I would like to establish a Figure of Merit that can be
applied to any design of an electrolyser. At 1.47 volts or
very close to this figure an electrolyzer is 100% efficient.
At this voltage it takes 8.06 BTU to make a liter of e-gas
and there is also 8.06 BTU in each Liter of e-gas at STP.
To make a liter of e-gas in 1 hour represents an input power of
(1.47 X 1.6 =) 2.3516 watts. So therefor if a given electrolyzer
produces X liters per hour at STP and draws Y watts it's Figure
of Merit would be calculated by dividing the watts drawn by
the liters produced per hour by the reciprocal of 2.3516 which
is 0.42524
Thus (Y/X)/0.42524 = Z
Where Z would be multiplyed by 100 to get the %.

There are electrolysers that are almost 115% efficient. The US patent
4,392,230 (by Henery K Puharich) shows a method that is
114.92 % efficient. Don Lancaster points out that operation in
the endothermic region requires only 1/6 of the energy in heat
input of the energy gain in productivity of the gas. This is
true O/U. Up to 116.66 % efficiency can be obtained by this
method. Peter Lawrie talks of operating at a voltage as low as
1.27 volts per cell. This is well into the endothermic region.

I am proposing that all resonant and HV cells be tested for gas
production and be rated by this Figure of Merit.

My vertical cell of 1998 that I thought was very efficient
turned out to have a Figure of Merit of only 39%