That is great... we need stuff like that today.

here is some more info on it. It still used electricity though (i believe) witch come from fossil fuel. Great stuff though...

2.2.2.1. Electrolysis of water
High/low heating values and efficiency
The heating value, i.e. the amount of heat energy that can be derived from a fuel by burning it, is rated with a high and a low value. The high value denotes the total energy of the fuel, while the low value takes into consideration that the resulting product gas can be condensed into water, subtracting this condensation energy (latent heat) component. When calculating the efficiency in a fuel cell, the low heating value is normally used, i.e.: electrical energy produced / low heating factor * 100%. In the electrolysis process, the high heating value is usually used.



Water electrolysis is splitting water into hydrogen and oxygen. An electrolyser is a device for electrolysis. Water is subjected to electrical power and the result is hydrogen and oxygen.

2H2O + energy -> 2H2 + O2

This is the opposite reaction of what happens in a fuel cell (see 2.3.1). It is common to classify electrolysers according to the electrolyte it uses. Several cells are connected to achieve the desired capacity, just as with fuel cells. Some common electrolysers are as follows:


Two atmospheric electrolysers, each at 200 Nm3/h
(photo: Norsk Hydro)

Norsk Hydro




Alkaline electrolysers
In alkaline electrolysers a liquid electrolyte is used ?? typically a 25% potassium hydroxide solution.
Hydrogen production using alkaline electrolysers is long-established in Norway. At Norsk Hydro, industrial water electrolysis of hydrogen for the production of ammonia was carried out from 1928 to 1988.

Norsk Hydro Electrolysers (NHE) is today a leading producer of alkaline electrolysers. Some of NHE??s electrolysers have an efficiency of over 80% (high heating value). Efficiency is an important factor in electrolysis because the use of energy (~4.5 kWh/NM3H2) makes up a significant portion of the costs at an electrolysis plant. (How much will depend on the cost of the electricity. NHE estimates approximately 2/3 of operating expenses as a rule of thumb.) Electrolysers are most effective when running on a low production rate, due to low current density. Optimum economy of operation will depend both on current density, cost of production materials and the demands for H2 production.

NHE and Gesellschaft für Hochleistungwasserelektrolyseure (GHW) have developed a compact electrolysis system that can produce hydrogen equivalent to the energy supply of a standard gasoline station. These electrolysers operate under pressure, and the product is hydrogen under moderate pressure (30 bar).

Another leading manufacturer of electrolysers, Stuart Energy, has also made a small prototype of a home garage electrolyser with compressor and everything else inside a small gray box.



Polymer electrolyte membrane (PEM) electrolysers
Another type of electrolyser utilises polymer membranes as electrolytes (PEM). Much of the heavy technological development which is currently going on in PEM fuel cells can be transferred to the electrolysers, which will probably benefit from the mass production of PEM fuel cells.

Several PEM electrolysers are already being sold today, even though this is relatively new technology compared to alkaline electrolysers. Efficiency factors for PEM electrolysers up to 94% are predicted, but this is only theoretical at this time. Today, the efficiency factors for PEM electrolysers are lower than for the best alkaline electrolysers. PEM electrolysers function very well with renewable energy systems where the amount of electricity varies greatly. Generally speaking, PEM electrolysers are best suited for small plants, especially plants with varying output, while alkaline electrolysers are clearly an advantage in larger systems which are connected to the power grid.



Steam electrolysers
A third type of electrolysers is the so-called steam electrolysers. These use a ceramic ion-conducting electrolyte. Steam electrolysers can reach a very high efficiency factor, but are currently not commercially feasible.[NYTEK 2000] A tubular steam electrolyser, which should also be able to be run in a fuel cell stack (fuel cells connected in a series), are under development at Lawrence Livermore National Laboratory. Another type of steam electrolyser is the German ??Hot Elly?; this system can reach an efficiency of 92%. [NREL 2000]