Energy loss converting water to hydrogen then back to water

[mrwabba]

i was doing a little thinking and have a pretty good idea but to see if it will even come close working i need to know how much energy loss is there converting water to hydrogen then back to water. using Electrolysis to split the water and a fuel cell to rejoin them back together. i know you can't get as much energy back as i put in just need to know the loss. in a percentage would work best.

 

[Danger]

Welcome to PF, Mrwabba. The efficiency of both processes depends upon how your approach them. There are different ways of doing both.

 

[engineroom]

If you used low cost electictiy to make the hydogen and then produced electricity for a higher cost you come out in front where it counts in the wallet.

Where I live night rate electicity is 8c/kWhr and day rate 22c/kWhr. If the efficency of the process was say 90% there is a way to make money. Each kilowatt hour of electricy would reep a nett return of 13c/kWhr.

Is it posiable to build a hydogen generator, storage cylinder and fuel cell relativly cheeply - might be worth building one for home use.