What if hydrogen, the most abundant element in the universe, could power everything from automobiles and trucks to homes and office buildings with little or no toxic or greenhouse gas emissions? Welcome to the dream of the “hydrogen economy.”
Does it seem like fantasy? For now, perhaps. But with many sharp minds focused on the science and some carefully directed private and public investment, this fantasy could become part of our everyday lives.
In fact, liquid hydrogen is already being used to send our spacecrafts into orbit, and the most promising of hydrogen technologies, the fuel cell, is already powering city buses in Chicago, office buildings in New York and homes in Tokyo. If so, why can’t we buy hydrogen-powered cars or pick up a fuel cell generator at the neighborhood hardware store? The primary reason, as is often the case with early-stage technologies, is the high cost. However, many other issues complicate the mainstreaming of hydrogen and fuel cells, including where we get the hydrogen and how we should distribute and store it.
Though it makes up more than three-fourths of the universe’s mass, hydrogen gas (H2) is not naturally occurring on earth. Rather it must be manufactured by splitting water molecules (electrolysis) or by extracting it from natural gas or other fossil fuels. Most environmentalists prefer that the method for isolating the hydrogen be as non-polluting as possible, otherwise the ecological benefit of hydrogen energy could be squandered. According to the David Suzuki Foundation of Vancouver, Alberta, Canada, current technology favors steam reformation of natural gas as the lowest contributor to carbon dioxide (greenhouse gas) emissions. Some scientists foresee zero emission hydrogen production through the use of solar and wind energy to power the relatively intensive electrolysis process.
The distribution and storage of hydrogen also present barriers to the growth of the industry. With massive infrastructure based on the distribution of fossil fuels, many experts are attempting to mimic and/or utilize some of this infrastructure to make hydrogen available to power vehicles and buildings. Hydrogen gas can be compressed and stored like many other industrial gases, and in theory at least, can be transported like natural gas in pipelines. Early economic analyses appear to demonstrate that hydrogen gas distribution through pipelines may experience a four-fold cost advantage over conventional high-voltage transmission lines.
Except for 3M Corporation’s development of proton exchange membrane components and some experimentation at the University of Minnesota, the nascent fuel cell industry has little presence in Minnesota. North American firms with the most advanced technologies include Ballard Power Systems of British Columbia, International Fuel Cells (United Technologies) of Connecticut, Fuel Cell Energy of Connecticut, H Power of New Jersey and Plug Power of New York. The best local resource for the fuel cell industry and the potential of a hydrogen economy is the non-profit Minnesotans for an Energy Efficient Economy located on the web at www.me3.org.
Powering the Future: The Ballard Fuel Cell and the Race to Change the World, Tom Koppel, 1999
Tomorrow’s Energy: Hydrogen, Fuel Cells, and the Prospects for a Cleaner Planet, Peter Hoffman, 2001
How a fuel cell works
The basic science of fuel cells is the stuff of high school chemistry. Like a standard battery, a fuel cell is considered an electrochemical process. Electricity is created when hydrogen fuel is delivered to one side (anode) of an electrolyte, and oxygen from the air is made available on the reverse side (cathode). Electrons from the hydrogen atom are released due to the opposing charges on each side of the electrolyte. The electrons create direct current (DC) power while the protons pass through the cell and join the oxygen atom to create water H20 and heat, the only other byproducts of the process.
Current fuel cell technologies. First invented by William Robert Grove in 1839, fuel cells have evolved considerably in the past 30 years. NASA has played a major role in the technological development of fuel cells, using them to provide electricity and drinking water for its spacecraft. During the last decade, for-profit enterprises have jumped into the fray, including U.S.-based United Technologies which is marketing a 200 kilowatt unit for specialized commercial and industrial applications. The following are fuel cell technologies currently in the market or under development:
- Phosphoric acid: currently in the market
- Alkaline: field testing (used by NASA)
- Molten carbonate: field testing
- Solid oxide: field testing
- Proton exchange membrane: early stage testing
- Direct methanol: early stage testing