Electrolysis is currently being used to produce extremely pure Hydrogen for use by the national space program (NASA) and by the private sector in the pharmaceutical, electronics, and food industry (DOE 1995). NASA uses electrolysis to produce hydrogen for use on the space shuttles. The hydrogen is used to fuel the rocket boosters as well as power the ships internal systems, fuel cells.
A high operating cost has forced the use of this production method to be limited. Using current technology, the cost of producing this extremely pure Hydrogen is relatively high, to the now popular method of hydrogen production through natural gas steam reforming. Most of the cost of electricity (80%) is that required to fuel the reaction. (DOE 1995). With present technology, the yield of hydrogen from electricity is less than 8%. The US DOE has set a goal to research different approaches until they reach an acceptable yield of 10% for widespread use. This yield will be reached with the advent of more efficient semi-conductors which can withstand corrosion introduced in this process. 揗ost semiconductors are thermodynamically unstable in water.?NREL 1999)
What is the optimum source for electric current to fuel the reaction? To keep this process completely renewable, proposals are being made and evaluated for the possibility to supply the electric current using one of three natural systems: Solar power, Wind power, and Hydropower. Of these three processes the process that is showing the most promise to researchers is Solar, or Photo Electrolysis.
Sources of Electricity
PhotoElectrolysis. In this process solar panels absorb sunlight and converts into a electric current for use in the electrolysis reaction.
Below is a schematic of the process for which a typical photoelectrolysis process will occur. Sunlight (hv) will be collected by the solar panels or 揝olar Cell.?nbsp; Here the sunlight will be converted into an electric current that will then proceed to the electrolyzer or 搒emiconductors.?Here the reaction will occur and the water will be split into hydrogen gas and oxygen gas.
The only long-term costs with this system will result from the water supply and periodic maintenance, if needed. The current problem with this system is the large initial startup cost. Currently the cost of efficient solar panels is astronomical, therefore not very practical.
Currently there are numerous studies as to the feasibility of photoelectrolysis. Numerous institutions are investigating the possible materials that can lower the cost for the solar panels to be used in this process.
Wind Electrolysis. The source of electricity for this process is, quite simply, wind. Wind will be harnessed through the use of windmills and power generators.
The windmills will power the generators that will then fuel the electrolysis process. At this time there is study in Southern New York, which, in cooperation with Cornell University, is studying the feasibility of 揥ind-Hydrogen Power.?nbsp;
Hydro Electrolysis. Hydro Electrolysis entails using hydroelectric power plants to fuel the electrolysis process. Using this process will be not as widespread as the above-mentioned processes. Currently Hydroelectric power plants are few and far between, and the environmental requirements for the construction and use of one are quite limiting factors.
