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close this bookBiodiversity in the Western Ghats: An Information Kit (IIRR, 1994, 224 p.)
close this folder9. Appreciating and conserving biodiversity
View the document9.1 Biodiversity and the media
View the document9.2 Role of non-government organizations in conservation
View the document9.3 Watershed management
View the document9.4 Energy conservation and alternatives
View the document9.5 Nature trails
View the document9.6 Sacred groves
View the document9.7 Rehabilitation of iron ore mine wasteland in Goa
View the document9.8 Reforestation to restore mining areas
View the document9.9 Mining: Social and environmental impacts
View the document9.10 Resource utilization in Uttar Kannada district
View the document9.11 Biodiversity of Dudhsagar valley

9.4 Energy conservation and alternatives

The economic growth and development of a country is directly dependent on its energy production and utilization. The crucial dilemma facing less-developed countries is how to reconcile development and poverty alleviation goals with responsible management of their environment-especially since such goals will require increased use of energy and raw materials.

Energy is used mainly for power generation, transportation, heating and cooking.

Energy sources

Major sources of energy are:

· coal, oil and natural gas (fossil fuels)
· hydroelectricity
· nuclear power
· wood and charcoal

Fossil fuels are exhaustible. World oil and natural gas supplies may last for barely another 25 years. Coal will last longer- about 150 years-but supplies will eventually run out.


Source of energy

Energy production causes pollution. Burning of wood or fossil fuels (especially coal) causes emission of gases such as carbon dioxide, sulphur dioxide and nitrogen oxides. These gases accumulate in the troposphere and cause global warning (the "greenhouse effect") and acid rain (with its adverse effects on forests and ecology). Despite stringent controls, the radiation hazards associated with nuclear power plants are well known. Hydroelectricity does not cause pollution, but the construction of dams drowns ecosystems and places pressure on the natural environment.


Source of energy

Until adequate, economic alternatives are developed, it is essential to minimize environment pollution associated with energy use, and conserve energy so as to minimize oil importsand save foreign exchange.

Technology can mitigate some of the environmental effects of burning fossil fuels.

· Sulphur can be removed by flue gas desulphurization and furnace sorbent injection techniques during the combustion of coal.

· Nitrogen oxides can be removed by selective catalytic reduction.

· Toxic suspended particulates can be removed by electrostatic precipitators.

Natural gas power stations are less polluting than coal- or oil-based plants. Controlling emissions from natural gas plants costs seven times less than in other plants.

Energy conservation

Energy can be conserved in various ways: reducing transmission and distribution losses, improving plant efficiencies, introducing efficient energy management programmes, and through technological innovations such as energy-efficient lamps. For instance, compact fluorescent lamps save 3/4 of the energy used by standard incandescent bulbs. Education for home users and energy audits for industries can also help cut losses.

Energy can be saved in transport through developing engines with lower fuel consumption, improved maintenance and retrofitting (incorporating improvements in existing engines).

Agriculture consumes over 27% of India's electricity. More than half of the country's 10 million electric pump sets operate at only 50% efficiency. Replacing valves, suction and delivery pipes can improve overall efficiency by 30%, saving over 3 million tonnes of coal a year.

India's 8 million diesel pumps require 8 billion litres of diesel annually. A 30% saving in diesel would reduce diesel imports by 1.2 million tonnes.

At present about 30% of natural gas produced is flared off. This is the equivalent of wasting about Rs 50,000,000,000 per year of resources. Natural gas can be better used through various technological improvements, including using gas turbine plants, producing energy intensive fuels (methanol, olefins, gasoline, kerosene), and using engines that burn compressed natural gas for vehicles.

Wood

In rural India, fuelwood is the main source of energy for both domestic and industrial use, contributing about 69% of total energy consumption. Wood is extensively used as fuel for small-scale industries such as tea and coffee processing, lime kilns, brick making, liquor production and food processing. Fuelwood production is a major cause of deforestation.


Wood

Fuelwood use can be reduced-and deforestation slowed-by turning to other sources of energy, using improved chullas, promoting afforestation, and improving and democratizing forest management.

Alternative energy sources

Various non-conventional source of energy are renewable and environmentally friendly.

Solar

Energy from the sun can be used in several ways:

· photovoltaic technology to generate electricity.
· solar ponds for electricity generation and heating.
· thermal (heating, cooking, drying, refrigeration, etc.)
· photoelectrochemical processes.


Solar source of energy

Geothermal

Geothermal energy taps the heat of the earth's interior. It is restricted to areas with natural sources such as hot springs and geysers, or to sites suitable for drilling geothermal wells.

Ocean

The oceans can produce energy by harnessing waves, wind and tides, and through "ocean thermal energy conservation", which exploits the temperature differences between warm, surface water and cold, deeper layers of the oceans.

Biological

· Solid wastes (garbage, municipal wastes, and crop residues such as rice husks and cow dung) can generate biogas.

· Energy-intensive plantations can be used to produce ethanol. Possible crops include marine plants, freshwater aquatics, woody crops, sugarcane and sweet potatoes. Ethanol can be used directly as a fuel or in gasohol (a mixture of ethanol and petrol).

· Catalytic processes can convert biomass to methanol, and methanol to gasoline.


Source of energy

Nuclear fusion

The process of mimicking stellar energy on earth is used in hydrogen bombs. Its controlled use for energy production is still in an experimental stage.

Hydrogen

Hydrogen burns without producing pollutants: its only byproduct is water vapour. It can be directly used as a fuel or for power generation through fuel cells. Hydrogen is a secondary energy source, produced using primary energy sources from hydrocarbons or by electrolysis of water.

Alternative vs conventional energy

These alternative energy technologies are at various stages of development, with some still only in the experimental stage. They cannot yet compete on price with other sources. But they are environmentally friendly and the raw materials are free or cheap.

Conventional power plants (such as coal, hydroelectricity and nuclear), on the other hand involve huge capital investments, heavy maintenance costs, and can have disastrous environmental effects.

All in all, solar-photovoltaic energy (backed up by wind/ocean and biomass energy), clearly emerges as a leader and protector of the environment. Hydrogen is the projected universal fuel of the 21 st century.


Alternative vs conventional energy

Prepared by Julio Fernandes