A coal-burning power plant in Ghana: How laudable?
Recent power shortfalls in the country have led to many people thinking of numerous cost effective ways of diversifying power generation. Gaining prominence now is the setting up of a coal-burning power plant which has been described as the most cost effective in the country. Coal is a fossil fuel formed from the decomposition of organic materials that has been subjected to geologic heat and pressure over millions of years.
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Is it really cost effective? Do the benefits outweigh the costs? What are the environmental impacts? Are we ready as a country to handle the environmental impacts of such a venture? These and many more are the questions that arise when one reads in the news about the setting up of a coal-burning plant in Ghana. Ghanaians should know what they are going in for by opting for a coal plant.
Electricity is generated in a coal-burning power plant by milling the coal into fine powder and blowing it into the combustion chamber of a boiler where it is burnt at high temperatures. The heat energy produced turns water in tubes lining the boiler into steam which in turn drives the turbines of a generator to generate electricity. A typical (500 megawatt) coal plant burns 1.4 million tonnes of coal each year.
Environmental Impacts
According to the Union of Concerned Scientists in the United States, coal plants are the nation’s top source of carbon dioxide (CO2) emissions, the primary cause of global warming. When coal is burned, carbon dioxide, sulphur dioxide, nitrogen oxides and mercury compounds are released. For that reason, coal-fired boilers are required to have control devices to reduce the amount of emissions that are released. The following poisonous emissions were noted by them with some technologies to reduce the emissions:
• Waste created by a typical coal plant includes more than 125,000 tonnes of ash and 193,000 tonnes of sludge from the smokestack scrubber each year. Toxic substances in the waste—including arsenic, mercury, chromium, and cadmium—can contaminate drinking water supplies and damage vital human organs and the nervous system.
One study found that one out of every 100 children who drink groundwater contaminated with arsenic from coal power plant wastes was at risk of developing cancer. Ecosystems have also been damaged—sometimes severely or permanently—by the disposal of coal plant waste.
• Sulphur dioxide (SO2): Coal plants are the United States’ leading source of SO2 pollution, which takes a major toll on public health, including its contributing to the formation of small acidic particulates that can penetrate human lungs and be absorbed by the bloodstream. SO2 also causes acid rain which damages crops, forests, and soils, and acidifies lakes and streams. A typical uncontrolled coal plant emits 14,100 tonnes of SO2 per year. A typical coal plant with emissions controls, including flue gas desulfurisation (smokestack scrubbers), emits 7,000 tons of SO2 per year.
• Nitrogen oxides (NOx): NOx pollution causes ground level ozone, or smog, which can burn lung tissue, exacerbate asthma, and make people more susceptible to chronic respiratory diseases. A typical uncontrolled coal plant emits 10,300 tons of NOx per year. A typical coal plant with emissions controls, including selective catalytic reduction technology, emits 3,300 tons of NOx per year.
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• Particulate matter: Particulate matter (also referred to as soot or fly ash), can cause chronic bronchitis, aggravated asthma and premature death, as well as haze obstructing visibility. A typical uncontrolled plan emits 500 tons of small airborne particles each year. Baghouses installed inside coal plant smokestacks can capture as much as 99 per cent of the particulates.
• Mercury: Coal plants are responsible for more than half of the U.S. human-caused emissions of mercury, a toxic heavy metal that causes brain damage and heart problems. A typical uncontrolled coal plants emits approximately 170 pounds of mercury each year. Activated carbon injection technology can reduce mercury emissions by up to 90 per cent when combined with baghouses.
Even with the installation of the latest technologies to reduce drastically the harmful emissions from coal-burning power plants, tons of carbon monoxide, pounds of arsenic and other harmful emissions are still released into the environment with their catastrophic effects on the population and environment growing year in year out.
Hazardous air pollutants emitted by coal-fired power plants can cause a wide range of health effects, including heart and lung diseases such as asthma. Exposure to these pollutants can damage the brain, eyes, skin and breathing passages. It can affect the kidneys, lungs, and nervous and respiratory systems. Exposure can also affect learning, memory and behaviour.
Mercury pollutes lakes, streams, and rivers, and accumulates in fish. Just 1/70th of a teaspoon of mercury deposited on a 25-acre lake can make the fish unsafe to eat.
Are we as a country, with our already overburdened health delivery system, ready to take on all the associated health implications from the fallout of a coal-burning power plant?