Introduction to Energy Sources
Energy can define as the capacity to do work. Work such as pushing or pulling product of force. Thus, energy sources abstract concept. Though power is present in some forms like mechanical, thermal, chemical, biological, which differ fundamentally from one another but together constitute the physical reality of our universe.
We cannot see it or feel it, even if we have to pay for it. It is an essential factor in the growth of an economy. The demand for energy has increased with the economic development of the world.
In India, the per capita energy consumption is only 221 kg of oil equivalent/year, a meager rate compared with other countries. But, now due to the population growth energy consumption will increase day by day.
Conventional Energy Sources and its Problem
These include fossil fuels, e.g., coal, petroleum and natural Gas and nuclear gas, and atomic energy. These are the resources which are exhaustible and cannot replaces once they used. These are available in limited quantity and are of greatest-practical significance.
These include fossil fuels nuclear energy and all of which are mixtures of compounds containing carbon and hydrogen.
Advantages of Energy Sources
Available in the highly concentrated form.
Easy to store Reliable supply.
Lower cost per unit of energy produced as the technology matured
Disadvantages of Energy Sources
Limited supply and will one day get exhausted highly polluting.
For example, a coal-based power plant emits a significant amount of gaseous pollutant like (SO2, NO2, CO2) and a substantial amount of fly ash which causes many health problems as well as environmental problems.
Available only in a few places. (Non-uniform Oil distribution) for example, India has to import 70% of its crude oil requirement which increases import bills.
High running cost.
Extraction of fossil fuels causes various pollution. (In mining operation dust, the exhaust of equipment, etc. Cause air pollution Runoff from mines contains many toxic elements which create water pollution.
Environmental Impacts of a Coal-based Thermal Power Plant
Coal-based power plants are the primary source of air pollution and also a source of thermal pollution.
Coal-based thermal plants are significant contributors to greenhouse gases and also pollutants responsible for acid rain. Also, fly ash emitted from them cause many environmental and health problems.
Emission from thermal power plants:
The primary emissions from combustion of coal at thermal power plants are carbon dioxide (CO2), oxides of nitrogen (NOx, Sulphur dioxide(so2) particulate matter mainly fly ash and also traces of radioactive elements Power plants are the major contributor of CO2 which is a significant greenhouse gas responsible for global warming. CO2 emitted from power plants contribute almost 41% of the US human-made CO2 emissions.
Coal contains Sulphur. So, combustion of fuel will emit a significant amount of SO2 which is mostly responsible for acid rain and other health problems.
Use of coal having lower sulfur content can reduce so2 emissions. Also, washing of fuel mitigate the emission of another significant problem related to coal combustion is the emission of particulates that have a severe impact on public health.
Useful Link: Thermal Pollution Effects and it’s Causes
Particulate matter can irritate small airways in the lungs, which can lead to increased problems like asthma, chronic bronchitis, and airway obstruction.
The dominant form of particulate matter from coal-fired plants is coal fly Ash, but secondary sulfate and nitrate also comprise a significant portion of the particulate matter.
Coal fly ash is what remains after the coal has combusted. So, it consists of the incombustible mostly inorganic Matter found in the fuel.
As most of the ores in the Earth’s crust, coal also contains low levels Of uranium, thorium, and other naturally occurring radioactive isotopes. Whose release into environment leads to radioactive contamination.
These elements are present as tiny trace impurities in coal, but Amount of fuel burned in a power plant is very high. A 1000 MW coal Based power plant could release as much as 5.2 tons/year of uranium (containing 34 kg of uranium-23S) and 12.8 tons/year of thorium Power plants utilize only 1/3 of the energy provided by fossil fuels For their operation. Remaining 2/3 is generally lost in the form of heat to The water used for cooling.
So the water which discharged from the Power plants into the water bodies has L0-16″C higher temperature than the receiving waters which leads to thermal pollution.
This thermal pollution causes the reduction in dissolved oxygen which Effects of the aquatic animals. Also, the heat-sensitive organisms will die. Also, mining of coal will produce large-scale air, water, land, and noise pollution.