Renewable Resource as Energy
We
use energy for household use, agriculture, production of industrial goods and
for running transport. The sun is the primary energy source in our lives. We
use it directly for its warmth and through various natural processes that
provide us with food, water, fuel and shelter. The sun’s rays power the growth
of plants, which form our food material, give off oxygen that we breathe in and
take up carbon dioxide that we breathe out. Energy from the sun absorbs water
from oceans, river and lakes to form clouds that turn into rain. Electrical
energy produced in several ways, powers transport, artificial lighting,
agriculture and industry. Nuclear energy is held in the nucleus of an atom and
is now harnessed to develop electrical energy.
We
use energy for household use, agriculture, production of industrial goods and
for running transport. Modern agriculture uses chemical fertilizers, which
require large amounts of energy during their manufacture. Industry uses energy
to power manufacturing units. Energy-demanding roads and railway lines are
built to transport products from place to place and to reach raw materials in
mines and forests. These all energy use creates heat and contributes to
atmospheric temperature. Many forms of energy release carbon dioxide and lead
to global warming. Nuclear energy plants have caused enormous losses to the
environment due to the leakage of nuclear material.
Renewable energy is generally defined
as energy that comes from resources, which are naturally replenished, on a
human timescale such as sunlight, wind, rain, tides, and waves.
Non-renewable energy comes from
sources that will run out or will not be replenished in our lifetimes—or even
in many, many lifetimes. Most non-renewable energy sources are fossil fuels: coal,
petroleum, and natural gas. Carbon is the main element in fossil fuels.
Hydroelectric power
Hydroelectric Power -- what is it?
This
uses water flowing down a natural gradient to turn turbines to generate
electricity known as ‘hydroelectric power’ by constructing dams across rivers. Hydroelectric power comes from water at work,
water in motion. When
flowing water turns blades in a turbine, the form is changed to mechanical
(machine) energy. The turbine turns the generator rotor, which then converts
this mechanical energy into another energy form -- electricity. Once the
electricity is produced, it must be delivered to where it is needed -- our
homes, schools, offices, factories, etc. Dams are often in remote locations and
power must be transmitted over some distance to its users.
Hydropower is harnessed through the gravitational force of
falling or flowing water. The electricity is typically created when the water
is passed over large mechanical turbines; the water pressure forces the
turbines to turn, the mechanical energy created is then converted into
electricity.
India has the first hydroelectric
power were built in late 1800s by the TATA in the Western Ghats of Maharashtra.
Advantage: It is created by renewable nature of the energy source,
very low operating and maintenance coasts. Once a dam is constructed,
electricity can be produced at a constant rate. If electricity is not needed,
the sluice gates can be shut, stopping electricity generation. The water can be
saved for use another time when electricity demand is high. The power plants,
once in place, do not create any waste byproducts in their conversion. Dams
constructed can also shut their gates and conserve the water for use when power
is in higher demand.
1. Once a dam is constructed, electricity can be produced at a constant
rate.
2. If electricity is not needed, the sluice gates can be shut, stopping electricity generation. The water can be saved for use another time when electricity demand is high. 3. Dams are designed to last many decades and so can contribute to the generation of electricity for many years .
4. The lake that forms behind the dam can be used for water sports and
pleasure activities. Often large dams become tourist attractions in their own
right.
5. The lake's water can be used for irrigation purposes. 6. The buildup of water in the lake means that energy can be stored until needed, when the water is released to produce electricity. 7. When in use, electricity produced by dam systems do not produce green house gases. They do not pollute the atmosphere. |
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1.
Dams are extremely expensive to build and must be built to a very high
standard.
2. The high cost of dam construction means that they must operate for many decades to become profitable.
3. The flooding of large areas of land means that the natural environment is destroyed.
4. People living in villages and towns that are in the valley to be flooded, must move out. This means that they lose their farms and businesses. In some countries, people are forcefully removed so that hydropower schemes can go ahead.
5. The building of large dams can cause serious geological damage. For example, the building of the Hoover Dam in the USA triggered a number of earth quakes and has depressed the earth’s surface at its location.
6. Although modern planning and design of dams is good, in the past old dams have been known to be breached (the dam gives under the weight of water in the lake). This has led to deaths and flooding.
7. Dams built blocking the progress of a river in one country usually means that the water supply from the same river in the following country is out of their control. This can lead to serious problems between neighboring countries.
2. The high cost of dam construction means that they must operate for many decades to become profitable.
3. The flooding of large areas of land means that the natural environment is destroyed.
4. People living in villages and towns that are in the valley to be flooded, must move out. This means that they lose their farms and businesses. In some countries, people are forcefully removed so that hydropower schemes can go ahead.
5. The building of large dams can cause serious geological damage. For example, the building of the Hoover Dam in the USA triggered a number of earth quakes and has depressed the earth’s surface at its location.
6. Although modern planning and design of dams is good, in the past old dams have been known to be breached (the dam gives under the weight of water in the lake). This has led to deaths and flooding.
7. Dams built blocking the progress of a river in one country usually means that the water supply from the same river in the following country is out of their control. This can lead to serious problems between neighboring countries.
8.
Building a large dam alters the natural water table level. For example, the building
of the Aswan Dam in Egypt has altered the level of the water table. This is
slowly leading to damage of many of its ancient monuments as salts and
destructive minerals are deposited in the stone work from ‘rising damp’ caused
by the changing water table level.
Solar
energy
(Related to sun energy)
Today we have developed
several methods of collecting this energy for heating water and generating
electricity. Solar power is the
conversion of sunlight
into electricity.
Solar energy is the
most readily available source of energy. When
we hang out our clothes to dry in the sun, we use the energy of the sun. In the
same way, solar panels absorb the energy of the sun to provide heat for cooking
and for heating water. Such systems are available in the market and are being
used in homes and factories. Solar energy can also be used to meet our
electricity requirements.
Through Solar Photovoltaic (SPV) cells, solar
radiation is converted into DC electricity directly. This electricity can be
used either as it is or can be stored in the battery. This stored electrical
energy then can be used at night. SPV can be used for a number of applications
such as domestic lighting, street lighting, village electrification, water
pumping, and desalination of salty water.
Advantage:
Solar
water heating: These systems have two main parts: the
solar collector and the storage tank. The solar energy collector heats the
water, which then flows to a well-insulated storage tank. Solar water-heating
systems cannot heat water when the sun is not shining.
Solar
cooker: The heat produced by the sun can be
directly used for cooking using solar cookers. It is a metal box, which is
black on the inside to absorb and retain heat. It reduces the need for wood,
and pollution from smoky wood fires.
Other
solar-powered devices: Solar desalination systems
(for converting saline or brackish water into pure water) have been developed. In
future, they should become important alternatives for man’s future economic
growth in areas where fresh water is not available.
Advantage:
Solar energy is a resource that is not only sustainable for
energy consumption; it is indefinitely renewable (at least until the sun runs
out in billions of years). Solar power can be used to generate electricity; it
is also used in relatively simple technology to heat water. Solar panels also
require little maintenance. After installation and optimization they are very
reliable due to the fact that they actively create electricity in just a few
millimeters and do not require any type of mechanical parts that can fail. Solar
panels are also a silent producer of energy.
Disadvantage: The
primary disadvantage of solar power is that it obviously cannot be created
during the night. The power generated is also reduced during times of cloud
cover. Solar panel energy output is maximized when the panel is directly facing
the sun. Solar power is used to charge batteries so that solar powered devices
can be used at night. The batteries can often be large and heavy, taking up
space and needing to be replaced from time to time. It is generally argued that
solar energy production is relatively inefficient. Usually, a solar panel can
convert 22% of the energy it gets from the sun into electrical energy, meaning
you need a big surface area to produce the desired amount of electricity.
Biomass energy
When a log is burned we are
using biomass energy. Because plants and trees depend on sunlight to grow,
biomass energy is a form of stored solar energy. Although wood is the largest
source of biomass energy, we also use agricultural waste, sugarcane wastes, and
other farm byproducts to make energy. Waste material can be converted into
electricity by combustion boilers or steam turbines. Biogas is produced from
plant material and garbage, waste from households and some types of industrial
wastes, such as sewage treatment plants. It is a mixture of gases which
includes carbon dioxide, hydrogen sulphide.
Biomass
fuels come from things that once lived: wood products, dried vegetation,
crop residues, aquatic plants and even garbage.
There
are three ways to use biomass:
1.
It can be burned to produce heat
and electricity
2.
To make such type of gas
3.
In creating some type of liquid
form like, alcohol, fossil fuel to run trucks-buses-trains etc.
How
biomass converted into energy?
This is a
very common way of converting organic matter into energy. Burning stuff like
wood, waste and other plant matter releases stored chemical energy in the form
of heat, which can be used to turn shafts to produce electricity.
Importance of biomass energy:
- Biomass energy resources
are readily available in rural and urban areas of all countries.
- Biomass energy has rapidly
become a vital part of the global renewable energy mix and account for an
ever-growing share of electric capacity added worldwide.
- Biofuels —
Converting biomass into liquid fuels for transportation,
- Biopower — Burning biomass
directly, or converting it into gaseous or liquid fuels that burn more
efficiently, to generate electricity.
- Biogas
plants have become increasingly popular in India in the rural sector. The
fibrous waste of the sugar industry is the world’s largest potential source of
biomass energy.
Advantage:
No Harmful Emissions: Biomass energy, for the most part, creates no harmful carbon
dioxide emissions. Many energy sources used today struggle to control their
carbon dioxide emissions, as these can cause harm to the ozone layer.
Reduce Dependency on Fossil Fuels: It has developed as an alternate source of fuel for many
homeowners and have helped them to reduce their dependency on fossil
fuels.
Reduce Landfills: Another benefit of this
energy is that it can take waste that is harmful to the environment and turn it
into something useful. For instance, garbage as landfill can, at least
partially, be burned to create useable biomass energy.
Can be Used to Create Different Products:
Biomass energy is also versatile, as different forms of organic matter can be
used to create different products. Ethanol and similar fuels can be made from
corn and other crops. With so many living things on the planet, there is no
limit to how many ways it can be found and used.
Disadvantage:
Besides
above advantages, there are also some downsides to it. Let’s see below some of
its disadvantages.
Expensive:
Firstly, its expensive. Living things are expensive to care for, feed, and
house, and all of that has to be considered when trying to use waste products
from animals for fuel.
Harmful
to Environment: Biomass
creates some pollutants, including carbon dioxide, when burned or converted
into energy. In terms of air pollutants, biomass generate less relative to
fossil fuels. Biomass is naturally low in sulphur and therefore, when burned,
generates low sulphur dioxide emissions. waste products, there is the
smell to consider. While it is not physically harmful, it is definitely
unpleasant, and it can attract unwanted pests (rats, flies) and spread bacteria
and infection.
Wind
Power
Wind was the
earliest energy source used for transportation by sailing ships. Wind
energy (or wind
power) describes the process by which wind is used to generate
electricity. Wind turbines convert the kinetic energy in the wind into
mechanical power. A generator can convert mechanical power into electricity.
Mechanical power can also be utilized directly for specific tasks such as
pumping water.
Wind is caused by the uneven heating
of the atmosphere by the sun, variations in the earth's surface, and rotation
of the earth. Mountains, bodies of water, and vegetation all influence wind
flow patterns. Wind turbines
convert the energy in wind to electricity by rotating propeller-like blades
around a rotor. The rotor turns the drive shaft, which turns an electric
generator.Most of the early work on generating electricity from wind was carried out in Denmark, at the end of the last century. Today, Denmark and California have large wind turbine cooperatives which sell electricity to the government grid. In Tamil Nadu, there are large wind farms producing 850 megawatts of electricity. At present, India is the third largest wind energy producer in the world.
Advantages:
- Energy
is generated without polluting environment.
- Like solar energy and hydropower,
wind power taps a natural physical resource.
- Windmill generators don’t
emit any emissions that can lead to acid rain or greenhouse effect.
- Wind Energy can be used directly
as mechanical energy.
- In remote areas, wind turbines
can be used as great resource to generate energy.
- In combination with Solar Energy
they can be used to provide reliable as well as steady supply of electricity.
Renewable & Sustainable:
Wind energy itself is both renewable and sustainable. The wind
will never run out, unlike the earth’s fossil fuel reserves (such as coal, oil
and gas), making it the ideal energy source for a sustainable power supply.
Environmentally Friendly:
Wind energy is one of the most environmentally friendly
energy sources available today. After the manufacture and installation of wind
turbines, there will be little to no pollution generated as a result of the
wind turbines themselves.
Wind Energy is Free:
Unlike some other energy sources, wind energy is completely free. There’s no
market for the supply and demand of wind energy, it’s there to be used by
anyone and will never run out. This makes wind energy a viable option for
generating cheap electricity.
Low Running Costs:
As wind energy is free, running costs are considered to be low. The only
ongoing cost associated with wind energy is for the maintenance of wind
turbines, which are considered low maintenance in nature anyway.
Increases Energy Security:
By using wind energy to generate electricity, we are helping to reduce our
dependency on fossil fuel alternatives such as coal, oil and gas. In many
cases, these natural resources are often sourced from other countries.
War,
politics and overall demand often dictate the price for natural resources,
which can fluctuate and cause serious economic problems or supply shortages for
some countries. By using renewable energy sources a country can help to reduce
its dependency on global markets and thus increase its energy security.
Disadvantage:
- Wind energy requires
expensive storage during peak production time.
- It is
unreliable energy source as winds are uncertain and unpredictable.
- Requires
large open areas for setting up wind farms.
- The principle problems of wind
power are bird kills, noises, effect on TV reception. It
can be a threat to wildlife. Birds do get killed or injured when they fly into
turbines.
- Siting windmills offshore reduces their demand
for land and visual impact.
- Wind
energy can be harnessed only in those areas where wind is strong enough and
weather is windy for most parts of the year.
- Usually
places, where wind power set-up is situated, are away from the places where
demand of electricity is there. Transmission from such places increases cost of
electricity.
- The average efficiency of
wind turbine is very less as compared to fossil fuel power plants. We might
require many wind turbines to produce similar impact.
- Maintenance
cost of wind turbines is high as they have mechanical parts.
Threat to Wildlife:
It’s widely reported that wind turbines pose a threat to wildlife, primarily
birds and bats. It is however believed that wind turbines pose less of a threat
to wildlife than other manmade structures such as cell phone masts and radio
towers. Nevertheless, wind turbines are contributing to mortality rates among
bird and bat populations.
Noise Pollution:
One of the most popular disadvantages of wind turbines is the noise pollution
that they generate. A single wind turbine can be heard from hundreds of meters
away. Combine multiple wind turbines and the audible effects can be much
greater.
Noise
pollution from wind turbines has ruined the lives of some homeowners. Although
steps are often taken to site wind turbines away from dwellings, they do
sometimes get built too close to where people live and this is why new wind
farms often come up against strong public objection.
Tidal
and Wave power
The earth’s surface is 70% water. By warming the water, the sun,
creates ocean currents and wind that produces waves. The energy of waves in the
sea that crash on the land of all the continents is estimated at 2 to 3 million
megawatts of energy. In a two way system power is generated from both the
incoming as well as the outgoing tide. Wave power converts the motion of waves
into electrical or mechanical energy. For this, an energy extraction device is
used to drive turbo-generators. Electricity can be generated at sea and
transmitted by cable to land. Another
developing concept harnesses energy due to the differences in temperature
between the warm upper layers of the ocean and the cold deep sea water. These
plants are known as Ocean Thermal Energy Conversion. Tidal power,
also called tidal energy, is a
form of hydropower
that converts the energy obtained from tides
into useful forms of power, mainly electricity. Tidal power has potential for
future electricity
generation. Tides are more predictable than wind energy
and solar power.
The world's first large-scale tidal power plant is the Rance
Tidal Power Station in France. Wave
energy is
as source of power that comes from the endless march of the waves as they roll
into the shore then back out again.
Advantage:
Renewable: The best thing about wave
energy is that it will never run out. There will always be waves crashing upon
the shores of nations, near the populated coastal regions. The waves flow back
from the shore, but they always return. Waves are not limited by a season, they
require no input from man to make their power, and they can always be counted
on.
Widely Available:
Another benefit to using this energy is its nearness to places that can use it.
Lots of big cities and harbors are next to the ocean and can harness the power
of the waves for their use. Coastal cities tend to be well-populated, so lots
of people can get use from wave energy plants.
No
Damage to Land:
Unlike fossil fuels which cause massive damage to land as they can leave large
holes while extracting energy from them, wave power does not cause any damage
to earth. It is safe, clean and one of the preferred method to extract energy
from ocean.
Effective Even At Low Speeds:
Since water is much denser than air, the amount of movement needed to generate power
is very low. It has been proven that tidal energy can still be harnessed even
if the water is only moving at 3 feet per second.
Completely Green: There are no carbon
emissions from tidal energy plants, making it an energy source that does not
negatively affect the global environment.
Disadvantage:
Effect
on marine Ecosystem:
As clean as wave energy is, it still creates hazards for some of the creatures
near it. Large machines have to be put near and in the water to gather energy
from the waves. These machines disturb the seafloor, change the habitat of
near-shore creatures (like crabs and starfish) and create noise that disturbs
the sea life around them. There is also a danger of toxic chemicals that are
used on wave energy platforms spilling and polluting the water near them.
High Construction Costs:
The costs of the tricky on the water construction and the expensive equipment
necessary to build a tidal energy plant can add up very quickly.
Difficult Sea Usage: The
tidal plant could greatly impact the access of the sea. This could affect
transportation of goods and other vessels that need to travel by the ocean.
Location Limits: There are very few ocean
shores that are suitable for the construction of a tidal energy plant. Research
has shown that only around 20 areas in the entire world would work to harness
tidal energy.
Nuclear power
In 1938, two German scientists Otto Hahn
and Fritz Strassman demonstrated nuclear fission. They found they could split
the nucleus of a uranium atom by bombarding it with neutrons. As the nucleus
split, some mass was converted to energy. India has 10 nuclear reactors at 5
nuclear power stations that produce 2% of India’s electricity. These are
located in Maharashtra), Rajasthan, Tamil Nadu, Uttar Pradesh and Gujarat. 
The nuclear reactors use Uranium 235 to produce
electricity. Nuclear power is the
use of nuclear reactions that release nuclear energy[5]
to generate heat, which most frequently is then used in steam
turbines to produce electricity in a
nuclear power plant. Nuclear energy can be used
to make electricity. But first the energy must be released. It can be released
from atoms in two ways: nuclear fusion and nuclear fission. In nuclear fusion,
energy is released when atoms are combined or fused together to form a larger
atom. This is how the sun produces energy. In nuclear fission, atoms are split
apart to form smaller atoms, releasing energy. Nuclear power plants use nuclear
fission to produce electricity.
Advantage:
Expense: Less uranium is needed to produce the same amount of energy as coal or oil, which lowers the cost of producing the same amount of energy. Uranium is also less expensive to procure and transport, which further lowers the cost.
Geographical limitations: nuclear power plants do not require a lot of space; they do not need a large plot like a wind farm. However, they have to be built near a large body of water for cooling purposes - using the water as a heat sink.
- Nuclear power stations do
not contribute to carbon emissions - no CO2 is
given out - it therefore does not contribute to global warming.
- Nuclear
energy is by far the most concentrated form of energy - a lot of
energy is produced from a small mass of fuel. This reduces
transport costs.
Reliability:
Nuclear power is reliable. It does not depend on the
weather.
Disadvantage:
- The reaction releases very
hot wastewater that damages aquatic ecosystems.
- The disposal of nuclear
waste is becoming an increasingly serious issue. The cost of Nuclear Power
generation must include the high cost of disposal of its waste and the
decommissioning of old plants.
- These have high economic as
well as ecological costs that are not taken into account when developing new
nuclear installations.
Energy
Conservation
Energy conservation refers
to reducing energy consumption through using less of an
energy service. Energy conservation differs from efficient energy use, which refers to using
less energy for a constant service. Driving less is an example of energy
conservation.
Why
should you conserve energy and why is conservation important?
Most
of our energy use comes from fossil fuels like petroleum and coal that provide
electricity and gas to power our growing energy needs. These resources are
non-renewable which means that we will eventually run out.
Conserving
energy not only helps to conserve resources but also translates into financial
savings. When we drive our cars, wash our hands and turn lights on, we usually
don’t stop to assess the amount of resources we are using. We also don’t stop
to think that we are depleting resources that are not boundless.
India
needs to rapidly move into a policy to reduce energy needs and use cleaner
energy production technologies. India must reduce its dependency on imported
oil. At present we are under-utilizing our natural gas resources. We could
develop thousands of mini dams to generate electricity. India wastes great
amounts of electricity during transmission. It is easy to waste energy but
cheaper to save it than generate it. We can conserve energy by Preventing or
reducing waste of energy and by using resources more efficiently. People waste
energy because government subsidies it. If the real cost was levied, people
would not be able to afford to waste it carelessly.
Industry
and transport are the main growing users of energy in India. Industries that
are known for generating pollution also waste the most energy. These include
chemical industries, especially petrochemical units, iron and steel, textiles,
paper, etc. Unplanned and inefficient public transport systems, especially in
cities, waste large amount of energy. Using bicycles is an excellent method to
reduce the use of energy. In agriculture, irrigation pumps to lift water are
the most energy intensive agricultural use. These are either electrical or run
on fossil fuels.
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