A booming segment of the Perpetual Motion Machine industry is capitalizing on the hype over the "Hydrogen Economy" with claims to produce Hydrogen for impossibly low cost.

2005-02-16

Genesis Scientific Efficiency

It's simple to compare the production numbers Genesis claims for its electrolysis to ideal electrolysis. As we discussed earlier, their "test results" page claims that their "g-cell" can produce 5.3439 cc/minute/square cm using 0.2509 Watts/square cm. Simply dividing the flow per area by the power per area, and dividing by 60 to convert from minutes to seconds, shows 0.3550 cc/Joule. To convert to Joules per mol, we need to convert from cc to mol, for which the ideal gas law calculator provides 4.46175159318548e-05 mol/cc. Also note that even if the vapor is perfectly dry, it's 1/3 O2. So multiply the 0.3550 cc/Joule by 2/3 and 4.4617e-5, and invert the result to obtain 94.71kJ/mol. This compares to an ideal of 285.83 kJ/mol, for 301.8% efficiency.

Genesis's efficiency claims are clearly wrong. It's possible the numbers are simply made up. If there really was a test, it's impossible to say where they went wrong, since the procedures are not spelled out. The Alberta Research Council report on the Xogen process (reviewed earlier) provided enough detail that it was possible to figure out what mistakes they had made.

Genesis has updated their report to state the voltage of their "e-cell" fuel cells, 0.714V. The potential change in for burning Hydrogen is 1.48V, so if their fuel cells operate as they claim, they would convert chemical energy stored in Hydrogen to 48.2% electrical power, and 51.8% waste heat. The waste heat situation is more drastic than the 51.% suggests. Assume, for argument that the 301.8% efficiency claimed for the g-cell is correct. The energy from burning H2 would consist of waste heat (heat), useful energy (useful), and the energy required to produce the H2 (self).

1 - Just from the heat of combustion of H2, we have:
heat + useful + self = 285.83 kJ/mol

2 - From the e-cell performance reported, we have that:
heat/(useful + self) = 51.8/48.2
heat = 1.076 * (useful + self)

Substituting into 1 we get:
2.076 * (useful + self) = 285.83 kJ/mol
useful + self = 137.7 kJ/mol

Subtracting the (impossibly good) 94.7 kJ/mol claimed for the g-cell we get
useful=43.0 kJ/mol

Dividing by 285.83 to convert to percent, we now get that the energy produced by the fuel cell would be allocated:
51.8% - waste heat
33.1% - H2 generation
15.0% - useful energy

So for every Watt of useful power generated, it would generate 3.45 W of heat. Genesis claims they have plans to produce units that would power a home. To produce 10 kW of power, it would produce 34.5 kW of heat. That's as much as two commercial pizza ovens. That would call for a pretty fancy cooling system.