ERRATA: I have written above erroneously that the weight of the required water would be "about two thirds". Hours later, when going to sleep, I remembered that

ERRATA: I have written above erroneously that the weight of the required water would be "about two thirds". Hours later, when going to sleep, I remembered that I had made this mistake. The correct water weight is about 39% of the sodium weight, but this does not change in any way what I had written, because with this additional water weight plus the weight of its container plus the weight of the air humidifier plus air pumps plus the starter battery and the heater plus electronic controller etc., it seems unlikely that the specific energy of the electrode stack will be reduced by a factor of only 1500/1000 for the complete system.