Apparent excess heat is observed in light wafer electrolytic cells con
taining a variety of nickel cathodes, a platinum anode, and an electro
lyte of K-2 CO3 in H2O. High-accuracy calorimetric measurements show a
pparent excess heat in the range of 15 to 37% of input power if a 100%
Faraday efficiency is assumed for H-2 and O-2 gas release. The H-2 an
d O-2 gases released during electrolysis are recombined in a vessel ex
ternal to the cell, and the quantity of recombined H2O is compared wit
h the quantity of H2O expected from 100% efficient electrolysis. The m
easured Faraday efficiency is shown to be significantly <100%, and con
ventional chemistry can account for the entire amount of observed appa
rent excess heat to within an accuracy of better than 0.5%.