Climate policies for road transport revisited (I): Evaluation of the current framework

The global rise of greenhouse gas (GHG) emissions and its potentially devastating consequences require a comprehensive regulatory framework for reducing emissions, including those from the transport sector. Alternative fuels and technologies have been promoted as a means for reducing the carbon intensity of the transport sector. However, the overall transport policy framework in major world economies is geared towards the use of conventional fossil fuels. This paper evaluates the effectiveness and efficiency of current climate policies for road transport that (1) target fuel producers and/or car manufacturers, and (2) influence use of alternative fuels and technologies. With diversifying fuel supply chains, carbon intensity of fuels and energy efficiency of vehicles cannot be regulated by a single instrument. We demonstrate that vehicles are best regulated across all fuels in terms of energy per distance. We conclude that price-based policies and a cap on total emissions are essential for alleviating rebound effects and perverse incentives of fuel efficiency standards and low carbon fuel standards. In tandem with existing policy tools, cap and price signal policies incentivize all emissions reduction options. Design and effects of cap and trade in the transport sector are investigated in the companion article (Flachsland et al., in this issue).     

Deployment of fuel cell vehicles in China: Greenhouse gas emission reductions from converting the heavy-duty truck fleet from diesel and natural gas to hydrogen

Hydrogen fuel cells, as an energy source for heavy duty vehicles, are gaining attention as a potential carbon mitigation strategy. Here we calculate the greenhouse gas (GHG) emissions of the Chinese heavy-duty truck fleet under four hydrogen fuel cell heavy-duty truck penetration scenarios from 2020 through 2050. We introduce Aggressive, Moderate, Conservative and No Fuel Cell Vehicle (No FCV) scenarios. Under these four scenarios, the market share of heavy-duty trucks powered by fuel cells will reach 100%, 50%, 20% and 0%, respectively, in 2050. We go beyond previous studies which compared differences in GHG emissions from different hydrogen production pathways. We now combine an analysis of the carbon intensity of various hydrogen production pathways with predictions of the future hydrogen supply structure in China along with various penetration rates of heavy-duty fuel cell vehicles. We calculate the associated carbon intensity per vehicle kilometer travelled of the hydrogen used in heavy-duty trucks in each scenario, providing a practical application of our research. Our results indicate that if China relies only on fuel economy improvements, with the projected increase in vehicle miles travelled, the GHG emissions of the heavy-duty truck fleet will continue to increase and will remain almost unchanged after 2025. The Aggressive, Moderate and Conservative FCV Scenarios will achieve 63%, 30% and 12% reductions, respectively, in GHG emissions in 2050 from the heavy duty truck fleet compared to the No FCV Scenario. Additional reductions are possible if the current source of hydrogen from fossil fuels was displaced with increased use of hydrogen from water electrolysis using non-fossil generated electricity.     

Pathways to Mexico’s climate change mitigation targets: A multi-model analysis

Mexico’s climate policy sets ambitious national greenhouse gas (GHG) emission reduction targets—30% versus a business-as-usual baseline by 2020, 50% versus 2000 by 2050. However, these goals are at odds with recent energy and emission trends in the country. Both energy use and GHG emissions in Mexico have grown substantially over the last two decades. We investigate how Mexico might reverse current trends and reach its mitigation targets by exploring results from energy system and economic models involved in the CLIMACAP-LAMP project. To meet Mexico’s emission reduction targets, all modeling groups agree that decarbonization of electricity is needed, along with changes in the transport sector, either to more efficient vehicles or a combination of more efficient vehicles and lower carbon fuels. These measures reduce GHG emissions as well as emissions of other air pollutants. The models find different energy supply pathways, with some solutions based on renewable energy and others relying on biomass or fossil fuels with carbon capture and storage. The economy-wide costs of deep mitigation could range from 2% to 4% of GDP in 2030, and from 7% to 15% of GDP in 2050. Our results suggest that Mexico has some flexibility in designing deep mitigation strategies, and that technological options could allow Mexico to achieve its emission reduction targets, albeit at a cost to the country.     

Assessing the economic efficiency of bioenergy technologies in climate mitigation and fossil fuel replacement in Austria using a techno-economic approach

The core issues of the Austrian energy policy agenda include reducing greenhouse gas (GHG) emissions and dependence on fossil fuels. Within this study, the costs of GHG mitigation and fossil fuel replacement (abatement costs) of established and upcoming bioenergy technologies for heat, electricity and transport fuel production are assessed. Sensitivity analyses and projections up to 2030 illustrate the effect of dynamic parameters on specific abatement costs.     

Supply elasticity matters for the rebound effect and its impact on policy comparisons

We develop a model of the rebound effect which explicitly accounts for both the demand and supply sides of the energy sources. We consider a transportation sector originally using a “dirty” (fossil) fuel and examine the relative effectiveness of alternative policies: efficiency improvements in the dirty fuel technology sector (e.g., CAFE standards) and technology shifts by partial adoption of a new clean technology (e.g., low-carbon fuel standards). The model generates endogenous equilibrium quantities and prices for the dirty and clean fuels. We characterize the magnitude of the rebound effect as a function of demand and supply elasticities and use the equilibrium values to compare policy options. When the supply of the dirty fuel is inelastic, we find that introducing a new technology with non-zero emissions may actually increase the total level of emissions, similar to the leakage effect. A technology shift policy can perform better than an efficiency improvement policy in the dirty fuel sector only when the dirty fuel supply is sufficiently elastic, the emission intensity of the new technology very low, and the technology shift is greater than a threshold value. Using data for gasoline (as a proxy for the dirty technology) and several other cleaner technologies, we show that these conditions are satisfied by a hypothetical zero-emission technology, but not by electric vehicles using the average US generation mix or the current US corn based E85. Our results demonstrate the importance of accounting for the supply side in estimating the magnitude of the rebound effect and its impact on fuel consumption in a large-scale policy implementation.     

Towards real energy economics: Energy policy driven by life-cycle carbon emission

Alternative energy technologies (AETs) have emerged as a solution to the challenge of simultaneously meeting rising electricity demand while reducing carbon emissions. However, as all AETs are responsible for some greenhouse gas (GHG) emissions during their construction, carbon emission “Ponzi Schemes” are currently possible, wherein an AET industry expands so quickly that the GHG emissions prevented by a given technology are negated to fabricate the next wave of AET deployment. In an era where there are physical constraints to the GHG emissions the climate can sustain in the short term this may be unacceptable. To provide quantitative solutions to this problem, this paper introduces the concept of dynamic carbon life-cycle analyses, which generate carbon-neutral growth rates. These conceptual tools become increasingly important as the world transitions to a low-carbon economy by reducing fossil fuel combustion. In choosing this method of evaluation it was possible to focus uniquely on reducing carbon emissions to the recommended levels by outlining the most carbon-effective approach to climate change mitigation. The results of using dynamic life-cycle analysis provide policy makers with standardized information that will drive the optimization of electricity generation for effective climate change mitigation.     

Assessment of mitigation options for the energy system in Bulgaria

The Bulgarian greenhouse gas (GHG) emission profile reveals the energy sector as the most significant emission source and also as an area where great potential for GHG emissions reduction exists. Mitigation options in energy supply were selected considering the potential of fossil fuel substitution and new energy technology implementation in the context of the existing structure of energy system and projects for mid- and long-term development. Basically three modules of ENPEP were used: BALANCE — to calculate the energy flows and energy cost from primary fuel resources and fuel import to energy end-use, IMPACT — to calculate GHG emissions, and ELECTRIC — to project the electric system long-term development. Different mitigation measures combined in four scenarios were developed. The integrated mitigation scenario incorporated a mix of mitigation measures in the energy demand and supply. Implementation of CO₂ mitigation measures both in energy demand and energy supply would reduce the 2020 emission level by 34.3 Tg (29.1%), and by 544.2 Tg (21.7%) for the entire study period 2000 – 2020, compared to the baseline scenario.     

Viability of CCS: A broad-based assessment for Malaysia

Climate change is fast becoming the major environmental and energy concern worldwide. There is a major dilemma between the continued reliance on fossil fuel for our energy supply and the pressing need to address the problem of greenhouse gas (GHG) emissions from combustion process. This paper reviews the potential for carbon capture and storage (CCS) as a part of the climate change mitigation strategy for the Malaysian electricity sector using a technology assessment framework. The nation's historical trend of high reliance on fossil fuel for its electricity sector makes it a prime candidate for CCS adoption. The suitability and practicality of the technology was reviewed from a broad perspective with consideration of Malaysia-specific conditions. It is apparent from this assessment that CCS has the potential to play an important role in Malaysia's climate change mitigation strategy provided that key criteria are fulfilled.     

Air quality and climate change co-benefits for the industrial sector in Durban,South Africa

Industries in Durban, South Africa, are a major source of air pollutant emissions and large users of fossil fuel based energy. Durban’s energy strategy prioritises energy efficiency at industries as a key action, whilst industries are also the focus of the city’s air quality management plan (AQMP). In this paper, measures that have been introduced in industries in Durban to effect air quality improvements and reduce energy consumption are examined in terms of their respective impacts on greenhouse gas (GHG) and air pollutant emissions. It was found that co-benefits for GHG mitigation were achieved when petroleum refineries switched from using heavy fuel oil to refinery gas and methane rich gas. Within other industries, co-benefits for air quality stemmed from reducing fossil fuel energy consumption and the improved efficiency of combustion systems. Air quality and energy policies in the city are being executed independently, without consideration of the trade-offs or synergies of the interventions being implemented. Recommendations are made for authorities and industries to consider the co-benefits for GHG mitigation in their AQMPs and where these are not possible to consider offsetting the increased GHG emissions through improved alignment with energy strategies.     

Greenhouse gas implications of using coal for transportation: Life cycle assessment of coal-to-liquids,plug-in hybrids,and hydrogen pathways

Using coal to produce transportation fuels could improve the energy security of the United States by replacing some of the demand for imported petroleum. Because of concerns regarding climate change and the high greenhouse gas (GHG) emissions associated with conventional coal use, policies to encourage pathways that utilize coal for transportation should seek to reduce GHGs compared to petroleum fuels. This paper compares the GHG emissions of coal-to-liquid (CTL) fuels to the emissions of plug-in hybrid electric vehicles (PHEV) powered with coal-based electricity, and to the emissions of a fuel cell vehicle (FCV) that uses coal-based hydrogen. A life cycle approach is used to account for fuel cycle and use-phase emissions, as well as vehicle cycle and battery manufacturing emissions. This analysis allows policymakers to better identify benefits or disadvantages of an energy future that includes coal as a transportation fuel. We find that PHEVs could reduce vehicle life cycle GHG emissions by up to about one-half when coal with carbon capture and sequestration is used to generate the electricity used by the vehicles. On the other hand, CTL fuels and coal-based hydrogen would likely lead to significantly increased emissions compared to PHEVs and conventional vehicles using petroleum-based fuels.     

Energy and greenhouse gas balances of cassava-based ethanol

Biofuel production has been promoted to save fossil fuels and reduce greenhouse gas (GHG) emissions. However, there have been concerns about the potential of biofuel to improve energy efficiency and mitigate climate change. This paper investigates energy efficiency and GHG emission saving of cassava-based ethanol as energy for transportation. Energy and GHG balances are calculated for a functional unit of 1 km of road transportation using life-cycle assessment and considering effects of land use change (LUC). Based on a case study in Vietnam, the results show that the energy input for and GHG emissions from ethanol production are 0.93 MJ and 34.95 g carbon dioxide equivalent per megajoule of ethanol respectively. The use of E5 and E10 as a substitute for gasoline results in energy savings, provided that their fuel consumption in terms of liter per kilometer of transportation is not exceeding the consumption of gasoline per kilometer by more than 2.4% and 4.5% respectively. It will reduce GHG emissions, provided that the fuel consumption of E5 and E10 is not exceeding the consumption of gasoline per kilometer by more than 3.8% and 7.8% respectively. The quantitative effects depend on the efficiency in production and on the fuel efficiency of E5 and E10. The variations in results of energy input and GHG emissions in the ethanol production among studies are due to differences in coverage of effects of LUC, CO₂ photosynthesis of cassava, yields of cassava, energy efficiency in farming, and by-product analyses.     

Multi-objective regulations on transportation fuels: Comparing renewable fuel mandates and emission standards

We compare two types of fuel market regulations — a renewable fuel mandate and a fuel emission standard — that could be employed to simultaneously achieve multiple outcomes such as reduction in fuel prices, fuel imports and greenhouse gas (GHG) emissions. We compare these two types of regulations in a global context taking into account heterogeneity in carbon content of both fossil fuels and renewable fuels. We find that although neither the ethanol mandate nor the emission standard is certain to reduce emissions relative to a business-as-usual baseline, at any given level of biofuel consumption in the policy region, a mandate, relative to an emission standard, results in higher GHG emissions, smaller expenditure on fuel imports, lower price of ethanol-blended gasoline and higher domestic fuel market surplus. This result holds over a wide range of values of model parameters. We also discuss the implications of this result to a regulation such as the US Renewable Fuel Standard given recent developments within the US such as increase in shale and tight oil production and large increase in average vehicle fuel economy of the automotive fleet.     

Energy security implications of a national low carbon fuel standard

This paper discusses the potential energy security implications of a national low carbon fuel standard (NLCFS). A low carbon fuel standard is designed to reduce greenhouse gas (GHG) emissions by targeting the fuel portion of the fuel-vehicle system. Specifically, a NLCFS would set national targets for the average carbon intensity (CI) of motor fuels, and establish a market for credits that allows fuel producers and importers to respond in a variety of ways to the signal provided by the credit price. An important method for lowering the CI of transportation is to substitute lower-carbon alternative fuels such as advanced biofuels, electricity, CNG, and H2. Despite the focus on GHGs, so long as transportation fuels remain dominated by petroleum, transportation fuel policies like a NLCFS also will be evaluated in terms of their energy security impacts. We examine the fuel substitutions that are projected to be induced by a NLCFS and consider the energy security implications of displacing higher carbon fuels, such as imported Canadian Oil Sands oil or certain imported crude oils, with lower-carbon domestic oil, biofuels, or lower carbon oil imported from other sources.     

Potential impact of transition to a low-carbon transport system in Iceland

This paper develops a system dynamics model of Iceland׳s energy sector (UniSyD_IS) that is based on the UniSyD_NZ model of New Zealand׳s energy economy. The model focuses on the energy supply sector with endogenous representation of road transport energy demand. Equilibrium interactions are performed across electricity, hydrogen, biofuels, and road transport sectors. Possible transition paths toward a low-carbon transport in Iceland are explored with implications for fuel demand, greenhouse gas (GHG) emissions and associated costs. The consumer sector simulates the long-term evolution of light and heavy-duty vehicles through a vehicle choice algorithm that accounts for social influences and consumer preferences. Through different scenarios, the influences of four fundamental driving factors are examined. The factors are oil price, carbon tax, fuel supply-push, and government incentives. The results show that changes in travel demand, vehicle technologies, fuel types, and efficiency improvements can support feasible transition paths to achieve sufficient reduction in GHG for both 4 °C and 2 °C climate scenarios of the Nordic Energy Technology Perspectives study. Initial investment in supply infrastructure for alternative fuels will not only mitigate GHG emissions, but also could provide long-term economic benefits through fuel cost saving for consumers and reduced fuel import costs for government.     

Cost-effective policy instruments for greenhouse gas emission reduction and fossil fuel substitution through bioenergy production in Austria

Climate change mitigation and security of energy supply are important targets of Austrian energy policy. Bioenergy production based on resources from agriculture and forestry is an important option for attaining these targets. To increase the share of bioenergy in the energy supply, supporting policy instruments are necessary. The cost-effectiveness of these instruments in attaining policy targets depends on the availability of bioenergy technologies. Advanced technologies such as second-generation biofuels, biomass gasification for power production, and bioenergy with carbon capture and storage (BECCS) will likely change the performance of policy instruments. This article assesses the cost-effectiveness of energy policy instruments, considering new bioenergy technologies for the year 2030, with respect to greenhouse gas emission (GHG) reduction and fossil fuel substitution. Instruments that directly subsidize bioenergy are compared with instruments that aim at reducing GHG emissions. A spatially explicit modeling approach is used to account for biomass supply and energy distribution costs in Austria. Results indicate that a carbon tax performs cost-effectively with respect to both policy targets if BECCS is not available. However, the availability of BECCS creates a trade-off between GHG emission reduction and fossil fuel substitution. Biofuel blending obligations are costly in terms of attaining the policy targets.     

Embedded energy and total greenhouse gas emissions in final consumptions within Thailand

In order to quantify the total Greenhouse Gas (GHG) emissions from different commodities, the contribution of emissions in all subprocess chains has to be considered. In embedded energy analysis, the higher order production processes are usually truncated due to a lack of data. To fill the truncated subprocesses up to infinite process chains, energy intensities and GHG emission factors of various final consumptions in the economy evaluated by the Input–Output Analysis (IOA) must be applied. The direct GHG emissions in final consumptions in Thailand are evaluated by imitating the approach in the energy sector of the revised 1996 Intergovernmental Panel on Climate Change (IPCC) guidelines for national GHG inventories. The indirect energy and indirect emissions are evaluated by using the 1998 Input–Output (I–O) table. Results are presented of emissions in the main process, indirect processes, and on each subprocess chain order. The trend of energy intensity and emission factors of all final consumptions for 1995, 1998, 2001 and 2006 are also presented. Results show that the highest energy intensive sector is the electricity sector where fossil fuel is primarily used, but the highest total GHG emitter is the cement industry where the major sources of the emissions are industrial processes and the combustion of fossil fuels. Implication of the emission factors on electricity generating technologies shows that various cleaner electricity generating technologies, including renewable energy technology, could help in global GHG mitigation.     

Long term climate change mitigation goals under the nuclear phase out policy: The Swiss energy system transition

The Swiss electricity system is dominated by low-carbon hydro and nuclear generation. The Government's decision to phase-out nuclear energy exacerbates Switzerland's climate change mitigation goals. Response to this challenge requires systemic changes to the energy system, which is generally a long-term, uncertain and systemic process, affected by technology choices across the entire energy system. A comprehensive Swiss TIMES Energy system Model (STEM) with high temporal detail has been developed for the analysis of plausible low-carbon energy pathways focusing on uncertainties related to policy (climate change mitigation and acceptability of new centralised electricity generation) and international fuel prices. Increasing electrification of end-uses is seen across the scenarios, resulting in continuous growth in electricity demands. The electrification of heating and e-mobility substitute direct use of fossil fuels in end-use sectors and contribute to a significant carbon dioxide emission (CO₂) reduction. Centralised gas power plants and renewables become key source of electricity supply. Given the phaseout of nuclear generation, clear policy signals are required to ensure capacity is built to achieve a low-carbon energy system. At the same time, it is also essential to ensure consistency between the electricity sector and end-use energy policies. For the long-term carbon reduction target, some non-cost-effective conservation measures are important early in the period because they are available only at the time of building renovation.     

Household energy use,energy efficiency,emissions, and behaviors

Energy and greenhouse gas (GHG) emissions generally aim to (i) reduce energy use and hence emissions, (ii) steer consumers away from fossil fuels and/or electricity generated from fossil fuels, and (iii) align demand and supply, making sure that the existing infrastructure can handle times of high demand. Policies thus include a variety of pricing schemes, taxes on energy inputs, energy efficiency standards and incentives, and renewables standards and incentives. Ex ante and ex post analyses of their effectiveness thus rely crucially on understanding how consumers respond to pricing schemes, taxes, and other policies. This paper presents an overview of the challenges faced when empirically estimating household energy demand. It describes the difficulties associated with estimating the price elasticity of demand, discussing behavioral responses that may make consumers relatively insensitive to price changes or taxes. It also surveys empirical evidence about non-price policies, such as clearer information or real-time feedback about energy use, and appeal to norms. The paper concludes discussing evidence about the rebound effect, the energy efficiency gap, and how suppliers respond to a variety of policies.     

Crop residues as raw materials for biorefinery systems – A LCA case study

Our strong dependence on fossil fuels results from the intensive use and consumption of petroleum derivatives which, combined with diminishing oil resources, causes environmental and political concerns. The utilization of agricultural residues as raw materials in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, thus mitigating climate change and enhancing energy security. This paper focuses on a biorefinery concept which produces bioethanol, bioenergy and biochemicals from two types of agricultural residues, corn stover and wheat straw. These biorefinery systems are investigated using a Life Cycle Assessment (LCA) approach, which takes into account all the input and output flows occurring along the production chain. This approach can be applied to almost all the other patterns that convert lignocellulosic residues into bioenergy and biochemicals. The analysis elaborates on land use change aspects, i.e. the effects of crop residue removal (like decrease in grain yields, change in soil N₂O emissions and decrease of soil organic carbon). The biorefinery systems are compared with the respective fossil reference systems producing the same amount of products/services from fossils instead of biomass. Since climate change mitigation and energy security are the two most important driving forces for biorefinery development, the assessment focuses on greenhouse gas (GHG) emissions and cumulative primary energy demand, but other environmental categories are evaluated as well.Results show that the use of crop residues in a biorefinery saves GHG emissions and reduces fossil energy demand. For instance, GHG emissions are reduced by about 50% and more than 80% of non-renewable energy is saved. Land use change effects have a strong influence in the final GHG balance (about 50%), and their uncertainty is discussed in a sensitivity analysis. Concerning the investigation of the other impact categories, biorefinery systems have higher eutrophication potential than fossil reference systems. Based on these results, a residues-based biorefinery concept is able to solve two problems at the same time, namely find a use for the abundant lignocellulosic residues and ensure a mitigation effect for most of the environmental concerns related to the utilization of non-renewable energy resources.Therefore, when agricultural residues are used as feedstocks, best management practices and harvest rates need to be carefully established. In fact, rotation, tillage, fertilization management, soil properties and climate can play an important role in the determination of the amount of crop residue that can be removed minimizing soil carbon losses.