Life cycle analysis of energy use and greenhouse gas emissions for road transportation fuels in China

Life cycle analysis is considered to be a valuable tool for decision making towards sustainability. Life cycle energy and environmental impact analysis for conventional transportation fuels and alternatives such as biofuels has become an active domain of research in recent years. The present study attempts to identify the most reliable results to date and possible ranges of life cycle fossil fuel use, petroleum use and greenhouse gas emissions for various road transportation fuels in China through a comprehensive review of recently published life cycle studies and review articles. Fuels reviewed include conventional gasoline, conventional diesel, liquefied petroleum gas, compressed natural gas, wheat-derived ethanol, corn-derived ethanol, cassava-derived ethanol, sugarcane-derived ethanol, rapeseed-derived biodiesel and soybean-derived biodiesel. Recommendations for future work are also discussed.     

Energy and associated greenhouse gas emissions from household appliances in Malaysia

Today, electricity is an indispensable key for civilization and development. The trend of electricity consumption is rather escalating. Electricity generation principally depends upon fossil fuels. In one hand, the stocks of these fuels have been confirmed to be critically limited. On the other hand, in process of electricity generation by means of these fuels, a number of poisonous by-products adversely affect the conservation of natural eco-system. Further, electricity driven appliances use emanate anti-environmental gases that also affect human health and climate. Therefore, estimation of energy consumption for operating household appliances, savings of energy under policy intervention, and emission of poisonous gases in a fast developing country deserve academic attention.     

Reduce energy use and greenhouse gas emissions from global dairy processing facilities

Global butter, concentrated milk, and milk powder products use approximately 15% of annual raw milk production. Similar to cheese and fluid milk, dairy processing of these products can be energy intensive. In this paper, we analyzed production and energy data compiled through extensive literature reviews on butter, concentrated milk, milk and whey powder processing across various countries and plants. Magnitudes of national final and primary specific energy consumption (SEC) exhibited large variations across dairy products; in addition, the final SEC of individual plants and products exhibited significant variations within a country and between countries. Furthermore, we quantified national energy intensity indicators (EIIs) accounting for dairy product mixes and technological advancement. The significant variations of SEC and EII values indicate a high degree of likelihood that there is significant potential for energy savings in the global dairy processing industry. Based upon the study samples, we estimate potential energy savings for dairy processing industry in selected countries, and estimates annual reduction of 9–14 million metric-ton carbon-equivalent¹ could be achieved if measures are implemented to lower SEC values by 50–80% in half of global dairy plants. The paper calls for publication of more energy data from the dairy processing industry.     

Energy demand and greenhouse gas emissions from urban passenger transportation versus availability of renewable energy: The example of the Canadian Lower Fraser Valley

The energy consumption and greenhouse gas emissions of all private and transit vehicles from the Lower Fraser Valley, British Columbia, Canada are analysed for the year 2000. The energy figures are then compared with the Province's renewable energy potential. Results indicate that electric trolley buses and the automated rapid transit SkyTrain were eight times as energy efficient as private vehicles. These two modes were also 100 times as emission efficient as private vehicles in terms of greenhouse gas emitted per passenger-kilometer. Analysis of a minimal greenhouse gas emissions scenario, based on local renewable energy resources, electrolytic hydrogen production, and conversion of all private vehicles to fuel-cell technology indicates that such a strategy would utilize between 40% and 60% of the Province's renewable energy resources. We conclude that, if the use of renewable energy resources is chosen to reduce emissions from urban passenger transportation, probability of success will be increased by reducing the sector's energy demand through a transfer of ridership to the most energy efficient modes.     

Life-cycle energy consumption and greenhouse gas emissions for electricity generation and supply in China

The Well-to-Meter (WTM) analysis module in the Tsinghua-CA3EM model has been used to examine the primary fossil energy consumption (PFEC) and greenhouse gas (GHG) emissions for electricity generation and supply in China. The results show that (1) the WTM PFEC and GHG emission intensities for the 2007 Chinese electricity mix are 3.247 MJ/MJ and 297.688 g carbon dioxide of equivalent (gCO_2,e)/MJ, respectively; (2) power generation is the main contributing sub-stage; (3) the coal-power pathway is the only major contributor of PFEC (96.23%) and GHG emissions (97.08%) in the 2007 mix; and (4) GHG emissions intensity in 2020 will be reduced to 220.470 gCO_2,e/MJ with the development of nuclear and renewable energy and to 169.014 gCO_2,e/MJ if carbon dioxide capture and storage (CCS) technology is employed. It is concluded that (1) the current high levels of PFEC and GHG emission for electricity in China are largely due to the dominant role of coal in the power-generation sector and the relatively low efficiencies during all the sub-stages from resource extraction to final energy consumption and (2) the development of nuclear and renewable energy as well as low carbon technologies such as CCS can significantly reduce GHG emissions from electricity.     

Energy balance and greenhouse gas emissions from the production and sequestration of charcoal from agricultural residues

Agricultural residues (wheat/barley/oat straw) can be used to produce charcoal, which can then be either landfilled off-site or spread on the agricultural field as a means for sequestering carbon. One centralized and five portable charcoal production technologies were explored in this paper. The centralized system produced 747.95 kg-CO₂eq/tonne-straw and sequestered 0.204 t-C/t-straw. The portable systems sequestered carbon at 0.141–0.217 t-C/t-straw. The net energy ratio (NER) of the portable systems was higher than the centralized one at 10.29–16.26 compared to 6.04. For the centralized system, the carbon sequestration and the cumulative energy demand were most sensitive to the charcoal yield. Converting straw residues into charcoal can reduce GHG emissions by 80% after approximately 8.5 years relative to the baseline of in-field decomposition, showing these systems are effective carbon sequestration methods.     

Energy resources' utilization in organic and conventional vineyards: Energy flow, greenhouse gas emissions and biofuel production

An energy analysis, in conventional and organic vineyards, combined with ethanol production and greenhouse gas emissions, is useful in evaluating present situation and deciding best management strategies. The objective of this study was to evaluate the differences in the energy flow between organic and conventional vineyards in three locations, to calculate CO₂, CH₄ and N₂O-emissions based on the used fossil energy and to explore if wine industry wastes can be used to extract bioethanol. The data were collected through personal interviews with farmers during 2004–2005. Eighteen farmers, who owned vineyards about 1 ha each, were randomly selected to participate in this study [(3 conventional and 3 organic) × 3 locations]. The means averaged over all locations for fertilizer application, plant protection products application, transportation, harvesting, labor, machinery, fuels, plant protections products and tools energy inputs, total energy inputs, outputs (grapes), outputs (grapes + shoots), grape yield, man hour, pomace and ethanol from pomace were significantly higher in conventional than in organic vineyards, while the opposite occurred for the pruning. Means averaged over two farming systems for harvesting, tools energy inputs, energy outputs (grapes), grape yield, pomace and ethanol from pomace were significantly higher at location A, followed by location C and location B. Finally, for irrigation, the means averaged over the two farming systems were significantly lower at location C. Greenhouse gas emissions were significant lower in organic than in conventional vineyards. The results show a clear response of energy inputs to energy outputs that resulted from the farming system and location.     

Reducing greenhouse gas emissions by inducing energy conservation and distributed generation from elimination of electric utility customer charges

This paper quantifies the increased greenhouse gas emissions and negative effect on energy conservation (or “efficiency penalty”) due to electric rate structures that employ an unavoidable customer charge. First, the extent of customer charges was determined from a nationwide survey of US electric tariffs. To eliminate the customer charge nationally while maintaining a fixed sum for electric companies for a given amount of electricity, an increase of 7.12% in the residential electrical rate was found to be necessary. If enacted, this increase in the electric rate would result in a 6.4% reduction in overall electricity consumption, conserving 73 billion kW h, eliminating 44.3 million metric tons of carbon dioxide, and saving the entire US residential sector over $8 billion per year. As shown here, these reductions would come from increased avoidable costs, thus leveraging an increased rate of return on investments in energy efficiency, energy conservation behavior, distributed energy generation, and fuel choices. Finally, limitations of this study and analysis are discussed and conclusions are drawn for proposed energy policy changes.     

Energy intensities and greenhouse gas emission mitigation in global agriculture

Energy efficiency and greenhouse gas emissions are closely linked. This paper reviews agricultural options to reduce energy intensities and their impacts, discusses important accounting issues related to system boundaries, land scarcity, and measurement units and compares agricultural energy intensities and improvement potentials on an international level. Agricultural development in recent decades, while increasing yields, has led to lower average energy efficiencies when comparing the 1960s and the mid 1980s. In the two decades thereafter, energy intensities in developed countries increased, but with little impact on greenhouse gas emissions. Efficiency differences across countries in the year 2000 suggest a maximum improvement potential of 500 million tons of CO₂ annually. If only below average countries would increase their energy efficiency to average levels of the year 2000, the resulting emission reductions would be below 200 million tons of CO₂ annually.

Oil and natural gas prices and greenhouse gas emission mitigation

The hikes in hydrocarbon prices during the last years have lead to concern about investment choices in the energy system and uncertainty about the costs for mitigation of greenhouse gas emissions. On the one hand, high prices of oil and natural gas increase the use of coal; on the other hand, the cost difference between fossil-based energy and non-carbon energy options decreases. We use the global energy model TIMER to explore the energy system impacts of exogenously forced low, medium and high hydrocarbon price scenarios, with and without climate policy. We find that without climate policy high hydrocarbon prices drive electricity production from natural gas to coal. In the transport sector, high hydrocarbon prices lead to the introduction of alternative fuels, especially biofuels and coal-based hydrogen. This leads to increased emissions of CO₂. With climate policy, high hydrocarbon prices cause a shift in electricity production from a dominant position of natural gas with carbon capture and sequestration (CCS) to coal-with-CCS, nuclear and wind. In the transport sector, the introduction of hydrogen opens up the possibility of CCS, leading to a higher mitigation potential at the same costs. In a more dynamic simulation of carbon price and oil price interaction the effects might be dampened somewhat.     

Design issues in a mandatory greenhouse gas emissions registry for the United States

On March 10, 2009, the US Environmental Protection Agency (EPA) proposed a new rule, Mandatory Reporting of Greenhouse Gases. When final, the rule would compel most large sources of greenhouse gases (GHGs) to report their emissions to EPA as well as fossil fuel suppliers and vehicle engine manufacturers to report their fuel sales and engine emissions rates, respectively. We suggest a number of improvements to the rule that would enhance compatibility with expected future climate legislation and enable a broader range of policies and analysis: (1) lower the threshold for reporting to a level more consistent with expected future legislation, (2) require reporting of electricity use along with direct emissions, (3) require reporting of emissions per unit output for a small number of selected sectors, (4) include a system of identifying corporate ownership of reporting facilities, and (5) identify a path toward coverage for sectors that were left out of the proposal due to underdeveloped reporting protocols.     

Energy inputs and crop yield relationship in greenhouse tomato production

This study examines energy use patterns and the relationship between energy inputs and yield for greenhouse tomato production in Antalya province of Turkey. The data used in this study were based on cross-sectional data collected from growers by using a face to face survey. The results revealed that diesel (34.35%), fertilizer (27.59%), electricity (16.01%), chemicals (10.19%) and human power (8.64%) consumed the bulk of energy. In the surveyed farms, average yield and energy consumption were calculated as around 160000 kg/ha and 106716.2 MJ/ha, respectively. The results also showed that output–input, specific energy and energy productivity were 1.2, 12380.3 MJ/t and 0.09 kg/MJ, respectively. The results implied that small size farms were more efficient than large ones in terms of output–input ratio. An econometric model was developed to estimate the impact of energy inputs on yield. Therefore, tomato yield, an endogenous variable was assumed to be a function of exogenous variables; fertilizer, chemicals, machinery, human, water for irrigation and seed energy. The empirical results indicated that all exogenous variables except seed energy were found statistically significant and contributed to yield. Among all statistically significant exogenous variables, human, fertilizer, water, chemicals and machinery were ranked in terms of elasticities. These results indicate that the Turkish greenhouse industry heavily depends on fossil fuels.     

Energy demand and emissions from road transportation vehicles in China

Rapidly growing energy demand and emissions from China's road transportation vehicles in the last two decades have raised concerns over oil security, urban air pollution and global warming. This rapid growth will be likely to continue in the next two to three decades as the vehicle ownership level in China is still very low. The current status of China's road transport sector in terms of vehicles, infrastructure, energy use and emissions is presented. Mitigation measures implemented and those that can reasonably be expected to be adopted in the near future are analysed. Recent studies exploring the future trends of road vehicle energy demand and emissions under various strategies are reviewed. Moreover, those studies which assessed various fuel/propulsion options in China from a life cycle perspective are examined to present an overview of the potential for reducing energy use and emissions. Recommendations for further developments are also made. It is concluded that comprehensive and appropriate strategies will be needed to minimise the adverse impacts of China's road vehicles on energy resources and the environment. Fortunately, China appears to be heading in this direction.     

The impact of fuel cell vehicle deployment on road transport greenhouse gas emissions: The China case

Considerable attention has been paid to energy security and climate problems caused by road vehicle fleets. Fuel cell vehicles provide a new solution for reducing energy consumption and greenhouse gas emissions, especially those from heavy-duty trucks. Although cost may become the key issue in fuel cell vehicle development, with technological improvements and cleaner pathways for hydrogen production, fuel cell vehicles will exhibit great potential of cost reduction. In accordance with the industrial plan in China, this study introduces five scenarios to evaluate the impact of fuel cell vehicles on the road vehicle fleet greenhouse gas emissions in China. Under the most optimistic scenario, greenhouse gas emissions generated by the whole fleet will decrease by 13.9% compared with the emissions in a scenario with no fuel cell vehicles, and heavy-duty truck greenhouse gas emissions will decrease by nearly one-fifth. Greenhouse gas emissions intensity of hydrogen production will play an essential role when fuel cell vehicles' fuel cycle greenhouse gas emissions are calculated; therefore, hydrogen production pathways will be critical in the future.     

Weekly greenhouse gas emissions of municipalities: Methods and comparisons

Local authorities need timely information on their greenhouse gas (GHG) emissions and their causes, comparison with other municipalities and tools for dissemination of information to the citizens. This paper presents a weekly GHG emission calculation system, CO₂-report, which provides such data for citizens and local decision-makers in a timely manner, in contrast to the official emissions statistics, which are available on an annual basis 1–2 years afterwards. In this paper, we present the methodology and three main outputs of CO₂-report: (1) weekly GHG emissions; (2) advance annual emissions; and (3) final annual emissions for 2009 with comparison of 64 municipalities in Finland. We explain the reasons for the large variability of annual emissions, from 5 to 13 t CO₂-eq/capita, discuss the accuracy of advance and final emission estimates at local level, and show the weekly variability of emissions for three example municipalities with different emission profiles.     

Fuel conservation and GHG (Greenhouse gas) emissions mitigation scenarios for China’s passenger vehicle fleet

Passenger vehicles are the main consumers of gasoline in China. We established a bottom-up model which focuses on the simulation of energy consumptions and greenhouse gas (GHG) emissions growth by China’s passenger vehicle fleet. The fuel conservation and GHG emissions mitigation effects of five measures including constraining vehicle registration, reducing vehicle travel, strengthening fuel consumption rate (FCR) limits, vehicle downsizing and promoting electric vehicle (EV) penetration were evaluated. Based on the combination of these measures, the fuel conservation and GHG emissions mitigation scenarios for China’s passenger vehicle fleet were analyzed. Under reference scenario with no measures implemented, the fuel consumptions and life cycle GHG emissions will reach 520 million tons of oil equivalent (Mtoe) and 2.15 billion tons in 2050, about 8.1 times the level in 2010. However, substantial fuel conservation can be achieved by implementing the measures. By implementing all five measures together, the fuel consumption will reach 138 Mtoe in 2030 and decrease to 126 Mtoe in 2050, which is only 37.1% and 24.3% of the consumption under reference scenario. Similar potential lies in GHG mitigation. The results and scenarios provided references for the Chinese government’s policy-making.     

Sectoral trends in global energy use and greenhouse gas emissions

Integrated assessment models have been used to project both baseline and mitigation greenhouse gas emissions scenarios. Results of these scenarios are typically presented for a number of world regions and end-use sectors, such as industry, transport, and buildings. Analysts interested in particular technologies and policies, however, require more detailed information to understand specific mitigation options in relation to business-as-usual trends. This paper presents sectoral trend for two of the scenarios produced by the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios. Global and regional historical trends in energy use and carbon dioxide emissions over the past 30 years are examined and contrasted with projections over the next 30 years. Macro-activity indicators are analyzed as well as trends in sectoral energy and carbon demand. This paper also describes a methodology to calculate primary energy and carbon dioxide emissions at the sector level, accounting for the full energy and emissions due to sectoral activities.     

Benchmarking energy use and greenhouse gas emissions in Singapore’s hotel industry

Hotel buildings are reported in many countries as one of the most energy intensive building sectors. Besides the pressure posed on energy supply, they also have adverse impact on the environment through greenhouse gas emissions, wastewater discharge and so on. This study was intended to shed some light on the energy and environment related issues in hotel industry. Energy consumption data and relevant information collected from hotels were subjected to rigorous statistical analysis. A regression-based benchmarking model was established, which takes into account, the difference in functional and operational features when hotels are compared with regard to their energy performance. In addition, CO₂ emissions from the surveyed hotels were estimated based on a standard procedure for corporate GHG emission accounting. It was found that a hotel’s carbon intensity ranking is rather sensitive to the normalizing denominator chosen. Therefore, carbon intensity estimated for the hotels must not be interpreted arbitrarily, and industry specific normalizing denominator should be sought in future studies.     

Structural decomposition analysis of Australia's greenhouse gas emissions

A complex system of production links our greenhouse gas emissions to our consumer demands. Whilst progress may be made in improving efficiency, other changes in the production structure may easily annul global improvements. Utilising a structural decomposition analysis, a comparative-static technique of input–output analysis, over a time period of around 30 years, net greenhouse emissions are decomposed in this study into the effects, due to changes in industrial efficiency, forward linkages, inter-industry structure, backward linkages, type of final demand, cause of final demand, population affluence, population size, and mix and level of exports.Historically, significant competing forces at both the whole of economy and industrial scale have been mitigating potential improvements. Key sectors and structural influences are identified that have historically shown the greatest potential for change, and would likely have the greatest net impact. Results clearly reinforce that the current dichotomy of growth and exports are the key problems in need of address.     

Reductions in greenhouse gas emissions and cost by shipping at lower speeds

CO₂ emissions from maritime transport represent a significant part of total global greenhouse gas (GHG) emissions. According to the International Maritime Organization (Second IMO GHG study, 2009), maritime transport emitted 1046 million tons (all tons are metric) of CO₂ in 2007, representing 3.3% of the world's total CO₂ emissions. The International Maritime Organization (IMO) is currently debating both technical and market-based measures for reducing greenhouse gas emissions from shipping. This paper presents investigations on the effects of speed reductions on the direct emissions and costs of maritime transport, for which the selection of ship classes was made to facilitate an aggregated representation of the world fleet. The results show that there is a substantial potential for reducing CO₂ emissions in shipping. Emissions can be reduced by 19% with a negative abatement cost (cost minimization) and by 28% at a zero abatement cost. Since these emission reductions are based purely on lower speeds, they can in part be performed now.