Technical ReportPDF Available

Environmental aspect of electric energy generation

Authors:

Abstract

This seminar focuses on the type of electrical energy generations and its worse aspects to an environment. Pollutants know no geographical boundary, as a result the pollution issue has become a nightmarish problem and strong national and international pressure groups have sprung up and they are having a definite impact on the development of energy resources. Governmental awareness has created numerous legislation at national and international levels, which power engineers have to fully aware with the practice of their profession and survey and planning of large power projects. This seminar includes the environmental pollution caused by various power plants, atmospheric pollution, and thermal pollution, effects on biodiversity, greenhouse gas emission, ozone layer depletion and changes in climate both locally and globally.
ENVIRONMENTAL ASPECT OF ELECTRIC
ENERGY GENERATION
A Seminar Report
Submitted by
GOM DORJI
EDE2011008
Department of Electrical Engineering
College of Science and Technology
Rinchending Phuentsholing
25th October 2014
Abstract
This seminar focuses on the type of electrical energy generations and its worse aspects to an
environment. Pollutants know no geographical boundary, as a result the pollution issue has
become a nightmarish problem and strong national and international pressure groups have
sprung up and they are having a definite impact on the development of energy resources.
Governmental awareness has created numerous legislations at national and international
levels, which power engineers have to fully aware with the practice of their profession and
survey and planning of large power projects. This seminar includes the environmental
pollution caused by various power plants, atmospheric pollution, and thermal pollution,
effects on biodiversity, greenhouse gas emission, ozone layer depletion and changes in
climate both locally and globally.
ii
ACKNOWLEDGEMENT
I would like to thank our seminar guide for guiding me in writing this seminar, Environmental
aspects of electric energy generation.
I also render my sincere thanks to Liberian of College of Science and Technology for
providing me required material in writing this seminar.
I am also grateful to my roommate for being supportive and providing necessary opinion on
power generations.
Without above helping hand, my work would not have been successful one. Once again I
would like to express my heart full gratitude for your kind support.
1
Table of Contents
CONTENTS
1 Introduction ...................................................................................................................... 3
2 IMPORTANCE OF ELECTRICAL ENERGY ............................................................ 4
3 SOURCE OF ENERGY ................................................................................................... 4
4 TYPES OF ENERGY ....................................................................................................... 5
4.1 Non-Conventional Form of Energy ............................................................................. 5
4.2 Conventional Form of Energy ..................................................................................... 6
4.2.1 Comparison of conventional and non-conventional form of energy Document .. 6
5 RENEWABLE ELECTRICITY GENERATION TECHNOLOGIES ....................... 6
6 ENVIRONMENTAL ASPACT OF ELECTRIC ENERGY GENERATION ............ 7
6.1 Thermal ........................................................................................................................ 7
6.1.1 Coal as thermal fuel .............................................................................................. 7
6.1.2 Coal mining .......................................................................................................... 8
6.1.3 Oxides of sulphur (SO2) ....................................................................................... 9
6.1.4 Acidification ......................................................................................................... 9
6.1.5 Impact on Biodiversity ....................................................................................... 10
6.2 Natural Gas ................................................................................................................ 10
6.2.1 Global environmental impact ............................................................................. 10
6.2.2 Greenhouse effect ............................................................................................... 11
6.2.3 Ozone layer depletion ......................................................................................... 11
6.3 Nuclear power generation .......................................................................................... 11
6.3.1 Heat rejection ...................................................................................................... 13
6.3.2 Gaseous emission ............................................................................................... 13
6.3.3 Environmental Impact ........................................................................................ 14
6.4 Hydropower generation ............................................................................................. 15
6.4.1 Land use .............................................................................................................. 15
2
6.4.2 Wildlife Impact ................................................................................................... 16
6.4.3 Life cycle global warming emission ................................................................... 16
6.5 Wind power generation .............................................................................................. 17
6.5.1 Environmental Impact ........................................................................................ 17
6.5.2 What about batteries? ......................................................................................... 18
6.6 Power transmission and Distribution ......................................................................... 19
7 Conclusion ....................................................................................................................... 20
3
1 INTRODUCTION
Electricity is a basic necessity for the economic development of a country. Many functions
necessary to present day living grind halt when the supply of energy stops. It is practically
impossible to estimate the actual magnitude of the part that energy has played in the building
up of present day civilization. The availability of huge amount of energy in the modern times
has resulted in a shorter working day, higher agriculture and industrial production, healthier
and more balanced diet and better transportation facilities. As a matter of fact, there is the
closed relationship between the energy used per person and his standard of living. The greater
the per capita consumption of energy in a country, the higher is the standard of living of its
people.
Energy exit in different forms in nature but most important form is the electrical energy. The
modern society is so much dependent upon the use of electrical energy that it has become a
part of electrical energy that it has become a part and parcel of our life. Modern society uses
large amounts of electrical power. Power plants convert some other kind of energy into
electrical power. The sources which provide energy required for the power plants are fossil
fuels, nuclear power, hydroelectric power, tidal power, biomass, wind power, geothermal
power, solar power, concentrated solar power. All the systems which generate power have
some advantages and disadvantages. But all most every system shows some environmental
impacts. During the time of construction and even during the time of generation, it has
environmental impacts like air pollution, water pollution, land pollution and etc.
4
2 IMPORTANCE OF ELECTRICAL ENERGY
Energy may be needed as heat, as light, as motive power etc. The present day advancement in
science and technology has made it possible to convert electrical energy into any desired
form. This has given electrical energy a place of pride in the modern world. The survival of
industrial undertaking and our social structures depends primarily upon low cost and
uninterrupted supply of electrical energy. In fact, the advancement of the country is measured
in terms of per capita consumption of electrical energy.
Electrical energy is superior to all other forms of energy due to the following points;
1. Convenient form-Easily convertible form one form of energy to other forms of energy
such as heat, light etc.
2. Easy control-The electrically operated machines have simple and convenient starting,
control and operation.
3. Greater Flexibility-can be transported form one place to another using conductors.
4. Cleanliness and cheaper.
5. Transmission efficiency.
3 SOURCE OF ENERGY
The sources of electrical energy are;
1) The sun
2) The wind
3) Water
4) Thermal
i) Fuels (coal, oil, gas)
ii) Nuclear energy
Out of above listed sources, the sun and wind energy has not been used advance due to its
drawbacks. In present world, water, fuel and nuclear energy are primarily used for the
generation of electrical energy.
5
4 TYPES OF ENERGY
4.1 Non-Conventional Form of Energy
The contemporary non-conventional sources of energy like wind, tidal, solar etc. were the
Conventional sources until James Watt invented the steam engine in the eighteenth century.
In fact, the New World was explored by man using wind-powered ships only. The non-
conventional sources are available free of cost, are pollution-free and inexhaustible. Man has
used these sources for many centuries in propelling ships, driving windmills for grinding corn
and pumping water, etc. Because of the poor technologies then existing, the cost of harnessing
energy from these sources was quite high. Also because of uncertainty of period of
availability and the difficulty of transporting this form of energy, to the place of its use are
some of the factors which came in the way of its adoption or development. The use of fossil
fuels and nuclear energy replaced totally the non-conventional methods because of inherent
advantages of transportation and certainty of availability; however these have polluted the
atmosphere to a great extent. In fact, it is feared that nuclear energy may prove to be quite
hazardous in case it is not properly controlled.
In 1973 the Arab nations placed an embargo on petroleum. People began to realise that the
fossil fuels are not going to last longer and that remaining reserves should be conserved for
the petro-chemical industry. But unfortunately, both nuclear and coal energy pose serious
environmental problems. The combustion of coal may upset the planet’s heat balance. The
production of carbon dioxide and sulphur dioxide may adversely affect the ability of the
planet to produce food for its people. Coal is also a valuable petro-chemical and from long
term point of view it is undesirable to burn coal for generation of electricity. The major
difficulty with nuclear energy is waste disposal and accidental leakage (e.g. leakage at
Chernobyl nuclear power plant (1986) and latest example is Fukushima Daiichi Nuclear
power plant during Tsunami, 2011)
As a result of these problems, it was decided by almost all the countries to develop and
harness the non-conventional sources of energy, even though they are relatively costlier as
compared to fossil-fuel sources.
6
4.2 Conventional Form of Energy
The conventional sources of energy are generally non-renewable sources of energy, which are
being used since a long time. These sources of energy are being used extensively in such a
way that their known reserves have been depleted to a great extent.
At the same time it is becoming increasingly difficult to discover and exploit their new
deposits. It is envisaged at known deposits of petroleum in the world will get exhausted by the
few decades and coal reserves are expected to last for another hundred years. The coal,
petroleum, natural gas and electricity are conventional sources of energy.
4.2.1 Comparison of conventional and non-conventional form of energy Document
5 RENEWABLE ELECTRICITY GENERATION
TECHNOLOGIES
A renewable electricity generation technology harnesses a naturally existing energy flux, such
as wind, sun, heat, or tides, and converts that flux to electricity. Natural phenomena have
varying time constants, cycles, and energy densities. To tap these sources of energy,
renewable electricity generation technologies must be located where the natural energy flux
occurs, unlike conventional fossil-fuel and nuclear electricity-generating facilities, which can
be located at some distance from their fuel sources. Renewable technologies also follow a
paradigm somewhat different from conventional energy sources in that renewable energy can
be thought of as manufactured energy, with the largest proportion of costs, external energy,
and material inputs occurring during the manufacturing process. Although conventional
sources such as nuclear- and coal-powered electricity generation have a high proportion of
CONVENTIONAL ENERGY
NON-CONVENTIONAL ENERGY
Commonly used form the long
time.
Readily available
Environmental pollution
Expansive to used
Cost of fuel.
Rarely used
New source of energy
Not readily available
Recently developed energy form
Less pollution
7
capital-to-fuel costs, all renewable technologies, except for biomass-generated electricity (bio
power), have no fuel costs. The trade-off is the ongoing and future cost of fossil fuel against
the present fixed capital costs of renewable energy technologies.
6 ENVIRONMENTAL ASPACT OF ELECTRIC ENERGY
GENERATION
6.1 Thermal
6.1.1 Coal as thermal fuel
Coal is the raw fuel that provides 42% of the world’s electricity (Maden & Mole, 1996).This
distinguishes coal as the world’s primary energy source for electricity generation. In 1997,
China, the United States, India, Australia, and Russia together produced 68 percent of total
amount of coal mined world-wide (U.S. Department of Energy, 1999).
The name coal refers to a family of solid, organic fuels with different properties. Coal is
mainly composed of elemental carbon and is formed by the conversion of deposited organic
(primarily plant) material. In most cases this transformation takes place under water. The
lowest grade of coal formed is peat. Under the influence of high pressures and temperatures,
the peat is transform into the coal. Using coal to generate power or heat is an old technique.
Therefore, the technology is conventional and well proven. Below are descriptions of some of
the main technologies in the coal power generation lifecycle and its environmental impacts.
The coal is used as fuel. The heat energy of these fuels is converted into mechanical energy
by suitable prime movers such as steam engines, steam turbines, internal combustion engines
etc. The prime mover drives the alternator which converts mechanical energy into electrical
energy. Although fuels continue to enjoy the place of chef source for the generation of
electrical energy, yet their reserves are diminishing day by day. Moreover its electrical energy
generation has wild impact to environment.
8
6.1.2 Coal mining
There are two types of coal mining, strip mining and underground long wall mining. The
environmental impacts from surface versus underground mining are not significantly
different. The main difference between these two mining techniques is that the surface mining
subsystem results in a higher amount of airborne ammonia emissions due to the production of
ammonium nitrate explosives which are used at the mine. Another important difference is that
underground mining requires limestone which emits a large amount of particulates during its
production.
The problematic pollutants in emission of coal based generating plants are;
SO2
NOx, nitrogen oxides
CO
CO2
Certain hydrocarbons
Particulates
Coal power life cycles lead to larger emissions of greenhouse gases (GHG) than any other
electricity generation option. This greenhouse gas caused global warming. Most of the
emissions stem from combustion. This is unavoidable since burning coal is essentially turning
carbon into CO2. Other fossil fuels, i.e. oil and natural gas, contain additional elements that
are oxidized to other compounds during combustion which means that the overall emission of
greenhouse gases, from purely stoichiometric reasons, are lower than those formed when coal
is burned. The amount of GHG released per kilowatt-hour also depends on power plant
efficiency, which is to a large extent related to the heat content of the fuel. Fairly large
quantities of the greenhouse gas methane are also released by hard coal mining activities. In
addition, emissions also occur during fuel transport. When hard coal is transported
internationally over long distances significant emissions can result. For the coal life cycle
assessment, the emission of CO2 from transport amounts to a few percent of the total when
the coal is imported from abroad; the magnitude of the emissions depending on the transport
distance.
9
6.1.3 Oxides of sulphur (SO2)
Most of the sulphur present in the fossil is oxidized to SO2 in the combustion chamber before
being emitted by the chimney. In atmosphere it gets further oxidized to H2SO4 and metallic
sulphates which are the major source of concern as these can cause acid rain, impaired
visibility, damage to buildings and vegetation. Sulphate concerntrations of 9-20 µg/m3 of air
aggravate asthma, lung and heart disease. It may also be noted that although sulphur do not
accumulate in air, it does so in soil.
6.1.4 Acidification
Acidification is one of the main problems arising from existing coal power. It takes place
during many steps in the life cycle of electricity produced by coal combustion. Pumped mine
water contains mud, dissolved sulphate and metal ions. It is also acidic and, therefore, needs
to be neutralize before being discharged (Stjernquist, 1986). Drainage water from refuse piles
with excavated and residual minerals can be very acidic, particularly if the rocks contain
pyrite (ferric sulphide) that undergoes oxidation processes when exposed to the atmosphere.
These oxidation processes take place in natural environments, but are greatly accelerated by
mining activities, especially when no alkaline rocks are present to neutralize the acid formed.
The result is low pH values and a release of certain elements, which are normally
encapsulated within the bedrock matrix such as aluminum, copper, cobalt, and/or lead
(Gantner & Hofstetter, 1996). Trace elements are also released when acid drainage percolates
through a rock and soil waste pile (spoil pile). This is partly due to ion exchange processes as
a consequence of the buffering caused by the carbonates and silicates from the overburden
material present in the spoil (European Commission, 1995). Wastewater from coal handling
plants may be acid due to presence of soluble salts of iron carbonates and pyrite from the coal.
Coal combustion gives rise to airborne emissions of sulphur dioxide (SO2) and nitrogen
oxides (NOx), both kinds of compounds being readily dissolved in water and transformed into
sulphur and nitric acid, respectively. There are a number of NOx reducing systems and
desulfurization systems available to the electric utility industry that can markedly lower these
emissions (Sloss, 1998).
10
http://saferenvironment.files.wordpress.com/2008/09/pollution.jpg
6.1.5 Impact on Biodiversity
The main environmental effect of electricity produced by coal combustion is probably related
to the ubiquitous emission of greenhouse gases. The release to the atmosphere of such gases is
larger from coal use than for any other fuel used for generating electricity. It is a general
contention that any additional increase of greenhouse gases in the atmosphere will exacerbate
global warming. This can lead to rapid changes in local weather conditions and can thus have
many and profound influences on biodiversity. Organisms that cannot adapt or migrate
successfully under changing climate conditions will be adversely affected. Some species that
are endangered because of other anthropogenic disturbances can be especially at risk since
their habitats have already been reduced.
6.2 Natural Gas
Natural gas is a naturally occurring mixture of hydrocarbons found in porous geological
formations, often in association with petroleum. The principal compound is methane (75-95
percent of volume) but there are also small quantities of other gases such as nitrogen oxide
and carbon dioxide. Natural gas is a variety of fossil fuel together with coal, petroleum and
their derivatives. In 1990, Natural gas accounted for 23% of all non-renewable fuel used
world-wide (Golob & Brus, 1993) and was responsible for 12% of all electricity generation
(Maden & Mole, 1996).
6.2.1 Global environmental impact
Natural gas is the cleanest burning fossil fuel and the use of natural gas can, in effect, improve
the environment when it is used instead of other fossil fuel options. The benefits of natural
11
gas combustion over other fossil fuels include reduced CO2 and NOx emissions and
essentially no SO2 or particulate matter emissions (National Gas Supply Association, 1998).
6.2.2 Greenhouse effect
Greenhouse gases are emitted both during combustion and fuel production. In addition,
methane is released during transportation when natural gas is distributed by pipeline. As more
natural gas is produced and as longer pipelines are built to transport natural gas over larger
distances more greenhouse gases will be emitted unless tighter controls on leakage are
implemented.
6.2.3 Ozone layer depletion
Since the 1980’s seasonal, polar ozone layer depletion has been a concern. Anthropogenic
emissions of several suspect chemicals have been targeted and the long residence time of
these substances has aroused concern in the scientific community. A reduced ozone layer may
contribute to a greater risk of cancer, mutations in the animal kingdom, and other
environmental harm. Though the methane and NOx are substances that can potentially
degrade the stratospheric ozone layer, the specific effects and interactions attributable to these
greenhouse gases emitted as part of the natural gas life cycle assessment are difficult to assess
and predict.
6.3 Nuclear power generation
The use of nuclear power as a source of domestic energy has increased significantly over the
past decade and is expected to continue to do so in the years to come. However, the use of this
form of energy does not come without a unique set of consequences. These can range from
environmental impact, altering to a great extent the balance in the flora and fauna of a region,
causing social problems to do with social consensus and risk perceptions of people living in
the vicinity of such a plant. This paper discusses some of the down-sides nuclear power
generation is credited for.
A nuclear power plant starts disturbing the environment during the plant construction. This
kind of disturbance, however, is a common problem to any major enterprise, as for example, a
non-nuclear power plant. Normal processes of plant construction as well as ancillary
12
operations, not necessarily related to the nuclear nature of the power plant fuel, do disturb the
surrounding environment. New roads, increasing traffic flow in the existing roads,
excavations, cutting trees and other plants, frightened animals, are some of the environmental
impacts to be expected from the construction of a power plant. In the case of a hydroelectric
plant a large man-made lake which will replace free-flowing rivers is also to be built. In
addition to all those impacts the builders of power plants should minimize, under the guidance
of the legally competent authorities, disturbance to any prehistoric petrified plants and
animals or to any archaeological remains of early civilizations, graveyards, monuments, ruins,
aqueducts and so on. Site selection for nuclear power plants should be carefully made to
avoid, or minimize to the extent possible, most of those impacts.
Thermal discharges of unused heat from fossil fuel or from fission in the nuclear fuel constitute
another kind of environmental impact. Thermal effects in biota include problems with
reproduction, growth, survival of larval forms, juveniles and adults.
Regulatory agencies establish water temperature standards to govern heated discharges from the
power plants to prevent catastrophic kills to occur, or thermally induced demise of aquatic
populations. Fish, plankton and benthos are all affected at various degrees by thermal discharges
from power plants.
Other environmental impact common to all nuclear power plants are the highly visible
transmission lines associated with the generation and distribution of electricity. Underground
cables are not yet an economically feasible solution for most cases of transmission of electricity.
http://images4.fanpop.com/image/photos/21900000/pollution-smog-global-warming-
prevention-21986545-570-381.jpg
13
6.3.1 Heat rejection
As is with the case of thermal power plants (based on fossil fuels), nuclear power plants
require some means by which they can expel heat as part of their condenser system. The
amount of heat varies from the different components used in the plant but on an average about
60 to 70% of thermal energy from the nuclear fuel is rejected out of the plant. Some plants
use cooling towers while some use a large body of water, such as an artificial lake or a natural
body of water such as a lake or a river. It also adversely affects the aquatic life of the
ecosystem into which heat is rejected. In some cases, the heat rejected into water bodies can
cause fluctuations in flow rates of rivers and anomalies in sea level. One particular research
done showed an average rise in sea level of about 3mm/yr. of the Northeast coast of US (N.
Kopytko & J. Perkins, 2011).
6.3.2 Gaseous emission
The gaseous emissions from a nuclear power plant can be of different forms and intensities.
Nuclear power plants use diesel generators as a means for back-up electric power in case of
emergencies. Most are also required to run and test these systems once every month to ensure
their working. As such, they release greenhouses gases into the atmosphere. These gases
primarily consist of carbon dioxide, carbon monoxide, nitrous oxides and sulphur dioxides.
Apart from greenhouse gases, exhaust gases from buildings containing radioactive processes
is radioactive in nature. In addition, in plants with boiling water reactors, the air ejector
exhaust is radioactive as well. Such exhausts are passed through delay pipes, storage tanks
and hydrogen recombines before release into the environment to ensure that radiation levels
are in accordance to regulations. Radioactive exhaust from nuclear power plants is also
known to cause skin problems of several kinds.
14
http://images4.fanpop.com/image/photos/21900000/POLLUTION-SMOG-global-warming-
prevention-21986545-570-381.jpg
https://www. -daiichi-nuclear-2011.jpg
6.3.3 Environmental Impact
Perhaps the impact which is easiest to notice is the effect on the environment, particularly in
terms of flora and fauna. To start with, the setting up of a nuclear plant requires a large area,
preferably situated near a natural water body. This is usually accompanied with clearing of
15
forests which disturbs the natural habitat of several creatures and gradually upsets the
ecological balance of the region. Apart from this, studies have shown that due to the heat
rejected into the water bodies, there have been significant drops in the populations of several
species of fish in certain regions of US. Another significant effect is the increased amount of
sulphur dioxide in the air which causes acid rain to form which then leads to contamination of
surface water bodies of the region, reduction of productivity of the soil, and has several other
negative effects on the region's vegetation and human health.
6.4 Hydropower generation
6.4.1 Land use
The size of the reservoir created by a hydroelectric project can vary widely, depending largely
on the size of the hydroelectric generators and the topography of the land. Hydroelectric
plants in flat areas tend to require much more land than those in hilly areas or canyons where
deeper reservoirs can hold more volume of water in a smaller space.
Flooding land for a hydroelectric reservoir has an extreme environmental impact: it destroys
forest, wildlife habitat, agricultural land, and scenic lands. In many instances, such as the
Three Gorges Dam in China, entire communities have also had to be relocated to make way
for reservoirs.
16
http://images4.fanpop.com/image/photos/21900000/soilerosion-prevention-21986545-570-
381.jpg
6.4.2 Wildlife Impact
Dammed reservoirs are used for multiple purposes, such as agricultural irrigation, flood
control, and recreation, so not all wildlife impacts associated with dams can be directly
attributed to hydroelectric power. However, hydroelectric facilities can still have a major
impact on aquatic ecosystems. For example, though there are a variety of methods to
minimize the impact (including fish ladders and in-take screens), fish and other organisms can
be injured and killed by turbine blades.
Apart from direct contact, there can also be wildlife impacts both within the dammed
reservoirs and downstream from the facility. Reservoir water is usually more stagnant than
normal river water. As a result, the reservoir will have higher than normal amounts of
sediments and nutrients, which can cultivate an excess of algae and other aquatic weeds.
These weeds can crowd out other river animal and plant-life, and they must be controlled
through manual harvesting or by introducing fish that eat these plants.
In addition, if too much water is stored behind the reservoir, segments of the river
downstream from the reservoir can dry out. Thus, most hydroelectric operators are required to
release a minimum amount of water at certain times of year. If not released appropriately,
water levels downstream will drop and animal and plant life can be harmed. In addition,
reservoir water is typically low in dissolved oxygen and colder than normal river water. When
this water is released, it could have negative impacts on downstream plants and animals. To
mitigate these impacts, aerating turbines can be installed to increase dissolved oxygen and
multi-level water intakes can help ensure that water released from the reservoir comes from
all levels of the reservoir, rather than just the bottom (which is the coldest and has the lowest
dissolved oxygen).
6.4.3 Life cycle global warming emission
Global warming emissions are produced during the installation and dismantling of
hydroelectric power plants, but recent research suggests that emissions during a facility’s
operation can also be significant. Such emissions vary greatly depending on the size of the
reservoir and the nature of the land that was flooded by the reservoir.
17
Small run-of-the-river plants emit between 0.01 and 0.03 pounds of carbon dioxide equivalent
per kilowatt-hour. Life-cycle emissions from large-scale hydroelectric plants built in semi-
arid regions are also modest: approximately 0.06 pounds of carbon dioxide equivalent per
kilowatt-hour. However, estimates for life-cycle global warming emissions from hydroelectric
plants built in tropical areas or temperate peat lands are much higher. After the area is
flooded, the vegetation and soil in these areas decomposes and releases both carbon dioxide
and methane. The exact amount of emissions depends greatly on site-specific characteristics.
6.5 Wind power generation
This method can be used where the wind flows for a considerable length of time. The wind
energy is used to run the wind mill which drives small generator. In order to obtain the
electrical energy from a wind mill continuously, the generator is arranged to charge the
batteries. These batteries supply the energy when the wind stops. This method has advantages
that maintenance and generation costs are negligible (V.K Mehta & Rohit Mehta, 2013).
However the drawbacks of this method are variable output, unreliable (because of uncertainty
about wind pressure and power generated is quite small).
6.5.1 Environmental Impact
Electricity from the wind is clean during the operation except the production of noise during
the operation. The major disadvantage to environment is that, the large area needs to be
cleared for the wind farming. The cultivated lands are converted into unusable barren land. In
the wind energy, batteries may use to supply the energy when wind stops. The problem
associated with this method is the disposal of waste batteries. For detail on batteries waste is
discussed below.
18
6.5.2 What about batteries?
Batteries are used in wind power plant and the solar power plant. Batteries are a form of
electricity supply that we should not overlook. In many ways they are a mixed blessing.
Disposable (non-rechargeable) batteries are definitely NOT a green option. They take a lot of
energy to produce and once spent, can create a real environmental problem with their
disposal. However, rechargeable battery technology has come on in leaps and bounds in the
last few decades. Many of us now regularly use mobile telephones and laptops without regard
to the fact that these devices would have been impossible to use in the not-too-distant past,
and still would be unusable today, if it were not for the amazingly efficient rechargeable
batteries that we now have.
Although most batteries are not particularly environmentally friendly because of the
chemicals contained within them, rechargeable batteries ARE undoubtedly a great
contribution to leading a greener lifestyle, because they enable us to use electrical devices
without having to be connected with a cable to an electricity supply, and without having to
throw away old batteries and replace them with new ones on a regular basis.
An electric car is a perfect example of this ideology pushed to its extremes. Battery
technology has enabled this type of vehicle to just start to become a viable option, though
there is still a long way to go yet.
19
6.6 Power transmission and Distribution
The energy generated form any of the sources have to transmit and distributed to the
consumers. During the transmission time, wide area of land should be vacated for the erection
of transmission poles. For high voltage transmission line, the distances between the two
cables have to maintain more than five meters. In that case, wide area of land has to clear for
the transmission purposes.
http://www.bpc.bt/transmission-department
20
7 CONCLUSION
In this paper, I have presented the environmental aspect of electric energy generation form
various sources like hydro, wind, solar and thermal. Under the thermal, I have presented the
energy generated by fossil fuels like coal, natural gas and nuclear action. Out of above listed
source, hydro, solar and wind have less environmental effect compared with thermal source of
energy. The thermal source of energy produces SO2. CO2, CO, NOx and other greenhouse gas
that affects the atmosphere and caused global warming.
Generation of electric energy also affects the habitants of biota in river, and other land
animals. The radioactive gas produces from the nuclear power plant is danger to human as
well.
Pollutions are produced not only during the generation time but also produces during the
construction time. New roads, increasing traffic flow in the existing roads, excavations,
cutting trees and other plants, frightened animals, are some of the environmental impacts to be
expected from the construction of a power plant. In the case of a hydroelectric plant a large
man-made lake which will replace free-flowing rivers is also to be built. In addition to all
those impacts the builders of power plants should minimize, under the guidance of the legally
competent authorities, disturbance to any prehistoric petrified plants and animals or to any
archaeological remains of early civilizations, graveyards, monuments, ruins, aqueducts and so
on. Site selection for nuclear power plants should be carefully made to avoid, or minimize to
the extent possible, most of those impacts.
21
References
International Energy Agency. (JUNE 2002). ENVIRONMENTAL AND HEALTH IMPACTS
OF ELECTRICITY GENERATION.
N.Kopytko&J.Perkins. (2011). Climate change, nuclear power, and the adaptation-
Mitigation Dilemma.
Nagrath, D. P. (2001). Modern Power System Analysis. New Delhi: McGraw- Hill offices.
P.Anandan & R.Kumaravelan. (2006). Environmental Science & Engineering. t.Nagar,
Chennai: SCITECH PUBLICATIONS(INDIA) PVT LTD.
(2010). Renewable Electricity Generation Technologies. In N. A. Science, Electricity from
Renewable Resources: Status, Prospects, and Impediments (pp. 67-130).
V.K Mehta & Rohit Methta. (2013). PRINCIPLE OF POWER SYSTEM. S.chand and
company ltd: S. Chand.
Retrieved from: http://www.eolss.net
... The number of local generators in each district is different as a result of different population density in each quarter (Ali, et al., 2015). Electricity is a major requirement for sustainable development (Dorji, 2015). ...
Article
Full-text available
Koya city, like any other city in the world, faces a critical environmental problem which is global warming and the increase in the rate of production of gaseous pollutants. This research is involved with the negative effects of private Electrical Power Generators (EPGs) on the environment in Koya City. The environmental pollutants resulted from EPGs were investigated by performing an actual study on land for the number of (EPGs), types, and distribution. Koya city is divided into 18 quarters. The investigation covers a period from 2009 to 2017, included. The production of power was increased due to the increase in the number of generators and supplying hours. The power production in 2009 was 23,850 megawatt (MW) whereas it was 49,635 MW in 2017. The amount of fuel consumed in 2009–2017 was relatively increased from 30,000 to 62,500 barrel/year. The total amount of pollutants was increased by about 108% during the period 2009–2017. The results showed that the most significant increase in pollutants was carbon dioxide (CO2). The annual amount of (CO2) emitted in 2009 was 6588 tons whereas it has increased in 2017–13710 tons. The conclusion of this study was that the highest pollution occurred in the center of Koya City in Nabeel quarter, which represented 22% of the whole pollutants.
... This aspect involves the identification of mitigation measures that will not affect the livelihood of the project area negatively; keeping renewable harvest rates within regeneration rates; keeping emissions to a bare minimum; ensuring that sources of raw materials needed by humanity should not be exhausted for electricity generation especially with regards biomass and hydro power generation; ensuring job creation [33]; and ensuring that livelihood of the inhabitants of the project area is improved. ...
Article
Full-text available
Combating climate change issues resulting from excessive use of fossil fuels comes with huge initial costs, thereby posing difficult challenges for the least developed countries in Sub-Saharan Africa (SSA) to invest in renewable energy alternatives, especially with rapid industrialization. However, designing renewable energy systems usually hinges on different economic and environmental criteria. This paper used the Multi-Objective Particle Swarm Optimization (MOPSO) technique to optimally size ten grid-connected hybrid blocks selected amongst Photo-Voltaic (PV) panels, onshore wind turbines, biomass combustion plant using sugarcane bagasse, Battery Energy Storage System (BESS), and Diesel Generation (DG) system as backup power, to reduce the supply deficit in Sierra Leone. Resource assessment using well-known methods was done for PV, wind, and biomass for proposed plant sites in Kabala District in Northern and Kenema District in Southern Sierra Leone. Long term analysis was done for the ten hybrid blocks projected over 20 years whilst ensuring the following objectives: minimizing the Deficiency of Power Supply Probability (DPSP), Diesel Energy Fraction (DEF), Life Cycle Costs (LCC), and carbon dioxide (CO 2 ) emissions. Capacity factors of 27.41 % and 31.6 % obtained for PV and wind, respectively, indicate that Kabala district is the most feasible location for PV and wind farm installations. The optimum results obtained are compared across selected blocks for DPSP values of 0–50% to determine the most economical and environmentally friendly alternative that policy makers in Sierra Leone and the region could apply to similar cases.
Article
Full-text available
Many policy-makers view nuclear power as a mitigation for climate change. Efforts to mitigate and adapt to climate change, however, interact with existing and new nuclear power plants, and these installations must contend with dilemmas between adaptation and mitigation. This paper develops five criteria to assess the adaptation-mitigation dilemma on two major points: (1) the ability of nuclear power to adapt to climate change and (2) the potential for nuclear power operation to hinder climate change adaptation. Sea level rise models for nine coastal sites in the United States, a review of US Nuclear Regulatory Commission documents, and reports from France's nuclear regulatory agency provided insights into issues that have arisen from sea level rise, shoreline erosion, coastal storms, floods, and heat waves. Applying the criteria to inland and coastal nuclear power plants reveals several weaknesses. Safety stands out as the primary concern at coastal locations, while inland locations encounter greater problems with interrupted operation. Adapting nuclear power to climate change entails either increased expenses for construction and operation or incurs significant costs to the environment and public health and welfare. Mere absence of greenhouse gas emissions is not sufficient to assess nuclear power as a mitigation for climate change.
Environmental Impact Perhaps the impact which is easiest to notice is the effect on the environment, particularly in terms of flora and fauna. To start with, the setting up of a nuclear plant requires a large area, preferably situated near a natural water body
Environmental Impact Perhaps the impact which is easiest to notice is the effect on the environment, particularly in terms of flora and fauna. To start with, the setting up of a nuclear plant requires a large area, preferably situated near a natural water body. This is usually accompanied with clearing of References International Energy Agency. (JUNE 2002). ENVIRONMENTAL AND HEALTH IMPACTS OF ELECTRICITY GENERATION.