Ecology: Biology of Interaction. VI-11. The Energy Supply Problem

Appendices: Curriculum. Questions. References. Personalities. Glossary. R Commands.

VI-11. The Energy Supply Problem
In 1983–1984, the UN General Assembly established the WCED (World Commission on Environment and Development), otherwise known as the “Brundtland Commission” after its chairman, Norwegian Prime Minister Gro Harlem Brundtland. In 1987, this commission presented the report “Our Common Future”, dedicated to the prospects for civilisation’s development at the end of the 20th and in the 21st centuries.
The potential capacity of renewable energy sources is approximately 10–13 TW (terawatts, billions of kilowatts) of energy, which is of the same order of magnitude as humanity’s needs. At the time of the WCED report’s preparation (1987), approximately 2 TW was in use, i.e. 21% of world consumption, of which 15% came from biomass (firewood and agricultural waste) and 6% from hydroelectric power. The use of firewood as an energy source cannot grow and must decline.
Renewable energy sources:
— river flow energy (solar energy converted by the hydrological cycle) is used to the greatest extent but is still insufficient; its development comes at the cost of ecosystem destruction and the displacement of people in flooded areas, the release of toxic gases from submerged organic matter, the development of diseases like schistosomiasis, obstacles to the movement of fish and terrestrial animals, and the risk of catastrophes if dams collapse;
— the burning of wood can no longer rely on natural forests and requires the special cultivation of fuel wood within agrosystems; the burning of wood pollutes the atmosphere, and the release of pesticide residues in smoke is particularly dangerous;
— burning fuel derived from biomass; threatens the release of a number of toxic substances into the environment and requires technological development (in 1984, Brazil replaced 60% of its petrol with ethanol from sugarcane, producing approximately 10 billion litres; when oil prices fell, this activity ceased to be profitable);
— the use of solar energy for heating and electricity generation is a very promising sector, whose development is constrained by the relative cost of the necessary materials;
“Some difficulties in the use of solar energy are associated, surprisingly, with injuries from falling off roofs during the servicing and repair of solar installations, and the damage caused by dazzling glass surfaces” (Report of the UN World Commission on Environment and Development, 1987).
— the use of wind energy is one of the oldest and most promising methods (a significant portion of energy in the Netherlands comes from windmills); the costs are noise and vibration, and the alienation of part of the territory;
— the use of geothermal energy is possible in some regions and is now being actively developed;
— other sources (tidal power stations, the use of natural temperature differential energy, etc.).
With the use of renewable energy sources, there is no additional heating of the biosphere, since energy is merely converted from one form to another; their use does not lead to thermal pollution. There is a thermal limit to the use of non-renewable sources, amounting to approximately 100 TW (this is still far off, but if current development rates are maintained, this limit would be reached by the middle of the 21st century).
In 1900, Rudolf Diesel presented an engine running on peanut oil at an international exhibition in Paris. Currently, the technology for producing biodiesel fuel from soybean and rapeseed oil is considered promising; it can be used either in pure form or mixed with petroleum products. Vegetable oils are esters of fatty acids with the trihydric alcohol glycerine. By replacing glycerine with monohydric alcohols (methanol or ethanol), biodiesel is obtained — a fluid yellow liquid with the smell of popcorn or fried potatoes.