Marriott Joe, Matthews H Scott
Department of Civil and Environmental Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA.
Environ Sci Technol. 2005 Nov 15;39(22):8584-90. doi: 10.1021/es0506859.
Although many studies of electricity generation use national or state average generation mix assumptions, in reality a great deal of electricity is transferred between states with very different mixes of fossil and renewable fuels, and using the average numbers could result in incorrect conclusions in these studies. We create electricity consumption profiles for each state and for key industry sectors in the U.S. based on existing state generation profiles, net state power imports, industry presence by state, and an optimization model to estimate interstate electricity trading. Using these "consumption mixes" can provide a more accurate assessment of electricity use in life-cycle analyses. We conclude that the published generation mixes for states that import power are misleading, since the power consumed in-state has a different makeup than the power that was generated. And, while most industry sectors have consumption mixes similar to the U.S. average, some of the most critical sectors of the economy--such as resource extraction and material processing sectors--are very different. This result does validate the average mix assumption made in many environmental assessments, but it is important to accurately quantify the generation methods for electricity used when doing life-cycle analyses.
尽管许多发电研究采用国家或州的平均发电组合假设，但实际上，大量电力在化石燃料和可再生燃料组合差异很大的州之间传输，使用平均数据可能会导致这些研究得出错误结论。我们根据现有的州发电概况、州电力净进口量、各州的产业分布以及一个用于估算州际电力交易的优化模型，为美国的每个州和关键行业部门创建电力消费概况。在生命周期分析中，使用这些“消费组合”可以更准确地评估电力使用情况。我们得出结论，对于进口电力的州而言，已公布的发电组合具有误导性，因为该州消费的电力构成与所发电的电力构成不同。而且，虽然大多数行业部门的消费组合与美国平均水平相似，但一些最关键的经济部门——如资源开采和材料加工部门——却大不相同。这一结果确实验证了许多环境评估中所采用的平均组合假设，但在进行生命周期分析时准确量化所使用电力的发电方法非常重要。
