We characterize the effect of regional temperature differences on battery electric vehicle (BEV) efficiency, range, and use-phase power plant CO2 emissions in the U.S. The efficiency of a BEV varies with ambient temperature due to battery efficiency and cabin climate control. We find that annual energy consumption of BEVs can increase by an average of 15% in the Upper Midwest or in the Southwest compared to the Pacific Coast due to temperature differences. Greenhouse gas (GHG) emissions from BEVs vary primarily with marginal regional grid mix, which has three times the GHG intensity in the Upper Midwest as on the Pacific Coast. However, even within a grid region, BEV emissions vary by up to 22% due to spatial and temporal ambient temperature variation and its implications for vehicle efficiency and charging duration and timing. Cold climate regions also encounter days with substantial reduction in EV range: the average range of a Nissan Leaf on the coldest day of the year drops from 70 miles on the Pacific Coast to less than 45 miles in the Upper Midwest. These regional differences are large enough to affect adoption patterns and energy and environmental implications of BEVs relative to alternatives.

We compare life cycle greenhouse gas (GHG) emissions from several light-duty passenger gasoline and plug-in electric vehicles (PEVs) across US counties by accounting for regional differences due to marginal grid mix, ambient temperature, patterns of vehicle miles traveled (VMT), and driving conditions (city versus highway). We find that PEVs can have larger or smaller carbon footprints than gasoline vehicles, depending on these regional factors and the specific vehicle models being compared. The Nissan Leaf battery electric vehicle has a smaller carbon footprint than the most efficient gasoline vehicle (the Toyota Prius) in the urban counties of California, Texas and Florida, whereas the Prius has a smaller carbon footprint in the Midwest and the South. The Leaf is lower emitting than the Mazda 3 conventional gasoline vehicle in most urban counties, but the Mazda 3 is lower emitting in rural Midwest counties. The Chevrolet Volt plug-in hybrid electric vehicle has a larger carbon footprint than the Prius throughout the continental US, though the Volt has a smaller carbon footprint than the Mazda 3 in many urban counties. Regional grid mix, temperature, driving conditions, and vehicle model all have substantial implications for identifying which technology has the lowest carbon footprint, whereas regional patterns of VMT have a much smaller effect. Given the variation in relative GHG implications, it is unlikely that blunt policy instruments that favor specific technology categories can ensure emission reductions universally.

Battery degradation strongly depends on temperature, and many plug-in electric vehicle applications employ thermal management strategies to extend battery life. The effectiveness of thermal management depends on the design of the thermal management system as well as the battery chemistry, cell and pack design, vehicle system characteristics, and operating conditions. We model a plug-in hybrid electric vehicle with an air-cooled battery pack composed of cylindrical LiFePO 4 /graphite cells and simulate the effect of thermal management, driving conditions, regional climate, and vehicle system design on battery life. We estimate that in the absence of thermal management, aggressive driving can cut battery life by two thirds; blended-operation (gasoline-electric mix used when the battery is charged) can quadruple battery life relative to all-electric operation (electric only when the battery is charged); larger battery packs can extend life by an order of magnitude relative to small packs used for all-electric operation; and batteries last 73-94% longer in mild-weather San Francisco than in hot Phoenix. Air cooling can increase battery life by a factor of 1.5 to 6, depending on regional climate and driving patterns. End of life criteria has a substantial effect on battery life estimates.

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The global warming and climate change problem can be solved by emitting less greenhouse gases by transportation. Switching from fossil fuel burning cars to electric vehicle cars is one of the most promising solutions, however; they are as clean as their energy source. In this study, a generic model to estimate energy generation from PV-covered parking lot system and energy demand from electrical cars is established, and Istanbul is selected for a case study. Two main effects are investigated in the demand side: i) ambient temperature and; ii) driving style. In this study, it is considered that a 150 m2 parking lot for 10 cars is covered with 90 PV modules, size of 22.5 kW, to charge EVs in Istanbul, Turkey. The results show that the total annual energy consumption can be covered by a grid-connected PV system. Additionally, an off-grid PV system can cover about 198 and 268 days of energy demand in a year for the urban and highway driving conditions, respectively. Overall, ambient and driving conditions can affect the energy demand by 40%–60%.   Keywords: Driving cycles, electric vehicle, solar charging, temperature effect.