Energy safety
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Description
Energy safety encompasses the effects of generation of energy on the environment and human health and safety. To avoid futile discussions on such matters as car accidents, this article has been restricted to the various methods of generating electricity. It is very difficult to obtain precise data on the effects of electricity generation and any article on the subject must involve a certain amount of speculation. For this reason, the whole article has been tagged as controversial.
Detailed description
Nuclear
Environment
The environmental effects of a modern nuclear power station are very small. The energy required for its construction is high, possibly on a par with a large hydroelectric scheme. However, this is amortised by the energy produced in a very short time. There remains the thorny problem of used fuel. We have the technology to recycle most of it, although this is not universally applied. We also have the technology to dispose of the rest safely and with little effect on the environment. The fact that we have not been able to do so in many places is partially because of the shortsighted view of politicians who see only their reelection in a few years and do not wish to make decisions which are emotionally charged and may be unpopular. The real problem is that used fuel rods are stored for 40 or 50 years in cooling baths before they can be disposed of; this appears to take away the urgency of the problem.
Of course, a major nuclear accident such as the Chernobyl disaster has widespread environmental effects over large areas because of the spread of radionuclides. It is to be hoped that this accident is a one-off event; it simply cannot happen with modern nuclear power stations. Natural disasters, such as earthquakes, and man-made accidents such as large aircraft crashing into a power station are not likely to cause major leaks of radioactive material. A major earthquake in Japan developed a fault line straight through the site of a nuclear power station without any important problem developing[1]. Lessons have been learnt from the less important nuclear accidents, such as Windscale and Three Mile Island, and safety measures have been incorporated in both existing and future nuclear reactors, as a result.
Human H&S
Of course, the Chernobyl disaster is foremost in everybody's mind when discussing the health and safety aspects of nuclear technology. The most serious of the various reports published on the subject indicate that the death toll, including long-term future deaths, is not likely to exceed 5000. This was based on various studies in three countries and by various international organisations including the World Health Organisation. Other publications, not involving serious epidemiological studies, have cited figures up to about 50,000; one non-scientific study, published by an eco-political organisation opposed to nuclear power, cited 200,000. See Chernobyl disaster for fuller details with references.
In the interests of fairness, the media often report fatal accidents at nuclear power stations which have nothing whatsoever to do with radioactivity. It is not uncommon, for example, with all types of thermal power station to have live steam escape accidentally for one reason or another. If a person happens to be where this occurs, then his death is usually instantaneous. There are probably 20 to 30 deaths per year in thermal power stations from this cause, of which one or two may be in nuclear power stations; only these latter get mentioned in the international media because it makes good news coverage, while distorting the truth. Another example of this is that a transformer burning for two hours at the Japanese power station hit by the earthquake, mentioned in the last section, received as much attention as 1.2 tonnes of slightly radioactive water escaping into sea. If this had happened in a conventional power station, it is probable that it would not have received more than a small paragraph in the local newspaper, let alone the international news agencies.
In proportion to the quantity of energy generated by the different types of power station, nuclear energy is probably safer to humanity, averaged over the last 50 years, than any other form of power generation, even taking into account the most pessimistic figures from the Chernobyl disaster.
Fossil fuels
All fossil fuels have both environmental and health and safety impacts. Depending on conditions, these can be very serious.
Coal
Environment
The total "cradle to grave" environmental impact of burning coal is enormous. No matter whether the coal comes from deep mines or opencast pits, the energy required to obtain it, sort it and transport it to the power station is important. Some methane is released at all stages, varying with the grade of coal. At the power station, it is ground into a very fine powder to form a fluidised bed for the combustion. This grinding also releases some methane and a very fine coal dust which floats everywhere.
The combustion itself releases between 3 1/2 and 4 1/2 times the weight of coal in carbon dioxide. It also produces considerable fly ash which has to be disposed of. Worse again, as the quantity of sulphur dioxide emitted, along with other pollutants, such as heavy metals, including mercury, and even radioactive materials. (It is often said that more radioactive material is omitted from a coal fired power station than from a nuclear power station!)
For further information on the environmental effects of the use of coal, please see the article Coal.
Human H&S
It is impossible to obtain reliable data on deaths related to mining the coal, transporting it, burning it and being affected by the pollution that is produced. It is estimated that between 5 000 and 10 000 are killed in mine accidents each year, on average. On top of that, at least double this figure die from pneumoconiosis. Assuming that half the coal mined is used to generating electricity, this means that 20 000 people, as a minimum, die prematurely each year before the coal is even burned to produce electricity.
It is possibly ironic that the country which suffered the worst nuclear disaster is also one of the countries with the worst statistics for mining accidents, in terms of the quantity of coal mined. Ukraine has consistently suffered from various types of mining accident over the years.
The following quotation from the Earth Policy Institute (© 2004, with tacit permission) illustrates the effects of pollution from coal burning plant in the USA[2].
In the United States, 23,600 deaths each year can be attributed to air pollution from power plants. Those dying prematurely due to exposure to particulate matter lose, on average, 14 years of life. Burning coal also is responsible for some 554,000 asthma attacks, 16,200 cases of chronic bronchitis, and 38,200 non-fatal heart attacks each year. Atmospheric power plant pollution in the United States racks up an estimated annual health care bill of over $160 billion.
Other figures quote annual death toll of 400 000 in China[3]. It is difficult to find corresponding figures for India and other countries. It nevertheless seems probable, even using the most conservative data, that the number of persons dying prematurely each year from coal-burning electricity generation must be in the hundreds of thousands (and not necessarily in the countries which produce the pollution!
Natural Gas
Environment
Contrary to popular belief, if taken holistically, natural gas has probably a similar if not worse impact on greenhouse gas emissions than coal or oil. It is a "clean" fuel only for the consumer, although it still produces 2.74 kg of carbon dioxide for every kilogram of natural gas. For a full study of this phenomenon, please see the article on natural gas.
Because natural gas is almost pure methane by the time it reaches the consumer, it does not have any significant quantities of the dangerous pollutants associated therewith other fossil fuels, such as sulfur, mercury or radioactive substances. However, these have all been removed as a prior stage and how they are disposed of is often a moot point.
Human H&S
No figures have been found regarding worldwide accidents involving natural gas. However, the figure must be relatively high as major explosions are reported quite frequently in the international media. Researching the Internet reveals literally many hundreds of cases of explosions, often with fatalities of a number of persons. Less frequent, there are also cases reported of people dying from carbon monoxide inhalation due to partial combustion; this is often associated with water heaters. At the beginning of the chain, wellhead accidents also happen, sometimes with death tolls of 200. There are also fatalities in the distribution; compressed natural gas, as in pipelines, is particularly hazardous. It is impossible to cite an accurate figure from all causes, but the global death rate probably counts in a few hundred each year.
Oil
Environment
Oil is particularly hazardous for the environment. Obviously, the catastrophes provoked by the shipment of crude oil spring to mind. However, the multitude of small spills probably accounts for much more damage than a major tanker disaster, because they are happening all the time , everywhere. A small quantity of, say, heating oil entering into groundwater may render it unfit for human consumption over long periods of time. Even worse, is when the oil is deliberately released into the environment.
Other than oil spills, volatile oil products, allowed to evaporate, are greenhouse gases, as well as volatile organic compounds. The leakage of oil from the engines some of badly maintained cars also constitute a hazard to the environment along with the exhaust fumes from the same cars.
Probably 95% of all the oil extracted is used as fuel of some sort or another. The combustion, of course, produces carbon dioxide at the rate of 3.0 to 3.8 kg per kilogram of oil burnt. This is intermediate between the values for natural gas and coal.
Human H&S
It cannot be said that oil is without problems regarding human health and safety. Obtaining the oil from out of the ground has always been a hazardous affair, especially with offshore oil rigs. Apart from that, untreated oil products contain relatively high quantities of pollutants and when these are burnt relatively high quantities of sulphur dioxide are emitted. Possibly, one of the biggest problems is the emission of particulates from poorly refined products. For example, an official of the Indian Ministry of Transport has stated that there are five million deaths per year in India alone from the effects of exhaust emissions. Anyone who has visited a large city in India is aware of the problem. Of course, apart from the death rate, it must be assumed that there are 10 times as many persons who are in need of medical attention from the same causes. Without any doubt, the death toll from vehicle emissions must account for millions of people throughout the world, even if no figures are available.
Renewable Generation
Hydroelectricity
Environment
The impact of hydroelectric generation on the environment depends largely on the type of hydroelectric installation. This is a subject on its own, far too long to incorporate within this article because of the many types of installation, and is treated independently under hydroelectricity.
Human H&S
All hydroelectric installations present more or less risk for human life. Over the last 50 years, over 200,000 lives have been lost due to accidents in such installations. Certain types of installation present less risk than others. The events following the 2008 earthquake in Szechuan, China, has been a recent reminder of the hazards related to hydroelectricity, due to dam failure. This subject has been treated in more detail in the article on hydroelectricity.
Garbage generation
Environment
Generating electricity from household garbage in a modern installation has a very low impact on the environment; in fact, it is, by far, more positive than negative, in that the benefits of not landfilling are striking. This subject has been dealt with in more detail in the article on household garbage.
Human H&S
The only major health and safety risk with proper garbage to energy installations, over and above that of any power station, is from the collection of the garbage. The fact that this collection is identical to that of any other form of garbage collection means that the generation of electricity from this source is neither positively nor negatively influenced by an increased risk of human error.
Wind
Environment
It is difficult to be categorical regarding the environmental impact of wind generation. Much depends on the individual site. The actual installation is also variable. Offshore wind generation requires vast quantities of concrete and protective coatings, all of which are energy intensive in their manufacture. Onshore installations are somewhat less onerous, both economically and environmentally. It is evident that onshore installations are best sited in places where the land is unsuitable for intensive agriculture. Wind generators do tend to be noisy and should be kept well away from habitations. One of the biggest problems for both onshore and offshore units is to ensure that they are never installed in the migration path of birds. Many large birds, especially waterfowl and raptors, are killed by the rotating blades.
Human H&S
Provided that the wind generators are kept well away from human habitations there are few health and safety impacts. In the case of offshore installations, care must be taken to avoid any risk of accidents with seagoing vessels; fishing boats are especially vulnerable because they often do their work away from established maritime lanes. In poor visibility, they could become a hazard.
Solar
Environment
Small-scale solar heating or photovoltaic units such as installed on the roofs of habitations have practically zero impact on the environment. Large-scale solar flash distillation and photovoltaic installations have an impact on the use of the land they occupy, which can be several hectares.
Human H&S
Other than the occasional inevitable accident during installation, there is no known health and safety impact due to either small-scale or large scale solar thermal or photovoltaic installations.
