HYDROGEN: Fuel of the (near) Future
PHILIP S WENZ
March 2003
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Perhaps one of the greatest ironies of America's current geopolitical crisis caused, in part, by it's dependence on foreign oil is that there already exists a viable alternative to fossil fuels. That alternative is hydrogen, found almost everywhere in prodigious quantities, free, but for it's extraction, one hundred percent pollution free (or very close, at least), and potentially available to every country, village and person on the planet. Public buses powered by clean, quiet hydrogen fuel cells (HFCs) are already on the road in several countries, and major automotive manufacturers and their suppliers are tooling up for mass production. Industrial standards are being set, and several companies, including Ford, Chrysler and Toyota plan to have HFC cars in the showroom and on the road by the end of this decade. The country of Iceland has already adopted a national program to convert its public transit and fishing fleet to run on hydrogen fuel.
 A Toyota prototype for a hydrogen fuel car. |
We are on the verge of a hydrogen revolution, a new and possibly final energy regime for humankind. The sooner we turn to hydrogen fuel, the sooner we can, potentially, find universal prosperity, the prerequisite to peace.
This article provides a brief overview of hydrogen as a fuel and hydrogen fuel cells (HFCs), the current status of the hydrogen revolution and some thoughts on the future. It is meant to compliment the reviews of three excellent books, The Hydrogen Economy, Tomorrow's Energy, and Powering the Future now featured in ECOTECTURE's Book Review section. The books themselves should be read. Between them, they cover much of the basic material all ecological designers should know about the energy revolution we are about to witness. This article provides background information for the reviews, as all three books, especially The Hydrogen Economy, presume a basic familiarity with hydrogen fuel technology.
To understand hydrogen fundamentals, it is important to keep in mind that hydrogen fuel is just that, a fuel. (As is oil, which is frequently, and mistakenly, called "energy.") Hydrogen is matter that stores energy, not energy itself.
For the earth, sunlight is the primary energy source. It heats the planet, drives the winds for windmills, can be converted directly to electricity using photovoltaic cells and evaporates sea water which, falling as alpine rain or snow, can be used for generating hydroelectric power. Far, far more sunlight falls upon the earth's surface than is needed to support all life on earth and meet all human energy demands. For practical purposes we have, in the sun, a limitless energy supply.
| Like the biological matrix in which it is embedded, civilization should use direct energy when it is available and store the surplus for "down times." |
There is a problem, however, in the nature of sunlight and, for that matter, all forms of energy—electromagnetic, electrical or heat. Energy only performs work while it is flowing. It can't be stored except as potential energy trapped in matter. So while direct sunlight can heat and light our homes and be used to produce direct electricity during the day, we must find another source of power at night.
Living organisms have long since solved this problem by devising a means for storing the sun's energy. Photosynthetic plants use sunlight and simple chemicals to build sugars which can be broken down, freeing energy for life's processes on demand. Almost all other living things— the animals that eat the plants, the microbes that consume those animals' waste and so on—depend on this basic energy storage "technology" evolved by green plants. Humans, too, must capture and store energy when it is available to be used when it is not. Unlike other organisms, however, our energy storage requirements extend beyond the elementary food supplies needed by our bodies to those required by our civilization's lights, furnaces and machinery. Still, the principles are the same. Like the biological matrix in which it is embedded, civilization should use direct energy when it is available and store the surplus for "down times."
Another distinction between energy use by humans and other biota is that human creations ranging from light bulbs to trains use energy at a much faster rate than is needed by organisms for their metabolism. While direct sunlight can warm a well designed building, cost effective residential photovoltaic systems have their hands full keeping up with the basic needs of a typical household. The sun's energy must be stored and concentrated over time, as it is in chemical batteries, to achieve high enough power levels to run machinery or cars. Oil, is, in fact, stored solar energy that was captured by plants eons ago, then concentrated and purified through lengthy geochemical processes.
| Power dams are environmental problems in and of themselves |
Of course we use stored solar energy, primarily hydroelectric and fossil fuel energy, to achieve the high power levels we need and to the get us through the night. The energy source for hydroelectric dams is stored for us by nature, without our having to expend any effort. Sunlight evaporates water which is then deposited at high altitudes as rain or snow. To take advantage of this gift, we only need to build dams that store the runoff water and uses it, at a controlled rate, to drive turbines to produce electricity.
There are numerous problems and limitations with hydroelectric energy, however. Power dams are environmental problems in and of themselves, their reservoirs destroying natural areas, farmlands and archeological treasures and sometimes displacing masses of people. Dams are expensive to build and their reservoirs fill up with sediment fairly quickly —in 50 to 75 years for most dams—so they soon become quite expensive to dredge and maintain. Also, dams are behemoth, centralized energy facilities requiring massive capitalization and encouraging top-down administration with its concomitant problems of price gouging and various forms of corruption.
Hydroelectric efficiencies are generally low. A great deal of the power that is produced is wasted when it is distributed, often over great distances, across elaborate wire grids.
Finally, like sunlight, electricity only produces work while it is flowing—it is used at the same instant that it is produced. The principal means of storing electricity, chemical batteries, is limited and has environmental drawbacks. While we can light and, with less efficiency, heat buildings directly from the electric grid, battery capacities limit them to backup roles and battery power, unless combined with combustion driven engines, is inadequate for most vehicle applications.
We return, then, to the need for fuel—chemicals with high levels of potential energy that can be safely and economically stored, readily transported and easily converted to kinetic energy on demand. Wood filled this need for most of humanity throughout most of history, but wood's obvious limitations—low calorie-output-to-mass ratio and corresponding high pollution index and low transportation efficiency, reduced supply, and the environmental value of standing forests makes wood of limited use in meeting our current needs. It is no accident that we had a relatively low level of material comfort when wood was humanity's primary fuel source, and that it rose when we converted to fossil fuels—first coal, then oil.
| The horseless carriage was a welcome innovation, destined to solve many problems—and create many more. |
Fossil fuels enjoy the obvious advantage of a high calorie-output-to-mass ratio, so high, in fact, that they can propel vehicles beyond the earth's gravitational field. They have also been relatively plentiful and cheap and in some ways even clean. In the 1880s, for example, New York City was getting buried in horse manure. All the local truck farms had more fertilizer than they could use, manure dumps were full and steaming and the stuff just kept piling up. The horseless carriage was a welcome innovation, destined to solve many problems—and create many more.
The familiar disadvantages of fossil fuels, their concentration in certain regions of the world, many of which are politically unstable and all of which invite violent competition for monopolistic ownership, their pollutants, and the undeniable fact that we are running out of them means that we are rapidly coming to the end of the fossil fuel era—it will be over in a few decades. It is imperative that we find a substitute fuel, preferably one without the drawbacks of coal, natural gas and oil.
There is nuclear energy, but its problems are legendary. Along with the massive expenses and potential dangers, ranging from meltdown to terrorism to hot waste involved in centralized atomic energy production, there remain the same underlying limitations of hydroelectric power—inefficient grid distribution and end use that is mostly limited to stationary facilities. Atomic energy used to charge chemical batteries to run short-ranged electric cars does not sound like the wave of the future. Hydrogen fuel does.
Fortunately for humans, crisis and opportunity can, and often have gone hand in hand. Just when we are about to annihilate ourselves fighting over the vestiges of an outmoded energy regime, we find, right under our noses—actually, in our noses—the seed of the future. To understand why hydrogen appears to be the answer to our current quandary, we must begin at the beginning.
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