CHAPTER 1
Our Hunger for Energy

Most people will have heard of the cult TV series, Star Trek. Thanks to this programme, we know that in the not-too-distant future humans will start exploring the infinite expanses of the universe. The energy issue will have been resolved long before then. The Warp drive discovered in 2063 provides unlimited energy that Captain Kirk uses to steer the starship Enterprise at speeds faster than light to new adventures. Energy is available in overabundance; peace and prosperity rule on Earth and environmental problems are a thing of the past. But even this type of energy supply is not totally without its risks. A warp core breach can cause as much damage as a core meltdown in an ancient nuclear power plant. Warp plasma itself is not a totally safe material, as the regular viewers of Star Trek very well know.

Unfortunately – or sometimes fortunately – most science fiction is far removed from the real world. From our perspective the discovery of a warp drive seems highly unlikely, even if dyed-in-the-wool Star Trek fans would like to think otherwise. We are currently not even close to mastering comparatively simple nuclear fusion. Consequently, we must rely on known technology, whatever its drawbacks, to solve our energy problems.

In reality, energy use has always had a noticeable impact on the environment. Looking back today, it is obvious that burning wood was less than ideal, and that the harmful noxious fumes created by such fires considerably reduced the life expectancy of our ancestors. A fast-growing world population, increasing prosperity and the hunger for fuel that has developed as a consequence have led to a rapid rise in the need for energy. Although the resulting environmental problems may only have affected certain regions, the effects of our hunger for energy can now be felt around the world. Overconsumption of energy is the main trigger for the global warming that is now threatening to cause devastation in many areas of the world. However, resignation and fear are the wrong responses to this ever-growing problem. There are alternative energy sources to be tapped. It is possible to develop a long-term safe and affordable energy supply that will have only a minimal and manageable impact on the environment. This book describes the form this energy supply must take and how each individual can contribute towards a collective effort to halt climate change. But first it is important to take a close look at the causes of today's problems.

1.1 Energy Supply – Yesterday and Today

1.1.1 From the French Revolution to the Early Twentieth Century

At the time of the French Revolution at the end of the eighteenth century, animal muscle power was the most important source of energy. Around 14 million horses and 24 million cattle with an overall output of around 7.5 billion watts were being used as work animals [Köni99]. This corresponds to the power of more than 100 000 mid-range cars.

Power and Energy, or the Other Way Around

The terms ‘power’ and ‘energy’ are closely linked, and for this reason they are often confused with one another and used incorrectly.

Energy is stored work; thus, the possibility to perform work. It is identified by the symbol E. The symbol for work is W.

Power (symbol: P) indicates the time during which the work is to be performed or the energy used.

For example, if a person lifts a bucket of water, this is considered work. The work that is performed increases the potential energy of the bucket of water. If the bucket is lifted up twice as quickly, less time is used and the power is doubled, even if the work is the same.

The unit for power is the watt (abbreviation: W) (The fact that the abbreviation for watt is the same as the symbol for work does not simplify matters.)

The unit for energy is watt second (Ws) or joule (J). Other units are also used for energy. Appendix A.1 provides the conversion factors between the different units of energy.

As the required powers and energies are often very high, prefixes such as mega (M), giga (G), tera (T), peta (P), and exa (E) are frequently used (see Appendix A.1).

The second staple energy source at this time was firewood, which was so important that it probably changed the political face of Europe. It is believed today that the transfer of the Continent's centre of power from the Mediterranean to north of the Alps came about because of the abundance of forests and associated energy potential there. Although the Islamic world was able to maintain its position of power on the Iberian peninsula well into the fifteenth century, one of the reasons why it lost its influence was the lack of wood. The problem was that there was not enough firewood that could be used to melt down metal to produce cannons and other weapons. This goes to show that energy crises are not just a modern phenomenon (Figure 1.1).

Figure 1.1 Firewood, working animals, wind and water power supplied most of the energy needed in the world as late as the eighteenth century.

In addition to muscle power and firewood, other renewable energies were used intensively until the beginning of the twentieth century. Between 500 000 and 600 000 water mills were in operation in Europe at the end of the eighteenth century. The use of wind power was also widespread, particularly in flat and windy areas. For example, the United Netherlands had around 8000 working windmills at the end of the seventeenth century.

For a long time, fossil energy sources were only of secondary importance. Although coal from underground deposits was known to be a source of energy, it was largely avoided. It was not until a lack of wood in certain areas of Europe led to energy shortages that coal deposits began to be exploited. In addition, the higher energy density of coal proved to be an advantage in the production of steel. In 1800, 60% of coal was used to provide domestic heat, but 40 years later far more coal was used in ironworks and other factories than in homes.

Fossil Energy Sources – Stored Solar Energy

Fossil energy sources are concentrated energy sources that evolved from animal and plant remains over very long periods of time. These sources include oil, gas, hard coal, brown coal, and turf. The base materials for fossil energy sources could only develop because of their conversion through solar radiation over millions of years. In this sense, fossil energy sources are a form of stored solar energy.

From a chemical point of view, fossil energy sources are based on organic carbon compounds. Burnt in conjunction with oxygen, they not only generate energy in the form of heat, but also always produce the greenhouse gas carbon dioxide as well as other exhaust gases.

In around the year 1530, coal mines in Great Britain were producing about 200 000 tons of coal annually. By 1750 it was about 5 million tons, and in 1854 an astonishing 64 million tons. By 1900 three countries, Britain, the USA, and Germany, had an 80% share of world production [Köni99].

Renewable Energies – Not That New

The supplies of fossil energies, such as oil, natural gas, and coal, are limited, and they will be depleted within a few decades and cease to exist. Renewable energy sources, on the other hand, ‘renew’ themselves on their own. For example, if a hydropower plant takes the power of the water from a river, the river will not stop flowing. The energy content of the river renews itself on its own because the sun evaporates the water and the rain feeds the river again.

Renewable energies are also referred to as ‘regenerative’ or ‘alternative’ energies. Other renewable energies include wind power, biomass, the natural heat of the earth, and solar energy. Even the sun will eventually disappear in around four billion years. Compared to the few decades that fossil energy sources will still be available to us, this time period seems infinitely long.

Incidentally, renewable energies have been used by mankind for considerably longer than fossil fuels, although the current systems for using these fuels are vastly more advanced than in the past. Therefore, it is not renewable energies that are new, but rather the knowledge that in the long term renewable energies are the only option for a safe and environmentally compatible energy supply.

At the end of the twentieth century, worldwide coal production reached almost four billion tons. With an overall share of less than 3% of the world market, Germany and Britain had lost their former position of supremacy in the coal industry. China and the USA are currently the main coal-producing countries by a considerable margin. Most of the coal produced today is used in power plants.

1.1.2 The Era of Black Gold

Like coal, oil consists of conversion products from animal and plant substances, the biomass of primeval times. Over millions of years plankton and other single-celled organisms were deposited in sea basins. Due to the lack of oxygen, they were unable to decompose. Chemical processes of transformation eventually turned these substances into oil and gas. The biomass that was originally deposited originated from the sun, which means that fossil energy sources like...