MARIE-CURIE CONFERENCE - STEYR/UPPER AUSTRIA, 16-19 MAY, 2001
ENVIRONMENTAL ASPECTS OF ENERGY-
Physikalisch-Chemisches Institut der Universität Heidelberg
1.1 Historical notes
Wind and water were important sources of energy for many activities in the centuries up to the industrial revolution. Indeed, water power largely drove the economy of Europe  and continued to play a role long after the introduction of steam power and electricity . Traditionally, wood and peat were employed for heating and cooking, but coal burning was also known. Archaeological evidence suggests that as early as
ndrdthe 2 and 3 Centuries AD, the Romans had used coal [3,4]. An early archival record of coal mining exists from 1296 in the Dortmund area. The good heating power of coal was recognised by medieval industries,
ththbut it was not popular for domestic use, due to the heavy smoke and sulphur emissions. In the 13 and 14
centuries, laws were passed in some countries that restricted or forbade the burning of coal [1,4-6]. From
ththe early 18 century coke was produced, which could be used to fuel forges in the steel and iron industry.
thThe real motor for the expansion of mining/excavation and large-scale fossil fuel conversion in the late 18
thand 19 centuries was the enormous energy requirement for the new technologies and industries. Many activities were rapidly mechanised as a result of key inventions such as J. Watt?s steam engine of 1764 , the thermodynamic cycle process of S. Carnot (1824), the 4-stroke gas engine of N.A. Otto (1876), the first usable turbogenerator by C.A. Parsons (1884) and the Diesel engine with air intake by R. Diesel (1897)[9,11]. The dominant supplier worldwide of energy soon became coal – it was used to power steam
engines, steamships and for steel production. In the 1880s coal was first used to generate electricity for homes and factories.
As technology advanced and new industries were founded and rapidly expanded, voices were increasingly being raised about environmental concerns. Already in 1661, John Evelyn had written his book "Fumifugium, or the Inconvenience of the Aer and Smoake of London Dissipated" to propose remedies for London's air pollution problem. In 1819 a British Parliamentary committee expressed the hope that steam engines and furnaces "could work in a manner less prejudicial to public health”. In time, several pieces of legislation were passed , but in general, these were not very effective. For example, the Improvement Clauses Act of 1847 tried to reduce factory smoke and the Public Health Act of 1875 contained smoke abatement legislation that has been used to the present day. The term “acid rain” was used from about 1856, that of “smog” from 1905, following a number of serious smog incidents in London and other major
thcities in the late 19 century. The worse smog event ever was in London in 1952, when about 4000 persons died. This lead to the UK Clean Air Acts in 1956 and 1968, which introduced smoke-free zones in the cities and sought to control industrial sources of pollution by using tall chimneys for waste gas dispersal. In the power sector, new pollution control technologies were introduced and the chief pollutant, SO, began to fall 2
dramatically in the industrialised countries from the early 1980s.
The advent of motorised transport was largely responsible for the steady increase of NO, CO and other x thpollutants in the atmosphere from the later part of the 19 century. A strong rise in these emissions came in
the 1950s with the large increase in road traffic. Then from the early 1990s, after the introduction of emissions control technology, levels of NOx and other pollutants fell sharply in western industrialised countries, though remains dangerously high in some developing parts of the world.
Serious concerns about climate change did not develop until a much later date, although J.B. Fournier had, in 1826, expounded his theory of the greenhouse effect and S. Arrhenius had warned about the possibility of warming of the earth in 1896 . It was simply assumed that all the carbon dioxide would be taken up by the oceans. Only in 1957 was concrete evidence obtained by Revelle and Suess, who measured the
14oceanic distribution of C, to show that CO-uptake was in fact much slower than its release into the 2
atmosphere. Direct measurements since 1958 on antarctic ice borings demonstrated the rise in atmospheric CO since industrial times , which by the mid-seventies had become fairly obvious. Today, the average 2
CO concentration in the atmosphere is around 365 ppm, compared to the estimated level of 280 ppm in 2
In 1979, the first World Climate Conference was held in Geneva. This and other meetings held under the auspices of the World Meteorological Organisation and the UN Environment Programme in the 1980s began focussing scientific research on the greenhouse effect. On one hand, a wide variety of environmental data was required and on the other, the needs for technology development had to be addressed. This lead to the initiation of various energy RTD programmes (e.g. EU, DOE)[15,16]. Then in 1988, the WMO and UNEP set up the Intergovernmental Panel on Climate Change (IPCC) whose task is to evaluate data on climate change and propose reaction strategies. The IPCC has so far published three major assessment reports (1990, 1995, 2001) on its findings. In the early 1990s, the level of political activity increased markedly and a series of International Negotiating Committee (INC) meetings led to the drafting of the UN Framework Convention on Climate Change, which came into force in 1994. The parties to the convention hold regular meetings (COP); from the third meeting (COP3) the Kyoto Protocol emerged, which was intended to be a legal commitment to limit emissions of six greenhouse gases to certain percentages compared to the 1990 levels.
1.2 Distribution of energy forms in the world
As mentioned above, coal became the primary energy carrier during the Industrial Revolution. In the early th20 century, oil and gas began to expand (Fig. 1). Since the 1960s there has been a steady shift away from
coal, e.g. in Germany, the share is now down to 揘ew?
24%, whereas use of gas has increased to 21%, Biomass100oil to around 38% and nuclear to 12%. Poland, Traditional biomassOtherson the other hand, which started a similar
80Nucleardevelopment only after 1990, the coal share is
still about 67%, while that for gas is 10% and oil
Oil6018%. In some countries, e.g. France, Sweden,
gePercentanuclear energy makes a major share at 35-40%,
40while in Norway, the hydroelectric share is close
to 40%. Traditionally, biomass energy had been
associated with primitive domestic households. 20
In developing countries, it is the main energy
source for many artisan and cottage industries 01900200018501950Fig. 1. Development of energy carriers in the world
such as baking, brewing, textile manufacture, brick-making, etc. For example, in Asia, rural industries account for at least 20% of the region's wood energy consumption . In many African countries, reliance on biomass is on average 60% (if Egypt, Algeria and South Africa are excluded). In contrast, in Paraguay, which previously relied predominantly on traditional biomass, the construction of large hydroelectric dams in the 1980s and 1990s changed the picture completely; this country now obtains 54% of its primary energy supply from water power. Today, biomass is increasingly being used in a sustainable way and there is a wide variety of industrial applications in both developing and industrial countries, including CHP, electricity generation, space-heating boilers in public buildings, domestic heating boilers etc. Some European countries already have substantial shares in the “new” biomass e.g., 12% in Austria, 18% in Sweden, 23% in Finland. Detailed statistics of the energy forms around the world in the last decade can be found in refs. 20-25.
Despite the enormous progress achieved in a range of renewable technologies in the last 10 years, fossil fuels will continue to play a major role in the energy supply for many decades to come. Projected statistics for a variety of scenarios[20-22], show the share of renewables (wind, sun, water, biomass etc.) rising to anything from 15-30% by 2020 and 25-50% by 2050, depending on the prognosis for the different variables (population trends, economic patterns, technology developments etc.).
2. ENVIRONMENTAL IMPACTS
2.1 Impacts for different energy forms
Fossil fuels. The main gaseous emissions from power production are SO, CO and NOx,, contributing 22
60%, 38% and 20% of these emissions respectively[19, Fig. 2]. Carbon dioxide is the well-known greenhouse gas and is discussed further below, while SO and NOx are associated with acidification, 2
deposition and smog problems, affecting air and water quality, human health, buildings and ecology. Although the levels of SO and NOx emissions have fallen in many countries since the introduction of 2
pollution control measures, the pressure to continue reduction continues. In addition, toxic heavy metals such as lead and mercury, which are present in the coal and heavy oils, may be enriched in the conversion process and emitted either in gaseous form or on particulate matter . It should be noted that environmental impacts associated with fossil fuels are not restricted to the energy production process. Mining, excavation and other preparatory activities bear certain risks, e.g. spontaneous combustion, explosions as well as acid drainage. Large excavation facilities also cause pressure on land use. In the course of transportation and storage, there is the potential risk of blowouts, fires and explosions in tanks,
pipelines, spills and leakages. These can lead to
120human risks and impacts on ecology, air and Energy productionEnergiegewinnungwater quality. In the case of oil, tanker accidents Other industriesandere Industrien100TransportStrassenverkehrand spillages have lead to widespread marine and HouseholdHaushaltAgriculturecoastal pollution. Finally, disposal of wastes from Landwirtschaft80
energy production and pollution control, such as 60ash and sludge must be carefully planned to
minimize effects on land(scape), water and 40
20 % of total emissions for respective species
Road traffic also makes a large contribution to 0SO2NOxNMVOCNH3N2OCO2COCH4emissions of greenhouse gases and pollutants
Fig. 2. Principle gaseous emissions according to
sector (EEA 1998)
such as NMVOC, NOx and CO while being the fastest-growing energy consumption sector worldwide. Each year the transportation sector produces 1800 million tonnes of carbon equivalent emissions (MTCe), or 30% of world carbon emissions . It is estimated that by 2010, the present 550 million cars will have increased to 1.1 billion, with a rise in CO emissions by 65% over the 1990 level, due to increased use of 2
oil-derived liquid fuels. Because of the rapid growth of the transport sector, further efforts to improve abatement strategies are also needed here.
Nuclear energy. During normal operation in modern facilities with the highest international safety standards, radioactive emissions from ore excavation, energy production and transportation are normally at a low level not classed as hazardous. High-level emissions occur following accidents, spills and leakages, in some cases causing serious health hazards. Disposal of radioactive waste and spent fuel as well as decommissioning of facilities can pose potential problems and health hazards.
Biomass. In its traditional form, biomass energy is usually used very inefficiently and can have serious environmental impacts, including health hazards, due to SO, NOx, hydrocarbon and smoke emissions. The 2
greenhouse gases CO, CH, NO are also released. Biomass burning may also affect biogeochemical 222
cycling of nitrogen and carbon compounds from the soil to the atmosphere as well as the hydrological cycle (run off and evaporation), land reflectivity and emissivity and the stability of ecosystems and ecosystem biodiversity.
The reduction of such impacts will depend on sociocultural changes, especially cooking practices, economic factors and technological improvement, e.g., better cooking stoves. At the same time, new strategies to use biomass as a modern, CO-neutral energy carrier offer good opportunities to reduce polluting and 2
greenhouse gas emissions and these are mentioned in section 3.1.
In the 1960as and 1970s, it was widely believed that large-scale deforestation had occurred (e.g. in African and S. American countries) due to overcutting of forests for fuel wood. It now seems likely that overcutting was usually a secondary consequence of the failure to care for diminishing forest lands and resources. Much of the fuel wood and charcoal was obtained not from forests but from scattered trees on farms and during expansion of agricultural and pasture land .
Other renewables. In this group of energy resources, impacts due to gaseous emissions are mostly relatively small. Methane emissions (a greenhouse gas) arise during construction of hydroelectric dams, due to flooding and subsequent decay of vegetation, but this can be reduced by careful planning and design. The main impacts for renewables are associated with land use and siting, landscape and ecology. There are also visual impacts, so that solar and wind installations have to be carefully sited. In addition, for large
facilities such as hydroelectric dams, whole
Local-RegionalGlobalcomm-unities of people and animals can be O Deplet.Troposph. OToxic pollut.Climate ch.Acidification33affected due to the need to flood large areas. 2)SO22)Manufacturing, decommissioning and waste NOXAmmonia2)disposal poses some concerns for solar 1)2)MNVOC2)COfacilities, which use a variety of toxic CO2materials, e.g. zinc compounds and alloys CH4NOcontaining selenium, arsenic etc. 2HFC, PFCSF6Reviews and information sheets on Heavy Metals, Pb,Hg..environmental impacts for various energy ParticlesPOPs (e.g. PAH)carriers can be found e.g. in refs. 28-31. Fig. 2