The fact that coal energy is nonrenewable means that it is a type of energy that cannot be re-created. Coal is made up of a variety of solid, combustible, sedimentary organic rock. The composition of coal is mainly carbon and varying amounts of other components such as hydrogen, oxygen, sulphur and moisture.
Many different classifications of coal are used around the world, reflecting a broad range of ages, compositions and properties.
According to the International Energy Agency (IEA), coal currently provides 40 per cent of the world’s electricity needs. It is the second source of primary energy in the world after oil, and the first source of electricity generation.
It has become the fastest-growing global energy source since the beginning of the 21st century.
Developing economies experience economic growth in the use of coal. Countries that generate electricity almost entirely from coal are South Africa, 93 per cent ; Poland, 87 per cent; China, 79 per cent; Australia, 78 per cent; Kazakhstan, 75 per cent; India, 65 per cent; Israel, 58 per cent; Morocco, 51 per cent and USA, 45 per cent.
According to World Energy Council, the global consumption of coal is growing and is expected to increase even more as developing countries expand their energy needs.
However, irrespective of its economic benefits for the countries, the environmental impact of the use of coal, especially carbon dioxide emissions, should not be overlooked.
Advantages of using coal to produce electricity:
• Coal energy is an affordable energy source because of the coal’s stable price compared to other fuel sources
• Coal is easy to burn
• Coal produces high energy upon combustion
• Coal energy is inexpensive
• Coal is abundant
• Coal energy is a reliable energy source.
Disadvantages of using coal to produce electricity:
• Coal energy produces large amounts of carbon dioxide, which lead to global warming and climate change
• The burning of coal is not environmental friendly, because it produces harmful byproducts and gas emissions such as sulphur dioxide, carbon dioxide and nitrogen oxide that pollute the environment, including acid rain.
• Coal energy is a nonrenewable energy source
• Coal is fast depleting because we consume too much of it
• Coal mining ruins the environment and puts the lives of people, especially the coal miners, in danger.
The situation in Ghana
The growing concern about Ghana’s consistent power crisis and rising energy prices and Ghana’s target of increasing its current installed generation capacity of about 2,800 MW to 5000MW by 2016 has sparked the rush for coal for the generation of electricity.
Currently, Shenzhen Energy Group (SEG), the mother Company of Sunon-Asogli, an Independent Power Producer in the power sub-sector, has proposed to build a 700MW coal-fired power plant in Ghana. The project, which is expected to take 24-30 months to complete, will also include the construction of a coal port with approximately 50,000 tons berth.
The project is estimated to cost about $700 million and will need two million tons of coal per year to run when completed. The proposed plant will import coal from South Africa.
Although a coal fired power station for the generation of electricity will assist in finding a solution to the electricity crisis in the country, it has received numerous criticisms.
It is believed that Ghana’s current emission of about 24 megatonnes of carbon dioxide a year will increase with the coming on line of a coal fired power station. This will add to the burden of greenhouse gas emissions, subsequently contributing to global warming.
Additionally, there will be an increase in the emission of noxious gases like sulphur dioxide and nitrogen dioxide, which will lead to the incidence of acid rain in certain geographic areas. Coal-fired power is one of the most polluting forms of energy available, particularly when compared to renewable energy alternatives such as wind, solar and geothermal power.
The idea to establish a coal power plant in the country has received unwelcome reception, with a section of youth along the coastal belt describing the idea as detrimental to their environment and health. Below are some of the effects
Clean Coal Technologies
Despite the adverse impacts of using coal for power generation, there are technologies that will mitigate the impacts. An integrated gasification combined cycle technology allows coal to be gasified and then fed into a gas turbine.
Further, the exhaust heat is used to raise steam for further generation of power, thereby increasing the thermal efficiency of the generation process. This is a relatively modern technology and is being applied in some developed countries.
One may also use flue gas desulphurisation technology. In this case, the emitted gases are scrubbed by passing through a limestone slurry spray in which the slurry reacts with most of the sulphur dioxide in the gases to form calcium sulphite in absorber towers of the facility. The spray will fall back into the lower section of the absorber tower, which acts as storage for the re-circulating slurry, where air is blown into the stored slurry.
Elsewhere, the carbon dioxide, which is emitted and leads to global climate change, is absorbed using a cutting-edge technology – carbon capture and storage.
