Model for developing an eco-driving strategy of a passenger vehicle based on the least fuel consumption

Additional consumption of fuel in an intense traffic condition is inevitable. Excess fuel consumption may be avoided, if an optimal driving strategy is implemented subject to the surrounding condition of a vehicle and existing constraints. Development of an optimal driving strategy has been the subject of eco-driving. A model of optimal driving strategy has been developed and it has been applied for assessment of eco-driving rules. The model may be categorized as an optimal control and the objective function is minimization of fuel consumption in a given route. Vehicle speed and gear ratio are identified as control variables. The effect of working load has been considered according three engine running processes of Idle, part-load and wide open throttle. The model has then been applied to identify the optimal driving strategy of a vehicle in different traffic congestion based on eco-driving rules.     

Energy efficiency technologies for road vehicles

A key message of the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change is that improved energy efficiency is one of society’s most important instruments for combating climate change. This article reviews a range of energy efficiency measures in the transportation sector as discussed in AR4 and assess their potentials for improving fuel efficiency. The primary focus is on light-duty vehicles because they represent the largest portion of world transport energy use and carbon dioxide emissions; freight trucks, a rapidly expanding source of greenhouse emissions, are also discussed. Increasing energy efficiency can be achieved by improving the design and technology used in new vehicles, but vehicle technology is only one component of fleet fuel economy. Measures that create strong incentives for customers to take energy efficiency into consideration when buying and operating their vehicles will be crucial to policy success.

The role of market and technical downsizing in reducing carbon emissions from the Swedish new car fleet

Doubts have been raised on whether the car industry will manage to reach the goal set by the Voluntary Agreement with the European Commission, unless tougher measures are taken to reduce CO₂ emissions. Taking a stance from the concept of downsizing, we study the historical development of two strategies: first, shifting the market toward smaller cars, market downsizing; second, a technical downsizing, i.e., technical improvements that have enabled a reduction of engine size. We focus on the Swedish new car market from 1975 to 2002. Analysis is done by combining sales statistics with databases over car model parameters. The development of the top and bottom 10% and 20% of the car market of various parameters points to an increased differentiation of the market; still, the market share of small models remains low. We identify the potential for downsizing created by increase of maximum specific torque and power and conclude that these have enabled the cylinder volume to stabilize around 2 l. Increase in engine size has also partly been dampened by the utilization of supercharging. The potential savings of fuel use presented by the introduction of a sixth gear in manual gearboxes have not materialized since gearshifts have not systematically been used to lower engine speed. We conclude that there are few signs of a downsizing in the Swedish new car fleet. From a market perspective, larger cars are still dominant and the technical potentials to reduce engine size have not been harnessed.

Feedback on household electricity consumption: a tool for saving energy?

Improved feedback on electricity consumption may provide a tool for customers to better control their consumption and ultimately save energy. This paper asks which kind of feedback is most successful. For this purpose, a psychological model is presented that illustrates how and why feedback works. Relevant features of feedback are identified that may determine its effectiveness: frequency, duration, content, breakdown, medium and way of presentation, comparisons, and combination with other instruments. The paper continues with an analysis of international experience in order to find empirical evidence for which kinds of feedback work best. In spite of considerable data restraints and research gaps, there is some indication that the most successful feedback combines the following features: it is given frequently and over a long time, provides an appliance-specific breakdown, is presented in a clear and appealing way, and uses computerized and interactive tools.

An energy efficient Swedish pulp and paper industry – exploring barriers to and driving forces for cost-effective energy efficiency investments

Despite the need for increased industrial energy efficiency, studies indicate that cost-effective energy efficiency measures are not always implemented, which is explained by the existence of barriers to energy efficiency. This paper investigates whether this holds for the Swedish pulp and paper industry, and if so, investigates the barriers inhibiting and the driving forces stressing cost-effective energy efficiency investments. By so, this case study covers about 2% of the EU-25 industrial end-use of energy. The overall results from a questionnaire show that there is an energy efficiency gap in the sector and that the largest barriers were technical risks such as risk of production disruptions, cost of production disruption/hassle/inconvenience, technology inappropriate at the mill, lack of time and other priorities, lack of access to capital, and slim organization. As regards the driving forces for energy efficiency, the highest ranked driving forces were cost reductions resulting from lower energy use, people with real ambition, long-term energy strategy, the threat of rising energy prices, the electricity certificate system, the PFE. The results show that many of the barriers and driving forces were not solely market-related, e.g., lack of time or other priorities, slim organization, other priorities for capital investments, lack of staff awareness, and long decision chains indicate that firm-specific barriers plays an important role. These barriers may not be overcome by market-related public policy instruments but is rather a consequence of how the energy issue is organized within the firms. The second and the third largest driving forces, people with real ambition and a long-term energy strategy further support this.

Overview of energy consumption and GHG mitigation technologies in the building sector of Japan

This paper outlines the energy consumption and greenhouse gas emission trends in the residential and commercial sectors in Japan. The results showed that the increase in residential energy consumption in Japan is mainly caused by the widespread use of heating equipment, hot water supply apparatus, and other household electrical appliances. On the other hand, it was indicated that the increase in commercial energy use is mainly due to the increase of the floor area of buildings, particularly hotels, hospitals, and department stores. The paper also describes political measures to promote energy conservation, including the building energy conservation standard, Comprehensive Assessment System for Building Environmental Efficiency, top runner programs, financial incentives, and the dissemination of the Cool Biz concept. Finally, the projections of CO₂ emissions until 2050 are presented.

Estimating the potential CO2 mitigation from agricultural energy efficiency in the United States

Energy efficiency in agriculture is an underanalyzed aspect of a potential climate change mitigation strategy. According to the Fourth Assessment Report, experts report only medium agreement and medium evidence that energy efficiency can provide substantial reductions (Smith et al. 2007). This paper estimates the CO₂ mitigation potential achievable through improvements in energy efficiency in the US agriculture sector. The data are presented in three formats: the cost data or break-even points of each technology, a marginal abatement supply curve expressed in terms of reduction in energy use by fuel category, and a marginal abatement supply curve expressed in terms of CO₂ emission reductions by fuel category. The largest sources of energy use in the sector were identified as motors used in irrigation systems or other pumping operations; farm machinery such as tractors used in daily farm operations; and space conditioning, such as HVAC systems for livestock and crop-drying systems.

Life cycle cost analysis of energy efficiency design options for refrigerators in Brazil

The purpose of this paper was to present the results of a life cycle cost analysis concerning the purchase and operation of a more efficient popular refrigerator model compared with a baseline design in Brazil. The summarized results may be useful for organizations working to promote sustainable energy development. This paper specifically focuses on refrigerators, since their energy consumption is predicted to constitute over 30% of the total average domestic electricity bill in Brazilian households. If all new Brazilian refrigerators had an energy efficiency at the level consistent with the least life cycle cost of ownership, it would result in an annual savings of 2.8 billion dollars (US$) in electricity bills, 45 TWh of electricity demand, and 18 Mt of CO₂ emissions, with a respective payback period of 7 years which is less than half the average estimated lifetime of a refrigerator. The analysis was conducted following the guidelines of similar analyses available from the US Department of Energy and the Collaborative Labeling and Appliance Standards Program.

New thinking on the agentive relationship between end-use technologies and energy-using practices

The subject of efficient technologies and how to get them into the homes and hands of users has been at the centre of energy efficiency policy from its inception. What the record shows is that efficient technologies may well increase the efficiency of energy throughput but that promised reductions in energy demand seldom pan out. Confronted with this problem, the usual policy approach has been to work harder to get markets, incentives and information to loosen up the ‘barriers’ to technology penetration. Social scientists have been recruited to facilitate markets with better information and incentives, in other words, to improve the behaviour of energy end-users. The paper argues that both technologists and behaviouralists have oversimplified the ways that technologies and socio-cultural contexts interact to affect energy-using practices. The concept of distributed agency is introduced to capture the theoretical link between technology and behaviour. The examples of air conditioning and food refrigeration are used to illustrate these points.

Industrial energy efficiency and climate change mitigation

Industry contributes directly and indirectly (through consumed electricity) about 37% of the global greenhouse gas emissions, of which over 80% is from energy use. Total energy-related emissions, which were 9.9 GtCO₂ in 2004, have grown by 65% since 1971. Even so, industry has almost continuously improved its energy efficiency over the past decades. In the near future, energy efficiency is potentially the most important and cost-effective means for mitigating greenhouse gas emissions from industry. This paper discusses the potential contribution of industrial energy-efficiency technologies and policies to reduce energy use and greenhouse gas emissions to 2030.

Breaking down the silos: the integration of energy efficiency, renewable energy, demand response and climate change

This paper explores the feasibility of integrating energy efficiency program evaluation with the emerging need for the evaluation of programs from different “energy cultures” (demand response, renewable energy, and climate change). The paper reviews key features and information needs of the energy cultures and critically reviews the opportunities and challenges associated with integrating these with energy efficiency program evaluation. There is a need to integrate the different policy arenas where energy efficiency, demand response, and climate change programs are developed, and there are positive signs that this integration is starting to occur.

Multiple instruments to change energy behaviour: The emperor’s new clothes?

Over the last few decades, several instruments have evolved to deal with similar energy and environmental challenges. For instance, the economic literature prescribes separate tax or cap-and-trade systems to internalize negative environmental externalities and subsidies to internalize positive externalities such as research and development. However, policy is not straightforward because of the influence on cost and competition and concerns for regional employment, economic activity within certain industries and any distributional effects. Tax discrimination, subsidies and regulations then undermine the efficiency of energy instruments. To balance any environmental concerns, other instruments, including green and white certificates, have been created. While innovative, these work as simple combinations of taxes and subsidies. While the extant literature thoroughly analyzes the partial effects of these instruments, there has been little focus on their basics and the effects of aggregate taxes and subsidies. This complexity calls for research on the efficiency of each instrument, including the administration and transaction costs associated with holding a large set of instruments. We should consider the coordination and simplification of policy tools before complicating the system further by introducing new, primarily equivalent, instruments.

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.

The role of energy intensity improvement in the AR4 GHG stabilization scenarios

This study analyzes the role of energy intensity improvement in the short term (to the year 2020) and midterm (to the year 2050) in the context of long-term greenhouse gases (GHG) stabilization scenarios. The data come from the latest Emissions Scenarios Database and were reviewed in the Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change. In this study, quantitative decomposition analyses using the extended Kaya identity are applied to the stabilization scenarios in Categories I to IV of Table SPM.5 in the AR4. Furthermore, quantitative decomposition analyses of Category IV scenarios are conducted for major GHG-emitting countries, such as the USA, Western Europe, China, and India, by utilizing the large number of reports in the database. This study provides in-depth analyses of the relationship between energy intensity improvement and other major indicators. One finding is that energy intensity improvement plays an important role in the short term, and the rate of energy intensity improvement is assumed to be around 2% per year as a median value across Categories I–III in the midterm on the global scale. However, achieving stringent stabilization levels requires various other measures regarding the use of less-carbon intensive fossil fuels, the shift to non-fossil fuel energies, and advanced technologies such as carbon capture and storage.

The business case for energy management in high-tech industries

The high-technology sector – characterized by facilities such as laboratories, cleanrooms, and data centers – is often where innovation first occurs. These facilities are sometimes referred to as the “racecars” of the buildings sector because new technologies and strategies to increase performance often trickle down to other building types. Although these facilities are up to 100 times as energy-intensive as conventional buildings, highly cost-effective energy efficiency opportunities are often overlooked. Facility engineers are in the trenches identifying opportunities to improve energy productivity but often are unable to make the broader business case to financial decision makers. This article presents the technical opportunities for reducing energy costs, along with their broader strategic value for high-tech industries.

Tradeable energy efficiency certificates in Australia

Tradeable energy efficiency certificates are created in Australia as part of a larger baseline-and-credit emissions trading scheme, the Greenhouse Gas Reduction Scheme (GGAS) that operates in the State of New South Wales and the Australian Capital Territory. GGAS aims to reduce greenhouse gas emissions associated with the generation and use of electricity through project-based activities to offset the production of emissions. GGAS applies in two jurisdictions that are part of a wholesale electricity market operating across a total of six jurisdictions and this imposes some constraints on scheme design. Nevertheless, GGAS has developed a set of comprehensive operational systems and procedures to validate energy efficiency projects and verify the abatement they produce. To the end of calendar year 2006, nearly ten million energy efficiency certificates have been created under GGAS, representing nearly ten million tonnes of CO2-e abatement. Some significant issues have arisen regarding the creation of certificates from the mass distribution of small energy-efficient household appliances. However, the experience with GGAS still demonstrates that tradeable energy efficiency certificates can be an effective mechanism for incentivising greenhouse gas emissions abatement in the context of a baseline-and-credit emissions trading scheme.

Interactions of white certificates with other policy instruments in Europe

In a tradable white certificate (TWC) scheme, each certificate issued represents a certain amount of energy saved. Used in conjunction with an energy-saving obligation on certain parties in the energy supply chain and with rules for trading, monitoring and verification established, an efficient market for energy savings in sectors not covered by the European Union (EU) Emissions Trading Scheme can be established. However, a plethora of other mechanisms are already in place to promote a more sustainable use of energy in Europe. This paper analyses the interactions (both potential and realised in existing schemes) between TWCs and other policy instruments including tradable green certificates, the European Union Emissions Trading Scheme, the European Union Energy Performance in Buildings Directive as well as taxes, subsidies and loans. Measures implemented through a TWC scheme that reduce the consumption of electricity can make targets under a tradable green certificate scheme easier to attain. Where a tradable green certificate scheme contains relative targets, the target should be increased to achieve the same absolute amount of renewable power. A TWC scheme can also reduce the number of allowances electricity generators will need to surrender under the EU Emissions Trading Scheme. By reducing the available emission rights in the National Allocation Plans, this effect is possible to counteract.

Tradable white certificate schemes: fundamental concepts

A number of European countries have introduced market-based instruments to encourage investment in energy efficiency improvement and achieve national energy savings targets. Some of these schemes are based on quantified energy savings obligations imposed on energy distributors or suppliers, coupled with a certification of the energy savings (via white certificates), and a possibility to trade certificates. The paper describes the concept and the main elements of a tradable white certificate scheme, where appropriate giving examples from existing schemes in Europe. It discusses design and operational features that are key to achieve the overall savings targets, such as delineation of the scheme in terms of obliged parties, eligible projects and technologies, institutional structure, and processes to support the scheme, such as measurement and verification. Finally, the paper looks at a number of open issues, most importantly the possibility of creating a voluntary market for white certificates via integration into the carbon market.

Towards a sustainable energy balance: progressive efficiency and the return of energy conservation

We argue that a primary focus on energy efficiency may not be sufficient to slow (and ultimately reverse) the growth in total energy consumption and carbon emissions. Instead, policy makers need to return to an earlier emphasis on “conservation,” with energy efficiency seen as a means rather than an end in itself. We briefly review the concept of “intensive” versus “extensive” variables (i.e., energy efficiency versus energy consumption) and why attention to both consumption and efficiency is essential for effective policy in a carbon- and oil-constrained world with increasingly brittle energy markets. To start, energy indicators and policy evaluation metrics need to reflect energy consumption, as well as efficiency. We introduce the concept of “progressive efficiency,” with the expected or required level of efficiency varying as a function of house size, appliance capacity, or more generally, the scale of energy services. We propose introducing progressive efficiency criteria first in consumer information programs (including appliance labeling categories) and then in voluntary rating and recognition programs such as ENERGY STAR. As acceptance grows, the concept could be extended to utility rebates, tax incentives, and ultimately to mandatory codes and standards. For these and other programs, incorporating criteria for consumption, as well as efficiency, offers a path for energy experts, policymakers, and the public to begin building consensus on energy policies that recognize the limits of resources and global carrying capacity. Ultimately, it is both necessary and, we believe, possible to manage energy consumption, not just efficiency, in order to achieve a sustainable energy balance. Along the way, we may find it possible to shift expectations away from perpetual growth and toward satisfaction with sufficiency.