I cant find my reference books that have the hydrogen related conversion info.
(I cleaned house some and now I cant find anything!)
I do recall that a KG of hydrogen gas takes something like 26 KWH of electricity to produce. But without my reference material I dont recall how many liters that actually equates to at standard temperature and pressure. But its allot!
If your going to be needing any quantity of hydrogen gas I hope you live in the United states! Its legal to buy it at any big welding supply store.
You just have fill out the safety paper work and thats about all.
I have a T size tank that costs me $26 a year for the lease and about $22 to get it refilled. I think it holds something like 280 Cubic Feet at around 3000 PSI.
You will need a high pressure regulator to bring it down to a normal working pressure first.
There is no way I can make my own yet at the volume that this tank holds and still have the high purity too! For baseline reference testing you cant beat it!
As far as making hydrogen Or HHO gas the information on the web is more often than not grossly wrong!
I have worked on it personally and you do not need high voltage ever! You do need high current though. A simple electrolysis cell takes around two volts.
There are many types of electrode materials that work but I have found to work good and use is called type 403 stainless steel and it works super with sodium hydroxide and water as the electrolyte.
Sodium hydroxide (Na-OH) is commonly sold as Red Devil Drain Cleaner. It is 100% sodium hydroxide in crystal form. Very cheap too!
A good secret to getting great gas production is to actually scuff up the Electrode surfaces with very course sand paper and then clean them with alcohol. And try to keep the electrode plates about 1/8 of an inch apart.
The Na-OH electrolyte should be mixed to its saturation point. That is you keep adding it to distilled water until it will no longer dissolve.
Being Na-OH is a solid at normal temperatures it will stay in the electrolyte and only the water gets turned into HHO gas. All you ever need to do is add more water to your system.
Putting the electrolysis cells in series will also allow you to use normal voltages to do the HHO production. So you wont need a 2 volt 1000 amp power source to do it. A stack of cells can run at 20 amps and 100 volts and still give you the same gas volume outputs.
And above all, use saftey to an obsessive level. You are working with water and electricity along with chemicals that eat flesh rather well and you are making an explosive mixture of gasses!
You have electrocution, explosion and chemical burns all working together to try and kill you!