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British National Party

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Energy Alternatives

Let us have a look at some of the alternative energy sources that have been mooted, dabbled with, researched, piloted or are actually already in use.

Wind ¦ Solar ¦ Wave ¦ Tidal ¦ Nuclear ¦ Bio-fuels ¦ Hydrogen

We could involved in some in depth chemistry here. But this is a political site and not a chemistry site so we need to keep things basic for the lay persons.

Essentials

The basics of hydrogen technology are as follows.

1. Hydrogen is the most abundant element in the universe. It is found on earth in many forms but the most practical one for human use is the globally abundant water, good old H2O.

2. Sending an electric current through water splits water molecules into hydrogen and oxygen. Every schoolchild will have performed this experiment. It is called electrolysis and for every molecule of water, two atoms of hydrogen and one atom of oxygen are produced. Energy in leads to hydrogen and oxygen out.

3. The reverse process of combining atoms of hydrogen with oxygen generates energy which can be captured as electricity, the only other product is a harmless one - water!

4. The reverse process is the basis of a fuel cell, where hydrogen and oxygen react with one another on a surface of something called a catalyst, a chemical which facilitates the chemical reaction.

5. Fuel cells have been built in laboratories and pilot units. The most common catalyst used in these pilot and experimental units is platinum.

6. The hydrogen can be produced by a variety of means but the most attractive option for a future hydrogen based economy would be electrolysis. The electricity for electrolysis would have to be generated from a renewable source in a post oil situation and the hydrogen stored and distributed via pipelines or tankers.

7. It is envisaged that fuel cells will be used to drive motor vehicles. Motor vehicles will be filled at "gas stations" in a similar way to existing petrol stations. The gas stations might be the same places where the hydrogen is produced. Arrays of solar panels on the roof of a gas station will generate the electricity to perform the electrolysis. The hydrogen will be stored on site and vehicle drivers will come along and refuel their fuel cell driven cars.

Clean, pollution free, sound very neat doesn't it, except for a few major shortcomings.

Lightest element

First off, because hydrogen is the simplest element, it will leak from any container, no mater how strong and no matter how well insulated. For this reason, hydrogen in storage tanks will always evaporate.

Hydrogen is very reactive. When hydrogen gas comes into contact with metal surfaces it decomposes into hydrogen atoms, which are so very small that they can penetrate metal. This causes structural changes that make the metal brittle.

Perhaps the largest problem for hydrogen fuel cell transportation is the size of the fuel tanks. In gaseous form, a volume of 62,880 gallons of hydrogen gas is necessary to replace the energy capacity of 20 gallons of petrol. The arithmetic doesn't look good so far.

However demonstrations of hydrogen-powered cars have depended upon compressed hydrogen. Because of its low density, compressed hydrogen will not give a car as useful a range as gasoline. In addition compressed hydrogen fuel tank would be at risk of developing pressure leaks either through accidents or through normal wear, and such leaks could result in explosions.

If the hydrogen is liquefied, this will give it a density of 0.07 grams per cubic centimetre. At this density, it will require four times the volume of gasoline for a given amount of energy. Thus, a 15-gallon gas tank would equate to a 60-gallon tank of liquefied hydrogen. Beyond this, there are the difficulties of storing liquid hydrogen. Liquid hydrogen needs to be stored at -253 C. That is colder than the surface of planet Pluto!

Refrigeration costs

Beyond this, there are the energy costs of liquefying the hydrogen and refrigerating it so that it remains in a liquid state. No studies have been done on the energy costs here, but they are sure to further decrease the Energy Return on Energy Invested (EROEI) of hydrogen fuel.

A third option is the use of powdered metals to store the hydrogen in the form of metal hydrides. In this case, the storage volume would be little more than the volume of the metals themselves. Moreover, stored in this form, hydrogen would be far less reactive. However, as you can imagine, the weight of the metals will make the storage tank very heavy.

The basic problem of hydrogen fuel cells is that the second law of thermodynamics dictates that we will always have to expend more energy deriving the hydrogen than we will receive from the usage of that hydrogen. The common misconception is that hydrogen fuel cells are an alternative energy source when they are not. They are a form of energy storage - a big difference!

Because of the second law of thermodynamics, hydrogen fuel cells will always have a bad EROEI. If fossil fuels are used to generate the hydrogen, either through the Methane-Steam method or through Electrolysis of Water, there will be no advantage over using the fossil fuels directly. The use of hydrogen as an intermediate form of energy storage is justified only when there is some reason for not using the primary source directly. For this reason, a hydrogen-based economy must depend on large-scale development of nuclear power or solar electricity.

Therefore, the development of a hydrogen economy will require major investments in fuel cell technology research and nuclear or solar power plant construction. On top of this, there is the cost of converting all of our existing technology and machinery to hydrogen fuel cells. And all of this will have to be accomplished under the economic and energy conditions of post-peak fossil fuel production.

Further reading

For those readers who want to find out more about the underlying chemistry and physics of fuel cells and hydrogen should have a look at the following:

ABCs of Hydrogen and Fuel Cells