffektiviseringsindex – granskades tillsammans med andra energieffektivitetsindikatorer med hjälp av de ovan nämnda statistiska metoderna. Resultaten visade att specifik energikonsumtion inte fångar karaktären av stålprodukternas värdekedjor. Indikatorn är därför inte tillräcklig för att fånga energieffektivitet inom järn- och stål-industrier. Tidigare studier föreslår att använda indikatorer baserade på ekonomisk produktion (exempelvis förädlingsvärdet) då de representerar värdekedjan till högre grad. Förädlingsvärdet kan dock inte uppskattas tillförlitligt för företag som tillhör större internationella grupper. Trend-erna hos båda typerna av indikatorer tenderar dessutom att påverkas av strukturella förändringar, vilka döljer den riktiga effektivitetsutvecklingen. En jämförelse gjordes även av energianvändningsstatistik publicerad av olika internationella organisationer för det svenska fallet. Resultaten demonstrerade att internationella organisationer använder olika metoder för att allokera energianvändning mellan konsumtions- och omvandlings-sektorer i statistiken. Metoden påverkar observerade trender signifikant om de baseras på öppet tillgänglig statistik. Avhandlingen kompletterar tidigare forskning genom att belysa innebörden av traditionella energieffektiviseringsindikatorer baserade på företagsdata, nationell statistik eller öppet tillgänglig statistik samt bidrar med insikter som kommer att vara väsentliga för framtida satsningar i att förbättra energieffektiviseringsindikatorer för stålindustrin.