How many KG if H2 to produce 1 KWH of electrcity

In general, to produce 1 kilowatt (kW) of electricity for 1 hour (one kilowatt-hour, kWh) from a proton exchange membrane (PEM) fuel cell requires about 25-27 standard cubic feet (scf) of hydrogen. A standard cubic foot (scf) is the amount of hydrogen that occupies one cubic foot of space when it is not pressurized (in other words, at regular atmospheric pressure) and at 60 degrees F (a little cooler than room temperature). However, if multiple fuel cells can work in serial and reuse h2 again and again then possibily we can generate more electricty based of the fuel cells.