TurbuGrid is the name of a small plastic grid approximately 16 x 16 cm that can markedly increase the efficiency of an air-cooled fuel cell stack. Tests by AAU researchers show an increase in efficiency of at least 33.5 percent, but this may be even greater if the grid is added to entirely new fuel cell stacks. The increase is due to the fact that the grid adds turbulence to the air flowing into the channels in the stack. Turbulence has a major effect on the heat transfer that occurs in fuel cells, and this has important implications for how high a power density can be achieved from the fuel cells.