This release is an update and expansion of the information provided in Release 1.0 of the Metering Best Practice Guide that was issued in October 2007. This release, as was the previous release, was developed under the direction of the U.S. Department of Energy's Federal Energy Management Program (FEMP). The mission of FEMP is to facilitate the Federal Government's implementation of sound cost-effective energy management and investment practices to enhance the nation's energy security and environmental stewardship. Each of these activities is directly related to achieving requirements set forth in the Energy

SummaryThere is a growing need for high efficiency, portable and distributed electric power generation. One family of technologies to meet these needs consists of the various forms of fuel cells. This paper is focused on the assessment of sensors and measurement technologies needed to give improved control, diagnostics and data for prognostics for use with high temperature ceramic fuel cells, and for initial demonstration of solid oxide fuel cells (SOFC). This paper also highlights the many challenges and complexities involved with SOFC technology, such as the lack of continuity between research projects, making it difficult to advance the technology in a cooperative manner. Research programs are noted; particularly those that are starting to provide continuity across the wide variety of research projects underway, such as the International Energy Agency. This paper is the result of an extensive literature review and technology evaluation, performed to determine the status of sensors and measurement technologies. It became apparent that many researchers are trying to overcome the same fuel cell design challenges. All researchers have found it difficult to obtain sound data from measurements inside inaccessible designs and heavily insulated enclosures operating at high temperatures. Although some advancement has been made in materials, systems modeling, and innovative manufacturing techniques, few answers have been found in the measurement and diagnostics field.Understandably, most approaches to measurements and diagnostics in fuel cells have been to extend an existing practice to solid oxide fuel cells, such as adapting established aqueous electrochemistry techniques (i.e., impedance spectroscopy). Although this technique has manifested some key characteristics of the SOFC, and is arguably one of the most advanced techniques in this field, work is still needed to resolve disagreements on the application and interpretation methods.Realizing the many constraints involved in SOFC testing and resolved to the fact that simple approaches may not be the complete answer, several innovative techniques and geometries have been tried and included in this report. Many researchers are using a combination of in-situ and ex-situ tests, involving a variety of disciplines and multiple steps to compile a range of diagnostic tools, as well as data acquisition and analysis equipment, which can be adopted to the SOFC technology. This has merit, but requires extensive cooperation between all involved throughout all the stages of the product development. These measurement tools will enable analysis of degradation mechanics leading to development of prognostic tools that can be used to analyze fuel cells and balance of plant (BOP) systems during research and development, subsequently minimizing operating costs and enhancing overall system efficiency. v

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