GEOGRAPHY A LEVEL(FORM SIX) NOTES – 5.3 SUSTAINABLE USE OF FUEL AND POWER

5.3 SUSTAINABLE USE OF FUEL AND POWER

Exploitation means the use of something in order to gain advantages from it.

Power means the rate at which electrical energy is converted to other forms such as motion or heat.

Energy is the ability or capacity to do work.

Uses of Energy

• Energy is used to run machines in industry.
• Energy is used in cooking and warming the body.

Classification of Energy

Energy resources can be classified in two ways:

1. Renewable resources
2. Non-renewable resources

Renewable resources are those that can be replaced after being used and are sustainable, for example, HEP, tidal energy, solar energy, and biogas.

Non-renewable energy resources are known as exhaustible resources; once used up, they cannot be replaced. Examples include coal, petroleum, natural gas, fuel wood, and nuclear energy resources.

NB.

Non-renewable Energy Sources

Coal is a word derived from the Old English term meaning mineral of fossilized carbon. Coal is a black or brown rock consisting of carbon, usually occurring in rock strata in layers or veins. Coal forms as a result of vegetative matter being deposited and compressed under high pressure and heat, turning the vegetative matter into coal. Coal is one of the oldest sources of fuel used by mankind, dating back about 3000 million years ago. Historically, coal has been used as an energy resource, primarily burned for the production of electricity and heat, and also used in industrial purposes such as refining metals. Coal formed by dead plant matter is converted into lignite, then sub-bituminous coal, followed by bituminous coal, and lastly anthracite. This involves biological and geological processes that took place over millions of years.

TYPES OF COAL

• PEAT
  It is not a true coal but represents the first stage of coal formation. It is a brownish fibrous substance formed as a result of partial decomposition of vegetative matter compressed by overlying layers of silt. It has a lot of moisture and a high content of volatile matter, with carbon making only one third of its bulk. It has low heating value. In some parts of the USA, it is used as a domestic fuel. It mainly decomposes in the USSR, USA, and Canada.
• LIGNITE
  It is the second stage after peat. It has a high content of moisture with carbon less than 40%. It still retains a brownish woody appearance but is more compact than peat. It gives only a moderate amount of heat and breaks up easily when exposed to air.
• BITUMINOUS
  It is hard, black, compact coal with a carbon content between 40% and 75%. It has a very high calorific value and is further classified into gas coal and cooking coal.

COAL MINING METHODS

1. Open cast mining method
   Also known as strip mining, it is the most economical way of mining coal. It is used where seams are near the surface. The top layer of soil is removed and then quarried by mechanical excavators.
2. Shaft mining method
   This involves sinking vertical shafts down to the coal seams, then horizontal tunnels (galleries) are made from the shaft as the coal seams are dug out. It is the most common type of mining method and is used where the seams of coal are deep.
3. Adit or drifting method
   Used to extract coal from horizontal or gently sloping seams that outcrop along valleys or hillsides. It is commonly used to extract coal in the valleys of the Appalachian Mountains.

ADVANTAGES OF COAL

1. It is used to produce other energy sources like oil and gas. For example, South Africa uses coal to produce oil at Sasolburg.
2. It has promoted industrial development such as iron and steel manufacturing and the production of locomotives and ships.
3. It has promoted the development of transport systems like railways and roads.
4. It leads to the creation of employment opportunities.
5. It facilitates domestic activities like cooking and warming.

DISADVANTAGES OF COAL

1. It is a non-renewable resource; once exhausted, it cannot be replaced.
2. It leads to air pollution by emitting carbon dioxide, which contributes to global warming, and sulfur dioxide, which causes acid rain.
3. It causes destruction of land space.
4. It is heavy and bulky, making it difficult and costly to transport.
5. It requires a lot of capital for exploitation, which can lead to the decline of other sectors.

COAL IN CHINA

China ranks third in terms of both total production and reserves of coal. Coal in China has been used for over 3000 years. The types of coal found in China include bituminous, anthracite, and lignite.

Coal is found in almost every province but is actively exploited in the following principal areas:

• Shanxi and Shaanxi regions: These two regions hold over 47% of China’s coal reserves.
• Inner Mongolia: Accounts for 25% of China’s total coal reserves. Main mining centers include Fenhe Valley, Ningwu, and the Datong Plateau.
• Manchurian coal field: Located in the provinces of Jilin and Heilongjiang, supporting industries such as steel, machinery, tractors, electrical apparatus, cars, and aircraft.
• Sichuan basin: Deposits are extensive but rarely near the surface. Supports a wide range of light and heavy industries around Chongqing and Chengdu.
• Other coal deposits: Lesser amounts found in Guizhou, Jiangxi, and Hunan.

FACTORS WHICH HAVE FACILITATED THE USE OF COAL AS A SOURCE OF ENERGY IN CHINA

1. The presence of large deposits of coal in almost all provinces.
2. The presence of heavy industries that require large amounts of power, providing a steady market for coal.
3. The use of mechanized methods in coal extraction due to advanced technology.
4. The depth of coal deposits allows for cheap open-cast mining in some places like Fushun and Fuxin.
5. Availability of labor due to a high population of over 1.3 billion people.

IMPORTANCE OF COAL MINING IN CHINA

1. It has stimulated the development of industries such as metallurgical industries in Heilongjiang province.
2. It has provided employment to many people, reducing unemployment.
3. It has contributed to government revenue and capital for further economic development.
4. It has stimulated the development of transport and communication systems like railways and roads. Car industries, shipbuilding, and other transport-oriented industries have developed as a result.

PROBLEMS ENCOUNTERED IN THE EXTRACTION OF COAL IN CHINA

1. In some places, deposits are becoming deeper, increasing the cost of extraction.
2. Some coal seams, such as those in Mongolia, are folded or faulted, creating extraction difficulties.
3. Some deposits are scattered, like in the Sichuan coal fields.
4. Coal is an unclean energy source that causes health problems during extraction.

COAL IN TANZANIA

Tanzania has large coal resources in the southwest of the country, in the Ruhuhu Basin, the Kete Waka–Mchuchuma area, and the Songwe–Kiwira area. Active mining takes place in Songwe–Kiwira to supply coal to the cement industry.

The resources at the Ruhuhu Basin and Kete Waka–Mchuchuma areas are estimated at over 5,000 million tons of recoverable high-quality coal. At Songwe–Kiwira, reserves are estimated at over 20 million tons. This zone holds future potential for the development of heavy industry in East Africa.

Mchuchuma–Kete Waka is the leading coal field in Tanzania, with coal capable of generating about 400MW.

IMPORTANCE OF COAL IN TANZANIA

1. It will stimulate the development of iron and steel industries in Liganga, where iron ore deposits exist, laying a strong base for large-scale industrialization.
2. It will create employment opportunities, helping to solve unemployment problems. Some people are already employed at the Songwe–Kiwira coal mining area.
3. It will further stimulate the development and expansion of transport systems like roads and railways.
4. It will promote the supply of energy for home use and local iron smelting industries like SIDO and other industries such as Mbeya Cement.
5. Some coal is exported to other countries like Zambia and Congo, earning foreign currency.

THE DRAWBACKS FACING COAL MINING IN TANZANIA

1. There is inadequate capital investment in the coal mining sector since Tanzania is economically poor.
2. There is a low industrial base, resulting in low market demand for coal, discouraging heavy investment.
3. Poor transport networks mean mining sectors are not well served by roads or railways.

DECLINE IN COAL

In the past, coal was in high demand in the international market. For example, by 1900, coal accounted for almost 90% of the world’s power requirements. Today, very little coal enters the international market due to declining demand. Reasons for the decline include:

• Coal has a lower calorific value compared to other sources.
• It causes environmental problems such as land and air pollution.
• Higher production costs because some coal seams lie deep below the surface, requiring expensive extraction methods like shaft mining.
• Coal is costly to transport due to its heavy and bulky nature.
• Competition from alternative energy sources that are more efficient and environmentally friendly, such as hydroelectric power (HEP).