Sprol

Hydrogen is a bright star on our horizon. It may become the fuel of choice to store the energy from clean sources to replace gasoline and perhaps even coal. The goal of the U.S. Department of Energy’s Hydrogen Program is for hydrogen to produce ten percent of our total energy by the year 2030. Hydrogen may reduce our dependence on foreign oil and provide clean renewable energy. However, before hydrogen can become a major factor in the U.S. energy infrastructure, many new systems must be designed and built.

First, there need to be cost-effective ways to produce hydrogen, and if it is to fulfill our need for clean energy, these methods need to be pollution free. If we generate lots of pollution in the process of generating clean hydrogen, we defeat the reason for going to hydrogen.

Second, we need economical and safe ways to distribute and to store hydrogen.

Third, we need economical yet effective ways to turn stored hydrogen back into useful energy. All of these must be reliable, safe and simple to use.

An economical way to store energy is key to the future development of the alternative power techniques now under development. Wind power is perhaps my favorite, I think of windmills in Holland pumping out water so they can reclaim the land. It sounds romantic, peaceful and pleasant. Since wind power is inherently clean and free, it may become a major component in reducing our usage of fossil and nuclear power, thus reducing the pollution that goes with them.

In states where the bulk of the electric power comes from fossil and from nuclear power sources there is a need to convert to clean power. In an article on “Alternative Power for Nebraska,” I pointed out that Nebraska is making good progress, especially in additional wind power, but not only do they need to reduce their fossil and nuclear power consumption, their hydroelectric capability is literally drying up. The river water in the Platte River, which provides more that half of Nebraska’s already small hydroelectric capability is dwindling. An economical way to store excess wind power energy such as clean hydrogen is key to the future development of wind power and may be the salvation of windy Nebraska. Note that here I use the words “clean hydrogen”, because there are “dirty” ways to make hydrogen, which generate pollution themselves.

Let’s look at two ways to generate hydrogen, one of them old and one very new, and two ways to use it, one of them also quite new, and then suggest a few possible improvements. The good news is that a lot of research and development is taking place on alternative power sources and as a result, good things are happening. With a huge fortune to be made by whoever solves the alternative power puzzle, companies are spending a lot on research looking for the holy grail of a economical pollution-free engine that burns clean, low cost fuel. Interestingly enough, the three corporations which spent the most on R&D in 2004 were Ford, Daimler-Chrysler and Toyota, automobile companies.

The first technique for generating clean hydrogen is electrolysis. To do electrolysis you run a DC current through water with some sulfuric acid in it. The water molecules separate into hydrogen and oxygen, one at one electrode and the other at the anode. I remember very clearly my high school chemistry class where we did this. You were supposed to tell which electrode had the hydrogen with a lit match. We did something wrong, and the whole apparatus blew up. I had holey acid-washed jeans, many years before they came into style. So hydrogen is potentially dangerous, and can produce an explosion. Techniques will be necessary to safely handle and store hydrogen, just as techniques had to be developed for safely handling gasoline.

Currently, generation of hydrogen by electrolysis is not considered very efficient. In an article in the March 2005 issue of IEEE Spectrum Prachi Patel Predd says that the current technique of generating hydrogen from natural gas costs about $4 to $5 per kilogram of hydrogen and generates a lot of pollution, while he says that electrolysis costs about $9.00 per kilogram and is not cost effective. (A kilogram of hydrogen has approximately the same energy as a gallon of gasoline)

However, if relatively free wind power is factored into the analysis, electrolysis may prove superior. A careful analysis matching the characteristics of the wind power source, the DC generator, and the electrolysis process could lead to a significant cost-reduction for wind driven electrolysis. My intuition says that electrolysis will probably not be the winning solution, but it should be evaluated fairly. Although a long shot, it might turn out to be the best solution. Remember before counting anything out, that a 19th century mathematician proved heavier than air flight to be impossible.

Before discussing the next technique for generating hydrogen we need to briefly look at fuel cells. A fuel cell is a device which combines hydrogen and oxygen to produce electricity and water. NASA use them on spacecraft since they are efficient, pollution-free, and they produce water to drink.

There is an exciting new development in the fuel cell field. The Department of Energy is testing a new type of fuel cell, not one that burns oxygen and hydrogen giving off electricity and water, but one that runs backwards. They apply water (steam) and electricity and generate clean hydrogen by running electricity through it.

In the March 2005 issue of IEEE Spectrum the article “Cheaper Hydrogen Beckons” says that the DOE has found that by running this type fuel cell at 850 °C, they can run fuel cells in reverse and use electricity to produce hydrogen. The DOE plan is to use nuclear power to generate the necessary high temperature steam. They estimate a resulting cost of about $1.50 per kilogram of hydrogen as opposed to about $4 to $5 per kilogram of hydrogen generated from natural gas and about $9.00 per kilogram for electrolysis generated hydrogen. However, they plan to develop a new type of nuclear reactor in order to handle the 850 °C temperatures. It is hard to justify this economically. The article points out if we are going to build more nuclear reactors to generate hydrogen, why not just use the new reactors to generate the power needed and skip the hydrogen.

Ways of turning stored hydrogen back into electricity include fuel cells and internal combustion hydrogen engines. Yes, hydrogen internal combustion engines exist! They are not “Pie in the Sky”. These engines burn hydrogen gas and, like fuel cells, the resulting waste product is water. Several companies are working to develop hydrogen engines, and several automakers have joined together to achieve faster results. However, Ford Motor Company is apparently going to beat it’s competition to market. According to a press release in February 2005, Ford Motor Company has already developed hydrogen powered automobile engines and put two different ones into calibration testing. Apparently, they passed the test, as the turbocharged one is part of Ford’s new “U” car, which they plan as the Model-T of the 21st century. If the auto manufacturers can get the price of hydrogen internal combustion engines low enough, these engines may turn out to be the best way to turn stored hydrogen back into electricity. With the huge amount of money to be made, I expect the automakers to pour a lot of resources into making this happen.

So electrolysis or reverse fuel cells can be used to generate clean hydrogen and fuel cells or internal combustion hydrogen engines used to turn stored hydrogen back into electricity. It will be interesting to see what the year 2030 will be like. I predict that the DOE is underestimating the rapidity of the change to clean energy.

References

http://www.eia.doe.gov/kids/energyfacts/sources/IntermediateHydrogen.html#Ho

IEEE SPECTRUM December 2005, “R&D” by Ron Hira and Harry Goldstein.
http://www.spectrum.ieee.org/mar05/2031 “Cheaper Hydrogen Beckons” by Prachi Patel Predd

http://auto.howstuffworks.com/fuel-cell.htm/

http://news.techwhack.com/index.php?s=hydrogen+engine&submit=Search

http://www.motorcities.com/contents/05/2005-Ford-Introduces-Hydrogen-Engines-to-Industrial-Market_05BR1544205593.html

http://www.ford.com/en/innovation/engineFuelTechnology/hydrogenInternalCombustion.htm