The Home of American Intellectual Conservatism — First Principles

December 16, 2017

The Energy Crisis
P. E. Hodgson - 08/15/08

The following is a featured essay in the current edition of Modern Age (50, no. 2; Spring 2008).

The world demand for energy is rapidly increasing. We need energy to warm our homes, to cook our meals, to travel and communicate, and to power our factories. The amount of energy available to us determines not only our standard of living, but also how long we live. Detailed statistics from many counties show that in countries where the available energy is 0.15 tons of coal equivalent per person per year the average life expectancy is about forty years, whereas countries in Europe and America where the available energy is a hundred times greater have an average life expectancy of about seventy-five years. It is well to remember that a shortage of energy is a minor inconvenience to us, but for people in poorer countries it is a matter of life and death.

The world energy demand is increasing due to population growth and to rising living standards. World population in doubling about every thirty-five years, though the rate of growth is very different in different countries. The world energy use is doubling every fourteen years and the need is increasing faster still. One of the main energy sources is oil and the rate of production is expected to peak in the next few years. There are still plentiful supplies of coal, the other principal energy source, but it is even more seriously polluting than oil, leading to acid rain and climate change. This combination of increasing need and diminishing supply constitutes the energy crisis. The world urgently needs a clean energy source that is able to meet world energy needs.

This is without doubt the most serious problem facing mankind. If we simply let things take their course, the world is heading for a catastrophe during the present century. To see what can be done about it, all possible energy sources have to be critically examined and their potential evaluated. [1]

Before considering the various energy sources in detail it is useful to list some of the difficulties in doing so. These arise partly from the complicated nature of the subject, which involves a range of scientific and technological specialties, and partly from the fierce political debates that surround it. The only way to assess the various criteria is to express them numerically as far as possible. Without the numbers it is all just a matter of words spiced with emotion, and it is never possible to reach an objective decision. These numbers seldom have the precision of scientific measurements, and some of them are inherently imprecise but it is better to have approximate numbers rather than no numbers at all. It is important to distinguish between precise measurements, reasonable estimates, guesses, commercial or political propaganda, and speculations. The speculations can be plausible and in accord with known scientific laws, or in contradiction to such laws. A further complication is that new scientific data often alter the picture; this is notably the case for climate change. The people providing the information can be completely objective, or they can be strongly influenced by commercial and political concerns.

The criteria used to assess the various energy sources are their capacity, reliability, cost, safety, and effects on the environment. No single source satisfies all these criteria so an energy mix is essential for each country. The optimum energy mix depends on the natural resources of that country, and so there is no general solution; each country must be considered separately.

No energy source is completely safe, so it is relatively easy to make a case against any particular source by emphasizing its hazards. What is needed is an objective comparison between the hazards of all the energy sources, based on numbers. This may be done by estimating the numbers of workers killed and injured in the course of producing a stated amount of electricity. This excludes the contribution of long-term effects. It is worth mentioning that the casualties due to energy production are small compared with those due to natural disasters. Thus, for example, the Chinese Seismological Bureau estimated that in the years from 1949 to 1976 about 27 million people died and 76 million were injured following about a hundred earthquakes. Huge numbers were also killed by tsunamis and hurricanes.

Every energy source has to be constructed and maintained, and this requires energy. It is thus some time before the energy produced by a device is sufficient to pay back the energy used initially. This payback time is an important parameter when comparing energy sources, but data are rather sparse.

There is one general classification of energy sources that provides a useful guide. This is the degree of concentration. To do anything useful the energy must be concentrated. Energy sources can be divided into three categories: the concentrated sources wood, oil, coal, gas, and nuclear; the intermediate category of hydro which is partly concentrated by the mountain valleys; and the least concentrated such as wind, solar, geothermal, wave, and tidal. These sources contain vast amounts of energy but it is thinly spread and only becomes useful when it is concentrated.

We tend to think that environmental degradation is a recent problem, beginning only with the Industrial Revolution; but in ancient times, when wood was the main fuel, the forests of the Mediterranean were cut down, often leaving deserts. Later on, many of the forests of northern Europe were also cut down for fuel. Wood together with crop residues and dried animal dung is still the principal fuel for most people in poorer countries. This practice impoverishes the soil and makes more deserts. Other ancient energy sources like windmills and waterwheels, although less polluting, produce limited quantities of power. The windmill is especially unreliable, although the waterwheel has developed into hydroelectric power in modern times.

Before considering the possible energy sources individually it is useful to make a few general remarks. While it is essential to express as much as possible numerically, the limitations on the numbers must be borne in mind. These numbers are vital to a proper assessment but are inevitably approximate. They differ from one county to another, and vary with time as new safety measures are introduced. They include all the direct hazards; in the case of coal for example, they include mining and transport hazards as well as those involved in the day to day running of the power stations. The manufacture of safety devices in factories brings with it more hazards, so it is just not possible to make any energy generating device absolutely safe.

The costs of energy generation vary from one country to another and with the distance from mine to power station, where appropriate. Power stations remain in operation for many decades, and during that time inflation affects the costs. The rate of interest on the dividends paid to the shareholders has a critical effect on the final cost.

The power output from energy generating devices estimated by the designer often differs substantially from what is actually achieved. It is therefore necessary to base figures for the power output and the costs on actual operating experience over a number of years. It is thus practically impossible to evaluate a new device without running it for several years.

It is often said that our energy problems could be solved if we used energy more carefully and avoided waste. There is certainly much that can and should be done. We can insulate our homes to conserve heat and avoid heating rooms that are not used. We can turn the heating down and wear more clothing. We can install energy-saving light bulbs. We can walk or use smaller automobiles and avoid unnecessary journeys. If everyone were to carry out these and many similar measures the energy use would be much reduced. It has even been suggested that in this way we can reduce energy use by a factor of four. [2] Some of these measures are easy and some are not. It is much easier, for example, to build an energy-saving house than to modify an existing house. Many of these measures, such as insulating our homes, require new materials that have to be made in factories. This inevitably requires energy, and we have to consider how long it will take to recover the energy expended. The main difficulty is to convince people to change their way of life. Certainly we have a serious obligation to do what we can to reduce energy use, but even if we do we will still need to generate large amounts of energy.

Energy-saving measures are most important. They can ameliorate the situation but are not able to avoid the energy crisis. We must therefore consider how the available sources of energy can be enhanced and used wisely.

Coal

Coal, together with oil and natural gas, is one of the fossil fuels, which come from the decay of vegetation many millions of years ago. They are all very reliable sources of energy and are not unreasonably expensive. Their main disadvantage is the pollution they cause, of the land, the sea, and the atmosphere.

The world consumption of coal has risen from 100 millions tons of oil equivalent energy in 1860, to 330 in 1900, to 1300 in 1950 and to 2220 in 2000. In 1950 it was by far the world’s largest energy source, but by 2000 it was easily exceeded by oil. The lifetime of world coal supplies is often calculated by dividing the coal reserves by the annual consumption, and this gives about 250 years. However Lomborg [3] has found that this ratio seems to stay the same from year to year, the increased consumption being balanced by the discovery of new reserves. This cannot go on indefinitely, but we can conclude that the above figure is an underestimate. There is plenty of coal for the foreseeable future.

The main concern about coal is the pollution it causes. A typical coal power station produces as solid waste over a million tons of ash, 21,000 tons of sludge, and half a million tons of gypsum and discharges into the atmosphere eleven million tons of carbon dioxide, 16,000 tons of sulphur dioxide, 29,000 tons of nitrogen oxides, and a thousand tons of dust, plus smaller amounts of aluminium, calcium, iron, potassium, nickel, titanium, and arsenic.

This anthropogenic pollution can be compared with that due to natural causes, such as bush fires due to lightning strikes and volcanic eruptions. Although the short term effects may be severe, the earth has great natural recuperative powers; and once the source of pollution is removed the land, lakes, and seas return to their previous state.

Unlike these natural events the pollution from energy generation builds up continuously, and so the earth cannot recover. The solid waste has to be deposited somewhere, often in the sea, hazarding aquatic life. The atmospheric waste produces acid rain and climate change. The acid rain causes plants and trees to weaken and die, and renders lakes sterile and kills the fish. By the 1980s, nearly 4,000 lakes in Scandinavia were dead and 5,000 had lost most of their fish.

It has been suggested that the carbon dioxide, which is the principal ingredient in atmospheric pollution, could be sequestered, that is put into liquid form and pumped into empty oil wells. This process is expensive and could increase the price of coal by a factor of two or three. Even if this were done, there would still remain the hazards of the other atmospheric discharges.

The vicinity of a coal power station is hardly an object of beauty. The waste from burning the coal is usually stored nearby and forms large, unsightly, and dangerous slag heaps. They are dangerous because after heavy rain they can collapse, overwhelming nearby buildings. This happened some time ago in the Welsh village of Aberfan. The slag flowed over the village school, killing over a hundred children.

Coal is by far the most hazardous of the energy sources. Mining is dirty and dangerous; over 80,000 miners were killed in accidents from 1873 to 1938. A detailed study [4] found that about forty miners are killed to produce a thousand megawatt years of energy, and many hundreds of thousands have had their health permanently impaired by silicosis and other diseases. For all these reasons it is imperative to phase out coal power stations as soon as possible.

Oil

The world consumption of oil increased very rapidly throughout the twentieth century, partly because it is easier to extract from the earth than coal and partly because it is easier to transport by pipeline or tanker from well to power station. It also has a higher calorific content than coal. In 1900 the world oil production was twenty million tons, 470 in 1950, and 3400 in 2000.

The safety of oil occupies an intermediate position with about ten deaths per thousand megawatt-years. This is mainly due to oil well fires. There were 63 accidents in the period 1969–1986, with an average of fifty deaths per accident.

Oil is serious threat to the environment because tankers are sometimes wrecked and the oil discharged into the sea, killing fish and seabirds, and destroying marine plant life. The polluted area soon recovers and it is worth mentioning that more oil pollution is caused by tankers cleaning out their tanks.

The main disadvantage of oil is that world oil production is expected to peak in about ten years and thereafter fall. This may be offset by new discoveries, although no large oilfields have been discovered since 1980. The demand for oil continually increases. Burning oil also produces large quantities of carbon dioxide, just like coal. Furthermore, oil is a valuable chemical with many applications principally as airplane fuels and in the pharmaceutical industry, and so burning it is very wasteful. A further complication is that the bulk of the remaining oil reserves are in the Middle East.

Oil can also be extracted from tar sands. There are enormous deposits in Northern Canada, estimated to be able to yield at least 170 billion barrels compared with about 260 billion barrels in Saudi Arabia. Venezuela also has substantial reserves. The oil is extracted by boiling water, and is an expensive and very polluting process. It costs about $25 to extract a barrel of oil, so the process is economic as long as it remains less than that from oil wells, as is the case at present.

Oil in the form of ethanol can be extracted from sugar cane and from maize. Already there are large plantations growing crops for this purpose; Brazil plans to plant 120 million hectares and an African consortium 380 million hectares. This takes up valuable agricultural land, however, leading to food shortages, and is also highly polluting. It is, therefore, unwise to rely on oil, even from vegetable sources, for our future energy supplies.

Natural Gas

Sometimes associated with oil and sometimes on its own, gas is an attractive energy source. It comes out of the ground easily and can be transported over large distances either by pipeline or less conveniently in liquid form by road, rail, and ship. It is widely used for domestic heating and cooking. It is one of the cheapest and safest energy sources, so many gas power stations are now being built. These power stations can be brought into action rapidly and so are useful when dealing with fluctuating demand. Natural gas is also the safest energy source, with an average of half a death per thousand megawatt years.

The contribution of natural gas to world energy consumption has risen from 170 million tons of oil equivalent in 1950 to 2020 million tons in 2000. A large gas field in Siberia now supplies around 20 percent of western European gas. Gas consumption in Britain is rising rapidly and with it the price. The calculated lifetime is about sixty years, but as in the case of coal and oil this is likely to be an underestimate. Ultimately gas production will fall, like that of oil.

The Renewable Energy Sources

Recognition of the pollution caused by fossil fuel power stations has led to strong advocacy of what are sometimes termed the “benign renewables.” This label is somewhat misleading, as statistics show that they are by no means benign. The word “renewable” implies that they do not rely on sources that are limited in amount; they rely on the practically inexhaustible sun. In all cases the energy available is enormous, but it is thinly spread and therefore costly to concentrate. It is regrettable that this renders most of them uneconomical for large-scale energy generation, except for hydropower where nature does the concentrating for us. They have many attractive and valuable features, but the laws of physics are inexorable.

Hydropower

Hydropower (hydro for short) is a well-established and reliable source that supplies most of the electrical power in mountainous countries like Norway and Switzerland. It is however limited worldwide by the number of suitable mountains and cannot ever supply more than about three per cent of the world’s energy needs. There are untapped sources in remote areas, but the electricity produced there has to be transported over long distances and the power lines are exposed to attacks by guerillas.

Hydropower is relatively safe, with a death rate of about four per thousand megawatt years. The dams that hold back the water seem so solid that even this hazard is surprising. However, it sometimes happens, especially with earthen dams, that water starts to trickle through small channels, gradually weakening the dam until it collapses. A wall of water then surges down the valley, obliterating everything in its path. If people are living there, a large number could be drowned. In the period 1969–1986 there have been more than eight dam collapses, with an average death toll of more than 200 people. In one case, about 2500 people were killed.

The lakes behind the dams provide a habitat for wild life, and they can be popular for boating. However in times of drought the water level falls and exposes ugly bands of mud. In addition, these lakes often inundate picturesque valleys and their villages, and destroy valuable agricultural land.

Wind

Of the remaining renewable energy sources, wind is the most promising. Windmills have been used since ancient times, and now wind turbines are a familiar sight in the countryside. They have several disadvantages, however, the main one being that the wind does not always blow and so the power output fluctuates instead of remaining steady. The fluctuations are magnified because the power output is proportional to the cube of the wind velocity. This means that energy is available only over a limited range of wind velocities; when the velocity is small very little energy is produced, while if it exceeds the safety limit the blades have to be feathered to avoid catastrophic damage.

The total energy in the wind is more than enough to satisfy all our energy needs but this cannot be realized because of the high cost (two or three times that of coal power), the unreliability, and the large amount of land required. It may however make a useful contribution if the costs can be substantially reduced.

Wind power is surprisingly dangerous at five deaths per thousand megawatt-years. This is due to the large number of turbines required, about a thousand, to equal the output of one coal power station. These have to be made in factories by processes which are inevitably hazardous. In addition, there are the hazards of construction and maintenance.

The environmental impact of wind turbines is increasingly recognized. They must be built in exposed positions where they can be seen for miles around. They emit a persistent humming sound which people living nearby find intolerable. Often people who moved to the country for peace and quiet are forced to leave and then find that no one wants to buy their house. Wind farms can also be built offshore but this increases the cost and may pose a danger to shipping.

In spite of intensive work over many years wind power is still uneconomical, and in most cases it relies on massive Government subsidies. It is fair to propose that research continues until this difficulty is overcome, but that until this is achieved it is unwise to deploy wind turbines on a large scale.

It is sometimes argued against wind power that turbine blades kill large numbers of birds, estimated to be about 70,000 a year in the United States. This figure should be put into perspective by comparing it with the numbers killed on motorways, amounting to 57 million per year in the United States, by colliding with glass windows (98 million per year), and by domestic cats (55 million a year in Britain).

At present wind contributes only about 0.2 percent of Britain’s energy. The Government has announced that the energy from all the renewables must be raised to 10 percent by 2010. This requires about 8,400 turbines spread over an area of about 1300 square kilometers. There is no hope of doing this, and even if it were achieved there would still be the problem of generating the remaining 90 percent. The situation is very similar in the United States.

Tidal

Some river estuaries are so formed that they experience high tides. When there is a high tide, the sea water flows in, sometimes to a surprising distance from the sea. Around low tide this water flows again back to the sea. If a barrier is put across the river the water flows through pipes to the sea. It is then easy to make this flow rotate a turbine and generate electricity. Such a device has operated in the La Rance estuary in France for many years, producing 65MW. It is reliable, although the peak periods vary according to the moon and not the sun, so the electricity is not always available when it is needed.

A similar though much larger scheme has been proposed for the Severn estuary between England and Wales. It would cost about fifteen billion pounds (about twenty-seven billion dollars) spread over about ten years to build and would produce about 7GW. The environmental effects are expected to be severe as the whole ecology of the area would be altered. The cost of the energy produced would be about twice that from a conventional power station. It is a practicable but hardly attractive prospect.

Wave

Once again the energy in the waves is enormous, but it is difficult to concentrate. A number of devices to do this have been built, but the output is not cost-effective. One such device, costing over a million pounds, had a power output of 75 kW, enough for 25 domestic electric heaters. Wave machines are, moreover, always at the mercy of storms, which can destroy them in a few minutes.

Solar

The sun pours energy on to the earth at the average rate of about 200 watts per square meter so that the amount of energy that we obtain is proportional to the area of the collectors. It has been estimated that to supply the energy needs of four houses requires a collector the size of a large radio telescope. The sunlight can be used directly to heat domestic water circulating in pipes on the roof. This process is reasonably economic and is widely used. Nevertheless, there has to be an additional source of energy for times when the sun is not shining. On a larger scale it is possible to focus the sun’s rays on a boiler at the center of an array of hundreds of mirrors. The steam produced can be used to drive a small turbine to produce electricity. The disadvantage is that the mirrors have to be constantly turned by servomechanisms to keep the sun’s rays focused on the boiler so the whole process is uneconomic.

Electricity can also be obtained using photoelectric cells. These are expensive to make and produce electricity with a low voltage. They are not economic for large-scale generation, but are very useful to generate electricity in situations where the other sources are impossible or impracticable, such as in satellites and traffic signals in remote areas.

Thus solar power has useful but small-scale applications that will certainly be developed further when the cost of photoelectric cells is reduced. It is not a practical economic source of energy for the major needs.

Geothermal

The interior of the earth is hot, and in some places hot water gushes out. This can be used as an energy source, but on a small scale in rather few places. Elsewhere it is possible to drill two nearby shafts, pulverize the rock between their ends, and then pump water down one and extract it by the other. Passing through the rock, the water is heated and is an energy source. However if the shafts are close the heat in the vicinity is soon used up, whereas if they are far apart the water has difficulty in passing from one shaft to the other. Trials show that this process is absolutely uneconomical.

Costs

In our society, costs are crucial. Even a small difference is enough to ensure the dominance of one product over another. With energy sources the situation is more complex because the choice depends on weighing the advantages and disadvantages of each source. This is difficult because they are often incommensurable: how much, for example, are we prepared to pay for increased safety or to reduce the effects on the environment? Finally, it is impossible to estimate the cost of delayed damage, such as that due to global warming and climate change. These costs could well be the greatest of all.

It is sometimes said that more research will improve existing sources and thus remove some current disadvantages. Generally this is true. But in some cases the disadvantage is a consequence of the laws of physics, and then it can never be overcome. An example is the fluctuating nature of wind energy; it is just not possible to make the wind blow steadily all the time.

The worldwide need for energy is so urgent that it is essential to use existing energy sources. It is of course necessary to continue research into new sources, but we cannot wait. Already over the years millions of people have been killed or had their lives impoverished, by energy shortages.

This survey shows that at a time of increasing energy demands the sources listed all have serious disadvantages: oil and natural gas are fast running out, and in any case, all fossil fuels, especially coal, are polluting. Hydropower is limited, and wind and solar energy are unreliable. If that were the end of the story the future would be bleak indeed. However there is another energy source, the nucleus of the atom. The potentialities of this energy source, its advantages and disadvantages, will be considered in the next article.

Notes

There are many books where more detailed accounts may be found:

  1. Wolf Hafele, ed., Energy in a Finite World: A Global Systems Analysis (Ballinger Publishing Company, 1981). P. E. Hodgson, Nuclear Power, Energy and the Environment (Imperial College Press, 1999).
  2. E. von Weiszacker, A. B. Lovins, and L. H. Lovins, Factor of Four: Doubling Wealth – Halving Resources (Earthscan Publications Ltd, 1996).
  3. Bjørn Lomborg, The Skeptical Environmentalist (Cambridge: Cambridge University Press, 1998).
  4. H. Inhaber, Risk of Energy Production (Ottawa: Atomic Energy Control Board, 1981).
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