Fuel Cells are Chemical Electricity Generators

The twenty-first century is being called the hydrogen age. The main player in this age is the fuel cell. Fuel cells are very clean generators of electricity that utilize the reverse chemical reaction from the electrolysis of water and cause hydrogen to react with oxygen from the air to produce electricity and hot water. On top of that, they are highly efficient in generating electricity, so that theoretically over eighty percent of the hydrogen energy can be extracted as electricity. One kilogram of hydrogen produces 40 kWh of power. In ecological units that is 17 eu, or the equivalent of enough food energy for a person to live on for seventeen days.

The principle involved was discovered in the 19th century, but put to practical use only in the second half of the twentieth century. These fuel cells were used in the US spaceships. On top of generating electricity for use aboard the spaceships, they also produced drinking water. Since then, the development of fuel cells for generating electricity and as cogeneration equipment has progressed to the point where by now the cells are even smaller, and it is hoped that they can be used for automobiles and in the home.


The Characteristics and Future of the Fuel Cell

Thermal power generation burns fuel. In other words, it produces heat energy to turn turbines. This means that it is transformed into kinetic energy, following which the generator transforms that output into electrical energy. There is a loss of energy at each stage so that only forty to fifty percent of the combustion energy in the original fuel can be turned into electricity.

Fuel cells extract electric energy directly from the fuel so that there is little energy loss and therefore the efficiency of the electrical generation is high. If we can use the hot water too, theoretically it is said that we could make use of close to 100 percent of the energy without any waste. There is no carbon in the water, so carbon dioxide is not formed. If there is no sulfur, sulfur dioxides will not be emitted and since nothing is burned, nitrogen oxides are not created. In this way extremely clean generation of electricity is possible. There is no motion, so that there is little vibration or noise. Furthermore, it is not just simply efficient and sanitary, but the clean production of hydrogen means we would not have to rely on limited underground resources. If fuel cells can be made smaller, scattering electrical production through the area where the energy is used would be a possibility. For these reasons, attention is being paid to many factors that may tie in directly with the actualization of an ideal future society.


Using Fuel Cells in Automobiles and Homes

Fuel cell cars are the zero-emissions cars of our dreams. Because 50 million cars a year are manufactured throughout the world, if fuel cells can be made practical for use in them, the cost should be lowered along with mass production. Already, since February 2001, test runs on the public roadways in Japan are being conducted and several manufacturers have announced that they will put such automobiles on the market in 2003-2004.

As you might guess from the fact that hydrogen is used as space rocket fuel, weight for weight, this material packs the most energy of any form. One kilogram is the equivalent of 40 kWh of electricity. Sixty grams is one eu. But since it is the lightest material of all, one kilogram of liquid hydrogen takes up fourteen liters in volume. To load the same weight as gasoline in a car, you need a fuel tank ten times as large. Also, it is difficult to make the necessary chamber airtight and since it is highly combustible, handling is not easy.

The world's auto makers, at the same time as developing hydrogen occlusion alloys and other safe methods of loading hydrogen, are also working on methods of loading the more easily handled fuels methanol and gasoline, and extracting hydrogen from them. With these methods, a small amount of carbon dioxide is emitted, but methanol can be obtained from natural gas and waste matter, and gasoline can be handled by now existing gas stations so that expenses for preparing the infrastructure would be small. Each has its own merits.

For home fuel cells, natural gas (city gas, composed mostly of methane) is a shortcut. The same city gas we now use to heat water could be used to supply electricity. At first it would be introduced on a scale of a single apartment block or an office building or convenience store, and we would not be surprised if, eventually, each home would have its own. In that case electricity companies would become back-up service companies and we would not need distant gigantic electric generation facilities or transmission lines.

We must not expect too much, but one cannot take one's eyes off this competition for technical development, now a reality. It holds the possibility for changing our society. Maybe it will not be long before the time comes when we can say, "Isn't the sky clear lately?"