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Finding The Right Yardsticks For Evaluating Future Energy Sources

by Carolyn Ribes Chair, Committee on Science
May 25, 2009 | A version of this story appeared in Volume 87, Issue 21

Credit: Al Ribes
Credit: Al Ribes

ENERGY. Our world confronts few, if any, challenges of a greater global importance. During recent years, and especially over the past few months, we have seen an increased emphasis on energy systems in the scientific literature, the popular press, and in legislative discourse. We read weekly about potential developments for alternative energy sources, distribution systems, and storage systems.

But the path forward is not clear. There are many parallel avenues for research with different goals and timelines. A number of the adjectives we apply to the word "energy" change our view of what we need for the future: affordable, available, secure, renewable, safe, environmentally friendly, accessible, et cetera. But all of these descriptors focus our attention on just one facet of our future energy supply needs. How do we, as a nation, select the right research and development projects to invest in? What is the desired outcome, and what data do we need to consider when comparing different platforms?

Earlier this year, ACS and the American Institute of Chemical Engineers (AIChE) issued a public policy statement entitled "Framework for a 21st Century United States Energy Strategy: Objective Decision-Making in a Complex Energy Landscape." The document described the need for a comprehensive framework for comparing various energy sources, both alternative and traditional. It called for setting appropriate boundaries and for developing consensus on critical factors to consider. The ACS/AIChE policy statement issued recommendations on the roles that various agencies and entities should play in assembling the data that will drive decision-making. This document can be found at on the Policy tab (then select "Public Policies"/"Foster Innovation"/ "Energy S&T").

We are now proceeding to the next phase of this process: defining the evaluation framework. As chemists, we are accustomed to measurements and the use of metrics for evaluating performance, processes, and products. When we apply the concept of metrics to our work, we realize that metrics are only valid when used for their intended purpose and are limited by specific constraints. Moreover, metrics cannot necessarily be extrapolated to other situations. We also know that boundaries and quantitation scales must be clearly defined. While this can be challenging enough in a laboratory or manufacturing environment, it can become a daunting task when trying to define metrics—including cradle-to-grave costs—across multiple societal, environmental, economic, and safety fronts.

How do we, as a nation, select the right research and development projects to invest in? What is the desired outcome, and what data do we need to consider when comparing different platforms?

Currently, a team with representation from several ACS committees is collaborating with AIChE to develop a recommendation that defines which evaluation criteria are most significant and should be weighed most heavily. There are myriad aspects to consider, and each may have several levels of complexity. For example, consider the economic impact: Do we worry only about the direct costs? What about intangible costs, long-term liabilities, and external costs? How important are these compared with the environmental impact of the technology? Do we have to account for the costs of carbon dioxide in addition to the costs of generating the energy? In addition to the economic and environmental aspects, how do we factor in societal and safety issues? Where do we start and stop the analysis—do we include distribution and storage, raw material production, et cetera? What are the boundaries of the metrics?

WHEN SELECTING these criteria and developing metrics, it is useful to consider broad and diverse perspectives, including those from various stakeholders. Collecting input from a number of sources is one way to ensure that we consider as many avenues as possible. Our team consists of members from the following ACS committees: Science, Environmental Improvement, Corporation Associates, and Chemistry & Public Affairs. Each will approach the issue from their particular point of view. However, we realize that many perspectives are not represented on this group of committees; broader views and experiences are needed. Therefore, we are inviting you to share your comments on the three most critical factors to consider when evaluating energy systems and sources.

How can you contribute your input? We have established a discussion forum on the ACS Network ( for this effort. If you are already a member of the network, take a look at the existing thread and add your comments. If you have not yet joined the network, register today at to participate in the discussion. Please post your suggestions and feel free to comment on other postings. If you are not able to access the network, you may e-mail comments to We will monitor data until July 15. After that, we will collate comments into a draft evaluation framework. We look forward to reading your opinions.

Views expressed on this page are those of the author and not necessarily those of ACS.



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