Hydrogen Energy: From Fuel Cells to Economics

by Scott M. "Lt. Dangle"

Hydrogen was first discovered by the British scientist Henry Cavendish. In a paper delivered before the Royal Society of London in 1776, he reported on an experiment in which he had produced water by combining Oxygen and Hydrogen with the aid of an electrical spark. Since the elements had not yet been named, he called one "life-sustaining air" and the other "inflammable air". The French chemist Antoine Laurent Lavoisier successfully repeated Cavendish's experiment in 1785 and called the "life-sustaining air" oxygen and the "inflammable air" Hydrogen [1].

Hydrogen is the most abundant element in existence, being the basis of all stars, and many "cloud nebulas" within the universe. "It makes up 75 percent of the mass of the universe and 90 percent of its molecules [2]." On Earth, naturally occurring Hydrogen gas exists only in the upper atmosphere. There is no effective way to mine Hydrogen gas from the sky, so to use it for fuel purposes, it must first be extracted and broken down from existing compounds found on the surface of Earth. Water covers nearly 75% of Earth's surface in the forms of oceans, lakes, rivers, and glaciers. Hydrogen can also be extracted from hydrocarbon fuels, such as oil, gasoline, natural gas and coal. Electricity is used to chemically separate water into its two components, Oxygen and Hydrogen, in a process known as electrolysis.

Electrolysis is also fundamentally used to power fuel cells, but in reverse. A fuel cell produces a "Direct Voltage" current (DC). This electricity can be used to power anything from automobiles to flashlights. A more practical application of the fuel cell is the Proton Exchange Membrane Fuel Cell (PEMFC). It may soon be used to power many automobiles and homes. There are four necessary parts for a PEM fuel cell. The anode, the negative part of a fuel cell, is an etched channel that is used to evenly spread Hydrogen molecules onto the catalyst. The catalyst, usually powered platinum spread onto a carbon paper or cloth, faces against the PEM. The PEM, or electrolyte, only conducts positive ions, thus blocking electrons. And finally, a cathode, the positive end of a PEM fuel cell. Like the Anode, it has small channels etched into the surface to evenly distribute Oxygen atoms. The Hydrogen is pumped into the anode channels and meets the oxygen gas from the cathode. The transfer of electrons from the anode to the cathode creates electricity and the end product is water.

Fuel cells like the Proton Exchange Membrane fuel cell may soon be applied to industries. This includes factories and power plants, rather than automobiles. The reason for this is the carbon dioxide emitted by power plants. According to David Keith, an engineering professor at Calgary University, "An economically sane, cost-effective attack on the climate problem wouldn't start with cars." "Cars and light trucks contribute roughly twenty percent of the carbon dioxide emitted in the U.S., while power plants burning fossil fuels are responsible for more than forty percent of CO2 emissions. Fuel cells designed for vehicles must cope with harsh conditions and severe limitations on size and weight [3]." So a realistical application to Hydrogen fuel cells may first begin in industrial areas, rather than personal or commercial.

Electricity used to separate Hydrogen and Oxygen in water to produce Hydrogen fuel accounts for 4% of all currently produced Hydrogen fuel annually. Most of the production comes from natural gas reforming, a process that breaks down natural gas into Carbon and Hydrogen gas. Hydrogen gas is produced, but Carbon is as well. This process will have a backwards effect, "The EPRI (Electric Power Research Institute) study forecasts that natural-gas generation will increase from 15 to 20 percent over the next twenty years with the introduction of hundreds of new gas-fired generation plants [4]." According to Jeremy Rifkin, author of The Hydrogen Economy: The Creation of the Worldwide Energy Web and the Redistribution of Power on Earth, "If natural gas production peaks, sending prices dramatically higher, a point could be reached where using renewable sources of energy to produce electricity for the electrolysis would be cheaper [5]." This includes nuclear power, and "renewable energy" sources. Such as wind turbines, hydroelectric power (dams), geothermal, and solar power (photovoltaic).

One oversight of the "Hydrogen Economy" is that Hydrogen, (liquid or gas) as fuel in electrolysis can only be used as an energy carrier, not an energy source. "Hydrogen is a currency, not a primary energy source [6]," according to Geoffrey Ballard, the co-founder of Ballard Fuel Systems. This means that all Hydrogen must be separated from water in a specialized extraction facility. "We'll never get more energy out of Hydrogen than we put into it [7]," says Ballard, though this is true for any conversion of fuel. In fact crude oil is only 73 to 91 percent energy efficient from oil wells to fuel pumps. But Hydrogen itself is only 70 to 75 percent efficient in electrolyzes [8]. So why isn't all this research on Hydrogen a waste of time? The answer lies in the "well-to-wheel" effiency data.

"Using Japanese round numbers from Toyota, 88% of oil at the wellhead ends up as gasoline in your tank, and then 16% of that gasoline energy reaches the wheels of your typical modern car, so the well-to-wheels effiency is 14%. A gasoline-fueled hybrid-electric car like the 2002 Toyota Prius nearly doubles the gasoline-to-wheels effiency from 16% to 30% and the overall well-to-wheels effiency from 14% to 26% [9]." According to Amory B. Lovins, of the Rocky Mountain Institute, "That "meager" conversion energy is then more than offset by an advanced fuel-cell drive system's superior 60% efficiency in converting that energy into traction, for an overall well-to-wheels efficiency of 42%. That's three times higher than the normal gasoline-engine car's, or 1.5 times higher than the gasoline-hybrid-electric car's [10]." Essentially, since a Direct-Voltage drive system (fuel cells) is more efficient than a gasoline combustion engine, the tradeoff of a little lost conversion energy is worth the cleaner, more versatile Hydrogen fuel. A Hydrogen reacting fuel cell also gives off heat, which can be used to heat water or furnaces inside an office building or a home. Thus increasing Hydrogen's net energy potential beyond that of any hydrocarbon fuel.

Works Cited

1.Jeremy Rufkin. "The Hydrogen Economy: The Creation of the Worldwide Energy Web and the Redistribution of Power on Earth", New York, NY: Jeremy P. Tarchet/Penguine, 2002

2."Hydrogen." The Columbia Encyclopedia, Sixth Edition. Columbia University Press, 2001

3.Michael Behar. "Warning: The Hydrogen Economy May Be More Distant Than It Appears." Popular Science, January 2005: 108 pages

4.Jeremy Rufkin. "The Hydrogen Economy: The Creation of the Worldwide Energy Web and the Redistribution of Power on Earth", New York, NY: Jeremy P. Tarchet/Penguine, 2002

5.Jeremy Rufkin. "The Hydrogen Economy: The Creation of the Worldwide Energy Web and the Redistribution of Power on Earth", New York, NY: Jeremy P. Tarchet/Penguine, 2002

6.Michael Behar. "Warning: The Hydrogen Economy May Be More Distant Than It Appears." Popular Science, January 2005: 108 pages

7.Michael Behar. "Warning: The Hydrogen Economy May Be More Distant Than It Appears." Popular Science, January 2005: 108 pages

8.R. Wurster & W. Zittel, "Hydrogen Energy", ECN, Petten, 11-12 April 1994, www.hydrogen.org/knowledge/ECN-hza.html>

9.Amory Blovins. "Twenty Hydrogen Myths." www.rmi.org. 20 June, 2003. Rocky Mountain Institute. 20 February, 2005 http://www.rmi.org/images/other/Energy/E03-05_20HydrogenMyths.pdf

10.Amory Blovins. "Twenty Hydrogen Myths." www.rmi.org. 20 June, 2003. Rocky Mountain Institute. 20 February, 2005 http://www.rmi.org/images/other/Energy/E03-05_20HydrogenMyths.pdf