VisionIAS - Video Classroom Lecture

Science and Technology Class 02

A BRIEF OVERVIEW OF THE PREVIOUS CLASS (01:02 PM)

OCEANIC ENERGY RESOURCES (01:04 PM)

OCEANIC ENERGY RESOURCES

WAVE ENERGY

It is an indirect form of Solar energy because Wind movements are always determined by pressure belts.

TIDAL ENERGY

Tides in the ocean are produced due to the gravitational pull of the Sun, Moon, and Earth.

OCEAN THERMAL ENERGY CONVERSION

Indirect form of Solar energy

OTEC-OCEAN THERMAL ENERGY CONVERSION
It is an indirect form of Solar energy.
In this energy resource, sunlight will heat the surface water, and heat energy from the surface water will reach greater depths through convection and conduction.
At a depth of 100-1000 meters thermal gradient will be established with a temperature difference of 20 degrees.
At this temperature, cold and hot water exists on both sides of Thermocline regions.
Hot water is used for converting Ammonia into steam which is further utilized for the production of electricity.
Cold water is used for condensation of Ammonia from Steam to Liquid.
India's first indigenously developed OTEC plant will be established at Lakshadweep Island and it will be used for Desalinization purposes. (Conversion of Saltwater to freshwater).
Point to be remembered
OTEC is possible only in tropical and sub-tropical regions of the world because of plenty of Sunlight availability.
Ocean Thermal energy after Solar and Wind has a huge estimated potentiality i.e. 180,000 MW. It is due to the longest coastline of India (7516 km).
TIDAL ENERGY
Tides in the ocean are produced due to the gravitational pull of the Sun, Moon, and Earth.
In India, the total estimated potentiality of Tidal energy is 12, 455 MW and it is concentrated in the following three states- Gujarat (Gulf of Khamat and Gulf of Kutchh), Tamilnadu (Palk Bay, Munnar channel), West Bengal (Hugli region, South Haldia and Sunderbans).
WAVE ENERGY
It is an indirect form of Solar energy because Wind movements are always determined by pressure belts.
When winds move from one place to another place and when it come into contact with water, it move the water in the form of waves. This is known as Wave energy.
The estimated potentiality of Wave energy is 40,000 MW.

WIND ENERGY (01:34 PM)

Source of Wind- Winds blow from High pressure to Low pressure
Winds always move from High-pressure areas to Low-pressure areas. By establishing wind turbines, the mechanical energy of the turbine will be converted into electrical energy, or the Kinetic energy of the wind is converted into electrical energy. A group of wind turbines together known as Wind Farms
These wind farms can be established in the following areas-
Wind farms- Mid-Oceans, coastal regions, Between the mountains and hills, Open plains, Top of the mountains/buildings
[* Currently in India, the majority of wind farms are established on the Top of mountains and in plain areas. Now we are focusing on the coastal areas]
[* In urban open plains, it is not established as these areas are crowded with Buildings]
Estimation of Wind energy Potentiality will be done by the National Institute of Wind Energy
Estimation of Wind energy potential will be done by using LIDAR technology which is a part of remote sensing. Wind energy potentiality will be estimated from the mean sea level to the height of 50m, 100, and 120 m.
At 50m height total estimated potentiality of wind energy is 60 GW.
At 100m height total estimated potentiality of wind energy is 302 GW.
At 120m height total estimated potentiality of wind energy is 695.5 GW.
[* LIDAR- Light detection ranging technology ]
In India, wind energy is confined to the following states- Gujarat, Rajasthan, Maharashtra, Tamilnadu, Madhya Pradesh, Karnataka, and Andhra Pradesh.
Even though India has well-developed wind energy technology, there are certain limitations:-
a) Installation costs are very high because of its remote locations
b) A large number of Birds are dying and hence it is showing the impact on the food chains of the ecosystem.
c) Acquisition of land is a difficult task.
d) Noise pollution
To overcome the above limitations, the Government of India is focusing on Off-shore wind farms (Except for installation cost).

GEOTHERMAL ENERGY (01:55 PM)

The total estimated potentiality of Geothermal energy, according to the geological survey of India is 10 GW.
Jammu and Kashmir, Himachal Pradesh, Maharashtra, and Uttarakhand are the states where Geothermal availability is very high.
The borewell temperature should be more than 100 degrees then only it is viable for the production of electricity.

Do you know?
Water is converted into vapor at any temperature but water will be converted into steam at 100 degrees Celsius and above.
Steam has more energy than hot water, hence steam can only rotate turbines.

The major limitation of Geothermal energy is that it leads to thermal pollution.
Without using the fuel, water is converted into steam. It is the only renewable energy that does not have any seasonal impacts and constant power production is possible similar to thermal power plants.

HYDROGEN FUEL (02:11 PM)

It is also called "Futuristic fuel".

Hydrogen

The lightest element in the Periodic table hence when we use it as fuel, the weight of the engine will be reduced as well as efficiency of the engine will be enhanced.

It is the most abundant element in Earth's Crust and hence it is cheapily available.

Among all other fuels, Hydrogen is the fuel that has a Calorific Value.

Combustion of Hydrogen takes place in the presence of Oxygen and results in water hence, the carbon footprint of India can be reduced as well and it is useful to achieve SDGs and the Paris Agreement

Do you know?
The elemental form of Hydrogen does not exist in nature. It exists only in molecular form.
The calorific value of Hydrogen is very high in terms of weight but not in terms of volume.
Calorific Value means the amount of energy that is produced by the combustion of 1 kg of fuel with the other existing fuels.
Limitations of Hydrogen Fuel
Lack of hydrogen fuel technology.
With existing technology, it is not possible to transport it over longer distances, new technological development is required, which requires huge investment.
The accidental rate is very high i.e. it easily catches fire.
Production and transportation of Hydrogen is too costly.
Types of Hydrogen

HYDROGEN- BASED ON THE SOURCE

BLUE HYDROGEN

CH4 + O2===> H2 + Co2
This CO2 is trapped and stored

GREY HYDROGEN

CH4===> H2 + Co2
CO2 released into the atmosphere

GREEN HYDROGEN

H2O====> H2 + O2 (In the presence of Solar and wind).
This process is called Electrolysis

Currently, the government of India is focussing on Green Hydrogen production because it is environment-friendly. To enhance the production of Green Hydrogen, the National Hydrogen Mission was launched.
As a part of this mission, Green Hydrogen is mandatory in the following sectors
a) Oil refinery
b) Fertilizer manufacturing
c) Iron and Steel Manufacturing
d) Bulk Chemicals Manufacturing.
This Green Hydrogen is an energy carrier in the following
i) Blending with Natural gas (India's first Hydrogen CNG plant was established at Faridabad)
ii) It can be used in Energy storage.
iii) It can be used in heavy vehicles as a part of Fuel cells.
iv) It can be used in Maritime and shipping.

Do you Know?
Benefits of Hydrogen and CNG Blending
a) Reduces hydrocarbon emission by up to 70%.
b) It reduces Fuel consumption.
c) Cost of the Fuel can be reduced.
d) Better performance of the Fuel because of high Octane rating.

HYDROPOWER PLANTS (03:02 PM)

HYDROPOWER

Based on River System

Run-off Hydro power plants

These are in the perennial river system

Water Storage hydro-power plants

These are in Non-perennial river systems

Based on Potentiality

Micro- 0-100 KW

Mini- 101-1000 Kw

Small- 1001-25000 Kw- Comes under MNRE

Large- above 25000 kw- Comes under the Ministry of Power

Small Hydropower plants in India are mostly concentrated in the Northern Part of India than in the Southern Part.
The Major problem with small hydropower plants in India is Fresh Water Gangetic Dolphin's habitat was affected.

NON-RENEWABLE ENERGY RESOURCES (15:14 PM)

FOSSIL FUELS

Fossil fuels are formed from the dead remnants of the living organisms. The process is called Fossilization. It takes place in the interior layers of the Earth Crust at high temperatures and pressure.

FOSSIL FUEL

Coal

Crude oil

(Method- Fractional distillation)

Natural Gas

Cleanest fossil fuel

Most Abundant

Based on Carbon Content

Anthracite- Highest Quality

Bituminous- 80%

Lignite- 70%

Peat- 50-60%

Diesel

Petrol

Kerosene

LPG

Plastics

Based on occurrence

Shale gas

Coal Bed Methane

Gas Hydrates

Natural Gas
It contains 95% CH4 and 5% Ethane/ Propane/ Butane.
Natural Gas is of conventional and Unconventional.
Due to the advancement in technology, Natural Gas resources were identified in the deeper layers of Earth's Crust, Such as Shale gas, Coal bed methane, and Gas hydrates. However, due to a lack of technology, these Natural gases are considered as Unconventional.
Natural Gas generally exists in 4 different basic forms-
a) LNG (Liquefied Natural Gas)
b) Regassified Liquefied Natural Gas
c) Compressed Natural Gas
d) Piped Natural Gas
Applications of Natural Gas
a) It is used in electricity generation
b) It is used in Fertilizer manufacturing industries i.e. Ammonia and Urea.
c) It is used as a Green Fuel in Automobile industries.
d) It can be used for Domestic and Commercial purposes.
e) It is used in Industries.
f) In Petrochemical industries- For the production of Methanol.

Do you Know?
Methane-
When it is released directly into the environment, it acts as a Green House gas
When it is combusted as a fuel, it becomes environment friendly.
Methane is produced from the interior layers of Earth's Crust i.e. from Rocks, then it is known as Natural Gas.
Methane produced by the decomposition and Degradation of Biomass, then it is known as Bio-gas
Methane produced from Marshy areas is known as Marsh gas.
Methane produced from cow dung i.e. Gobar called as Gobar Gas
Natural gas and Biogas, when they are compressed then it is known as CNG and CBG respectively
At a temperature of -162 degrees, it will be converted into Liquid for transportation, then it is known as Liquified Natural Gas

GAS HYDRATES (03:45 PM)

Dead living organisms when degrade and decompose they form methane.
Degradation and Decomposition happened in the presence of the Microorganism (Methanogenesis Bacteria and Fungus)
When this Methane is trapped in ice crystals, it is called as Methane Hydrates or Gas Hydrates.
Conditions required
a) Cold temperature
b) High Pressure
Gas Hydrates are available in oceans and polar regions.
Gas Hydrates are also known as "Fire-ice" or "Flammable Ice".
Recently, the largest deposits of Gas Hydrate resources were identified in Krishna and Godavari Basin followed by Andaman as well as in Mahanadi.
Methane in the Greater depths of the ocean is produced due to Microbial activity hence it is known as Biogenic methane.
These gas hydrates are available in polar regions as well as in Oceans.
In polar regions, Atmospheric methane will be trapped in the ice i.e. known as "Permafrost ice".
For extracting the gas hydrate resources, GoI has established a "National Gas Hydrate program".

TOPIC FOR THE NEXT CLASS:- SHALE GAS, COAL BED METHANE, COAL, ETC.