Rating the performance of residential fuel cells

Residential fuel cells sound almost too good to be true. Take a hydrocarbon fuel such as natural gas, use a catalyst to extract hydrogen from it, react the hydrogen with air and, presto, you have a home power plant!

As the hydrogen and the oxygen in the air combine, they produce electricity. The primary “waste products” of the whole process are water and heat. But that’s not all! The “waste” heat can be captured to provide space or water heating for the home.

Residential fuel cell systems can produce about five kilowatts of power or 120 kilowatt-hours of energy a day–more than enough to operate the average household. But a lack of performance data on how well fuel cells work under different conditions is one of several factors slowing marketplace acceptance of the new technology.

Researchers at the National Institute of Standards and Technology (NIST) have just launched an effort to supply the needed information. They are studying how changing electrical and heating demands, outside temperatures, humidity and power systems affect the efficiency of fuel cells made by different manufacturers.

NIST will submit its draft fuel cell test procedures and rating methodology to a standards committee composed of industry, independent standard organizations, government and academic representatives. With consensus procedures in place, fuel cell manufacturers should be able to evaluate and improve the electrical and thermal energy efficiency and output of their products. Ultimately, consumers will be able to use NIST-developed performance ratings to understand the financial costs and benefits of fuel cells operated in specific geographic and climate conditions, at different times of the year, and for different purposes such as heating or electricity generation.