Conventional (Non-Renewable) Energy Resources:

Fossil fuels
Fossil fuels are found inside the earth’s crust where they have formed through heat and compression of forests, waste and other organic matter, which got buried due to earthquake, landslide, etc.

Classification of Fossil Fuels
(A) Solid (e.g. Coal)
Coal is the most abundantly found fossil fuel in the world. It contains carbon, water, sulphur and nitrogen. Coal meets 70 per cent of the total energy needs of the world found and 87.4 per cent of all commercial energy. In India about 58 per cent of commercial energy is obtained from coal and 38 per cent from petroleum along with natural gas.
Coal is used for cooking, heating, in industries and thermal power plants. Petroleum is useful for transportation; agricultural equipments and, some industries. Natural gas is used both in cooking and in industries.

Types of Coal or Coal Energy
The amount of fixed carbon and hydro carbons forms the basis of classification of coal into various types given as under:
• Anthracite is a hard and dense coal which is relatively free of iron compounds and moisture. The amount affixed carbon may be as high as 95 percent. It is jet black, lustrous and has a fine texture. It burns with a blue flame and gives no smoke.
• Bituminous coal is unusually black and highly lustrous. The moisture content is relatively low. The fixed carbon content ranges from about 50 to over 80% and that of volatile matter from 40 to 15 per cent.
• Lignite is also known as brown coal. The higher grades vary from dark brown to almost black. It is characterized by high moisture content, generally about 40%. The fixed carbon content is also about 40%. The structure is fibrous, and sometimes woody. It has the tendency to crumble into fine coal in shipment and in storage.
• Peat occurs in bogs, especially in areas of cool temperate climates.

Advantages of Coal
• Coal is present in large amount (Most abundant). So it can be used as an energy source.

Disadvantages of Coal
• Release of CO2 and SO2 gas in the atmosphere cause Green House Effect and Global Warming.
• In thermal power plants, burning of coal also generates large amount of flyash. Flyash is a toxic waste, contains toxic heavy metals.
• Workers in the coal mines suffer from following lung diseases: Black-lung disease, Asthma, Bronchitis, Lung cancer.

(B) Liquid (e.g. Petroleum)

Petroleum or Crude Oil
• The gaseous fuels are basically derived from petroleum. It is a natural, underground fossil energy resource. It is formed due to decomposition of micro plankton deposited upon the sea beds, lakes and rivers for millions of years. The decomposition takes place by the action of bacteria, under lack of oxygen and also by catalytic cracking. It is also called crude oil.

• The following are the various uses of petroleum:
a) For heating homes particularly in the cold regions.
b) As industrial power to drive/move engines and for heating furnaces and producing thermal electricity.
c) As transport power for driving railways, motor cars, ships and aeroplanes.
d) As lubricants of machines especially high speed machines.
e) As a raw material in various petro-chemical industries, such as synthetic rubber, synthetic fibres, fertilizers, medicines, etc.

• Advantages of Petroleum
a) Liquid fuel (Petroleum) is easy to transport.
b) Liquid fuel (Petroleum) is comparatively cleaner.
c) They have made possible the introduction and development of newer means of transport.

• Disadvantages
a) After extraction it causes contamination in the water when the leakage takes place.
b) It’s burning produces CO2 and enhances the green house effect.
c) All combustion processes produce the pollutants like NO, SO2, CO, NO2, CO2, Smog.
d) Petroleum contributes to acid rain and urban pollution.

(c) Gaseous (e.g. Natural Gas)

• Natural gas is a fossil fuel.
• It is eco-friendly fuel.
• It is a mixture, of hydrocarbon gases trapped under the earth’s surface. It is mainly consisting of methane (CH4), Propane (C3H8) and Butane (C4H10). After processing it is transported to supply filling stations. Natural gas can be used in two different forms.

1. LPG (Liquefied petroleum Gas)
It is the mixture of Propane, Butane and Ethane.

2. CNG (Compressed Natural Gas)
It is mainly Methane (CH4.).
The major uses of natural gas include:
• It is widely used as fuel in industries and in domestic cooking.
• Petro-chemical industries use natural gas as fuel and raw material.
• Chemical industries such as artificial rubber, plastics, fertilizers, ink, carbon, etc. use natural gas as raw material.
• Natural gas is sometimes used for artificial lighting.

Advantages
• It is a clean fuel, requiring little processing.
• It can be readily transported.
• Smog formation is less in its use.
• It is cheaper than petroleum.

Disadvantages
• It requires both high pressure and low temperature for compression.
• Thick walled tanks are required for storage as it is stored at a high pressure.
• Methane is a green house gas.
• Leakage, in any case, is a serious threat to the environment.

Shale gas
Shale gas refers to natural gas that is trapped within shale formations. Shales are fine-grained sedimentary rocks that can be rich resources of petroleum and natural gas. Sedimentary rocks are rocks formed by the accumulation of sediments at the Earth’s surface and within bodies of water. Common sedimentary rocks include sandstone, limestone, and shale.

Environmental Impact
• Unavoidable impacts are area consumption due to drilling pads, parking and manouvering areas for trucks, equipment, gas processing and transporting facilities as well as access roads.
• Major possible impacts are air emissions of pollutants, groundwater contamination due to uncontrolled gas or fluid flows due to blowouts or spills, leaking fracturing fluid, and uncontrolled waste water discharge.
• Fracturing fluids contain hazardous substances, and flow-back in addition contains heavy metals and radioactive materials from the deposit. Groundwater contamination by methane, in extreme cases leading to explosion of residential buildings, and potassium chloride leading to salinization of drinking water is reported in the vicinity of gas wells.
• The impacts add up as shale formations are developed with a high well density (up to six wells per km²).

Coal bed Methane
• Coal Bed Methane is methane (natural gas) trapped in coal seams underground.
• To extract the gas, after drilling into the seam, it is necessary to pump large amounts of water out of the coal seam to lower the pressure.
• It is often also necessary to frack the seam to extract the gas.
• There are a similar catalogue of negative environmental and social effects as with Shale Gas.
• This includes methane migration, toxic water contamination, air pollution, increased carbon emissions and a general industrialisation of the countryside. Impacts that are specific to CBM include depletion of the water table and potentially subsidence. Conventional (Non-Renewable) Energy Resources
Fossil fuels
Fossil fuels are found inside the earth’s crust where they have formed through heat and compression of forests, waste and other organic matter, which got buried due to earthquake, landslide, etc.

Classification of Fossil Fuels
(A) Solid (e.g. Coal)
Coal is the most abundantly found fossil fuel in the world. It contains carbon, water, sulphur and nitrogen. Coal meets 70 per cent of the total energy needs of the world found and 87.4 per cent of all commercial energy. In India about 58 per cent of commercial energy is obtained from coal and 38 per cent from petroleum along with natural gas.
Coal is used for cooking, heating, in industries and thermal power plants. Petroleum is useful for transportation; agricultural equipments and, some industries. Natural gas is used both in cooking and in industries.

Types of Coal or Coal Energy
The amount of fixed carbon and hydro carbons forms the basis of classification of coal into various types given as under:
• Anthracite is a hard and dense coal which is relatively free of iron compounds and moisture. The amount affixed carbon may be as high as 95 percent. It is jet black, lustrous and has a fine texture. It burns with a blue flame and gives no smoke.
• Bituminous coal is unusually black and highly lustrous. The moisture content is relatively low. The fixed carbon content ranges from about 50 to over 80% and that of volatile matter from 40 to 15 per cent.
• Lignite is also known as brown coal. The higher grades vary from dark brown to almost black. It is characterized by high moisture content, generally about 40%. The fixed carbon content is also about 40%. The structure is fibrous, and sometimes woody. It has the tendency to crumble into fine coal in shipment and in storage.
• Peat occurs in bogs, especially in areas of cool temperate climates.

Advantages of Coal
• Coal is present in large amount (Most abundant). So it can be used as an energy source.

Disadvantages of Coal
• Release of CO2 and SO2 gas in the atmosphere cause Green House Effect and Global Warming.
• In thermal power plants, burning of coal also generates large amount of flyash. Flyash is a toxic waste, contains toxic heavy metals.
• Workers in the coal mines suffer from following lung diseases: Black-lung disease, Asthma, Bronchitis, Lung cancer.

(B) Liquid (e.g. Petroleum)
Petroleum or Crude Oil
• The gaseous fuels are basically derived from petroleum. It is a natural, underground fossil energy resource. It is formed due to decomposition of micro plankton deposited upon the sea beds, lakes and rivers for millions of years. The decomposition takes place by the action of bacteria, under lack of oxygen and also by catalytic cracking. It is also called crude oil.
• The following are the various uses of petroleum:
a) For heating homes particularly in the cold regions.
b) As industrial power to drive/move engines and for heating furnaces and producing thermal electricity.
c) As transport power for driving railways, motor cars, ships and aeroplanes.
d) As lubricants of machines especially high speed machines.
e) As a raw material in various petro-chemical industries, such as synthetic rubber, synthetic fibres, fertilizers, medicines, etc.
• Advantages of Petroleum
a) Liquid fuel (Petroleum) is easy to transport.
b) Liquid fuel (Petroleum) is comparatively cleaner.
c) They have made possible the introduction and development of newer means of transport.

• Disadvantage

a) After extraction it causes contamination in the water when the leakage takes place.
b) It’s burning produces CO2 and enhances the green house effect.
c) All combustion processes produce the pollutants like NO, SO2, CO, NO2, CO2, Smog.
d) Petroleum contributes to acid rain and urban pollution.
(c) Gaseous (e.g. Natural Gas)
• Natural gas is a fossil fuel.
• It is eco-friendly fuel.
• It is a mixture, of hydrocarbon gases trapped under the earth’s surface. It is mainly consisting of methane (CH4), Propane (C3H8) and Butane (C4H10). After processing it is transported to supply filling stations. Natural gas can be used in two different forms.

Shale gas
Shale gas refers to natural gas that is trapped within shale formations. Shales are fine-grained sedimentary rocks that can be rich resources of petroleum and natural gas. Sedimentary rocks are rocks formed by the accumulation of sediments at the Earth’s surface and within bodies of water. Common sedimentary rocks include sandstone, limestone, and shale.

Environmental Impact
• Unavoidable impacts are area consumption due to drilling pads, parking and manouvering areas for trucks, equipment, gas processing and transporting facilities as well as access roads.
• Major possible impacts are air emissions of pollutants, groundwater contamination due to uncontrolled gas or fluid flows due to blowouts or spills, leaking fracturing fluid, and uncontrolled waste water discharge.
• Fracturing fluids contain hazardous substances, and flow-back in addition contains heavy metals and radioactive materials from the deposit. Groundwater contamination by methane, in extreme cases leading to explosion of residential buildings, and potassium chloride leading to salinization of drinking water is reported in the vicinity of gas wells.
• The impacts add up as shale formations are developed with a high well density (up to six wells per km²).

Coal bed Methane
• Coal Bed Methane is methane (natural gas) trapped in coal seams underground.
• To extract the gas, after drilling into the seam, it is necessary to pump large amounts of water out of the coal seam to lower the pressure.
• It is often also necessary to frack the seam to extract the gas.
• There are a similar catalogue of negative environmental and social effects as with Shale Gas.
• This includes methane migration, toxic water contamination, air pollution, increased carbon emissions and a general industrialisation of the countryside. Impacts that are specific to CBM include depletion of the water table and potentially subsidence.