It warms and cools our homes, cooks our food, plays our music, and gives us pictures on television. Energy is defined as the ability or the capacity to do work. We use energy to do work and make all movements. When we eat, our bodies transform the food into energy to do work. When we run or walk or do some work, we ‘burn’ energy in our bodies. Cars, planes, trolleys, boats, and machinery also transform energy into work. Work means moving or lifting something, warming or lighting something. There are many sources of energy that help to run the various machines invented by man.
The discovery of fire by man led to the possibility of burning wood for cooking and heating thereby using energy. For several thousand years human energy demands were met only by renewable energy sources—sun, biomass (wood, leaves, twigs), hydel (water) and wind power. As early as 4000–3500 BC, the first sailing ships and windmills were developed harnessing wind energy. With the use of hydropower through water mills or irrigation systems, things began to move faster. Fuelwood and dung cakes are even today a major source of energy in rural India. solar energy is used for drying and heating.
With the advent of the Industrial Revolution, the use of energy in the form of fossil fuels began to grow as more and more industries were set up. This occurred in stages, from the exploitation of coal deposits to the exploitation of oil and natural gas fields. It has been only half a century since nuclear power began being used as an energy source. In the past century, it became evident that the consumption of non-renewable sources of energy had caused more environmental damage than any other human activity. Electricity generated from fossil fuels such as coal and crude oil has led to high concentrations of harmful gases in the atmosphere.
... upfront costs V. Comparison of the current energy source and the sources that I believe that we should move ... and positive aspects of the current types of energy sources that we are now currently using. A. ... of fossil fuels +can be a very cheap energy source - within a few hundred years all of ... cultural D. social E. political IV. Alternative Sources of energy IV A. Negatives of all these types 1 ...
This has in turn led to problems such as ozone depletion and global warming. There has been an enormous increase in the demand for energy since the middle of the last century as a result of industrial development and population growth. World population grew 3. 2 times between 1850 and 1970, per capita use of industrial energy increased about twentyfold, and total world use of industrial and traditional energy forms combined increased more than twelvefold. Due to the problems associated with the use of fossil fuels, alternative sources of energy have become important and relevant in today’s world.
These sources, such as the sun and wind, can never be exhausted and are therefore called renewable. Also known as non-conventional sources of energy, they cause less emission and are available locally. Their use can significantly reduce chemical, radioactive, and thermal pollution. They are viable sources of clean and limitless energy. Most of the renewable sources of energy are fairly non-polluting and considered clean. However, biomass is a major polluter indoors. Renewable energy sources include the sun, wind, water, agricultural residue, fuelwood, and animal dung. Fossil fuels are non-renewable sources.
Energy generated from the sun is known as solar energy. Hydel is the energy derived from water. Biomass – firewood, animal dung, and biodegradable waste from cities and crop residues – is a source of energy when it is burnt. Geothermal energy is derived from hot dry rocks, magma, hot water springs, natural geysers, etc. Ocean thermal is energy derived from waves and also from tidal waves. Through co-generation a cleaner and less polluting form of energy is being generated. Fuel cells are also being used as cleaner energy source. In India a number of initiatives have been taken.
A good example is the model village of Ralegaon Siddhi. FORMS OF ENERGY 1. RENEWABLE ENERGY 2. NON-RENEWABLE ENERGY 3. nuclear energy * RENEWABLE ENERGY In the past century, it has been seen that the consumption of non-renewable sources of energy has caused more environmental damage than any other human activity. Electricity generated from fossil fuels such as coal and crude oil has led to high concentrations of harmful gases in the atmosphere. This has in turn led to many problems being faced today such as ozone depletion and global warming. Vehicular pollution has also been a major problem.
... cons of solar energy? The pros of solar energy are as follows: 1) Solar energy is renewable source of energy. As long as the sun is shining, solar energy is able ... else. ) And last but not least, fossil fuels are a non-renewable source. And right now they are being used at an ... immediately useable. 3) And lastly, Biofuels are high quality fuels that have allowed us to reduce our dependence on fossil ...
Therefore, alternative sources of energy have become very important and relevant to today’s world. These sources, such as the sun and wind, can never be exhausted and therefore are called renewable. They cause fewer emissions and are available locally. Their use can, to a large extent, reduce chemical, radioactive, and thermal pollution. They stand out as a viable source of clean and limitless energy. These are also known as non-conventional sources of energy. Most of the renewable sources of energy are fairly non-polluting and considered clean though biomass, a renewable source, is a major polluter indoors. * NON-RENEWABLE ENERGY
Nonrenewable energy is energy that comes from the ground and is not replaced in a relatively short amount of time. Fossil fuels are the main category of nonrenewable energy. Fossil fuels include; coal, oil and natural gas. These resources come from animals and plants that have died millions of years ago and then decomposed to create a useable source of energy for humans. * NUCLEAR ENERGY Nuclear energy originates from the splitting of uranium atoms in a process called fission. At the power plant, the fission process is used to generate heat for producing steam, which is used by a turbine to generate electricity.
DIFFERENT TYPES OF RENEWABLE ENERGY 1. SOLAR ENERGY Solar energy is the most readily available source of energy. It does not belong to anybody and is, therefore, free. It is also the most important of the non-conventional sources of energy because it is non-polluting and, therefore, helps in lessening the greenhouse effect. Solar energy has been used since prehistoric times, but in a most primitive manner. Before 1970, some research and development was carried out in a few countries to exploit solar energy more efficiently, but most of this work remained mainly academic.
... harness energy from the sun is to use sunlight to produce heat. Fogel states that Solar One, the biggest solar power ... and also to produce electricity be means of Photovoltaics (2). This means that solar energy not only takes the ... electricity (Hydroelectric 3). Creating more hydroelectric projects will produce more clean and cost effective energy. Geothermal energy, another clean source of energy, ...
After the dramatic rise in oil prices in the 1970s, several countries began to formulate extensive research and development programmes to exploit solar 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. In the next few years it is expected that millions of households in the world will be using solar energy as the trends in USA and Japan show.
In India too, the Indian Renewable Energy Development Agency and the Ministry of Non-Conventional Energy Sources are formulating a programme to have solar energy in more than a million households in the next few years. However, the people’s initiative is essential if the programme is to be successful. India is one of the few countries with long days and plenty of sunshine, especially in the Thar desert region. This zone, having abundant solar energy available, is suitable for harnessing solar energy for a number of applications. In areas with similar intensity of solar radiation, solar energy could be easily harnessed.
Solar thermal energy is being used in India for heating water for both industrial and domestic purposes. A 140 MW integrated solar power plant is to be set up in Jodhpur but the initial expense incurred is still very high. Solar energy can also be used to meet our electricity requirements. Through Solar Photovoltaic (SPV) cells, solar radiation gets converted into DC electricity directly. This electricity can either be used 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: a. Domestic lighting b. Street lighting c. Village electrification . Water pumping e. Desalination of salty water f. Powering of remote telecommunication repeater stations and g. Railway signals. Advantages of Solar Energy * No green house gases- The major benefit of solar is avoiding green house gases that fossil fuels produce. The first and foremost advantage of solar energy is that it does not emit any green house gases. Solar energy is produced by conducting the sun’s radiation – a process void of any smoke, gas, or other chemical by-product. This is the main driving force behind all green energy technology, as nations attempt to meet climate change obligations in curbing emissions.
... substitute for our regular electricity, almost doesn't cost money and still provides the same electricity power. Moving to solar energy will preserve our ... electricity bills, power breaks and we won't has to. hear from the electricity company any more. The only problem with solar energy ... Israel. What is the problem with people not moving to solar energy? Are they afraid of it? Take for instance, ...
Italy’s Montalto di Castro solar park is a good example of solar’s contribution to curbing emissions. It avoids 20,000 tonnes per year of carbon emissions compared to fossil fuel energy production. * Infinite Free Energy- Another advantage of using solar energy is that beyond initial installation and maintenance, solar energy is one hundred percent free. Solar doesn’t require expensive and ongoing raw materials like oil or coal, and requires significantly lower operational labor than conventional power production.
Lower costs are direct as well as indirect – less staff working at the power plant as the sun and the solar semi conductors do all the work, as well as no raw materials that have to be extracted, refined, and transported to the power plant. * Decentralization of power- Solar energy offers decentralization in most (sunny) locations, meaning self-reliant societies. Oil, coal, and gas used to produce conventional electricity is often transported cross-country or internationally. This transportation has a myriad of additional costs, ncluding monetary costs, pollution costs of transport, and road wear and tear costs, all of which is avoided with solar. Of course, decentralization has its limits as some locations get more sunlight than others. * Going off the grid with solar- Solar energy can be produced on or off the grid. On grid means a house remains connected to the state electricity grid. Off grid has no connection to the electricity grid, so the house, business or whatever being powered is relying solely on the solar or solar-hybrid. The ability to produce electricity off the grid is a major advantage of solar energy for people who live in isolated and rural areas.
Power prices and the cost of installing power lines are often exorbitantly high in these places and many have frequent power-cuts. Many city-dwellers are also choosing to go off the grid with their alternate energy as part of a self-reliant lifestyle. * Solar jobs- A particularly relevant and advantageous feature of solar energy production is that it creates jobs. The EIAA states that Europe’s solar industry has created 100,000 jobs so far. Solar jobs come in many forms, from manufacturing, installing, monitoring and maintaining solar panels, to research and design, development, cultural integration, and policy jobs.
... power cars and provide electricity to homes. Some of the alternative energy sources include: wind energy, nuclear energy, and solar energy. Of the three, only solar ... these zero emission plants would make huge strides for better air quality and a healthier environment. Solar energy panels create ... run off of solar energy. These cost very little and do not need to be plugged in or powered by batteries. ...
The book Natural Capitalism has a very appropriate view of the employment benefits of green design and a prudent approach to using resources. The book proposes that while green technology and increased employment cost alot of money, much greater money can be saved through simple but drastically improved resource efficiency. With solar energy currently contributing only an estimated 4% of the world’s electricity, and an economic-model where raw materials don’t have to be indefinitely purchased and transported, it’s reasonable so assume solar jobs are sustainable if the solar industry can survive the recession. Solar’s avoidance of politics and price volatility- One of the biggest advantages of solar energy is the ability to avoid the politics and price volatility that is increasingly characterizing fossil fuel markets. The sun is an unlimited commodity that can be adequately sourced from many locations, meaning solar avoids the price manipulations and politics that have more than doubled the price of many fossil fuels in the past decade.
While the price of fossil fuels have increased, the per watt price of solar energy production has more than halved in the past decade – and is set to become even cheaper in the near future as better technology and economies of scale take effect. Furthermore, the ever-abundant nature of the sun’s energy would hint at a democratic and competitive energy market – where wars aren’t fought over oil fields and high-demand raw materials aren’t controlled by monopolies.
Of course, a new form of politics has emerged with regard to government incentives and the adoption of solar; however these politics are arguably incomparable to the fossil fuel status quo. * Saving eco-systems and livelihoods- Because solar doesn’t rely on constantly mining raw materials, it doesn’t result in the destruction of forests and eco-systems that occurs with most fossil fuel operations. Destruction can come in many forms, from destruction through accepted extraction methods, to more irresponsible practices in vulnerable areas, to accidents.
... as energy sources leading. Wind power refers to the energy extracted from wind through the use of windmills and wind turbines. The cost of wind-generated electric power recently ... quite a bit. Since 2004, wind power has become the least expensive alternative energy source to fossil fuels. Wind power is also growing quickly and becoming ...
Major examples include Canada’s tar sands mining which involves the systematic destruction of the Boreal Forest (which accounts for 25% of the world’s intact forest land), and creates toxic by-product ponds large enough to see from space. The Niger Delta is an example where excessive and irresponsible oil extraction practices have poisoned fishing deltas previously used by villagers as the main source of food and employment, creating extremely desperate poverty and essentially decimating villages. A more widely known, but arguably lower human-cost incident is the 2010 BP oil spill in the Gulf of Mexico.
It killed 11 people and spilled 780 thousand cubic meters of crude oil into the sea. Disadvantages of solar energy * Solar doesn’t work at night- Obviously the biggest disadvantages of solar energy production revolve around the fact that it’s not constant. To produce solar electricity there must be sunlight. So energy must be stored or sourced elsewhere at night. Beyond daily fluctuations, solar production decreases over winter months when there are less sunlight hours and sun radiation is less intense. * Solar Inefficiency- A very common criticism is that solar energy production is relatively inefficient.
Currently, widespread solar panel efficiency – how much of the sun’s energy a solar panel can convert into electrical energy – is at around 22%. This means that a fairly vast amount of surface area is required to produce a lot of electricity. However, efficiency has developed dramatically over the last five years, and solar panel efficiency should continue to rise steadily over the next five years. For the moment though, low efficiency is a relevant disadvantage of solar. Solar inefficiency is an interesting argument, as efficiency is relative. One could ask “inefficient compared to what? And “What determines efficiency? ” Solar panels currently only have a radiation efficiency of up to 22%, however they don’t create the carbon by-product that coal produces and doesn’t require constant extraction, refinement, and transportation – all of which surely carry weight on efficiency scales. * Storing Solar- Solar electricity storage technology has not reached its potential yet. While there are many solar drip feed batteries available, these are currently costly and bulky, and more appropriate to small scale home solar panels than large solar farms. * Solar panels are bulky- Solar panels are bulky.
This is particularly true of the higher-efficiency, traditional silicon crystalline wafer solar modules. These are the large solar panels that are covered in glass. New technology thin-film solar modules are much less bulky, and have recently been developed as applications such as solar roof tiles and “amorphous” flexible solar modules. The downfall is that thin-film is currently less efficient than crystalline wafer solar. * One of the biggest disadvantages of solar energy – COST- The main hindrance to solar energy going widespread is the cost of installing solar panels.
Capital costs for installing a home solar system or building a solar farm are high. Particularly obstructive is the fact that installing solar panels has large upfront costs – after which the energy trickles in for free. Imagine having to pay upfront today for your next 30 years worth of power. That’s an incredibly disadvantageous feature of solar energy production, particularly during a time of recession. Currently a mega watt hour of solar energy costs well over double a mega watt hour of conventional electricity (exact costs vary dramatically depending on location).
All is not lost though – nuclear is a good example (economically) of energy production that was initially incredibly expensive, but became more feasible when appropriate energy subsidies were put in place. 2. HYDEL ENERGY The energy in the flowing water can be used to produce electricity. Waves result from the interaction of the wind with the surface of the sea and represent a transfer of energy from the wind to the sea. Energy can be extracted from tides by creating a reservoir or basin behind a barrage and then passing tidal waters through turbines in the barrage to generate electricity.
Hydro power is one of the best, cheapest, and cleanest source of energy, although, with big dams, there are many environmental and social problems as has been seen in the case of the Tehri and the Narmada Projects. Small dams are, however, free from these problems. This is in fact one of the earliest known renewable energy sources, in the country (since the beginning of the 20th century).
In fact, for the last few hundred years, people living in the hills of the Himalayas have been using water mills, or chakki, to grind wheat. The 130 KW small hydropower plant in Darjeeling set up in 1897, was the first in India.
Besides being free from the problem of pollution, such plants are also free from issues and controversies that are associated with the bigger projects, namely affecting the lives of thousands of people living along the banks of the rivers, destruction of large areas under forest, and seismological threats. New environmental laws affected by the danger of global warming have made energy from small hydropower plants more relevant. These small hydropower plants can serve the energy needs of remote rural areas independently. The real challenge in a remote area lies in successful marketing of the energy and recovering the dues.
Local industries should be encouraged to use this electricity for sustainable development. It is a technology with enormous potential, which could exploit the water resources to supply energy to remote rural areas with little access to conventional energy sources. It also eliminates most of the negative environmental effects associated with large hydro projects. Large amounts of solar energy is stored in the oceans and seas. On an average, the 60 million square kilometre of the tropical seas absorb solar radiation equivalent to the heat content of 245 billion barrels of oil.
Scientists feel that if this energy can be tapped a large source of energy will be available to the tropical countries and to other countries as well. The process of harnessing this energy is called OTEC (ocean thermal energy conversion).
It uses the temperature differences between the surface of the ocean and the depths of about 1000m to operate a heat engine, which produces electric power. Energy is also obtained from waves and tides. The first wave energy, project with a capacity of 150MW, has been set up at Vizhinjam near Trivandrum. A major tidal wave power project costing of Rs. 000 crores, is proposed to be set up in the Hanthal Creek in the Gulf of Kutch in Gujarat. In some countries such as Japan small scale power generators run by energy from waves or the ocean, have been used as power sources for channel marking buoys. Advantages of Hydel Energy * Hydroelectricity is a renewable energy source that does not produce greenhouse gases. * Operation and maintenance costs for hydroelectricity plants are much lower than for thermal electricity power plants. Breakdowns are few because their mechanical design is relatively simple, and no excess heat is generated during operations. Hydroelectricity generating plants have a long life. * When a hydroelectricity water storage dam is built, the water in the dam can be used as a source of drinking water and for recreational purposes such as boating and fishing. * To meet any changes in demand for electricity, hydroelectricity generators can be stopped and started in minutes. A fossil fuel power station can take up to eight hours to shut down or restart and a nuclear power station can take up to several days. * Although dams prevent the natural flushing out of a river during a flood, they also control flooding downstream in times of high rainfall and snowmelt.
Disadvantages of Hydel Energy * Usually a large area of land has to be flooded to ensure a continuous flow of water to the turbine. In some cases when a dam is built, large populations have to be relocated. In China, the Three Gorges Dam Project on the Yangtze River will displace more than 1 million people. * Dams affect river ecosystems. Rivers usually experience seasonal flooding that flush out river backwaters and deposit silt on riverbanks. Dams prevent those seasonal floods and allow silt and vegetation to clog up river backwaters. This causes changes to the environments, which may impact plant and animal abitats. * Hydroelectricity dams are costly to build. * An adequate supply of water from rain or snow is required for hydroelectricity plants to continue operation. If a drought occurs, electricity production can be severely affected. Countries that produce hydroelectricity need alternative electricity supplies for such events. 3. wind energy Wind energy is the kinetic energy associated with the movement of atmospheric air. It has been used for hundreds of years for sailing, grinding grain, and for irrigation. Wind energy systems convert this kinetic energy to more useful forms of power.
Wind energy systems for irrigation and milling have been in use since ancient times and since the beginning of the 20th century it is being used to generate electric power. Windmills for water pumping have been installed in many countries particularly in the rural areas. Wind turbines transform the energy in the wind into mechanical power, which can then be used directly for grinding etc. or further converting to electric power to generate electricity. Wind turbines can be used singly or in clusters called ‘wind farms’. Small wind turbines called aero-generators can be used to charge large batteries.
Five nations – Germany, USA, Denmark, Spain and India – account for 80% of the world’s installed wind energy capacity. Wind energy continues to be the fastest growing renewable energy source with worldwide wind power installed capacity reaching 14,000 MW. Realizing the growing importance of wind energy, manufacturers have steadily been increasing the unit size of the wind electric generators since the late 1980s. Another important development has been the offshore (i. e. in the sea) wind farms in some regions of Europe, which have several advantages over the on-shore ones.
The third major development has been the use of new techniques to assess the wind resource for techno-commercial viability. In India the states of Tamilnadu and Gujarat lead in the field of wind energy. At the end of March 2000 India had 1080-MWs capacity wind farms, of which Tamilnadu contributed 770-MW capacity. Gujarat has 167MW followed by Andhra Pradesh, which has 88 MW installed wind farms. There are about a dozen wind pumps of various designs providing water for agriculture, afforestation, and domestic purposes, all scattered over the country.
The design of the Auroville multi-blade windmill has evolved from the practical experience gained in operating these mills over a period of 20 years or so. It has a high tripod tower and its double-action pump increases water output by about 60% compared to the conventional single-action pumps. Advantages of Wind Energy * Wind Energy is an inexhaustible source of energy and is virtually a limitless resource. * Energy is generated without polluting environment. * This source of energy has tremendous potential to generate energy on large scale. * 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. * Land around wind turbines can be used for other uses, e. g. Farming. Disadvantages of Wind Energy * Wind energy requires expensive storage during peak production time. * It is unreliable energy source as winds are uncertain and unpredictable. * There is visual and aesthetic impact on region. Requires large open areas for setting up wind farms. * Noise pollution problem is usually associated with wind mills. * 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. * It can be a threat to wildlife.
Birds do get killed or injured when they fly into turbines. * Maintenance cost of wind turbines is high as they have mechanical parts which undergo wear and tear over the time. 4. Biomass Biomass is a renewable energy resource derived from the carbonaceous waste of various human and natural activities. It is derived from numerous sources, including the by-products from the timber industry, agricultural crops, raw material from the forest, major parts of household waste and wood. Biomass does not add carbon dioxide to the atmosphere as it absorbs the same amount of carbon in growing as it releases when consumed as a fuel.
Its advantage is that it can be used to generate electricity with the same equipment or power plants that are now burning fossil fuels. Biomass is an important source of energy and the most important fuel worldwide after coal, oil and natural gas. Traditional use of biomass is more than its use in modern application. In the developed world biomass is again becoming important for applications such as combined heat and power generation. In addition, biomass energy is gaining significance as a source of clean heat for domestic heating and community heating applications.
In fact in countries like Finland, USA and Sweden the per capita biomass energy used is higher than it is in India, China or in Asia. Biomass fuels used in India account for about one third of the total fuel used in the country, being the most important fuel used in over 90% of the rural households and about 15% of the urban households. Instead of burning the loose biomass fuel directly, it is more practical to compress it into briquettes (compressing them through a process to form blocks of different shapes) and thereby improve its utility and convenience of use.
Such biomass in the dense briquetted form can either be used directly as fuel instead of coal in the traditional chulhas and furnaces or in the gasifier. Gasifier converts solid fuel into a more convenient-to-use gaseous form of fuel called producer gas. Scientists are trying to explore the advantages of biomass energy as an alternative energy source as it is renewable and free from net CO2 (carbon dioxide) emissions, and is abundantly available on earth in the form of agricultural residue, city garbage, cattle dung, firewood, etc.
Bio-energy, in the form of biogas, which is derived from biomass, is expected to become one of the key energy resources for global sustainable development. At present, biogas technology provides an alternative source of energy in rural India for cooking. It is particularly useful for village households that have their own cattle. Through a simple process cattle dung is used to produce a gas, which serves as fuel for cooking. The residual dung is used as manure. Biogas plants have been set up in many areas and are becoming very popular. Using local resources, namely cattle waste and other organic wastes, energy and manure are derived.
A mini biogas digester has recently been designed and developed, and is being in-field tested for domestic lighting. Indian sugar mills are rapidly turning to bagasse, the leftover of cane after it is crushed and its juice extracted, to generate electricity. This is mainly being done to clean up the environment, cut down power costs and earn additional revenue. According to current estimates, about 3500 MW of power can be generated from bagasse in the existing 430 sugar mills in the country. Around 270 MW of power has already been commissioned and more is under construction. Advantages of Biomass * It’s a renewable source of energy. It’s a comparatively lesser pollution generating energy. * Biomass energy helps in cleanliness in villages and cities. * It provides manure for the agriculture and gardens. * There is tremendous potential to generate biogas energy. * Biomass energy is relatively cheaper and reliable. * It can be generated from everyday human and animal wastes, vegetable and agriculture left-over etc. * Recycling of waste reduces pollution and spread of diseases. * Heat energy that one gets from biogas is 3. 5 times the heat from burning wood. * Because of more heat produced the time required for cooking is lesser.
Pressure on the surrounding forest and scrubs can be reduced when biogas is used as cooking fuel. * It is a more cost effective means of acquiring energy as compared to oil supplies. As oil supplies are getting depleted day by day, it is becoming a costly commodity. * Growing biomass crops use up carbon dioxide and produces oxygen. Disadvantages of Biomass * Cost of construction of biogas plant is high, so only rich people can use it. * Continuous supply of biomass is required to generate biomass energy. * Some people don’t like to cook food on biogas produced from sewage waste. * Biogas plant requires space and produces dirty smell. Due to improper construction many biogas plants are working inefficiently. * It is difficult to store biogas in cylinders. * Transportation of biogas through pipe over long distances is difficult. * Many easily grown grains like corn, wheat are being used to make ethanol. This can have bad consequences if too much of food crop is diverted for use as fuel. * Crops which are used to produce biomass energy are seasonal and are not available over whole year. 5. GEOTHERMAL ENERGY We live between two great sources of energy, the hot rocks beneath the surface of the earth and the sun in the sky.
Our ancestors knew the value of geothermal energy; they bathed and cooked in hot springs. Today we have recognized that this resource has potential for much broader application. The core of the earth is very hot and it is possible to make use of this geothermal energy (in Greek it means heat from the earth).
These are areas where there are volcanoes, hot springs, and geysers, and methane under the water in the oceans and seas. In some countries, such as in the USA water is pumped from underground hot water deposits and used to heat people’s houses.
The utilization of geothermal energy for the production of electricity dates back to the early part of the twentieth century. For 50 years the generation of electricity from geothermal energy was confined to Italy and interest in this technology was slow to spread elsewhere. In 1943 the use of geothermal hot water was pioneered in Iceland. In India, Northwestern Himalayas and the western coast are considered geothermal areas. The Geological Survey of India has already identified more than 350 hot spring sites, which can be explored as areas to tap geothermal energy.
Satellites like the IRS-1 have played an important role, through infrared photographs of the ground, in locating geothermal areas. The Puga valley in the Ladakh region has the most promising geothermal field. An experimental 1-kW generator is already in operation in this area. It is being used mainly for poultry farming, mushroom cultivation, and pashmina-wool processing, all of which need higher temperature. Advantages of Geothermal Energy * It is a renewable source of energy. * By far, it is non-polluting and environment friendly. * There is no wastage or generation of by-products. Geothermal energy can be used directly. In ancient times, people used this source of energy for heating homes, cooking, etc. * Maintenance cost of geothermal power plants is very less. * Geothermal power plants don’t occupy too much space and thus help in protecting natural environment. * Unlike solar energy, it is not dependent on the weather conditions. Disadvantages of Geothermal Energy * Only few sites have the potential of Geothermal Energy. * Most of the sites, where geothermal energy is produced, are far from markets or cities, where it needs to be consumed. * Total generation potential of this source is too small. There is always a danger of eruption of volcano. * Installation cost of steam power plant is very high. * There is no guarantee that the amount of energy which is produced will justify the capital expenditure and operations costs. * It may release some harmful, poisonous gases that can escape through the holes drilled during construction. 6. FUEL CELLS Fuel cells are electrochemical devices that convert the chemical energy of a fuel directly and very efficiently into electricity (DC) and heat, thus doing away with combustion. The most suitable fuel for such cells is hydrogen or a mixture of compounds containing hydrogen.
A fuel cell consists of an electrolyte sandwiched between two electrodes. Oxygen passes over one electrode and hydrogen over the other, and they react electrochemically to generate electricity, water, and heat. Though fuel cells have been used in space flights and combined supplies of heat and power, electric vehicles are the best option available to dramatically reduce urban air pollution. Compared to vehicles powered by the internal combustion engine, fuel-cell powered vehicles have very high energy conversion efficiency, (almost double that of currently used engines) and near-zero pollution, CO2 and water vapour being the only emissions.
Fuel-cell-powered EV’s (electric vehicles) score over battery operated EV’s in terms of increased efficiency and easier and faster refuelling. Canada’s Ballad’s Power Systems and Germany’s Dailmer-Benz are world leaders in the application of fuel cell technology for meeting transportation needs. In India, diesel-run buses are a major means of transport and these emit significant quantities of SPM and SO2. Thus, fuel-cell powered buses could be introduced with relative ease and yet make a positive impact on urban air quality. Such buses are already in operation in Vancouver in Canada and in Illinois and California in the USA.
Though rapid progress has been made, high initial cost is still the biggest hurdle in the widespread commercialization of fuel cells. Fuel cells for power generation – India has a large gap between the demand for and supply of power. Conventional large-scale power plants use non-renewable fuels with significant adverse ecological and environmental impacts. Fuel cell systems are excellent candidates for small-scale decentralized power generation. Fuel cells can supply combined heat and power to commercial buildings, hospitals, airports and military installation at remote locations.
Fuel cells have efficiency levels up to 55% as compared to 35% of conventional power plants. The emissions are significantly lower (CO2 and water vapour being the only emissions).
Fuel cell systems are modular (i. e. additional capacity can be added whenever required with relative ease) and can be set up wherever power is required. Advantages of Fuel Cells * High efficiency conversion- Fuel cells convert chemical energy directly into electricity without the combustion process. As a result, a fuel cell is not governed by thermodynamic laws, such as the Carnot efficiency associated with heat engines, currently used for power generation.
Fuel cells can achieve high efficiencies in energy conversion terms, especially where the waste heat from the cell is utilized in cogeneration situation. * High power density – A high power density allows fuel cells to be relatively compact source of electric power, beneficial in application with space constraints. In a fuel cell system, the fuel cell itself is nearly dwarfed by other components of the system such as the fuel reformer and power inverter * Quiet operation- Fuel cells, due to their nature of operation, are extremely quiet in operation.
This allows fuel cells to be used in residential or built-up areas where the noise pollution is undesirable * Fuel cells have a higher efficiency than diesel or gas engines. * Most fuel cells operate silently, compared to internal combustion engines. They are therefore ideally suited for use within buildings such as hospitals. * Fuel cells can eliminate pollution caused by burning fossil fuels; for hydrogen fuelled fuel cells, the only by-product at point of use is water. * If the hydrogen comes from the electrolysis of water driven by renewable energy, then using fuel cells eliminates greenhouse gases over the whole cycle. Fuel cells do not need conventional fuels such as oil or gas and can therefore reduce economic dependence on oil producing countries, creating greater energy security for the user nation. * Since hydrogen can be produced anywhere where there is water and a source of power, generation of fuel can be distributed and does not have to be grid-dependent. * The use of stationary fuel cells to generate power at the point of use allows for a decentralised power grid that is potentially more stable. * Low temperature fuel cells (PEMFC, DMFC) have low heat transmission which makes them ideal for military applications. Higher temperature fuel cells produce high-grade process heat along with electricity and are well suited to cogeneration applications (such as combined heat and power for residential use).
* Operating times are much longer than with batteries, since doubling the operating time needs only doubling the amount of fuel and not the doubling of the capacity of the unit itself. * Unlike batteries, fuel cells have no “memory effect” when they are getting refuelled. * The maintenance of fuel cells is simple since there are few moving parts in the system. Disadvantages of Fuel Cells High costs compared to other energy systems technology * Operation requires replenishable fuel supply * There are a number of other disadvantages such as the fact that fuel cells actually lose energy. It ends up costing more to produce energy than you actually get out of the fuel cell. There is also the difficult issue of finding a feasible way to produce, ship, and distribute hydrogen, which is used to fuel the fuel cell. And finally, units are bigger and bulkier than other comparable energy sources. * Fuel cells have a long way to go to catch up with other methods of energy development.
Future innovations may make them a more feasible source one day, but for now fuel cells have a disadvantage when placed against other forms of energy such as batteries and engines. 7. CO-GENERATION Co-generation is the concept of producing two forms of energy from one fuel. One of the forms of energy must always be heat and the other may be electricity or mechanical energy. In a conventional power plant, fuel is burnt in a boiler to generate high-pressure steam. This steam is used to drive a turbine, which in turn drives an alternator through a steam turbine to produce electric power.
The exhaust steam is generally condensed to water which goes back to the boiler. As the low-pressure steam has a large quantum of heat which is lost in the process of condensing, the efficiency of conventional power plants is only around 35%. In a cogeneration plant, very high efficiency levels, in the range of 75%–90%, can be reached. This is so, because the low-pressure exhaust steam coming out of the turbine is not condensed, but used for heating purposes in factories or houses. Since co-generation can meet both power and heat needs, it has other advantages as ell in the form of significant cost savings for the plant and reduction in emissions of pollutants due to reduced fuel consumption. Even at conservative estimates, the potential of power generation from co-generation in India is more than 20,000 MW. Since India is the largest producer of sugar in the world, bagasse-based cogeneration is being promoted. The potential for cogeneration thus lies in facilities with joint requirement of heat and electricity, primarily sugar and rice mills, distilleries, petrochemical sector and industries such as fertilizers, steel, chemical, cement, pulp and paper, and aluminum.
Advantages of Co-Generation * Lower primary energy consumption * Reduced energy bills * No transmission and distribution losses * Less burden on national government for power generation * Less environmental pollution * The CPP is not only energy-efficient, but also emits lower quantities of pollutants, compared to other energy processes. The visible emission coming out of the smokestacks is often mistaken for smoke; however, it is actually excess water vapor from steam production. The burning of natural gas does produce some chemical by-products.
However, the amounts of these chemicals are 42 percent less than the emissions standards set by the Michigan Department of Environmental Quality (MDEQ), and far below the emission levels of a typical coal-fired power plant. Disadvantages of Co-Generation The main disadvantage to using cogeneration is that the demand for steam and electricity must occur simultaneously in order for the process to work. This is not a problem during the winter months, when both steam and electricity are required on a relatively high and constant level. In the summer, however, there is little demand for steam heating.
To ensure there is a steam demand during the summer months, the University uses steam-powered air conditioning systems in many buildings. Although these systems are commonly more expensive than their electric counterparts, the long term savings more than make up for it. DIFFERENT TYPES OF NON – RENEWABLE ENERGY 1. COAL Coal is by far the most abundant fossil fuel on earth. It is essentially carbon and is mainly used as a combustion fuel. The large-scale use of coal began with the Industrial Revolution in the 19th century. As the number of industries increased, demand for more sources of energy grew.
Coal is the product of plants, mainly trees that died tens or hundreds of millions of years ago. Due to water logging in low-lying swampy areas or in slowly sinking lagoons, dead trees and plants did not decompose as they normally would. The dead plant matter was covered with water and protected from the oxidizing effect of air. The action of certain bacteria released the oxygen and hydrogen, making the residue richer and richer in carbon. Thick layers of this carbon-rich substance, called peat, built up over thousands of years. As more material accumulated above the peat, the water was squeezed out leaving just carbon-rich plant remains.
Pressure and temperature further compressed the material. This aided the process of producing coal as more gases were forced out and the proportion of carbon continued to increase. The carbon slowly metamorphosed into coal over millions of years. There are three main types of coal: lignite, bituminous, and anthracite. Lignite and bituminous have a lesser percentage of carbon in them and therefore burn faster. They release a great deal of pollutants into the atmosphere. Anthracite has about 98% carbon and therefore burns slowly and releases much less smoke. Coal of all types contains sulphur to some degree.
Sulphur is the worst of the pollutants and causes damage to human health and to vegetation. Though petroleum gained importance over the 20th century and continues to do so, coal remains essential for the industrial sector. It is the principal heat source for electricity generation in most countries and is used directly in such heavy industries as iron and steel making. Until recently, most coal came from underground mines. But now there are a large number of opencast mines. Underground coal mines are notorious killers due to roof falls and explosions. Accidents have resulted in the deaths of hundreds of miners.
Almost 80% of today’s coal comes from surface strip mines (opencast mines), which is much safer. Huge earth-moving equipment strips off the soils and rocks covering the buried coal seams. The land is backfilled and returned to normal after the coal has been removed, thereby repairing the landscape. But most companies do not refill the excavated area and leave it damaged. Most countries have now enforced backfilling by law. Coal mining in India- India has about seven per cent of the world’s proven coal reserves. Coal supplies more than 50% of the country’s total energy requirements.
By current estimates, the reserves are enough to meet India’s needs for at least another 100 years. Coal mining in India dates back to the 18th century. The regulation of its use in the industrial sector was conceived in 1923. In 1972-73, the Indian government nationalized the coal industry, primarily to develop the sector, since it was considered to be of strategic importance for rapid industrial development. India’s coal demand is expected to increase several fold within the next 5–10 years due to the completion of ongoing coal-based power projects, and demand from metallurgical and other industries.
Coal is the dominant source of fuel in the industrial sector, with a share of nearly 72. 5% in the total energy consumption. The industrial sector is the largest consumer of electricity, with a share of 41% of the total consumption. The transport sector is the largest consumer of petroleum products, and accounts for nearly 50% of the total consumption. The small amount of coal presently consumed adds atmospheric pollutants, some of which precipitate into the ground and water. This assault on the environment has been the cause of heavy pollution in many areas of the world
Advantages of Coal Energy * Abundance –Coal is located almost universally, it can be found on every continent in over 70 countries, with the biggest reserves in the USA, Russia, China and India. * Continuous, Predictable, Reliable Source of Power– Coal Based Energy can be generated almost 24? 7 unlike other forms of renewable energy like wind and solar that are intermittent in nature. * Low Capital Investment- The capital investment required for Coal based Power plants is relatively less at $1-2/watt of Thermal Capacity. Note wind energy is slightly higher while Solar is even higher.
Coal Mines are also quite cheap to build and Mine with Open Cast Mines providing Coal at a very Low Cost. * Low Cost– Coal is one of the cheapest forms of energy making it the energy of choice in developing countries like India and China. In India its possible to get cheap coal at just $20/ton while international prices of coal range in the region of $100/ton. Note Coal based electricity can be produced at 2-4c/Kwh making it the cheapest electricity source. * High Load Factor- Thermal Power Plants have very high load factors in excess of 80%. They can generate power almost 24/7 and only require shutdown for periodic maintenance.
Coal Based Plants which have become too old or have been shut down due to environmental concerns can still be used for backup power. * Large Potential compared to Oil– Coal Energy Potential is quite large compared to other Fossil Fuels like Oil and Gas. Coal Reserves globally are estimated to be around 1 trillion tons which implies that Coal can be consumed at the current rates for another 200 years. * Big Industrial Base- Coal Energy has been present since the start of the Industrial Revolution with the development of the Steam Engine based on Coal.
The technology and industry of the Coal Industry and Thermal Power Plants is well developed and mature. This allows a rapid deployment of Coal Power in most places in the world. * Coal to Liquids and Coal to Gases- Coal is now being looked upon as source of Transportation Fuels as Oil becomes scarce and increasingly costly. Coal to Liquid Plants are being constructed in India and China though the Technology is quite immature and the use of the technology is still questionable on environmental grounds. Disadvantages of Coal Energy Greenhouse Gas Emissions- One of the biggest cons of Coal Energy is that it releases Carbon Dioxide which has been sequestered for millions of years in the dead bodies of plant and animals. This transfer the Carbon from the Earth to the Environment leading to the Global Warming Effect. Global Treaties have failed in putting a Cost on this, though individual countries are tying to account for this through Carbon Taxes and Cap and Trade. * Coal Mining Deaths- Coal Mining has resulted in thousands of deaths each year ever since man discovered coal.
Note Coal Deaths happen not only in countries which don’t have good safety regulations like China but also in developed countries like USA and New Zealand. * Devastation of Earth and Scenery Near Coal Mines– Open Cast Mining of Coal has resulted in destruction of the habitat and destruction of the scenery. It leads to removal of trees and pollution of air and water in areas surrounding the mines. Coal Mine Fires have burned for hundreds of year underground and make living in those areas hazardous. Those burning underground can be difficult to locate and many cannot be extinguished.
Fires can cause the ground above to subside, their combustion gases are dangerous to life, and breaking out to the surface can initiate surface fires as well. * Displacement of Humans due to Mining Destruction- In West Bengal, India, people are being displaced in huge numbers as the hollowing of the earth due to underground coal mining has made those places unsafe as the Land Caves in without warning. * Emission of Harmful Substances like Sulfur Dioxide, Carbon Monoxide, Mercury, Selenium, Arsenic, Acid Rain – Thermal Plants emit harmful substances such as Mercury and Sulfur Dioxide which cause health hazards mong the surrounding population and Acid Rain. While modern equipment has reduced the emission of these harmful substances, it is still very harmful to humans. 2. OIL AND GAS Almost all oil and natural gas are found deep underground in tiny holes in rocks. Millions of years ago a sea covered much of what is now dry land. In prehistoric times, tiny plants and animals lived in the sea. When these creatures died, they sank to the bottom of the sea, and got buried in layers of mud and sand. As the ages passed, this organic material sank deeper and deeper.
The earth’s crust changed its shape, and put intense pressure and heat on what was once only plants and tiny animals. Heat from the earth’s interior and the weight of the overlying rocks gradually changed the energy-containing substances in the accumulated plants into hydrocarbon liquids and gases. As millions of years passed, these deposits turned into chemicals that are now called ‘hydrocarbons’. Hydrocarbons are simple molecules made up of carbon and hydrogen atoms joined together in chains or in rings.
These molecules, being light and mobile, migrated upwards through the rocks but eventually became trapped beneath impermeable rock structures in the earth’s crust. That is where oil and natural gas come from. Some were created millions of years ago, some were created thousands of years ago, and some are being created right now! Much of the oil and gas production now comes from underneath the sea-bed. As the technology for extraction continues to advance, production becomes possible from deeper and deeper waters. But the supplies are limited.
Every drop of oil burnt adds to the monumental environment problems already created by pumping gases like carbon dioxide into the atmosphere. Many scientists worry that this continual release of carbon dioxide is an important cause of global warming. Natural gas is usually found underground near an oil source. It is a mixture of light hydrocarbons including methane, ethane, propane, butane, and pentane. Other compounds found in natural gas include carbon dioxide, helium, hydrogen sulphide, and nitrogen. It is found around the world, but the largest reserves are in the former Soviet Union and the Middle East.
This gas is lighter than air and is highly flammable, made up mainly of a gas called methane. Methane is a simple chemical compound that is made up of carbon and hydrogen atoms. Natural gas usually has no odour and cannot be seen. Before it is sent to the pipelines and storage tanks, it is mixed with a chemical that gives it a strong odour, almost like rotten eggs. The odour makes it easy to detect a leak. Natural gas is the cleanest burning fossil fuel. When it is burned, it gives off less carbon dioxide than oil or coal, virtually no sulphur dioxide, and only small amounts of nitrous oxides.
Natural gas is mostly composed of methane and other light hydrocarbons. Both the carbon and the hydrogen in methane combine with oxygen when natural gas is burned, giving off heat. Coal and oil contain proportionally more carbon than natural gas, therefore giving off more carbon dioxide per unit of energy produced. Natural gas gives off 50% of the carbon dioxide released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Carbon dioxide is the most important greenhouse gas contributing to global warming.
To find oil and natural gas, companies drill through the earth to the deposits deep below the surface. The oil and natural gas are then pumped from below the ground by oil rigs. They then usually travel through pipelines. At oil refineries, crude oil is split into various types of products by heating the thick black oil. The products include gasoline, diesel fuel, aviation fuel, home heating oil, oil for ships, and oil to burn in power plants to make electricity. Oil is used for transportation—cars, airplanes, trucks, buses, and motorcycles. Oil is stored in large tanks until it is sent to various places to be used.
Oil is also made into many different products—fertilizers for farms, clothes, toothbrush, plastic bottle, and plastic pen. There are thousands of other products that come from oil. Almost all plastic comes originally from oil. Oil is transported in huge pipelines and tanker ships to places where it is made into other products. Advantages of Natural Gas * Burns clean compared to cola, oil (less polluting) * 70% less carbon dioxide compared to other fossil fuels * Helps improve quality of air and water (not a pollutant) * Does not produce ashes after energy release Has high heating value of 24,000 Btu per pound * Inexpensive compared to coal * No odor until added Disadvantages of Natural Gas * Not a renewable source * Finite resource trapped in the earth (some experts disagree) * Inability to recover all in-place gas from a producible deposit because of unfavorable economics and lack of technology (it costs more to recover the remaining natural gas because of flow, access, etc. ) Advantages of Crude Oil * Oil is one of the most abundant energy resources * Liquid form of oil makes it easy to transport and use * Oil has high heating value Relatively inexpensive * No new technology needed to use Disadvantages of Crude Oil * Oil burning leads to carbon emissions * Finite resources (some disagree) * Oil recovery processes not efficient enough—technology needs to be developed to provide better yields * Oil drilling endangers the environment and ecosystesm * Oil transportation (by ship) can lead to spills, causing environmental and ecological damage NUCLEAR ENERGY | Nuclear energy is the energy that is trapped inside each atom. The ancient Greeks believed that the smallest part of nature is an atom.
But they did not know 2000 years ago that atoms are made up of further smaller particles—a nucleus of protons and neutrons, surrounded by electrons, which swirl around the nucleus much like the earth revolves around the sun. One of the laws of the universe is that matter and energy can neither be created nor destroyed. But they can be changed in form. Matter can be changed into energy. Albert Einstein’s famous mathematical formula E = mc2 explains this. The equation says: E [energy] equals m [mass] times c2 [c stands for the speed or velocity of light].
This means that it is mass multiplied by the square of the velocity of light. Scientists used Einstein’s equation as the key to unlock atomic energy and to create atomic bombs. An atom’s nucleus can be split apart. This is known as fission. When this is done, a tremendous amount of energy in the form of both heat and light is released by the initiation of a chain reaction. This energy, when slowly released, can be harnessed to generate electricity. When it is released all at once, it results in a tremendous explosion as in an atomic bomb. Nuclear energy can also be harnessed by fusion.
A fusion reaction occurs when two hydrogen atoms combine to produce one helium atom. This reaction takes place at all times in the sun, which provides us with the solar energy. This technology is still at the experimental stage and may become viable in future. Uranium is the main element required to run a nuclear reactor where energy is extracted. Uranium is mined from many places around the world. It is processed (to get enriched uranium, i. e. the radioactive isotope) into tiny pellets. These pellets are loaded into long rods that are put into the power plant’s reactor.
Inside the reactor of an atomic power plant, uranium atoms are split apart in controlled chain reaction. Other fissile material includes plutonium and thorium. In a chain reaction, particles released by the splitting of the atom strike other uranium atoms and split them. The particles released by this further split other atoms in a chain process. In nuclear power plants, control rods are used to keep the splitting regulated, so that it does not occur too fast. These are called moderators. The chain reaction gives off heat energy. This heat energy is used to boil heavy water in the core of the reactor.
So, instead of burning a fuel, nuclear power plants use the energy released by the chain reaction to change the energy of atoms into heat energy. The heavy water from around the nuclear core is sent to another section of the power plant. Here it heats another set of pipes filled with water to make steam. The steam in this second set of pipes rotates a turbine to generate electricity. If the reaction is not controlled, you could have an atomic bomb. Experiences with nuclear programmes differ and the future of nuclear power remains uncertain because of public reaction.
But in the past few years the capacity of operating nuclear plants has increased more than twentyfold. There are more than 400 nuclear power plants providing about 7% of the world’s primary energy and about 25% of the electric power in industrialized nations. The growth of nuclear power combined with the shift from carbon-heavy fuels such as coal and oil to carbon-light gas contribute to the gradual ‘de-carbonization’ of the world energy system. Chernobyl, Three Mile Island, and other nuclear accidents have increased the fear of harnessing nuclear energy.
Another issue with international and local implications is the storage and disposal of radioactive wastes: both from nuclear reactors making electricity and from the production of military weapons. Earlier disposal practices, such as dumping of nuclear waste at sea, have been completely stopped by formal treaty because of environmental concerns (and by cessation of furtive scuttling of nuclear submarines).
Regimes for transport and temporary storage of civil and defence nuclear wastes now function, although sites and designs for permanent disposal have yet to be accepted.
People are concerned about both low- and high-level radioactive wastes; the latter, though smaller in volume is more technically problematic. With the rise of nuclear electrification, the volume of spent fuel and other wastes has risen substantially; but is still small. In some countries such as the US, the volume of high-level waste from commercial power plants has now reached hundreds of millions of tones. Advantages of Nuclear Energy * Nuclear power generation does emit relatively low amounts of carbon dioxide (CO2).
The emissions of greenhouse gases and therefore the contribution of nuclear power plants to global warming is therefore relatively little. * This technology is readily available; it does not have to be developed first. * It is possible to generate a high amount of electrical energy in one single plant. * They can be sited almost anywhere unlike oil which is mostly imported. * The plants almost never experience problems if not from human error, which almost never happens anyway because the plant only needs like 10 people to operate it. * A small amount of matter creates a large amount of energy. Current nuclear waste in the US is over 90% Uranium. If reprocessing were made legal again in the US we would have enough nuclear material to last hundreds of years. * A nuclear aircraft carrier can circle the globe continuously for 30 years on its original fuel while a diesel fueled carrier has a range of only about 3000 miles before having to refuel. * Theoretical Thorium reactors have many of the benefits of Uranium reactors while removing much of the risk for proliferation as it is impossible to get weapons-grade nuclear materials from Thorium Disadvantages of Nuclear Energy The waste from nuclear energy is extremely dangerous (radioactive)and it has to be carefully looked after for several thousand years * High risks: Despite a generally high security standard, accidents can still happen. It is technically impossible to build a plant with 100% security. A small probability of failure will always last. The consequences of an accident would be absolutely devastating both for human being as for the nature . * Nuclear power plants as well as nuclear waste could be preferred targets for terrorist attacks. No atomic energy plant in the world could withstand an attack similar to 9/11 in New York.
Such a terrorist act would have catastrophic effects for the whole world. * During the operation of nuclear power plants, radioactive waste is produced, which in turn can be used for the production of nuclear weapons. (nuclear proliferation).
* The energy source for nuclear energy is Uranium. Uranium is a scarce resource, its supply is estimated to last only for the next 30 to 60 years depending on the actual demand. * The time frame needed for formalities, planning and building of a new nuclear power generation plant is in the range of 20 to 30 years in the western democracies.
In other words: It is an illusion to build new nuclear power plants in a short time. * Nuclear plants are more expensive to build and maintain. * Early nuclear research and experimentation has created massive contamination problems that are still uncontained. Recently, for instance, underground contamination emanating from the Hanford Nuclear Reservation in Washington State in the U. S. was discovered and threatens to contaminate the Columbia River (the largest river in North America west of the continental divide).
* Nuclear power plants can be dangerous to its surroundings and employees.
It would cost a lot to clean in case of spillages. * There exist safety concerns if the plant is not operated correctly or conditions arise that were unforeseen when the plant was developed, as happened at the Fukushima plant in Japan; the core melted down following an earthquake and tsunami the plant was not designed to handle despite the world’s strongest earthquake codes. FUTURE OF ENERGY Since the industrial revolution 200 years ago, mankind has depended on fossil fuel. The notion that this might change is hard to contemplate. Greens may hector. Consciences may nag.
The central heating’s thermostat may turn down a notch or two. A less thirsty car may sit in the drive. But actually stop using the stuff? Impossible to imagine: surely there isn’t a serious alternative? Such a failure of imagination has been at the heart of the debate about climate change. The green message —use less energy—is not going to solve the problem unless economic growth stops at the same time. If it does not (and it won’t), any efficiency saving will soon be eaten up by higher consumption per head. Even the hair-shirt option, then, will bring only short-term relief.
And when a dire prophecy from environmentalism’s jeremiad looks as if it is coming true, as the price of petroleum rises through the roof and the idea that oil might run out is no longer whispered in corners but openly discussed, there is a temptation to believe that the end of the world is, indeed, nigh. Not everyone, however, is so pessimistic. For, in the imaginations of a coterie of physicists, biologists and engineers, an alternative world is taking shape. As the special report in this issue describes, plans for the end of the fossil-fuel economy are now being laid and they do not involve much self-flagellation.
Instead of bullying and scaring people, the prophets of energy technology are attempting to seduce them. They promise a world where, at one level, things will have changed beyond recognition, but at another will have stayed comfortably the same, and may even have got better. This time it is serious- Alternative energy sounds like a cop-out. Windmills and solar cells hardly seem like ways of producing enough electricity to power a busy, self-interested world, as furnaces and steam-turbines now do.
Though many are interested in environmental benefits, their main motive is money. They are investing their cash in ideas that they think will make them large amounts more. And for the alternatives to do that, they need to be both as cheap as (and cheaper than) and as easy to use as (or easier than) what they are replacing. For oil replacements, cheap suddenly looks less of a problem. The biofuels or batteries that will power cars in the alternative future should beat petrol at today’s prices. Of course, today’s prices are not tomorrow’s.
The price of oil may fall; but so will the price of biofuels, as innovation improves crops, manufacturing processes and fuels. Electrical energy, meanwhile, will remain cheaper than petrol energy in almost any foreseeable future, and tomorrow’s electric cars will be as easy to fill with juice from a socket as today’s are with petrol from a pump. Unlike cars powered by hydrogen fuel cells, of the sort launched by Honda this week, battery cars do not need new pipes to deliver their energy. The existing grid, tweaked and smartened to make better use of its power stations, should be infrastructure enough.
What matters is the nature of those power stations. The price is right- They, too, are more and more likely to be alternative. Wind power is taking on natural gas, which has risen in price in sympathy with oil. Wind is closing in on the price of coal, as well. Solar energy is a few years behind, but the most modern systems already promise wind-like prices. Indeed, both industries are so successful that manufacturers cannot keep up, and supply bottlenecks are forcing prices higher than they otherwise would be.
It would help if coal—the cheapest fuel for making electricity—were taxed to pay for the climate-changing effects of the carbon dioxide produced when it burns, but even without such a tax, some ambitious entrepreneurs are already talking of alternatives that are cheaper than coal. Older, more cynical hands may find this disturbingly familiar. The last time such alternatives were widely discussed was during the early 1970s. Then, too, a spike in the price of oil coincided with a fear that natural limits to supply were close. The newspapers were full of articles on olar power, fusion and converting the economy to run on fuel cells and hydrogen. Of course, there was no geological shortage of oil, just a politically manipulated one. Nor is there a geological shortage this time round. But that does not matter, for there are two differences between then and now. The first is that this price rise is driven by demand. More energy is needed all round. That gives alternatives a real opening. The second is that 35 years have winnowed the technological wheat from the chaff. Few believe in fusion now, though uranium-powered fission reactors may be coming back into fashion.
And, despite Honda’s launch, the idea of a hydrogen economy is also fading fast. Thirty-five years of improvements have, however, made wind, solar power and high-tech batteries attractive. As these alternatives start to roll out in earnest, their rise, optimists hope, will become inexorable. Economies of scale will develop and armies of engineers will tweak them to make them better and cheaper still. Some, indeed, think alternative energy will be the basis of a boom bigger than information technology. Whether that boom will happen quickly enough to stop the concentration of carbon dioxide in the atmosphere reaching dangerous levels is moot.
But without alternative energy sources such a rise is certain. The best thing that rich-world governments can do is to encourage the alternatives by taxing carbon (even knowing that places like China and India will not) and removing subsidies that favour fossil fuels. Competition should do the rest—for the fledgling firms of the alternative-energy industry are in competition with each other as much as they are with the incumbent fossil-fuel companies. Let a hundred flowers bloom. When they have, China, too, may find some it likes the look of. Therein lies the best hope for the energy business, and the planet. CONSERVATION OF ENERGY 1. More Pollutants in the Air When you conserve energy within your own life, you not only protect the environment that you live in but your wallet is protected as well. When we heat our homes in the winter or power our cars on a daily basis, we are using non-renewable resources for our energy. These resources release tons of pollutants into the air that we breathe, and they are being released by people worldwide. Whether you believe in global warming or not, these pollutants are not doing our environment any good and conserving energy in our own home is the only way that we can control our pollutant output.
If everyone would conserve energy a bit more there would be much less pollution in the world, making it a happier and healthier place. 2. Protect Your Wallet When you conserve energy within your own life, you not only protect the environment that you live in but your wallet is protected as well. Using too much energy takes a lot of extra cash, and most of us don’t just have that lying around. You are paying gas for your car, along with oil/electric for your home. You are paying for air filters in your home that get dirty fast because of all the dirt and dust in the air.
Clogged filters in turn make your air conditioner or furnace work harder which means more money from you on your next bill. Conserving energy is not only great for the environment, but it’s great for your financial life as well. 3. Fossil Fuels Won’t Last Forever Remember that the more energy we save today, the more is left for our children tomorrow! We will not be the only humans to live on this planet, and our ancestors have done a great job in keeping the environment in one piece. But with all the modernization occurring, along with rampant technology, our generation has seemed to put environment on the back burner.
Fossil fuels are constantly being used by us and they are not a renewable source of energy. They will run out. Along with that, they emit a very harmful gas that is not good for plants or for us. Using less energy will mean having to deal with less toxic gases in the air. 4. Be a Role Model Caring about and protecting your environment now will set the pace for future generations to come. Teach your children that the world we live in is precious and everything we do affects it in some way. Do not take the world for granted and treat every living thing with care.
Use energy carefully and do not use more than you need. Don’t leave things plugged in all the time and don’t underestimate what small changes can do for the world. If every person in the world would unplug their television when it was not in use, tons of gases would not be put into the environment. Conserving energy starts at home and can be continued wherever you may go. Save energy by riding a bus to the grocery store instead of taking your car, or perhaps turn the fans on in the summer instead of air conditioning all the time. Every small change counts. THANK YOU