Plug-in Hybrid Electric Vehicles Drivers Research Articles

Costs and potentials of reducing CO2 emissions in China's transport sector: Findings from an energy system analysis

As China's transportation system expands it is producing a large amount of end-use emissions. To derive cost-effective measures for CO2 mitigation, the authors of this paper develop a marginal abatement cost (MAC) curve for China's transport sector. Using the TIMES model, MAC curves are derived which identify the linkages among all transport modes, considering, among other uncertainties, the impacts of a carbon peaking policy and driver preferences for plug-in hybrid electric vehicles (PHEVs). The results underline that the intercity passenger transport sector has a cost advantage, with a huge potential for emissions reduction (accounting for almost 38.8% of all CO2 emissions mitigation). The freight sector is another potentially significant contributor to CO2 reduction, underlining its vital role for emission mitigation in the longer run. The carbon peak policy, while making alternative fuel vehicles (AFV) more efficient, is found to increase the overall cost of emissions reduction. A higher ratio of electricity to fossil fuel use by PHEVs drivers would help the transport sector to reduce CO2 much faster. The sensitivity analysis of these and other factors is also estimated in this paper. The final MAC curves provide valuable insights for future low-carbon energy development strategies of China's transport sector.

Characteristics and Experiences of Ride-Hailing Drivers with Electric Vehicles

Electrification of transportation network companies (TNCs), such as Uber and Lyft, can produce social and environmental benefits from reduced vehicle emissions and enhanced implementation of renewable electricity as well as private benefits to drivers via reduced vehicle fuel and maintenance costs compared to conventional vehicles. We conducted a survey of plug-in electric vehicle (PEV) drivers on the Uber platform in the US. This paper describes these drivers and their experiences to further understanding of motivations for and barriers to PEV adoption among TNC drivers. The TNC-PEV drivers in this sample clearly recognized, and were largely motivated by, economic benefits of fuel and maintenance savings, thus, increased net earnings, associated with using a PEV to provide ride-hailing services rather than a conventional internal combustion engine vehicle. Most drivers reported charging their PEV every day, most often at home and overnight. This is true even of those with plug-in hybrid electric vehicles (PHEVs) that can run on gas if not charged. Increased electric driving range topped the list of drivers’ wishes to better support PEVs on TNCs, and range limitations topped the list of reasons why PHEV drivers did not opt for a battery electric vehicle (BEV; that runs exclusively on electricity). The second most common wish among all PEV drivers was for more charger locations.

Potential Climate Impact Variations Due to Fueling Behavior of Plug-in Hybrid Vehicle Owners in the US

With the expected rapid growth of renewable electricity generation, charging plug-in hybrid electric vehicles (PHEVs) from the grid promise ever higher reductions in CO2 emissions. Previous analyses have found that the share that PHEVs are driven in electric mode can differ substantially depending on region, battery size, and trip purpose. Here, we provide a first fleet-wide emissions mitigation potential of US-based PHEV drivers adopting high or low shares of electric driving. Specifically, we illustrate scenarios of different combinations of PHEV uptake, renewable electricity generation shares, and PHEV fueling behavior. Across 21 analyzed scenarios, annual greenhouse gas (GHG) emissions of the light-duty vehicle (LDV) fleet could differ by an average of 21% (5–43% range) in 2050 depending alone on the fueling behavior of PHEV drivers. This behavior could further determine the discharge of about 1.3 (0.7–1.9) Gt CO2 (or roughly one year of current emissions) over the next three decades, significantly influencing the feasibility of reaching an 80% emission reduction target for the LDV sector. Governments can nudge PHEV drivers toward environmentally favorable fueling behavior. We discuss several options for nudging, including charging infrastructure availability, battery design, and consumer education.

Scenarios for transitioning cars from ICEV to BEVs and PHEVs using household level GPS travel data

There has been a continuous effort to quantify the expected greenhouse gas reductions from plug- in electric vehicles (PEVs). Most existing studies are based on standardized driving cycles to compare the performance of PEVs and conventional internal combustion engine (ICE) vehicles. This study is based on assigning the most efficient plug-in hybrid or full electric vehicle to a household based on the household travel behavior as collected by GPS tracking data of thousands of vehicles’ real trips in California, and it found that PEV adoption can reduce greenhouse gas emission by up to 65%. We further explore the market share difference in assigning optimal vehicle models by considering vehicle-based and household-based travel demand, and we found that, given currently available technology, in many cases adoption of Plug-in Hybrid Electric vehicles (PHEVs) will not necessarily result in significantly higher greenhouse gas (GHG) emissions (2.8% higher) compared to battery electric vehicles (BEVs), while PHEVs have advantages to satisfy household’s long-distance travel demand. However, if PHEV drivers never charge their vehicles, the achievable GHG emission reduction will be decreased by nearly 2/3.

Why do some consumers not charge their plug-in hybrid vehicles? Evidence from Californian plug-in hybrid owners

The environmental benefits of plug-in hybrid electric vehicles (PHEVs) are closely related to the driving and charging behavior of vehicle owners. It is often wrongly assumed that PHEV drivers plug-in once per day. Using data from drivers of the vehicles we show this is not the case and that some drivers rarely charge their PHEV. If the vehicle is not plugged-in regularly, the vehicle will drive fewer electric miles and more gasoline miles, thereby losing out on potential emission savings. Analyzing 30-day charging behavior of 5418 PHEV owners using a logistic regression model, we explore the factors that influence driver’s decisions to not charge their vehicle. Several factors play a role in drivers’ decision to plug-in their PHEV or not, including vehicle characteristics and the availability and cost of charging at various locations. Higher home electricity prices, lower electric driving range, lower electric motor power to vehicle weight ratios, lower potential cost savings from charging, and living in an apartment or condo, among other factors are related to not plugging in a PHEV. The findings have important implications in terms of future policy and vehicle design including which PHEVs policymakers should incentivize and what measures can encourage PHEV owners to plug-in their vehicles to help realize the environmental benefits of the technology.

Cost-Effectiveness Analysis of Plug-In Hybrid Electric Vehicles using Vehicle Usage Data Collected in Shanghai, China

This paper investigates the economic viability of plug-in hybrid electric vehicles (PHEV) in Shanghai, China based on a real-world in-use PHEV dataset. To quantify PHEV drivers’ gross profit compared with internal combustion engine vehicle (ICEV) owners, a total cost of ownership (TCO) model is adopted taking account of vehicle retail price, tax credits, subsidies, insurance, maintenance, energy prices, and resale value. The impact of the determinants for gross profit are examined in relation to vehicle distance traveled (VDT) electrically, gasoline price, electricity price, and car-buying cost. It is found that: (1) only 10% of the deployment of PHEVs (i.e., BYD Qin) is economically viable if the benefit from a free license plate is exempt; (2) the 100-kilometer gross profit of PHEVs increases linearly with the electric driving distance, while the saving of energy cost per kilometer decreases with the total VDT; (3) PHEVs’ profit could be significantly improved by reducing the car-buying cost—a decrease of 10% in car-buying cost makes 80% of the PHEV deployment feasible; and (4) if switching the daytime charges to off-peak hours, 50% of the PHEV deployment will become feasible.

Gas anxiety and the charging choices of plug-in hybrid electric vehicle drivers

Plug-in hybrid electric vehicles (PHEVs) can provide many of the benefits of battery electric vehicles (BEVs), such as reduced petroleum consumption and greenhouse gas emissions, without the “range anxiety” that can accompany driving a vehicle with limited range when there are few charging opportunities. However, evidence indicates that PHEVs are often plugged in more frequently than BEVs in practice. This is somewhat paradoxical: drivers for whom plugging in is optional tend to do so more frequently than those for whom it is necessary. This has led to the coining of a new term – “gas anxiety” – to describe the apparent desire of PHEV drivers to avoid using gasoline. In this paper, we analyze the variables influencing the charging choices of PHEV owners, testing whether drivers express preferences consistent with the concept of gas anxiety. We analyze data collected in a web-based stated preference survey using a latent class logit model. The results reveal two classes of decision-making patterns among the survey respondents: (1) those who weight the cost of gasoline and the cost of recharging approximately equally (the cost-minimizing class), and (2) those who weight the cost gasoline more heavily than the cost of recharging (the gas anxiety class). Respondents in the gas anxiety class expressed a willingness to recharge at a charging station even when doing so would cost approximately four times as much as the cost of the gasoline avoided. While the gas anxiety class represents the majority of our sample, more recent PHEV adopters are more likely to be in the cost-minimizing class. Looking forward, this suggests that public charging station operators may need to price charging competitively with gasoline on a per-mile basis to attract PHEV owners.

Cost-Effective and Ecofriendly Plug-In Hybrid Electric Vehicle Charging Management

This study explored two charging management schemes for plug-in hybrid electric vehicles (PHEVs). The PHEV drivers and the government were stakeholders who might have preferred different charging control strategies. For the former, a proposed controlled charging scheme minimized the operational cost during PHEV charge-depleting and sustaining modes. For the latter, the research minimized monetized carbon dioxide emissions from electricity generation for the PHEVs charging, as well as tailpipe emissions for the portion of PHEV trips fueled by gasoline. Hourly driving patterns and electricity data were leveraged. Both were representative of each of the eight North American Electric Reliability Corporation regions to examine the results of the proposed schemes. The model accounted for drivers’ activity patterns and charging availability spatial and temporal heterogeneity. The optimal charging profiles confirmed the differing nature of the objectives of PHEV drivers and the government; cost-effective charge should occur early in the morning, while ecofriendly charge should be late in the afternoon. Each control’s trade-offs between operation cost and emission savings are discussed for each North American Electric Reliability Corporation region. The availability of workplace and public charging was found to affect the optimal charging profiles greatly. Charging control is more efficient for drivers and government when PHEVs have greater electric range.

To save money or to save time: Intelligent routing design for plug-in hybrid electric vehicle

Electric vehicles (EVs) are promising alternative to conventional vehicles, due to their low fuel cost and low emissions. As a subset of EVs, plug-in hybrid electric vehicles (PHEVs) backup batteries with combustion engines, and thus have a longer traveling range than battery electric vehicles (BEVs). However, the energy cost of a PHEV is higher than a BEV because the gasoline price is higher than the electricity price. Hence, choosing a route with more charging opportunities may result in less fuel cost than the shortest route. Different with the traditional shortest-path and shortest-time routing methods, we propose a new routing choice with the lowest fuel cost for PHEV drivers. Existing algorithms for gasoline vehicles cannot be applied because they never considered the regenerative braking which may result in negative energy consumption on some road segments. Existing algorithms for BEVs are not competent too because PHEVs have two power sources. Thus, even if along the same route, different options of power source will lead to different energy consumption. This paper proposes a cost-optimal algorithm (COA) to deal with the challenges. The proposed algorithm is evaluated using real-world maps and data. The results show that there is a trade-off between traveling cost and time consumed when driving PHEVs. It is also observed that the average detour rate caused by COA is less than 14%. Significantly, the algorithm averagely saves more than 48% energy cost compared to the shortest-time routing.

Charging Behavior Impacts on Electric Vehicle Miles Traveled

The growing market for plug-in electric vehicles (PEVs) features new models of battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs) with varying battery sizes and electric driving ranges. How are the various models being used in the real world? A common assumption in PEV impact analysis is that PEV owners will maximize their vehicle's utility by appropriately sizing the battery to their driving needs and by charging their vehicle as much as possible to recover the cost of the vehicle purchase. On the basis of these assumptions, a high correlation between PHEV owner use of the vehicle and the number of plug-in events is expected, and drivers of PHEVs with a small battery are expected to plug in more than do owners of vehicles with a larger battery and similar driving patterns. The assumptions presented are examined through a survey of more than 3,500 PEV owners conducted in California in May and June 2013. The online survey included extensive data on driving and charging behavior using web map questions. Owners of all PEV models on the market, including more than 600 Volts and 800 Prius Plug-Ins, were surveyed. The results show that small-battery PHEV electric vehicle miles traveled are lower than longer-range PHEV or BEV electric vehicle miles traveled not only because of battery size but also because of public charging availability and charging behavior. Higher electric-range PHEV and BEV drivers charge more often and report more charging opportunities in areas where smaller-battery PHEVs could not find chargers.

Anticipating plug-in hybrid vehicle energy impacts in California: Constructing consumer-informed recharge profiles

Plug-in hybrid electric vehicles (PHEVs) can be powered by gasoline, grid electricity, or both. To explore potential PHEV energy impacts, a three-part survey instrument collected data from new vehicle buyers in California. We combine the available information to estimate the electricity and gasoline use under three recharging scenarios. Results suggest that the use of PHEV vehicles could halve gasoline use relative to conventional vehicles. Using three scenarios to represent plausible conditions on PHEV drivers’ recharge patterns (immediate and unconstrained, universal workplace access, and off-peak only), tradeoffs are described between the magnitude and timing of PHEV electricity use. PHEV electricity use could be increased through policies supporting non-home recharge opportunities, but this increase occurs during daytime hours and could contribute to peak electricity demand. Deferring all recharging to off-peak hours could eliminate all additions to daytime electricity demand from PHEVs, although less electricity is used and less gasoline displaced.

Driving Plug-In Hybrid Electric Vehicles

This article examines early users’ experiences with plug-in hybrid electric vehicles (PHEVs). At the time that this study was conducted, in the winter and spring of 2007, PHEVs were not yet commercialized. Still, Americans were becoming aware of PHEVs and 25 to 30 vehicles converted from hybrid electric vehicles (HEVs) to PHEVs were on the road. In interviews with 23 drivers of these vehicles, the present study explored their motivations for converting an HEV to PHEV operation, how they used and recharged their vehicles, and their visions for future PHEV designs. What drivers think about PHEVs, including the benefits and drawbacks that they perceive, was also investigated. Although today's PHEV drivers may not represent either present mainstream American car buyers or future buyers of PHEVs, their behavior and viewpoints offer hypotheses about what ideas might motivate other consumers and clues about how PHEVs will be used by other consumers and may shape both the PHEV technologies offered in the future and the reasons why future consumers will value PHEVs. For example, the group of PHEV pioneers evaluated in the present study is primarily interested in a greater all-electric driving range and performance; they are secondarily interested in high gasoline fuel economy, which they typically report without accounting for electricity from the grid. Which of these two ideas–-all-electric driving and high miles per gallon–-will motivate more consumers? The desirability of feedback to drivers on their on-road energy use and their total gasoline plus electric energy use is also highlighted.

Early U.S. Market for Plug-In Hybrid Electric Vehicles

Plug-in hybrid electric vehicles (PHEVs) are proposed as both a near-term technology to achieve energy and environmental goals and as a transitional step toward viable all-electric vehicles. To replace assumptions with observations of potential PHEV drivers’ behavior in market and impact analyses, an Internet-based survey of 2,373 new-car–buying households in the United States was conducted. The instrument required households to answer questions, complete a driving and parking diary, and then complete several PHEV design exercises. Three conclusions could be drawn from the resulting data. First, at least half of the target population is already equipped for at-home vehicle recharging but has little opportunity for recharging at the workplace or other locations. Second, the study found that the respondents had widely varied interests in four possible PHEV attributes: fuel economy (in both charge-depleting and charge-sustaining operations), blended versus all-electric operation, the distance over which the vehicle is in the charge-depleting mode, and the recharging speed. Nevertheless, the appeal of increased fuel economy appears to be the highest and that of faster recharging appears to be the lowest. Furthermore, there is little interest in all-electric operation. Third, given the previous two points, it was estimated that about a third of the target population has both the infrastructure to recharge a PHEV and interest in a vehicle with plug-in capabilities. Policy, technology, and energy providers may use this information to understand whether their plans, designs, and goals align with these present understandings or whether it would be collectively beneficial to foster new understandings of PHEVs among U.S. car buyers.