(Project member SATRAPS- University Technology Malaysia-UTM, Malaysia)
Introduction
The use of energy has been identified with the dawn of human civilization. At the beginning of human civilization , people used to draw their energy mostly from the exploitation of human and animal forces . Wood from forests were also another resource used for cooking and heating –though wind and water energy had also limited site specific use .In fact , till around a century and quarter back, vegetable oils /fats were the most popular and virtually the only resource for lighting purposes , throughout the globe with electricity an unknown commodity .
With the passage of time fossil fuels were discovered. Its use remarkably increased only after the industrial revolution in the 18th century—though coal was a not an unknown fuel in China since earliest times . The landmark discovery of steam engine in 1712 paved the way with accelerated growth of economy along with the faster use of fossil fuels The abundant resource of coal with much higher calorific value prompted the replacement of wood as a source of fuel. Advancement of economy started growing hand in hand with the availability and consumption of fossil fuel.
With the economy growing up , the standard of living improved ushering in the growth of industries like transport, mining, construction and chemicals coming up–opening up still further scope of use of fossil fuels With it the transition started shifting the world economy from the agricultural base to focussing on the lucrative growth of faster industrialisation on all fronts .The invention of electricity by the end of 19th century completely changed the dimension of mankind offering a much better quality of life .A new era started with power sectors coming up and thereby facilitating the economic growth of the nations Thus the hall mark of industrial nations with economic advancements has now been identified with the generation of electricity . As a result of this , the demand for consumption of fossil fuels grew with leaps and bounds, within the last 100 years we have consumed more fuel than that used since the last few millennium.
The big leap forward on fossil fuel consumption rate globally , began from the scope of availability of electricity harnessing the fossil fuels .It is of interest to note that the generation of electricity , first used in 1883 , was rather a costly process then -making it costlier than the equivalent heat energy available from these fossil fuels –coal/oil/gas .But the advantages gained from its wide scale services made it a key player in all sorts of technological advancements and thereby decisive in improving upon the economy of a country.
Of course there have been marked disparity in quantum of energy use and thereby of the degree of economic development between OECD (Organization of economic co-operation and development) and Non-OECD countries for obvious reasons . The former included developed countries like, USA , Canada , most European countries , Australia and lately Japan , plus some Latin American countries etc ; whence non-OECD countries are mainly the Asian countries excluding Japan , African and some Latin American countries.
.
There is a close relationship between the usage of energy with general level of economic activity. Also, the wide scope of use of fossil fuels (use of oil as transport fuel & in petrochemical productions in addition to power production, use of coal in metallurgical processes besides power generation etc) make their impact on local economy so deep , that for every price rise of fuel its impact is felt on the overall economy of the country causing increase in inflation. Because of these economic promises, the rather poorer non-OECD countries have projected a rather faster growth rate of energy use than that of the already developed OECD countries –whose present energy consumption rates are already many times higher than the non-OECD countries.
But such ever increasing faster usage rate of fossil fuels, to achieve economic progress , posed too big a burden for nature to cope up with. We are thus now confronted with the resource crunch of the energy rich fossil fuels threatening the sustained development.
In addition to it, the environmental issues like global warming, ozone hole and such eventualities from higher emission rate of green house gases has invited the attention of energy planners and policy makers –which is a much talked of topic now
Green House Gases and Global warming
The earth absorbs nearly 70% of the incoming solar radiation and then tries to cool down emitting long wavelength infrared radiation . This radiation is absorbed by some atmospheric gases , termed green house gases ; and the effect of temperature rise caused thereby trapping the escaping heat, is called the green house effect. The term is coined from the known practice of the gardeners growing vegetables in green house structures of glass/plastic canopy to trap the heat of the incident sunlight .
This phenomenon , first investigated by S. Arrhenius in 1896, showed that the green house gases emit also long infrared radiation up above the space and down below the earth. The warming of atmosphere is caused from the latter and the gases responsible for heating are : Water vapour , Carbon Dioxide, Argon, Neon, Helium, Methane, Hydrogen, Nitrous Oxide and Ozone.. Besides these atmospheric green house gases , there are other man-made green house gases as well , like the three groups of fluorinated compounds – Sulfur hexafluoride , HFCs and PFCs . But Oxygen and Nitrogen , the major atmospheric constituents , have no green house effect as they neither absorb nor emit infra-red radiation . This is because of the fact that they are homo nuclear diatomic molecules with no net change in dipole moment when they vibrate .
The role of water vapour in atmospheric heating is quite interesting . Water vapor [not cloud which rather restricts sun’s rays reflecting it back ] have rather synergistic effect in green house heating. Rise in temperature from green house effect results in increase in water vapor content , with further temperature rise in the troposphere, which is the atmospheric zone that we live in. This causes more evaporation of ocean water aggravating further temperature rise and the feedback cycle continues till the equilibrium is reached But the atmospheric heating from water vapour have only local and temporary effect with its fluctuating concentration in the atmosphere .
In fact , the three factors that influences the degree of warming from green house gases are – the global warming potential (GWP) of the particular gas, its concentration in the atmosphere and the mean life. CO2 (carbon-di-oxide) , that originates from burning of fossil fuels has GWP ‘1’, with lifetime of several hundred years ; but can increase to several thousand years in case of their large input in the atmosphere. CH4(methane), that may originate both from fossil fuel burning as well as degeneration from anaerobic bacteria over rice fields/wastes , has GWP ‘23’ over 100 years lifetime and just ‘7’ for over 500 years lifetime –because of its atmospheric degradation to water and CO2 over longer periods. Nitrous oxide originating from both fossil fuel burning /fertiliser plants etc type chemical industries , have a GWP ‘296’ with around 100 years lifetime. Man made CFCs and fluorinated compounds , made for refrigerants etc , have GWP several thousand with around 14 years life time.
However, contribution towards warming in case of other green house gases are negligible compared to CO2, despite their higher GWP values; because their atmospheric concentration is negligible . But it is also to be noted that, in an eventuality of desorption of clathrated methane from ocean bed/rocks etc or, the release of frozen methane from polar zone , it may play a havoc in global warming – in the eventuality of the release of methane from such sources in very large quantities.
It may be relevant to add that – but for the green house gases with no scope for retention of heat , we would have frozen during night time. The much-talked of global warming arises because of the unabated increment in concentration of green house gases , particularly CO2 – from large scale use of fossil fuels, resulting in the enhanced green house effect , which is in fact of global concern now,
If the CO2 concentration exceeds 450 PPM from the present 350 PPM level – then there may be irreversible temperature rise continuing for centuries. Sea level may rise by 5-12 m , drowning many low lying areas in the globe –from melting of snow in the ice cap of Greenland and Western Arctic region. On the one hand the draught affected areas may increase with simultaneous rise in the frequency of flood risk—due to the changes in rainfall pattern globally
Ozone Hole – In addition to the global warming from green house gases (CO2 mainly) we are confronted with another problem, termed ozone hole –which has already done some damage towards maintaining environmental equilibrium. Ozone (O3 ), the allotrope of Oxygen (O2 ), acts as a shield in the Stratosphere ( above the Troposphere that we live in ) – by interacting with, and thereby reducing the harmful ultraviolet rays of the sunlight reaching us. Ozone hole is the dent caused in the above ozone layer, from the chemical reaction of CFCs and such halides –breaking down the ozone molecules to Oxygen.
Ozone depletion as such is not directly linked to global warming , other than inviting health hazard from incoming ultraviolet rays of the sun .But the halides like , CFCs etc, responsible for breaking down the ozone layer, are themselves very potent in their green house effect as well . Hence , the production CFCs was restricted through an international treaty ,the Montreal agreement made in 1989 .
As a result of this treaty, steady decline has of course been observed in the production of CFCs and such harmful halides –that threatened Ozone hole formation ( besides global warming ). But the damage already done in depletion of ozone layer in Antarctic and such place , would take decades to get recovered.
Fossil fuel Resource Crunch .
The large scale usage of fossil fuel is inviting disastrous environmental consequences of global warming ,ozone hole etc problems. In addition to the above , the increasing trend of their use like , oil./gas /coal etc for achieving fast economic growth , we risk rapid depletion and exhaustion of these very fuels. It is only a question of time that these concentrated cheap fuel sources , that took million of years to be formed from biological and geological processes , run the risk of getting totally depleted ,sooner or later
It has been apprehended that the planet may get depleted from oil by next half a century , with the current rate of consumption. Coal may last a little longer, another century or so. In fact the production of fixed resources would follow the law of diminishing return – a sharp decline following the peak production. In fact on reaching the peak production a stage is reached when the energy required for production –like , manufacturing drilling rigs , process of exploring new oil field, and the various stages of production to lift the oil to surface –may far exceed the amount of energy as may be availed and also becomes economically non-viable
The ratio of reserve/production ,i.. e. the R/P ratio of fossil fuels in the global perspective with the present rated use has been predicted to be :– Oil – 40 years hence ; Natural gas -60 years; whence Coal may last a little longer – another 200 years. However , there remain uneven distribution of these resources , in the global perspective .
Sustainable Development .
It has been shown in previous sections how the immediate gains of economic improvements, from the increasing trend of fossil fuel exploitation, threatens our future. If the current trend of fossil fuel use continues ,we run the risk of meeting environmental disasters in addition to facing a retrograde movement of civilization with no electricity or power availability situation – having no fuel left for harnessing it . That is why scientists and planners started thinking ahead in terms of sustainable development . It means a developmental strategy that would be able to meet the needs of the present without compromising the ability of the future generation to meet their own needs.—both towards energy and raw materials .
It may be relevant to point out here , that the important policy decisions adopted by world bodies on sustainable development, does not confine in the energy issues only. It also ensures arresting species extinction ( plants and animals) , addressing to the environmental issues affecting soil /land/water, in addition to the gradual extinction of mineral and other resources including energy resources. The guiding principles underlying the sustainable development thus states categorically that :
• “Each generation should require the diversity of resource base so that it does not unduly restrict the options available to future generations.
• Each generation should maintain the planets overall qualities so that it does not get into worse condition than received.
• Members of every generation should have comparable rights of access to the legacy of past generation and should conserve this access to the future generations”
As Energy is the key player in all developmental work, Sustainable Development Commission in their 9th session in 2001, took a definite stand for adoption of alternate resources of energy which gets automatically replenished on consumption, termed as Renewable Energy, like sunlight, wind, hydropower etc. They are clean energy virtually free from generating green house gases and their large scale uses not only decrease the present increasing trend of green house gases , but assures steady and virtually unlimited supply of energy – from diverse sources , as suited to the site concerned .
Renewable Energy .
Resources of Renewable Energy could be from varied fields .Some of the important ones are:
• Tapping the energy of solar insolation over the earth’s surface –called the solar energy.
• Generating oils or , gases from decomposition /degeneration of bio sources , including bio-wastes – called bio-fuels.
• Tapping the hydro-power , either natural or creating artificial level difference of natural water bodies and/or the energy of the flow of water bodies.
• Wind energy of blowing wind.
• Tidal current , and
• The huge untapped reservoir of energy in Oceans –termed Ocean energy
But till date, only a small percentage of these are being tapped, compared with the conventional fossil fuels. Exhaustive R& D studies are hence undertaken in different countries to make such energy resources technically viable and economically affordable in the long run.
A brief account of some of these RE schemes are enumerated below.
Solar Energy– Direct tapping of solar radiation can be done, either by the generation of electricity from photovoltaic effect of incident solar radiation using solar cells (Photo -Voltaic -PV) ,or, utilizing the heating effect of the solar insolation. Solar cells (PV), mostly silicon based, are semiconductor materials, which conduct electricity when light falls upon them. It requires an array of batteries and inverters for storing the generated electricity, which can to be made available in the absence of sunlight (night time), and also for converting DC to AC power. These are particularly useful in inaccessible places.
Wind Energy (both off-shore & on-shore wind farms) -It involves around $1 million capital outlay per megawatt (MW) power generation, even for a good cut in wind speed (3 -5m/s, but not exceeding 15m/s). The scope of availability of wind resource with optimum wind speed -for both on shore and off-shore is however limited; though the latter has higher resource potential. Power production cost of wind energy are however, competitive with power generation cost from fossil fuel resources.
Bio-Fuels – They are availed at the cost of agricultural land use and with the requirement of abundant water supply for the growth of agricultural feedstock (biomass -which are plants or plant wastes consisting of cellulose, hemicellulose or lignin type carbon-based compounds); they being the primary resource for availing such energy type12. Of course, they have an advantage of their scope for use as transport fuel.
Ocean energy schemes- Amongst the three ocean energy schemes, wave energy, Ocean thermal energy conversion system (OTEC) and tidal energy, it is the tidal energy technology which is rather more matured from application point of view, though suitable exploitable sites of it are limited globally. La rance Barrage in France is producing 240MW power since 1969. Though it is available only 10hours a day, its power generation can however be properly programmed, being predictable.
However OTEC has immense potential of emerging as the viable technology in its 2nd/3rd generation schemes, mainly because of its scope of availability of huge by products providing not only commercially viable energy production but also providing food security and potable water.
Ocean Thermal Energy conversion (OTEC) system
Ocean receives huge radiant energy from the Sun which heats up the ocean surface water.The surface temperature profile of the ocean graduallly decreases with depth from the exponential decrease of light energy following Lambert’s law, making the bottom layer cooler, with further cooling caused from the flow of heavier bootom polar water at 4oC. Thus a temperature differential is caused in the ocean between the warm surface layer water and cooler bottom layer water. This opens up the scope of generating power using thermodyanamic cycle. Power generation from such method is termed as ocean thermal energy conversion (OTEC) system. Because of the high specific heat of water, the surface temperature of the ocean is mostly retained during night as well, assuring round the clock supply of power from OTEC. It has been estimated that heat energy available from 60 million sq. km. of tropical seas could be equivalent to 250 billion barrels of oil.
It is thought that power produced from OTEC if converted to the production of hydrogen (by splitting water from electrolysis) it would save cable cost of power transmission, since hydrogen fuel cell combine can produce electricity. Besides it offers a method on storage of electricity without the need for battery.
Hydrogen- It can be availed by splitting of water and also leaves behind nothing but water on its liberation of the energy, hence it has been identified to be the future energy source in the new millennium.
Thus hydrogen, the future energy source, ensures not only the energy supply & security, but also climate stewardship with ensured sustainability, with particular inclusion of transport sector providing mobile fuel.
Read more – Riot Days: An Account of Calcutta Tramwaymen and Religious Activism, 1946 – 47
