Can the cost of hydrogen from electrolyzed water go to $1 per cubic meter

First, let's look at the situation under ideal conditions. 1 mol of H2O reversibly (that is, very close to equilibrium and with no energy dissipation) electrolyzed to produce H2 and O2 (the pressure of the resulting gases is 100 kPa) at 298 K (25 degrees Celsius) and an external pressure of 100 kPa requires the consumption of 237.1 kJ of electrical energy in addition to the absorption of 48.7 kJ of heat.

Assume that hydrogen is an ideal gas. According to the ideal gas equation of state pV = nRT, 1 cubic meter of hydrogen at 298K, 1 standard atmospheric pressure has an amount of matter of 40.9mol, and requires at least electrical energy x 40.9 = 9,697,000J.

The actual need to use 5 kWh of electricity, 1 kWh is equal to 1,000 J / s × 3600s = 3.6 million J, 5 kWh is 18 million J, 969.7 ÷ 1800 = 54%. In many cases the actual results can be 20%-30% of the theoretical value is good, can have greater than 50% utilization is really not easy.