58) ENERGY AND ENVIRONMENT
Some of South Africa's most serious environmental problems are
associated with our use of energy. Coal-fired and nuclear power
stations for electricity generation, coal combustion in the
townships, SASOL coal to oil processes, petrol and diesel use in
vehicles for mass transportation, and over-exploitation of
fuelwood resources all result in serious, long term environmental
damage.
POLLUTION FROM COAL USE
More than three-quarters of South Africa's energy comes from
coal, approximately half of which is used to generate
electricity, a quarter to produce synthetic liquid fuels and
another quarter directly by industry and in homes. Air pollution
problems from coal combustion are serious. Medical studies are
revealing increased rates of respiratory disease in residents in
polluted areas.
ACID RAIN
Most of South Africa's power stations are concentrated within a
100 km radius in the Eastern Transvaal Highveld and this leads
to pollution problems. While all of Eskom's coal-fired power
stations are fitted with electrostatic precipitators to remove
dust and particulates from waste gases produced during coal
combustion, none are fitted with flue-gas scrubbers (cleaning
equipment) to remove oxides of sulphur and nitrogen. Tall chimney
stacks in power stations assist in releasing oxides of sulphur
and nitrogen into the upper atmosphere where atmospheric
conditions are more favourable for their dispersal and dilution.
Although this reduces ground level concentrations of these
pollutants, they may combine with moist air and rain at higher
levels and cause acid precipitation in areas far from the source
of pollution.
Whilst South Africa's coal has a relatively low sulphur content
there is considerable concern about the potential environmental
and economic impact of acid rain. Half of South Africa's
agriculturally productive land, half of its commercial forests
and a quarter of its surface water runoff are in the Eastern
Transvaal Highveld region.
POLLUTION FROM VEHICLES
Motor vehicle fumes make air pollution problems worse and are a
principal cause of photochemical smog in cities. There are now
plans to introduce unleaded fuel and the installation of
catalytic converters which will result in a significant reduction
in the release of carbon dioxide, hydrocarbons, and nitrogen
oxides. However, South Africa lags far behind other countries
(e.g. Japan, Germany) in legislation to control vehicle
emissions. Solutions to transport pollution and vehicle
congestion require long-term planning to introduce efficient
public transport systems in our cities.
DEFORESTATION
Another environmental concern associated with energy use is the
reliance by nearly half of all South Africans on fuelwood, once
a renewable resource, but now being used at a rate much greater
than that at which it is naturally regenerated. Fuelwood is an
inefficient source of energy for cooking and heating and its use
can cause increased respiratory illnesses. It has been estimated
that if current consumption trends continue, all natural woodland
in the former "homelands" will be denuded by 2020 AD. Some
500 000 ha of forest must be planted by the turn of the century
if this situation is to be reversed. However, before this time,
it is likely that a significant number of people will switch from
wood as a source of fuel to more convenient sources such as
paraffin, gas and electricity, thereby slowing down the rate of
deforestation.
GLOBAL WARMING
South Africa uses a great deal of energy, very much more per unit
of gross domestic product (GDP) than most other countries. The
combustion of coal, oil and wood results in increased carbon
dioxide production. This gas acts likes a greenhouse - it lets
short-wave, natural light through but traps out-going long-wave
(infra-red or heat) radiation. The potentially devastating
consequence is that the earth is slowly getting warmer, causing
the climate to change and sea levels to rise (see Enviro Facts
"Global Warming"). Although South Africa produces only a small
percentage (1,6%) of the total, global carbon dioxide emissions,
it plays a disproportionately large role per person in
contributing towards the greenhouse effect and global warming.
As a country needing rapid economic growth in the medium term to
satisfy the country's developmental needs, South Africa's
potential contribution to global warming is an area of concern.
NUCLEAR ENERGY
South Africa currently has one commercial nuclear power station
at Koeberg near Cape Town. It provides 1 800 MW of Eskom's
installed electricity generation capacity of 37600 MW, less than
5% of the total.
Electricity planners foresee that as electricity demand grows,
very many more nuclear power stations will be built. Nuclear
fission produces dangerous radioactive by-products. There is
considerable concern about their safe containment in the case of
accidents at nuclear power stations, the closing down
(decommissioning) of old power stations, and the storage of
highly toxic wastes. At present, low-level radioactive wastes
are stored in sealed containers which are buried underground at
disposal sites. No long-term solution has been agreed on for the
safe storage of high-level radioactive wastes, some of which
remain harmful for thousands of years.
TOPICS FOR DEBATE
* As there is no conclusive proof of significant damage to
agriculture or forestry in the Eastern Transvaal from acid rain,
should South Africa invest in expensive flue-gas scrubbers?
* Given the huge development challenges South Africa faces,
including providing greater access to electricity for poorer
urban and rural households, can South Africa afford to spend
money to reduce the possibility of acid-rain, or reduce its
contribution to global warming? Can we afford to spend money on
catalytic converters to reduce vehicle emissions?
* Given the environmental cost associated with coal combustion,
should South Africa's next power station be nuclear?
FURTHER READING
ATMOSPHERIC POLLUTION AND ITS IMPLICATIONS IN THE EASTERN
TRANSVAAL HIGHVELD.
P. D. Tyson et al. SA National Scientific Programmes Report No
150, CSIR. 1988.
GOING GREEN: PEOPLE, POLITICS AND THE ENVIRONMENT IN SOUTH
AFRICA.
J. Cock and E. Koch (eds). Oxford University Press, Cape Town,
1991.
SOUTH AFRICAN ENVIRONMENTS INTO THE 21ST CENTURY.
B. Huntley, R. Siegfried and C. Sunter. Human, Rousseau and
Tafelberg, Cape Town, 1989.
BACK TO EARTH.
J. Clarke. Southern Books, Johannesburg, 1991.
Enviro Facts: Global Warming, Deforestation
CONTACT ORGANISATIONS
Atomic Energy Corporation.
PO Box 582, Pretoria, 0001. Tel. 012-316 3270
Chemical Workers Industrial Union.
PO Box 3219, Johannesburg, 2000. Tel. 011-331 6861
CSIR: ENERTEK.
PO Box 395, Pretoria 0001. Tel. 012-841 4946.
Energy Research Institute.
UCT, Private Bag, Rondebosch 7700. Tel. 021-650 3230
Eskom.
Megawatt Park, P O Box 1091, Johannesburg, 2000. Tel. 011-800
Department of Mineral and Energy Affairs.
P/Bag X59, Pretoria, 0001. Tel. 012-317 9000.
|
