玉米——以及纤维素——制造的生物燃料是“最糟糕的选项”
一项根据能源使用的影响为未来能源排序的研究发现生物燃料是最糟糕的选项。
根据这项分析，使用乙醇导致了最多的气候破坏、空气污染、陆地和野生生物的破坏，以及化学废物。
该研究称这是“首次对已经提出的全球变暖、空气污染和能源保障的大规模解决方案的全面比较性评估”，它考虑了利用11种不同的能源为3种新技术汽车提供能量的影响。这些汽车使用电池、氢燃料电池或者乙醇燃料。
它权衡了它们对于全球变暖、空气和水污染以及热污染（例如电厂把冷却液中的热传递给水）。它还考虑了它们对于水资源供应、陆地使用、野生生物和资源可用性的影响。研究还考虑了对能源保障、核扩散、死亡率以及营养不良的间接影响。
该研究发现为电池汽车提供能量的风力发电的表现最佳。这一组合在7个问题上都表现最好，“包括最重要的问题——降低死亡率和气候破坏，”该研究的作者、美国斯坦福大学的大气/能量项目的负责人Mark Jacobson说。风电为燃料电池汽车提供能量的组合稍逊于前者。
居于第二层次的是利用太阳光伏发电或聚光太阳能发电（把大片太阳光聚集成高能量的光束）以及地热、潮汐和波浪发电的电力的电池汽车。第三层次包括利用氢能源、核能、使用碳捕获和贮存技术的煤电厂提供电力的电池汽车。
两个液体燃料选项——玉米-E85和纤维素-E85乙醇——排在最后。
但是约旦原子能委员会的燃料循环委员Ned Xoubi说：“发展中国家急需能源。能获得的可持续的、廉价的、清洁的能源的最佳选择是核能。”
“它是全世界最有竞争力的能源之一，比风电成本更低，需要的土地更少。”
埃及开罗的国立研究中心的生物技术专家Magdi Tawfik Abdelhamid说：“没有科学理由把生物燃料放在最糟糕的能源选项的清单上。发展中国家利用海藻生产生物燃料可以被认为是一种廉价、对环境友好的能源，它不会危及粮食安全。”
该研究发表在上月（12月1日）出版的《能源和环境科学》杂志上。（生物谷Bioon.com）
生物谷推荐原始出处：
Energy Environ. Sci., 2009DOI: 10.1039/b809990c
Review of solutions to global warming, air pollution, and energy security
This paper reviews and ranks major proposed energy-related solutions to global warming, air pollution mortality, and energy security while considering other impacts of the proposed solutions, such as on water supply, land use, wildlife, resource availability, thermal pollution, water chemical pollution, nuclear proliferation, and undernutrition. Nine electric power sources and two liquid fuel options are considered. The electricity sources include solar-photovoltaics (PV), concentrated solar power (CSP), wind, geothermal, hydroelectric, wave, tidal, nuclear, and coal with carbon capture and storage (CCS) technology. The liquid fuel options include corn-ethanol (E85) and cellulosic-E85. To place the electric and liquid fuel sources on an equal footing, we examine their comparative abilities to address the problems mentioned by powering new-technology vehicles, including battery-electric vehicles (BEVs), hydrogen fuel cell vehicles (HFCVs), and flex-fuel vehicles run on E85. Twelve combinations of energy source-vehicle type are considered. Upon ranking and weighting each combination with respect to each of 11 impact categories, four clear divisions of ranking, or tiers, emerge. Tier 1 (highest-ranked) includes wind-BEVs and wind-HFCVs. Tier 2 includes CSP-BEVs, geothermal-BEVs, PV-BEVs, tidal-BEVs, and wave-BEVs. Tier 3 includes hydro-BEVs, nuclear-BEVs, and CCS-BEVs. Tier 4 includes corn- and cellulosic-E85. Wind-BEVs ranked first in seven out of 11 categories, including the two most important, mortality and climate damage reduction. Although HFCVs are much less efficient than BEVs, wind-HFCVs are still very clean and were ranked second among all combinations. Tier 2 options provide significant benefits and are recommended. Tier 3 options are less desirable. However, hydroelectricity, which was ranked ahead of coal-CCS and nuclear with respect to climate and health, is an excellent load balancer, thus recommended. The Tier 4 combinations (cellulosic- and corn-E85) were ranked lowest overall and with respect to climate, air pollution, land use, wildlife damage, and chemical waste. Cellulosic-E85 ranked lower than corn-E85 overall, primarily due to its potentially larger land footprint based on new data and its higher upstream air pollution emissions than corn-E85. Whereas cellulosic-E85 may cause the greatest average human mortality, nuclear-BEVs cause the greatest upper-limit mortality risk due to the expansion of plutonium separation and uranium enrichment in nuclear energy facilities worldwide. Wind-BEVs and CSP-BEVs cause the least mortality. The footprint area of wind-BEVs is 2–6 orders of magnitude less than that of any other option. Because of their low footprint and pollution, wind-BEVs cause the least wildlife loss. The largest consumer of water is corn-E85. The smallest are wind-, tidal-, and wave-BEVs. The US could theoretically replace all 2007 onroad vehicles with BEVs powered by 73000–144000 5 MW wind turbines, less than the 300000 airplanes the US produced during World War II, reducing US CO2 by 32.5–32.7% and nearly eliminating 15000/yr vehicle-related air pollution deaths in 2020. In sum, use of wind, CSP, geothermal, tidal, PV, wave, and hydro to provide electricity for BEVs and HFCVs and, by extension, electricity for the residential, industrial, and commercial sectors, will result in the most benefit among the options considered. The combination of these technologies should be advanced as a solution to global warming, air pollution, and energy security. Coal-CCS and nuclear offer less benefit thus represent an opportunity cost loss, and the biofuel options provide no certain benefit and the greatest negative impacts.
