Results 1 - 10 of 249
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[en] Past investigations have shown that the current type-approval test cycles are not representative for real-world vehicle usage. Consequently, the emissions and fuel consumption of the vehicles are underestimated. Therefore, a new cycle is being developed in the UNECE framework (World-harmonised Light-duty Test Procedure, WLTP), aiming at a more dynamic and worldwide harmonised test cycle. To provide recommendations for the new cycle, we have analysed the noxious emission results of a test programme of seven vehicles on the test cycles NEDC (New European Driving Cycle) and CADC (Common Artemis Driving Cycles). This paper presents the results of that analysis to show the zones of the cycle that are causing the highest emissions, using two different approaches. Both approaches show that the zones with the highest emissions of modern vehicles differ from vehicle to vehicle. Consequently, a representative test cycle has to contain as many combinations of vehicle speed and acceleration that occur in real-world traffic as possible to prevent that a vehicle does not perform well for certain combinations because they are not included in the test cycle. Furthermore, the paper demonstrates that it is important to include a cold start to ensure rapid warm up of the catalysts. - Highlights: ► Vehicle emissions on the NEDC and CADC type-approval cycles are analysed. ► The zones within the cycles that produce the highest emissions are investigated. ► It is shown that these zones can differ significantly from one vehicle to another. ► The WLTP cycle should contain as many of the real-world driving zones as possible.
[en] A common assumption in lifecycle assessment (LCA) based estimates of greenhouse gas (GHG) benefits (or costs) of renewable fuel such as biofuel is that it simply replaces an energy-equivalent amount of fossil fuel and that total fuel consumption remains unchanged. However, the adoption of renewable fuels will affect the price of fuel and therefore affect total fuel consumption which, may increase or decrease depending on the policy regime and market conditions. Using a representative two-region model of the global oil market in which, one region implements a domestic biofuel mandate and the other does not, we show that the net change in global fuel consumption due to the policy, which we term indirect fuel use change (IFUC), can have a significant impact on the net GHG emissions associated with biofuel. If LCA-based regulations are designed to account for indirect emissions such as indirect land use change, then we argue that IFUC emissions cannot be ignored. Our work also shows how different policies can affect the environmental impact from adopting a given clean technology differently. (author)
[en] New fuel economy standards require new U.S. passenger vehicles to achieve at least 34.1 miles per gallon (MPG) on average by model year 2016, up from 28.8 MPG today. In this paper, the magnitude, combinations and timings of the changes required in U.S. vehicles that are necessary in order to meet the new standards, as well as a target of doubling the fuel economy within the next two decades are explored. Scenarios of future vehicle characteristics and sales mix indicate that the 2016 mandate is aggressive, requiring significant changes starting from today. New vehicles must forgo horsepower improvements, become lighter, and a greater number will use advanced, more fuel-efficient powertrains, such as smaller turbocharged engines, hybrid-electric drives. Achieving a factor-of-two increase in fuel economy by 2030 is also challenging, but more feasible since the auto industry will have more lead time to respond. A discussion on the feasibility of meeting the new fuel economy mandate is included, considering vehicle production planning realities and challenges in deploying new vehicle technologies into the market. (author)
[en] Using a unique database of end-user local energy data and the recently developed Autoregressive Distributed Lag (ARDL) bounds testing approach to cointegration, we estimate the long-run elasticities of the Namibian energy demand function at both aggregated level and by type of energy (electricity, petrol and diesel) for the period 1980-2002. Our main results show that energy consumption responds positively to changes in GDP and negatively to changes in energy price and air temperature. The differences in price elasticities across fuels uncovered by this study have significant implications for energy taxation by Namibian policy makers. We do not find any significant cross-price elasticities between different fuel types. (author)
[en] Energy related Principal–Agent (PA) problems cause inefficient combinations of investment, operating costs, and usage behavior. The complex market structure of the trucking industry contributes to split incentives because entities responsible for investments in energy efficiency do not always pay fuel costs and drivers are often not rewarded for fuel-efficient operation. Some contractual relationships exist in the trucking industry that hinder responses to fuel price signals. Up to 91% of total trucking fuel consumption in the U.S. is affected by “usage” PA problems, where the driver does not pay fuel costs and lacks incentive for fuel saving operation. Approximately 23% of trailers are exposed to an “efficiency problem” when owners of rented trailers do not pay fuel costs and therefore have little incentive to invest in efficiency upgrades such as improved trailer aerodynamics and reduced tire rolling resistance. This study shows that PA problems have the potential to significantly increase fuel consumption through avoided investments, insufficient maintenance, and fuel-wasting practices. Further research into the causes and effects of PA problems can shape policies to promote better alignment of costs and benefits, leading to reduced fuel use and carbon emissions. - Highlights: ► We identify and quantify principal agent market failures in the trucking industry. ► Up to 91% of truck fuel consumption is exposed to a usage principal–agent market failure. ► Twenty-three percent of trailers are exposed to an efficiency principal–agent market failure. ► These market failures at least partially insulate key decision makers from fuel price signals.
[en] This paper estimates the trends of fleet car fuel efficiency and new car fuel efficiency in Great Britain and analyses determining factors of the changes in car fuel efficiency. According to the analysis results, the pure technology effect was partly offset by the increase of average engine capacity of vehicles, especially since the late 1980s. Although in the 1990s, the pure technology effect itself was much reduced than in the earlier period, the shift in consumer choice to bigger cars also obstructed the improvement of fuel efficiency in this period. Meanwhile, this study found about a 10% gap between the official fuel consumption rate of new cars and on road fuel consumption rate, which generally confirms the result of earlier studies
[en] Energy and environmental concerns have spawned new policies aimed at reducing emissions and fuel consumption of heavy-duty vehicles (HDVs) worldwide. While such policies intend to reduce HDV energy consumption and emissions, energy savings that reduce transportation costs may lead to increased demand for HDV transportation services. Increased HDV transportation, in turn, can result in increased energy use and emissions—i.e., a direct “rebound effect.” This paper provides a critical review of the literature related to the HDV rebound effect. Results of this review demonstrate that the lack of focused studies in this area combined with the variability and heterogeneity of the trucking sector limit general understanding of the HDV rebound effect. Currently, the studies that do exist often create biased or erroneous rebound effect estimates by inappropriately relying on freight elasticities or applying metrics that omit important elements of fuel consumption. Research following a more transparent and coherent approach can improve estimates of the rebound effect from policy measures to improve HDV energy efficiency. - Highlights: ► Provides a critical review of HDV rebound effect literature. ► Demonstrates limitations of HDV rebound effect estimates. ► Provides framework for considering more complete HDV rebound effect.
[en] This paper explores the outlook for the oil product supply and demand balance in Korea and the implications for future refinery market conditions. Forecasts of demand growth are compared with the industry's recent capacity expansion to evaluate potential future market positions. The possible impact of the current deregulation process, started in January 1977, is summarized. In addition, the short-term and long-term uncertainties of the market are discussed. The future business environment for refiners in Korea is likely to be tougher than expected. Although substantial new refining capacity was added recently, the demand for oil products is expected to increase less rapidly. The overall product balance and the threat of imports from outside the region indicate that refiners may suffer from a decrease in utilization rate. Challenges lie ahead if Korean oil refiners are to be part of a successful and mature industry. (author)
[en] Many cities worldwide have considered vehicle restriction policies to curb proliferating problems related to traffic and pollution. At the beginning of 2011, Beijing became the first city to allocate vehicle license plates using a lottery. We provide a background on Beijing's lottery and analyze its short-term effects. We find that growth in new vehicle registrations has been sharply curtailed. However, this policy may not reduce fuel consumption as much as expected. - Highlights: • In 2011, Beijing became the first city to allocate vehicle license plates using a lottery. • We provide a background on Beijing's lottery and analyze its short-term effects. • Beijing's lottery has sharply curtailed new vehicle registrations and reduced the growth of cars in Beijing. • While the number of vehicles will be cut 11 percent, fuel consumption will be reduced by only 1 percent
[en] The purpose of Corporate Average Fuel Economy (CAFE) Standards is to enhance the fuel efficiency of passenger vehicles in the United States. Although these standards had been set constant for years, the National Highway Traffic Safety Administration (NHTSA) set increasing CAFE standards in 2011 based on vehicle's footprint, requiring vehicle manufacturers to improve the fuel economy of the vehicles they produce. This resulting improvement in vehicle fuel economy is likely to influence consumers’ decisions regarding new vehicle purchases, while the stringent CAFE standards are also likely to affect manufacturers’ production costs and benefits. In addition, the government provides various incentives to support the adoption of alternative fuel vehicles (AFVs), including electric vehicles (EVs), which in turn will likewise influences consumers’ decisions regarding purchasing a new vehicle. An agent-based model is developed in this paper to estimate the potential future market shares of EVs considering the existing inherent uncertainties under different policy scenarios, including the footprint-based CAFE regulation. The results show that, if implemented effectively in conjunction with the available government incentives, the CAFE regulation can accelerate EV market penetration and help the U.S. to move away from conventional vehicles, thus reducing fossil fuel dependency. - Highlights: • CAFE standards work best when implemented in conjunction with the financial support. • EV market penetration likely to increase faster with a greater deployment of recharging stations. • The manufacturers tend to comply with the CAFE standards by changing the design of ICEVs.