654Utilization

Reactant gas utilization also strongly influences the performance of fuel cells. Unlike combustion systems, fuel cells are not typically designed to utilize 100% of the reactants but, rather, a certain fraction of the reactants to allow the presence of reactants along the entire reactive surface area. Without this consideration, reactants would be consumed at the end of the flow channels through the cell, with the final portion of the cell unable to produce a voltage and reducing the overall performance.

The overall voltage of any fuel cell is determined by the portion of the cell with the lowest reactant gas concentration, which changes within each stream as the reactants are utilized. A fuel cell adjusts to the minimum local Nernst potential because the electrodes are typically good electronic conductors leading to isopotential surfaces. Therefore, less than 100% utilization is desired, with some type of reactor (usually catalytic) used to consume the remainder of the fuel to recover thermal energy for use within the system. This understanding notwithstanding, cell efficiency is directly increased with increases in utilization.

Solar Stirling Engine Basics Explained

Solar Stirling Engine Basics Explained

The solar Stirling engine is progressively becoming a viable alternative to solar panels for its higher efficiency. Stirling engines might be the best way to harvest the power provided by the sun. This is an easy-to-understand explanation of how Stirling engines work, the different types, and why they are more efficient than steam engines.

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