How much energy does it take to create 1 kg of H2 using electrolysis in KW?

Question

I was just sitting around thinking about this and wasn't sure how much energy an electrolysis devices uses. Does anybody know roughly the amount of energy they use? It doesn't have to be KW, if there is another unit that is more convenient please use it (Watts, etc).

Answer 1

you'd have to run 70,000 watts for 1 hour to get 1 Kg of H2 gas at atmospheric conditions.  Thats a 120HP engine running full out for an hour.  When you are done, the H2 gas could be fed into and engine and it would run the same 120 HP engine for 15 minutes.

stay away from H2.

Answer 2

Well for a start, kW-hr or joules would be better units, kilowatts is a unit if power not energy, power x time give you energy. Now if you specified a time period for producing the 1kg H2 then kW would be appropriate.

Do you want to know the theoretical value or the practical value? in real life the efficiency is not 100% and cheap (perhaps home made) cells are not as efficient as some more expensive ones.

However, I don't know a number. :(