PEM fuel cell efficiency

What is the typical electrical efficiency of a PEM fuel cell? Is there any
empirical data available on the Internet? Some posters in this forum
believe that 60% electrical efficiency has been achieve with PEM
technology. Can anyone cite data collected from an actual PEM fuel cell
that will support this figure?

If such data is available, I would like to understand how it was collected
and analyzed (for example, what figure was used for the heating value of
hydrogen?)

Don W.


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