latory standards, or both, to widely apply the new technologies.
- The unit cost of batteries will decline with increased production and development; additionally, the energy storage (in kWh) required for a given vehicle range will decline with vehicle load reduction and improved electrical component efficiency. Therefore battery pack costs in 2050 for a 100-mile real-world range are expected to drop by a factor of about 5 for the midrange case and at least 6 for the optimistic case. However, even these costs are unlikely to allow a mass-market vehicle with a 300-mile real-world range. In addition to the weight and volume requirements of these batteries, they are unlikely to be able to be recharged in much less than 30 minutes. Therefore BEVs may be used mainly for local travel rather than as all-purpose vehicles.
- BEVs and PHEVs are likely to use Li-ion batteries for the foreseeable future. Several advanced battery technologies (e.g., lithium-air) are being developed that would address some of the drawbacks of Li-ion batteries, but their potential for commercialization by 2050 is highly uncertain and they may have their own disadvantages.
- PHEVs offer substantial amounts of electric-only driving while avoiding the range and recharge time limitations of BEVs. However, their larger battery will always entail a significant cost premium over the cost of HEVs, and their incremental fuel savings will decrease as the efficiency of HEVs improves.
- The technical hurdles that must be surmounted to develop an all-purpose vehicle acceptable to consumers appear lower for FCEVs than for BEVs. However, the infrastructure and policy barriers appear larger. Well before 2050, the cost of FCEVs could actually be lower than the cost of an equivalent ICEV, and operating costs should also be lower. FCEVs are expected to be equivalent in range and refueling time to ICEVs.
- Making CNG vehicles fully competitive will require building large numbers of CNG fueling stations, moving to more innovative tanks to extend vehicle range and reduce the impacts on interior space, and developing manufacturing techniques to reduce the cost of CNG storage tanks.
- If CNGVs can be made competitive (both vehicle cost and refueling opportunities), they offer a quick way to reduce petroleum consumption, but the GHG benefits are not great.
- Codes and standards need to be developed for the vehicle-fueling interface.
- International harmonization of vehicle safety requirements is needed.
- While fundamental research is not essential to reach the targets calculated in this chapter, new technology developments would substantially reduce the cost and lead time to meet these targets. In addition, continued research on advanced materials and battery concepts will be critical to the success of electric drive vehicles. The committee recommends the following research areas as having the greatest impact:
—Low-cost, conductive, chemically stable plate materials: fuel cell stack;
—New durable, low-cost membrane materials: fuel cell stack and batteries;
—New catalyst structures that increase and maintain the effective surface area of chemically active materials and reduce the use of precious metals: fuel cell stack and batteries;
—New processing techniques for catalyst substrates, impregnation and integration with layered materials: fuel cell stack and batteries;
—Energy storage beyond Li-ion: PHEVs and BEVs;
—Reduced cost of carbon fiber and alternatives to PAN as feedstock;
—Replacements for rare earths in motors;
—Waste heat recovery: ICEVs, HEVs, and PHEVs; and
—Smart car technology.
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