• Energy Research

E-bikes are bicycles that provide pedal-assistance to aid people in cycling. Because of the potential of promoting sustainable transportation, more attention has been focused on the e-bike market. This paper investigates the differences of the cycling experience and perceptions between e-bike and conventional bicycle users, using samples drawn from independent bicycle dealer customers. A total of 806 respondents in the United States took the on-line survey, including 363 e-bike-owning respondents. The results show that e-bikes play a more important role in utilitarian travel, such as commuting and running errands, compared to a conventional bicycle. Conventional bicycle-owning respondents use their bicycles more for recreation and exercise. Also, e-bike owners tend to bike longer distances and take more trips per week. Both e-bike respondents and bicycle respondents stated that improved health was a key factor for cycling, while Millennials and Generation X respondents cycle to save time and improve the environment. Finally, an ordered logit model is proposed for evaluating factors that influence interest in future e-bike ownership. Travel purpose, e-bike familiarity, annual household income, and education level are statistically significant factors in the model. These findings begin to provide insight and a profile of potential new markets for e-bikes in the United States.

AbstractElectric bicycles (e-bikes) represent one of the fastest growing segments of the transport market. Over 31 million e-bikes were sold in 2012. Research has followed this growth and this paper provides a synthesis of the most pertinent themes emerging over the past on the burgeoning topic of e-bikes. The focus is transport rather than recreational e-bike research, as well as the most critical research gaps requiring attention. China leads the world in e-bike sales, followed by the Netherlands and Germany. E-bikes can maintain speed with less effort. E-bikes are found to increase bicycle usage. E-bikes have the potential to displace conventional motorised (internal combustion) modes, but there are open questions about their role in displacing traditional bicycles. E-bikes have been shown to provide health benefits and an order of magnitude less carbon dioxide than a car travelling the same distance. Safety issues have emerged as a policy issue in several jurisdictions and e-bike numbers are now appro...

In 2005, 10 million electric bikes were produced in China. Strong domestic sales are projected for coming years, raising concerns about the sustainability and potential regulation of this fairly new mode. Policy makers are wrestling with developing policy on electric bikes with little information about who uses them, why they are used, and what factors influence electric bike travel. This paper probes these questions by surveying electric bike usage in two large Chinese cities, Kunming and Shanghai. Demographic comparisons are made between the different modes and cities as well as differences in travel patterns. Electric bike users are found to travel considerably more than bicycle users. Also, most electric bike users would travel by bus if electric bikes were unavailable. This suggests that electric bikes are less of a transitional mode between human-powered bikes and full-blown automobile ownership, and more an affordable, higher quality mobility option to public transport.

E-bikes in China are the single largest adoption of alternative fuel vehicles in history, with more than 100 million e-bikes purchased in the past decade and vehicle ownership about 2× larger for e-bikes as for conventional cars; e-car sales, too, are rapidly growing. We compare emissions (CO(2), PM(2.5), NO(X), HC) and environmental health impacts (primary PM(2.5)) from the use of conventional vehicles (CVs) and electric vehicles (EVs) in 34 major cities in China. CO(2) emissions (g km(-1)) vary and are an order of magnitude greater for e-cars (135-274) and CVs (150-180) than for e-bikes (14-27). PM(2.5) emission factors generally are lower for CVs (gasoline or diesel) than comparable EVs. However, intake fraction is often greater for CVs than for EVs because combustion emissions are generally closer to population centers for CVs (tailpipe emissions) than for EVs (power plant emissions). For most cities, the net result is that primary PM(2.5) environmental health impacts per passenger-km are greater for e-cars than for gasoline cars (3.6× on average), lower than for diesel cars (2.5× on average), and equal to diesel buses. In contrast, e-bikes yield lower environmental health impacts per passenger-km than the three CVs investigated: gasoline cars (2×), diesel cars (10×), and diesel buses (5×). Our findings highlight the importance of considering exposures, and especially the proximity of emissions to people, when evaluating environmental health impacts for EVs.

Managing a fleet efficiently to address demand within cost constraints is a challenge. Mismatched fleet size and demand can create suboptimal budget allocations and inconvenience users. To address this problem, many studies have been conducted around heterogeneous fleet optimization. That research has not included an examination of different vehicle types with travel distance constraints. This study focuses on optimizing the University of Tennessee (UT) motor pool which has a heterogeneous fleet that includes electric vehicles (EVs) with a travel distance and recharge time constraint. After assessing UT motor pool trip patterns as a case study, a queuing model was used to estimate the maximum number of each vehicle type needed to minimize the expected customer wait time to near zero. The break-even point is used for the optimization model to constrain the minimum number of years that electric vehicles should be operated under the no-subsidy assumption. The results show that the fleet has surplus vehicles. In addition to reducing the number of vehicles, total fleet costs could be minimized by using electric vehicles for all trips less than 100 miles. The models are flexible and can be applied and help fleet managers make decisions about fleet size and EV adoption.

Many Asian cities are experiencing rapid growth in the ownership of personal gasoline-powered motorcycles, a shift away from relatively low-emitting modes of transportation that is contributing to deteriorated air quality. Electric two-wheelers have the potential for significant air pollution reductions as an alternative to gasoline-powered motorcycles; however, they have yet to penetrate many Asian markets. While previous research has examined the adoption of cleaner alternatives to gasoline-powered automobiles (e.g., hybrid electric cars), similar work on motorcycle alternatives is lacking. This study uses a stated preference survey of households in Hanoi, Vietnam to analyze adoption of electric two-wheelers, while focusing on the effects of economic incentives (e.g., differential sales taxes and fuel prices) and technological improvements (e.g., more efficient batteries). A choice model is estimated and market shares are calculated for scenarios involving different levels of electric two-wheeler technology, gasoline prices, and sales tax rates. Results indicate that technological improvements and economic incentives, particularly sales taxes, have significant effects on adoption.

Abstract This paper describes the operational concepts and system requirements of a fully automated electric bike (e-bike) sharing system demonstrated through a pilot project at the University of Tennessee, Knoxville (UTK) campus (deployed in September 2011). This project is part of a movement to develop a sustainable transportation system, and is one of the green initiatives on UTK campus. E-bikes are more energy efficient and produce fewer greenhouse gas (GHG) emissions per person compared to other transport modes such as car, bus, and motorcycle. Without empirical demand information for an e-bike sharing system, we simulated the operations of such a system to gain insights during the design process before field deployment. The simulation exercise focused on three critical demand parameters – distributions of trip rates, trip lengths, and trip durations – and coupled them with supply parameters – number of e-bikes, number of swappable batteries, and battery recharging profiles. The primary purpose of these simulations is to evaluate the efficiency of an off-board battery recharging system, where the depleted battery is removed from an e-bike upon its return and inserted into one of the charging slots at the kiosk. We tested various scenarios with different number of batteries always maintaining an initial condition with the battery to e-bike ratio greater or equal to 1.0 to ensure battery availability. We applied empirical battery recharging rates and system operations rules to determine the number of e-bikes and batteries available under different potential demand situations, with a focus on optimizing the number of batteries to meet user demands. By adjusting input parameters, numerous scenarios were simulated for sensitivity analysis. Based on the results of the simulation, this paper presents a cost constrained e-bike sharing system design that can maintain a high level of system reliability (e-bike and battery availability) through optimal battery charging and distribution management. We found that high demand scenarios require multiple swappable batteries per e-bike to reasonably meet the maximum demand. Trip duration has the most influence on e-bike and battery availability, followed by trip rate, and then trip length.

Abstract China and India are embarking on ambitious initiatives over the next decade to expand solar photovoltaic (PV) power in underserved regions. China proposes adding 1.6 GW of solar capacity by 2020, while India plans 12 GW in addition to 20 million solar lanterns by 2022. These technologies rely heavily on lead-acid batteries (LABs) for storage. China and India’s lead mining, battery production, and recycling industries are relatively inefficient—33% and 22% environmental loss rates, respectively. Based on the quantity of lead batteries employed in existing PV systems, we estimate environmental lead emissions in China and India for new units installed under their solar energy goals. The average loss rates are 12 kg (China) and 8.5 kg (India) of lead lost per kW-year of installed PV capacity in these countries. The planned systems added in China and India will be responsible for 386 and 2030 kt of environmental lead loss, respectively, over their lifespan—equal to 1/3 of global lead production in 2009. Investments in environmental controls in lead smelting, battery manufacturing, and recycling industries along with improvements in battery take-back policies should complement deployment of solar PV systems to mitigate negative impacts of lead pollution.

Many cities in the United States are facing challenges associated with antiquated urban arterials, whose purpose has changed greatly since their development. Once considered the main streets of the city, with thriving businesses and attractive residential development, many have deteriorated over the decades for a number of reasons, including shifting demand for housing and retail development and the construction of parallel high-speed urban expressways. Because of the complexity of the problems associated with these arterials, a great challenge of transportation and land use planners is to develop a systems-level approach to revitalize and reinvent these arterials in a manner that encourages environmental, economic, and social sustainability. Presented is a methodology to revitalize multimodal urban arterials that includes land use planning, traffic and transit operations management, street redesign, and community participation to improve the conditions of such arterials. Analysis is carried out by using these principles on San Pablo Avenue, a major arterial in the San Francisco Bay Area in California. By using these analysis techniques, land use and transportation recommendations are made that will facilitate sustainable development along this corridor.