Modeling the prospects of plug-in hybrid electric vehicles to reduce CO2 emissions

This study models the CO₂ emissions from electric (EV) and plug-in hybrid electric vehicles (PHEV), and compares the results to published values for the CO₂ emissions from conventional vehicles based on internal combustion engines (ICE). PHEVs require fewer batteries than EVs which can make them lighter and more efficient than EVs. PHEVs can also operate their onboard ICEs more efficiently than can conventional vehicles. From this, it was theorized that PHEVs may be able to emit less CO₂ than both conventional vehicles and EVs given certain power generation mixes of varying CO₂ intensities. Amongst the results it was shown that with a highly CO₂ intensive power generation mix, such as in China, PHEVs had the potential to be responsible for fewer tank to wheel CO₂ emissions over their entire range than both a similar electric and conventional vehicle. The results also showed that unless highly CO₂ intensive countries pursue a major decarbonization of their power generation, they will not be able to fully take advantage of the ability of EVs and PHEVs to reduce the CO₂ emissions from automotive transport.     

Effect of hybrid system battery performance on determining CO2 emissions of hybrid electric vehicles in real-world conditions

Hybrid electric vehicles (HEVs) can potentially reduce vehicle CO₂ emissions by using recuperated kinetic vehicle energy stored as electric energy in a hybrid system battery (HSB). HSB performance affects the individual net HEV CO₂ emissions for a given driving pattern, which is considered to be equivalent to unchanged net energy content in the HSB. The present study investigates the influence of HSB performance on the statutory correction procedure used to determine HEV CO₂ emissions in Europe based on chassis dynamometer measurements with three identical in-use examples of a full HEV model featuring different mileages. Statutory and real-world driving cycles and full electric vehicle operation modes have been considered. The main observation is that the selected HEVs can only use 67–80% of the charge provided to the HSB, which distorts the outcomes of the statutory correction procedure that does not consider such irreversibility. CO₂ emissions corrected according to this procedure underestimate the true net CO₂ emissions of one HEV by approximately 13% in real-world urban driving. The correct CO₂ emissions are only reproduced when considering the HSB performance in this driving pattern. The statutory procedure for correcting HEV CO₂ emissions should, therefore, be adapted.     

Modeling energy consumption and CO2 emissions at the urban scale: Methodological challenges and insights from the United States

Local policy makers could benefit from a national, high-resolution inventory of energy consumption and related carbon dioxide (CO₂) emissions based on the Vulcan data product, which plots emissions on a 100 km² grid. We evaluate the ability of Vulcan to measure energy consumption in urban areas, a scale of analysis required to support goals established as part of local energy, climate or sustainability initiatives. We highlight the methodological challenges of this type of analytical exercise and review alternative approaches. We find that between 37% and 86% of direct fuel consumption in buildings and industry and between 37% and 77% of on-road gasoline and diesel consumption occurs in urban areas, depending on how these areas are defined. We suggest that a county-based definition of urban is preferable to other common definitions since counties are the smallest political unit for which energy data are collected. Urban counties, account for 37% of direct energy consumption, or 50% if mixed urban counties are included. A county-based definition can also improve estimates of per-capita consumption.     

Electric and plug-in hybrid vehicles influence on CO2 and water vapour emissions

The main objective of this research is to quantify the impact of introducing electric vehicles and plug-in hybrid vehicles, including fuel cell on conventional fleets. The impact is estimated in terms of local pollutants, HC, CO, NO_x, PM, and in terms of CO₂ and water vapour global emissions. The specific fleet of Portugal, roughly 6 million light-duty vehicles (30% diesel, 70% gasoline) is considered, and the mobility indicator of the fleet, 90 thousand million p × km, is kept constant throughout the analysis. Probability density functions for energy consumption and emissions are derived for conventional, electric and plug-in hybrid vehicles, in charge depleting and charge sustaining modes. The Monte Carlo method is used to obtain average distribution estimates for discounting values of “old vehicles” that are removed from the fleet, and to add average distribution estimates for the “new vehicles” entering the fleet. Considering the actual Portuguese fleet as the reference case, local pollutant emissions decrease by a factor of 10-53%, for 50% fleet replacement. A potential 23% decrease of CO₂ is foreseen, and a potential 31% increase of H₂O emissions is forecasted. Life cycle water vapour emissions tend to rise and are, typically, 2-4 times higher than CO₂ values at the upstream stage, due to its release in the cooling towers of thermal power plants. It is interesting to note that considering 1 MJ of energy required at vehicle wheels, in an overall life cycle context, both fuel cell and electric modes have nearly twice as much H₂O emissions than internal combustion vehicles. CO₂ emissions tend to decrease with electric drive vehicles penetration due to the higher fleet life cycle efficiency.     

Potential cost savings from internal/external CO2 emissions trading in the Korean electric power industry

Korea plans to introduce an emissions trading scheme for the controlling greenhouse gas emissions in 2015. Using Shephard's (1970) output distance function, we first estimate the shadow price of CO₂ for power generators in the Korean fossil-fueled electric generation industry. Then, by assuming that each power generator is required to reduce CO₂ emissions by one ton, we compute the potential cost savings from internal trading among generators within the same plant and from external trading across plants at prevailing market prices. The results indicate that, on average, the generators paid $14.63 to abate one ton of CO₂ emissions in 2007. Plants realized additional gains through external trading. In particular, cost savings from trades between different fuel-fired plants were substantial.     

The impact of CHP generation on CO2 emissions

The combined generation of heat and power (cogeneration) is praised by many as a technique for reducing the emissions of CO₂ in industrialized nations. This is generally true but not always. In this article we discuss the impact of some major variables on the CO₂ emission reduction capacity of cogeneration. Two sets of variables are predominant: the characteristics of the CHP process and the composition of the electricity generation sector. We highlight the interaction between the two sets of variables with the help of diagrams.     

CO2 emissions from electricity generation in seven Asia-Pacific and North American countries: A decomposition analysis

The Logarithmic Mean Divisia Index (LMDI) method of complete decomposition is used to examine the role of three factors (electricity production, electricity generation structure and energy intensity of electricity generation) affecting the evolution of CO₂ emissions from electricity generation in seven countries. These seven countries together generated 58% of global electricity and they are responsible for more than two-thirds of global CO₂ emissions from electricity generation in 2005. The analysis shows production effect as the major factor responsible for rise in CO₂ emissions during the period 1990–2005. The generation structure effect also contributed in CO₂ emissions increase, although at a slower rate. In contrary, the energy intensity effect is responsible for modest reduction in CO₂ emissions during this period. Over the 2005–2030 period, production effect remains the key factor responsible for increase in emissions and energy intensity effect is responsible for decrease in emissions. Unlike in the past, generation structure effect contributes significant decrease in emissions. However, the degree of influence of these factors affecting changes in CO₂ emissions vary from country to country. The analysis also shows that there is a potential of efficiency improvement of fossil-fuel-fired power plants and its associated co-benefits among these countries.     

Allocation of CO2 emission permits—Economic incentives for emission reductions in developing countries

The economic impacts on developing regions following a global cap and trade system for carbon dioxide are assessed through the use of an energy-economy systems model. Both an equal per capita allocation and a contraction and convergence allocation with convergence of the per capita emissions by 2050 are shown to offer economic incentive for Africa, India and probably also Latin America to accept binding emissions commitments under a 450 ppm carbon dioxide stabilization scenario. The gain for Latin America is mainly a result of increased export revenues from sales of bio-fuels as a result of the climate policy. It is, on the other hand, unlikely that these allocation approaches would offer an economic incentive for China to join the regime because of its high economic growth, present higher per capita emissions than India and Africa, and more costly mitigation options than Latin America. A more stringent allocation for developing countries such as contraction with convergence of the per capita emissions by the end of this century is estimated to generate reduced net gains or increased net losses for the developing regions (though Africa is still expected to gain).     

CO2 emissions embodied in China's exports from 2002 to 2008: A structural decomposition analysis

This study examines the annual CO₂ emissions embodied in China's exports from 2002 to 2008 using environmental input–output analysis. Four driving forces, including emission intensity, economic production structure, export composition, and total export volume, are compared for their contributions to the increase of embodied CO₂ emissions using a structural decomposition analysis (SDA) technique. Although offset by the decrease in emission intensity, the increase of embodied CO₂ emissions was driven by changes of the other three factors. In particular, the change of the export composition was the largest driver, primarily due to the increasing fraction of metal products in China's total export. Relevant policy implications and future research directions are discussed at the end of the paper.     

Energy use, cost and CO2 emissions of electric cars

We examine efficiency, costs and greenhouse gas emissions of current and future electric cars (EV), including the impact from charging EV on electricity demand and infrastructure for generation and distribution.Uncoordinated charging would increase national peak load by 7% at 30% penetration rate of EV and household peak load by 54%, which may exceed the capacity of existing electricity distribution infrastructure. At 30% penetration of EV, off-peak charging would result in a 20% higher, more stable base load and no additional peak load at the national level and up to 7% higher peak load at the household level. Therefore, if off-peak charging is successfully introduced, electric driving need not require additional generation capacity, even in case of 100% switch to electric vehicles.GHG emissions from electric driving depend most on the fuel type (coal or natural gas) used in the generation of electricity for charging, and range between 0 g km⁻¹ (using renewables) and 155 g km⁻¹ (using electricity from an old coal-based plant). Based on the generation capacity projected for the Netherlands in 2015, electricity for EV charging would largely be generated using natural gas, emitting 35-77 g CO_2 eq km⁻¹.We find that total cost of ownership (TCO) of current EV are uncompetitive with regular cars and series hybrid cars by more than 800 € year⁻¹. TCO of future wheel motor PHEV may become competitive when batteries cost 400 € kWh⁻¹, even without tax incentives, as long as one battery pack can last for the lifespan of the vehicle. However, TCO of future battery powered cars is at least 25% higher than of series hybrid or regular cars. This cost gap remains unless cost of batteries drops to 150 € kWh⁻¹ in the future. Variations in driving cost from charging patterns have negligible influence on TCO.GHG abatement costs using plug-in hybrid cars are currently 400-1400 € tonne⁻¹ CO_2 eq and may come down to −100 to 300 € tonne⁻¹. Abatement cost using battery powered cars are currently above 1900 € tonne⁻¹ and are not projected to drop below 300-800 € tonne⁻¹.     

Determinants of variation in household CO2 emissions between and within countries

Variation in household CO₂ emissions between and within countries may have important consequences for the equity dimension of climate policies. In this study we aim to identify some determinants of national household CO₂ emissions and their distribution across income groups. For that purpose, we quantify the CO₂ emissions of households in the Netherlands, UK, Sweden and Norway around the year 2000 by combining a hybrid approach of process analysis and input–output analysis with data on household expenditures. Our results show that average households in the Netherlands and the UK give rise to higher amounts of CO₂ emissions than households in Sweden and Norway. Moreover, CO₂ emission intensities of household consumption decrease with increasing income in the Netherlands and the UK, whereas they increase in Sweden and Norway. A comparison of the national results at the product level points out that country characteristics, like energy supply, population density and the availability of district heating, influence variation in household CO₂ emissions between and within countries.     

Hydrogen impacts on performance and CO2 emissions from a diesel power generator

This work investigates the performance and carbon dioxide (CO₂) emissions from a stationary diesel engine fueled with diesel oil (B5) and hydrogen (H₂). The performance parameters investigated were specific fuel consumption, effective engine efficiency and volumetric efficiency. The engine was operated varying the nominal load from 0 kW to 40 kW, with diesel oil being directly injected in the combustion chamber. Hydrogen was injected in the intake manifold, substituting diesel oil in concentrations of 5%, 10%, 15% and 20% on energy basis, keeping the original settings of diesel oil injection. The results show that partial substitution of diesel oil by hydrogen at the test conditions does not affect significantly specific fuel consumption and effective engine efficiency, and decreases the volumetric efficiency by up to 6%. On the other hand the use of hydrogen reduced CO₂ emissions by up to 12%, indicating that it can be applied to engines to reduce global warming effects.     

CO2 emissions,energy consumption and economic growth in BRIC countries

This paper examines dynamic causal relationships between pollutant emissions, energy consumption and output for a panel of BRIC countries over the period 1971–2005, except for Russia (1990–2005). In long-run equilibrium energy consumption has a positive and statistically significant impact on emissions, while real output exhibits the inverted U-shape pattern associated with the Environmental Kuznets Curve (EKC) hypothesis with the threshold income of 5.393 (in logarithms). In the short term, changes in emissions are driven mostly by the error correction term and short term energy consumption shocks, as opposed to short term output shocks for each country. Short-term deviations from the long term equilibrium take from 0.770 years (Russia) to 5.848 years (Brazil) to correct. The panel causality results indicate there are energy consumption–emissions bidirectional strong causality and energy consumption–output bidirectional long-run causality, along with unidirectional both strong and short-run causalities from emissions and energy consumption, respectively, to output. Overall, in order to reduce emissions and not to adversely affect economic growth, increasing both energy supply investment and energy efficiency, and stepping up energy conservation policies to reduce unnecessary wastage of energy can be initiated for energy-dependent BRIC countries.     

CO2 emissions from the transport of China's exported goods

Emissions of greenhouse gases in many European countries are declining, and the European Union (EU) believes it is on track in achieving emission reductions as agreed upon in the Kyoto Agreement and the EU's more ambitious post-Kyoto climate policy. However, a number of recent publications indicate that emission reductions may also have been achieved because production has been shifted to other countries, and in particular China. If a consumption perspective is applied, emissions in industrialized countries are substantially higher, and may not have declined at all. Significantly, emissions from transports are omitted in consumption-based calculations. As all trade involves transport, mostly by cargo ship, but also by air, transports add considerably to overall emissions growth incurred in production shifts. Consequently, this article studies the role of transports in creating emissions of CO₂, based on the example of exports from China. Results are discussed with regard to their implications for global emission reductions and post-Kyoto negotiations.     

European CO2 prices and carbon capture investments

We assess the option to install a carbon capture and storage (CCS) unit in a coal-fired power plant operating in a carbon-constrained environment. We consider two sources of risk, namely the price of emission allowance and the price of the electricity output. First we analyse the performance of the EU market for CO₂ emission allowances. Specifically, we focus on the contracts maturing in the Kyoto Protocol's first commitment period (2008 to 2012) and calibrate the underlying parameters of the allowance price process. Then we refer to the Spanish wholesale electricity market and calibrate the parameters of the electricity price process.We use a two-dimensional binomial lattice to derive the optimal investment rule. In particular, we obtain the trigger allowance prices above which it is optimal to install the capture unit immediately. We further analyse the effect of changes in several variables on these critical prices, among them allowance price volatility and a hypothetical government subsidy.We conclude that, at current permit prices, immediate installation does not seem justified from a financial point of view. This need not be the case, though, if carbon market parameters change dramatically, carbon capture technology undergoes significant improvements, and/or a specific governmental policy to promote these units is adopted.     

Evaluation of lifecycle CO2 emissions from the Japanese electric power sector in the 21st century under various nuclear scenarios

The status and prospects of the development of Japanese nuclear power are controversial and uncertain. Many deem that nuclear power can play key roles in both supplying energy and abating CO₂ emissions; however, due to severe nuclear accidents, public acceptance of nuclear power in Japan has not been fully obtained. Moreover, deregulation and liberalization of the electricity market impose pressure on large Japanese electric power companies with regard to both the operation of nuclear power plants and the development of the nuclear fuel cycle. Long-term Japanese CO₂ reduction strategies up to 2100 are of environmental concern and are socially demanded under the circumstances described above. Taking these factors into account, we set the following two objectives for this study. One is to estimate lifecycle CO₂ (LCCO₂) emissions from Japanese nuclear power, and the other is to evaluate CO₂ emissions from the Japanese electric power sector in the 21st century by quantifying the relationship between LCCO₂ emissions and scenarios for the adoption of nuclear power. In the pursuit of the above objectives, we first create four scenarios of Japanese adoption of nuclear power, that range from nuclear power promotion to phase-out. Next, we formulate four scenarios describing the mix of the total electricity supply in Japan till the year 2100 corresponding to each of these nuclear power scenarios. CO₂ emissions from the electric power sector in Japan till the year 2100 are estimated by summing those generated by each respective electric power technology and LCCO₂ emission intensity. The LCCO₂ emission intensity of nuclear power for both light water reactors (LWR) and fast breeder reactors (FBR) includes the uranium fuel production chain, facility construction/operation/decommission, and spent fuel processing/disposal. From our investigations, we conclude that the promotion of nuclear power is clearly a strong option for reducing CO₂ emissions by the electric power sector. The introduction of FBR has the effect of further reducing CO₂ emissions in the nuclear power sector. Meeting energy demand and reducing CO₂ emissions while phasing out nuclear power appears challenging given its importance in the Japanese energy supply.     

CO2 emissions structure of Indian economy

This paper analyses carbon dioxide (CO₂) emissions of the Indian economy by producing sectors and due to household final consumption. The analysis is based on an Input–Output (IO) table and Social Accounting Matrix (SAM) for the year 2003–04 that distinguishes 25 sectors and 10 household classes. Total emissions of the Indian economy in 2003–04 are estimated to be 1217 million tons (MT) of CO₂, of which 57% is due to the use of coal and lignite. The per capita emissions turn out to be about 1.14 tons. The highest direct emissions are due to electricity sector followed by manufacturing, steel and road transportation. Final demands for construction and manufacturing sectors account for the highest emissions considering both direct and indirect emissions as the outputs from almost all the energy-intensive sectors go into the production process of these two sectors. In terms of life style differences across income classes, the urban top 10% accounts for emissions of 3416 kg per year while rural bottom 10% class accounts for only 141 kg per year. The CO₂ emission embodied in the consumption basket of top 10% of the population in urban India is one-sixth of the per capita emission generated in the US.     

The marginal cost of CO2 emissions

Haraden's model for estimating the economic cost of global warming is analysed. We change his method of discounting and some of his input parameters in a manner consistent with physical and economic theory as well as empirical data. We then find much higher costs than Haraden found. These costs are compared to the cost of reducing CO₂ emissions and we find that deep cuts of the emissions of CO₂ are preferable. A check of the sensitivity of our results with respect to some crucial parameter values does not alter that conclusion.     

A comparison of CO2 emissions from fossil and solar power plants in the United States

We present estimates of the lifetime carbon dioxide emissions from coal-fired, photovoltaic, and solar thermal power plants in the United States. These CO₂ estimates are based on a net energy analysis derived from both operational systems and detailed design studies. It appears that energy-conservation measures and shifting from fossil to renewable energy sources have significant long-term potential to reduce CO₂ production caused by energy generation. The implications of these results for a national energy policy are discussed.     

CO2 and pollutant emissions from passenger cars in China

In this paper, CO₂ and pollutant emissions of PCs in China from 2000 to 2005 were calculated based on a literature review and measured data. The future trends of PC emissions were also projected under three scenarios to explore the reduction potential of possible policy measures. Estimated baseline emissions of CO, HC, NO_x, PM₁₀ and CO₂ were respectively 3.16×10⁶, 5.14×10⁵, 3.56×10⁵, 0.83×10⁴ and 9.14×10⁷ tons for China’s PCs in 2005 with an uneven distribution among provinces. Under a no improvement (NI) scenario, PC emissions of CO, HC, NO_x, PM₁₀ and CO₂ in 2020 are respectively estimated to be 4.5, 2.5, 2.5, 7.9 and 8.0 times that of 2005. However, emissions other than CO₂ from PCs are estimated to decrease nearly 70% by 2020 compared to NI scenario mainly due to technological improvement linked to the vehicle emissions standards under a recent policy (RP) scenario. Fuel economy (FE) enhancement and the penetration of advanced propulsion/fuel systems could be co-benefit measures to control CO₂ and pollutant emissions for the mid and long terms. Significant variations were found in PC emission inventories between different studies primarily due to uncertainties in activity levels and/or emission factors (EF).