Solar Energy Project at the Weizmann Institute Promises to Advance the Use of Hydrogen Fuel

REHOVOT, ISRAEL -- August 6, 2005 -- Innovative solar technology that may offer a “green” solution to the production of hydrogen fuel has been successfully tested on a large scale at the Weizmann Institute of Science in Israel. The technology also promises to facili-tate the storage and transportation of hydrogen. The chemical process behind the techno-logy was originally developed at Weizmann, and it has been scaled up in collaboration with European scientists. Results of the experiments will be reported in August at the 2005 Solar World Congress of the International Solar Energy Society (ISES) in Orlando, Florida.

The solar project is the result of collaboration between scientists from the Weizmann Institute of Science, the Swiss Federal Institute of Technology, Paul Scherrer Institute in Switzerland, Institut de Science et de Genie des Materiaux et Procedes - Centre National de la Recherche Scientifique in France, and the ScanArc Plasma Technologies AB in Swe-den. The project is supported by the European Union's FP5 program.

Hydrogen, the most plentiful element in the universe, is an attractive candidate for beco-ming a pollution-free fuel of the future. However, nearly all hydrogen used today is produ-ced by means of expensive processes that require combustion of polluting fossil fuels. Moreover, storing and transporting hydrogen is extremely difficult and costly.

The new solar technology tackles these problems by creating an easily storable interme-diate energy source form from metal ore, such as zinc oxide. With the help of concentrated sunlight, the ore is heated to about 1,200°C in a solar reactor in the presence of wood char-coal. The process splits the ore, releasing oxygen and creating gaseous zinc, which is then condensed to a powder. Zinc powder can later be reacted with water, yielding hydrogen to be used as fuel, and zinc oxide, which is recycled back to zinc in the solar plant. In recent experiments, the 300-kilowatt installation produced 45 kilograms of zinc powder from zinc oxide in one hour, exceeding projected goals.

The process generates no pollution, and the resultant zinc can be easily stored and trans-ported, and converted to hydrogen on demand. In addition, the zinc can be used directly; for example, in zinc-air batteries, which serve as efficient converters of chemical to elec-trical energy.  Thus, the method offers a way of storing solar energy in chemical form and releasing it as needed.

“After many years of basic research, we are pleased to see the scientific principles develo-ped at the Institute validated by technological development,” said Prof. Jacob Karni, Head of the Center for Energy Research at Weizmann.

“The success of our recent experiments brings the approach closer to industrial use,” says engineer Michael Epstein, project leader at the Weizmann Institute.

The concept of splitting metal ores with the help of sunlight has been under development over the course of several years at the Weizmann Institute's Canadian Institute for the Energies and Applied Research, one of the most sophisticated solar research facilities in the world, which has a solar tower, a field of 64 mirrors, and unique beam-down optics. The process was tested originally on a scale of several kilowatts; it has been scaled up to 300 kilowatts in collaboration with the European researchers.

Weizmann scientists are currently investigating metal ores other than zinc oxide, as well as additional materials that may be used for efficient conversion of sunlight into storable energy.

The research from this press release will be presented at the ISES 2005 Solar World Congress - Bringing Water to the World (http://www.swc2005.org/), scheduled to take place during August 6 - 12, 2005 in Orlando, FL, US.

Prof. Jacob Karni's research is supported by the Sussman Family Center for the Study of Environmental Sciences; the Solomon R. and Rebecca D. Baker Foundation; the Angel Faivovich Foundation for Ecological Research; Mr. Nathan Minzly, UK; the Abraham and Sonia Rochlin Foundation; Mr. and Mrs. Larry Taylor, Los Angeles, CA; Dr. and Mrs. Robert Zaitlin, Los Angeles, CA; and the Arnold Ziff Charitable Foundation.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the na-tural and exact sciences, the Institute is home to 2,500 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

FAEC's COMMENT: On September 28th, 2005, we received the following comment from a reader, and we feel it deserves publication because it raises very important questions as to the real validity of the study and the project. We'll leave the debate open for other readers that might think different.

Dear Sirs:

There's a small problem with the report from Rehovot regarding the solar produc-tion of zinc. This problem goes under the name "wood charcoal," mentioned in the story.

What is passed over lightly is the obvious point (to any chemist) that the wood charcoal is needed to chemically reduce the zinc oxide to metallic zinc, which is what happens in any conventional metals production furnace.

The unmentioned second product is CO2 -- otherwise known as carbon dioxide. This comes from the wood charcoal.

The reaction is 2ZnO + C ---> Zn(metal) + CO2

No magic is involved, and the solar energy is used only to heat the zinc oxide and carbon to sufficient temperature so that they react. The improvement is that conventional metals production would require oil, coal, or natural gas to produce the needed heat.

So the production of CO2 is not reduced by this method of so-called hydrogen production. Most solar methods produce hydrogen by splitting water directly. Using carbon is cheating. The method is not much better than conventional water-gas technology.

Of course, some sort of energy input is also needed to coke the original wood into charcoal, not to mention the energy needed to manufacture the solar energy collectors. And so the net energy savings are likely to be modest.

I don't see any big breakthrough here at all, no matter all the hurrahs.

And my position on anthropogenic global warming, like yours, is that it is alarmist nonsense. Scientific sensibility is the only consistent position we should take.


Pat Frank
Patrick Frank
Department of Chemistry
Stanford University
Stanford, CA 94305-5080

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