What are the advantages and disadvantages of using coal to generate electricity?

Answer 1

Coal is a fossil fuel like oil and gas. Fossil fuels are all formed out of organic matter deposited, decomposed and compressed, storing all the carbon involved under the earth's surface for millions of years.

Some advantages of coal are -

• Easily combustible, and burns at low temperatures, making coal-fired boilers cheaper and simpler than many others
• Widely and easily distributed all over the world;
• Comparatively inexpensive to buy on the open market due to large reserves and easy accessibility
• Good availability for much of the world (i.e. coal is found many more places than other fossil fuels)
• Most coal is rather simple to mine, making it by far the least expensive fossil fuel to actually obtain
• Coal-powered generation scales well, making it economically possible to build a wide variety of sizes of generation plants.
• A fossil-fuelled power station can be built almost anywhere, so long as you can get large quantities of fuel to it. Most coal fired power stations have dedicated rail links to supply the coal.

However, the important issue as of now is whether there are more advantages than disadvantages of fossil fuels like coal!

Some disadvantages of coal are:

• it is Non-renewable and fast depleting;
• Coal has the lowest energy density of any fossil fuel - that is, it produces the least energy per ton of fuel
• It also has the lowest energy density per unit volume, meaning that the amount of energy generated per cubic meter is lower than any other fossil fuel
• high coal transportation costs due to the bulk of coal (as a result of the preceding two low energy density problems), especially for countries with no coal resources and hence will require special harbours for coal import and storage.
• Coal dust is an extreme explosion hazzard, so transportation and storage must take special precautions to mitigate this danger
• Coal storage cost is high especially if required to have enough stock for few years to assure power production availability.
• burning fossil fuels releases carbon dioxide, a powerful greenhouse gas, that had been stored in the earth for millions of years, contributing to global warming.
• it leaves behind harmful by-products upon combustion (both airborne and in solid-waste form), thereby causing a lot of pollution. In particular, air polution due to burning coal is much worse than any other form of power generation, and very expensive "scrubbers" must be installed to remove a significant amount of it; even then, a non-trivial amount escapes into the air.
• mining of coal leads to irreversible damage to the adjoining environment;
• It will eventually run out.
• It cannot be recycled.
• Prices for all fossil fuels are rising, especially if the real cost of their carbon is included.

Environmental Impact of Coal:

An average of 170 pounds of Mercury is made by one coal plant every year. When 1/70 of a teaspoon of mercury is put in to a 50-acre lake it can make the fish unsafe to eat. Coal power puts the lives of the people who dig the coal in danger, and it gives them poor lung quality. Also, it ruins the natural habitats of animals. See link below.

A coal plant generates about 3,700,000 tons of carbon dioxide every year; this is one of the main causes of global warming. A single coal plant creates 10,000 tons of sulfur dioxide, which causes acid rain that damages forests, lakes, and buildings. When people dig for coal, they cut down many trees. A coal plant also creates 720 tons of carbon monoxide; which causes headaches and place additional stress on people with Heart disease. See link below.

A 500-megawatt coal- fired plant draws about 2.2 billion gallons of water from near by bodies of water. This is enough water to support approximately 250,000 people. Some people have said that coal power is good, because coal power is reliable and affordable. It may be reliable and affordable, but in the future the damage that coal power would cause, would be much more expressive. see link below.

Coal slurry (a mix of rock and coal products left over after the mined coal has been treated for use as a fuel) is a severe environmental problem around coal mines. The slurry itself is a semi-liquid, and is generally stored in a pond or small lake near the mine exit. The slurry contains a whole host of nasty chemicals, mostly benzene relatives and derivatives, and is categorized as low-level toxic waste. Storing is a significant problem, as it has a tendency to leech into the local environment, contaminating groundwater and nearby croplands. The major problem is that the volume of coal slurry is quite high, relative to the amount of usable coal produced.