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    Energy Energy Document Transcript

    • Khulna University of Engineering & Technology Department of Electrical & Electronic Engineering ME-1203 Basic Mechanical EngineeringDefinition of energy:Energy means thing that is capable of doing something or having potential to make any change.Energy exists in several forms such as heat, stored energy (chemical, nuclear etc.), kinetic ormechanical energy, light, potential energy, or other forms.In thermodynamic view, energy is a thermodynamic quantity equivalent to the capacity of aphysical system to do work. For example when a fuel burns or changes its form, produce heat orany form of work that can be converted to useful form.Types of Energy:1. Kinetic EnergyThis is the energy associated with the motion of an object. If an object of mass m moves withspeed v, then its kinetic energy is mv2 /2.2. Gravitational Potential EnergyThis change in the gravitational potential energy is the work done when a mass is raised orlowered in a gravitational field. If the mass is raised, then some agent must push the mass"uphill" against the pull of gravity, and the potential energy of the mass has increased. Theenergy is called "potential" energy because it can be completely recovered (in principle) byletting the mass fall downhill again.3. Electrical Potential EnergyThis change in electrical potential energy is the work done when an electrical charge is moved inthe vicinity of other charges. Since like charges repel, it takes work to push two like chargescloser together, and that work, which must be done by some external agent, increases theelectrical potential energy of the system4. Chemical EnergyThis is the energy released during a chemical reaction. The energy often appears as kineticenergy of the products, which we usually think of as "heat." However, chemical reactions canalso produce electrical potential energy, as in a battery, for example5. Mass EnergyIt is possible to convert mass into energy and vice-versa. If a mass of m kilograms is convertedto energy, the energy released is E= mc, where c is the speed of light.6. Electromagnetic energyThis energy is carried by electric and magnetic fields. Although these fields usually originatefrom charges and their motions, the fields themselves can transmit energy through empty space.For example, this is the principal way that energy from the sun reaches us. Depending on thefrequency of the wave fields, we think of electromagnetic energy as light, radiant heat, x-rays orgamma rays, all of which are different manifestations of the same basic phenomenon.Sources of Energy:Energy resources are two types: • Conventional or non renewable sources • Non-conventional or renewable sourcesAccording to sources of energy, there are two types of energy: i) Non-renewable or conventionalenergy ii) Renewable or non-conventional energy.
    • Definitions of non renewable/ Conventional energy: Non-renewable energy is energy, taken from "finite resources that will eventually dwindle,becoming too expensive or too environmentally damaging to retrieve. This type of energy cannotbe replaced once it is used or energy that is not being replaced as fast as it is being used. Used todescribe energy sources that exist in a limited amount on Earth. They form from decaying plantand animal material over hundreds of thousands to millions of years.Non-renewable energy resources are those, which have been in use since a long time.Conventional sources of energy include fossil fuels, natural gas, nuclear energy and hydroelectricenergy. Fossil Fuels it includes fuels which are most commonly used such as wood, coal, peatand petroleum.Effects of Conventional energy sources:Conventional energy sources have demonstrated both extremely positive and negativeconsequences. These negative effects have fueled the proliferation of alternative energy sourcesin recent yearsPositive consequences of Conventional energy sources are: 1. Conventional energy sources are proven technologies which can provide energy regardless of the weather conditions unlike solar and wind power which may go for days without being able to produce substantial amounts of power. Currently, the financial costs are much lower than alternative energy sources. 2. Conventional energy sources made the Industrial Revolution possibleNegative consequences of Conventional energy sources are: 1. Being carbon-based, natural gas, oil and coal store carbon as potential energy and release it when burned. The Intergovernmental Panel on Climate Change states that carbon and other greenhouse gas emissions is a major culprit in climate change. 2. According to the Energy Information Administration, burning coal produces sulfur and nitrogen oxide, which can lead to acid rain and mercury, which is harmful to humans when ingested. All of these are known to have disastrous environmental and health consequences.Different types of Conventional energy sources:1) Fossil FuelsIt includes fuels which are most commonly used such as wood, coal and petroleum. These fossilfuels are non-renewable sources of energy. Therefore we need to conserve them.Wood • It is a major source of energy for man as it is widely used for cooking and heating • It is a primary fuel which can be used directly to produce heatDisadvantages of wood • A major portion of heat produced by burning wood is lost to the surroundings and only 8% of the total heat is actually used for cooking food leading to huge wastage of fuel • It produces a lot of smoke due to incomplete combustion leading to pollution and health hazards Coal Coal releases large amounts of energy when it is burned because of the density of hydrocarbons in the material. Coal is formed by dead plants being put under significant pressure and temperature for millions of years. There are four grades of coal: lignite, subbituminous, bituminous coal and anthracite. Bituminous coal is the best for releasing energy and is the most commonly mined type of coal in the United States.
    • Disadvantages of coal The oxides of carbon, nitrogen and sulfur are released on burning coal and petroleum which are acidic oxides. Thus, they lead to acid rain which affects our water and soil resourcesPetroleum Petroleum is formed from the compression of animal and plant remains over millions of years. Petroleum has to be drilled for because it is usually located deep below the earths surface and is then refined to produce a number of different products including gasoline, heavy fuel oil and diesel fuel.3) Nuclear PowerNuclear power plants run by splitting atoms and using the heat that is generated to turn waterinto steam. When the steam rises it spins turbines that generate electricity.Controlled fission of heavier unstable atoms such as U235, Th232 and artificial elements Pu239liberate large amount of heat energy. This enormous release of energy from a relatively smallmass of nuclear fuels makes this source of energy of great interest. The energy released by thecomplete fission, of one kilogram of U235 is equal to the heat energy obtained byburning 4500 tones of high grade coal. However, there are some difficulties in theuse of nuclear energy namely high capital cost of nuclear power plants, limitedavailability of raw materials difficulties associated with disposal of radioactivewastes and dearth of well trained personnel to handle the nuclear power plants.4) Crude OilOn- and off-short sites are drilled for crude oil which is refined for several uses, including jetfuel, gasoline and diesel fuel. In addition, 1.2 percent of the energy in the United States in 2009was generated by oil power plants, according to the Energy Information Administration.Definitions of renewable/ non conventional energy:The term renewable energy generally refers to energy generated from natural resourcesrenewable energy sources, such as wind, rain, solar, tides, geothermal, hydropower and variousforms of biomass--which are renewable (naturally replenished) and ecologically safe. Theseenergy sources are considered renewable sources because their fuel sources are continuouslyreplenished. These types of energy can be replenished at the same rate as it is used.Energy generated from resources that are unlimited, rapidly replenished or naturally renewablesuch as wind, water, sun, wave and refuse, and not from the combustion of fossil fuels.Non-conventional/ renewable sources of energy include: • Solar power • Hydro-electric power (dams in rivers) • Wind power • Tidal power • Ocean wave power • Geothermal power (heat from deep under the ground) • Ocean thermal power (the difference in heat between shallow and deep water) • Biomass (burning of vegetation to stop it producing methane)Non conventional Energy: WindWind has kinetic energy that can turn turbines and be converted to usable power. However, theamount of energy that can be derived depends on the speed of the wind. Wind power is one ofthe most cost-efficient forms of non-conventional energy. It is clean, renewable and safe, butfinding places in which wind turbines can be installed without interference have created someproblems.
    • Wind power can be made use of where wind at suitable velocity is available. Wind power iscapable of generating small amounts of electrical energy. It is successfully employed forpumping water from deep wells. Wind power has served many countries as a source ofpower in early days and was called as wind mills. The propulsive power of windcan be used to drive multi-bladed turbine wheel. Wind turbines prove to be costlyif designed to run at all wind speeds. They usually start running at wind speedsjust enough to overcome the system loses and develop full power at theprevailing speed for the locality.Non conventional Energy: SolarSolar power has become more widely used in recent years because it is safe, clean andrenewable. Many local governments provide incentives for the production of solar technologyand its installation in residences.Solar energy is collected from the sun. Electromagnetic waves released from the sun can be used as solar heating for homes and other buildings or as solar electricity to power appliances and other electronics. Energy gathered from the sun is stored in batteries because the sun does not shine anywhere on Earth constantly all year around. Some countries like India are in geographically ideal locations to collect solar energy. India can have from 250 to 300 sunny days in a given year.Solar energy can be applied in many ways, including to: • Generate electricity using photovoltaic solar cells. • Generate electricity using concentrating solar power. • Generate electricity by heating trapped air which rotates turbines in a solar updraft tower. • Generate hydrogen using photo electrochemical cells. • Heat water or air for domestic hot water and space heating needs using solar-thermal panels. • Heat buildings, directly, through passive solar building design. • Heat foodstuffs, through solar ovens. • Solar air conditioningSolar energy is effective only during day time and if power supply is to be made during nightalso then some reservoir of energy such as storage battery or heat accumulator should be used. Itis believed that solar power can become economically feasible with the following aims achieved: 1. Availability of better heat collector. 2. Availability of improved materials and manufacturing techniques. 3. Better techniques for storage and cheap distribution of solar power.Perhaps the great advantage of solar power is that the system is ideally suited to the humanenvironment being free from pollution and noise. Besides, maintenance is cheap and convenient.Of all the non-conventional energy sources, solar power is much cheaper for cooking, streetlighting and water heating.Non conventional Energy: WaterEnergy in water (in the form of kinetic energy, temperature differences) can be harnessed andused. Since water is about 800 times denser than air, even a slow flowing stream of water, ormoderate sea swell, can yield considerable amounts of energy.There are many forms of water energy Hydroelectric energy is a term usually reserved for large-scale hydroelectric dams. Hydropower is created by damming rivers and using the currents to spin turbines, thus creating energy. Although capital cost of hydroelectric power plants is higher as compared to other types of power plants but their operating costs are quite low.
    • Wave power uses the energy in waves but it is difficult to tap into this particular energy source. Wave power machines usually take the form of floating or neutrally buoyant structures which move relative to one another or to a fixed point. Tidal Power: Ocean waves and tides contain large amount of energy. Such tides rise and fall and water can be stored during rise period and it can be discharged during fall. Advantages: The various advantages of tidal power plants are as follows: (i) The power generated does not depend on rain. Therefore there is certainty of power supply as the tidal cycle is very definite. (i) The tidal power plants are free from pollution. (ii) Unhealthy wastes like ash, gases etc. are not produces. (iii) These plants require lesser space. (iv) Such plants have a unique capacity to meet the peak power demand effectively when they work in combination with hydro power plants and steam power plants. Disadvantages: The various disadvantages of tidal power plants are as follows: (i) The capital cost of a tidal power plant is considerably large as compared to steam power plant and hydro power plant. (ii) The supply of power is not continuous as it depends upon the timing of tides. (iii) Tidal power plants are located away from load centres. This increases power transportation cost.Non conventional Energy: GeothermalGeothermal energy is energy obtained by tapping the heat of the earth itself being a cleanersource of energy. It can be used to produce heat as well as electricity. This type of energy isproduced by radioactive decay from the Earths core. According to the Geothermal EducationOffice, "Steam, heat or hot water from geothermal reservoirs come out of earths surface andprovides the force that spins the turbine generators and produces electricity. The used geothermalwater is then returned down an injection well into the reservoir to be reheated, to maintainpressure, and to sustain the reservoir.There are two main applications of geothermal energy: The first is based on using heat from theearth to create electricity or to provide direct services, such as hot water heating or warming ofgreenhouses. This heat may be derived from geothermal geysers that naturally come all the wayup to the earths surface, or accessing this heat may require drilling down into the earths crust toreach areas that are hot enough to use for energy production. These resources typically are foundfrom a few hundred meters to about 3,000 meters below the earths surface. The secondapplication of geothermal energy is based on using the thermal mass of soil or ground water todrive a heat pump, which can be used for either heating or cooling applications. These are knownas geothermal ground source heat pump applications.What types of geothermal are considered renewable & why?All types of geothermal energy are renewable as long as the rate of heat extraction from the earthdoes not exceed the rate at which the thermal reservoir it depends upon is recharged by theearths heat. For electricity generation, it may take several hundred years for a geothermalreservoir to recharge after it has been fully depleted. District heating systems may take 100-200years to recharge, and for geothermal heat pumps, reservoir recovery may take 30years or so.One can argue that geothermal energy is not truly renewable, because over time the earths corewill cool and the radioactive decay of elements that help keep the earths core warm will
    • decrease. However, because the earth’s geothermal heat reservoirs are immense inmagnitude compared to humanitys rate of use, geothermal energy is effectivelyrenewable. Geothermal power plants that tap the earths heat for energyproduction do have finite lives of typically 30-50 years because, eventually, theplants equipment wears out. However, by re-injecting the water that comes outof a geothermal well back into the system, or by using other water sources, suchas reclaimed waste water, the life of geothermal wells can be extended, andproduction increased.Non conventional Energy: OceanThe ocean can produce two types of energy: thermal energy from the suns heat, and mechanicalenergy from the tides and waves.Oceans cover more than 70% of Earths surface, making them the worlds largest solar collectors.The suns heat warms the surface water a lot more than the deep ocean water, and thistemperature difference creates thermal energy. Just a small portion of the heat trapped in theocean could power the world. Ocean thermal energy is used for many applications, includingelectricity generation. There are three types of electricity conversion systems: closed-cycle,open-cycle, and hybrid. Closed-cycle systems use the oceans warm surface water to vaporize aworking fluid, which has a low-boiling point, such as ammonia. The vapor expands and turns aturbine. The turbine then activates a generator to produce electricity. Open-cycle systemsactually boil the seawater by operating at low pressures. This produces steam that passes througha turbine/generator. And hybrid systems combine both closed-cycle and open-cycle systems.Non conventional Energy: Biomass/BiofuelsBiomass or biofuel is material derived from recently living organisms, recently dead biologicalmaterial or certain fossil fuels. This includes plants, animals and their by-products. For example,manure, garden waste and crop residues are all sources of biomass.Most commonly, biomass refers to plant matter grown for use as bio fuel, but it also includesplant or animal matter used for production of fibers, chemicals or heat. Biomass may alsoinclude biodegradable wastes that can be burnt as fuel. It excludes organic material which hasbeen transformed by geological processes into substances such as coal or petroleum.Biomass is grown from several plants, including miscanthus, switchgrass, hemp, corn, poplar,willow, sugarcane and oil palm (palm oil). The particular plant used is usually not veryimportant to the end products, but it does affect the processing of the raw material. Production ofbiomass is a growing industry as interest in sustainable fuel sourness growing.Although fossil fuels have their origin in ancient biomass, they are not considered biomass by thegene1 ally accepted definition because they contain carbon that has been "out" of the carboncycle for a very long time. Their combustion therefore disturbs the carbon dioxide content in theatmosphere.Plastics from biomass, like some recently developed to dissolve in seawater, are made the sameway as petroleum-based plastics, are actually cheaper to manufacture and meet or exceed mostperformance standards. But they lack the same water resistance or longevity as conventionalplastics.Bio-energy: Bio energy is energy contained in "biomass" such as plant matter and animal waste.These sources can provide energy in the form of electricity, heat, steam, and fuels.Why bio-energy is considered renewable?Biomass is a replenishable resource—it can be replaced fairly quickly withoutpermanently depleting the Earths natural resources. By comparison, fossil fuelssuch as natural gas and coal require millions of years of natural processes to be
    • produced. Therefore, mining coal and natural gas depletes the Earths resourcesfor thousands of generationsSome advantages of this renewable energy are • It is renewable • Sources are commonly available • Sources are locally produced • Uses low-cost waste products • Proven technology • Biogases can be used in high-efficiency combined cycle plants • Reducing greenhouse gases • DIY biomass energy- it can be easyTypes of biofuelLiquid biofuelLiquid biofuel is usually either a bioalcohol such as ethanol fuel or oil such as biodiesel orstraight vegetable oil. Biodiesel can be used in modern diesel vehicles with little or nomodification to the engine. It can be made from waste and virgin vegetable and animal oils andfats (lipids). Virgin vegetable oils can be used in modified diesel engines. In fact the dieselengine was originally designed to run on vegetable oil rather than fossil fuel. A major benefit ofbiodiesel use is the reduction in net CO2 emissions, since all the carbon emitted was recentlycaptured during the growing phase of the biomass. The use of biodiesel also reduces emission ofcarbon monoxide and other pollutants by 20 to 40%.In some areas corn, cornstalks, sugarbeets, sugar cane, and switchgrasses are grown specificallyto produce ethanol (also known as grain alcohol) a liquid which can be used in internalcombustion engines and fuel cells. Ethanol is being phased into the current energy infrastructure.E85 is a fuel composed of 85% ethanol and 15% gasoline that is sold to consumers. Biobutanolis being developed as an alternative to bioethanol.Another source of biofuel is sweet sorghum. It produces both food and fuel from the same crop.Some studies have shown that the crop is net energy positive ie. it produces more energy than isconsumed in its production and utilization.Solid biomassSolid biomass is most commonly used directly as a combustible fuel, producing 10-20 MJ/kg ofheat. Its forms and sources include wood fuel, the biogenic portion of municipal solid waste, orthe unused portion of field crops. Field crops may or may not be grown intentionally as anenergy crop, and the remaining plant byproduct used as a fuel. Most types of biomass containenergy. Even cow manure still contains two-thirds of the original energy consumed by the cow.Energy harvesting via a bioreactor is a cost-effective solution to the waste disposal issues facedby the dairy farmer, and can produce enough biogas to run a farm.With current technology, it is not ideally suited for use as a transportation fuel. Mosttransportation vehicles require power sources with high power density, such as that provided byinternal combustion engines. These engines generally require clean burning fuels, which aregenerally in liquid form, and to a lesser extent, compressed gaseous phase. Liquids are moreportable because they can have a high energy density, and they can be pumped, which makeshandling easier.Non-transportation applications can usually tolerate the low power-density of externalcombustion engines that can run directly on less-expensive solid biomass fuel, for combined heatand power. One type of biomass is wood, which has been used for millennia. Two billion peoplecurrently cook every day, and heat their homes in the winter by burning biomass, which is amajor contributor to man-made climate change global warming. The black soot that is beingcarried from Asia to polar ice caps is causing them to melt faster in the summer. In the 19thcentury, wood-fired steam engines were common, contributing significantly to industrial
    • revolution unhealthy air pollution. Coal is a form of biomass that has been compressed overmillennia to produce a non-renewable, highly-polluting fossil fuel.Wood and its byproducts can now be converted through processes such as gasification intobiofuels such as woodgas, biogas, methanol or ethanol fuel; although further development maybe required to make these methods affordable and practical. Sugar cane residue, wheat chaff,corn cobs and other plant matter can be, and are, burned quite successfully. The net carbondioxide emissions that are added to the atmosphere by this process are only from the fossil fuelthat was consumed to plant, fertilize, harvest and transport the biomass.Processes to harvest biomass from short-rotation trees like poplars and willows and perennialgrasses such as switchgrass, phalaris, and miscanthus, require less frequent cultivation and lessnitrogen than do typical annual crops. Pelletizing miscanthus and burning it to generateelectricity is being studied and may be economically viable.BiogasBiogas can easily be produced from current waste streams, such as paper production, sugarproduction, sewage, animal waste and so forth. These various waste streams have to be slurriedtogether and allowed to naturally ferment, producing methane gas. This can be done byconverting current sewage plants into biogas plants. When a biogas plant has extracted all themethane it can, the remains are sometimes more suitable as fertilizer than the original biomass.Alternatively biogas can be produced via advanced waste processing systems such as mechanicalbiological treatment. These systems recover the recyclable elements of household waste andprocess the biodegradable fraction in anaerobic digesters.Renewable natural gas is a biogas which has been upgraded to a quality similar to natural gas. Byupgrading the quality to that of natural gas, it becomes possible to distribute the gas to the massmarket via the existing gas grid.Processing and usesBiomass which is not simply burned as fuel may be processed in other ways such as corn.Low tech processes include: • composting (to make soil conditioners and fertilizers) • anaerobic digestion (decaying biomass to produce methane gas and sludge as a fertilizer) • fermentation and distillation (both produce ethyl alcohol)More high-tech processes are: • Pyrolysis (heating organic wastes in the absence of air to produce gas and char. Both are combustible.) • Hydrogasification (produces methane and ethane) • Hydrogenation (converts biomass to oil using carbon monoxide and steam under high pressures and temperatures) • Destructive distillation (produces methyl alcohol from high cellulose organic wastes • Acid hydrolysis (treatment of wood wastes to produce sugars, which can be distilled)Sources of biomass energy:Sources of biomass are many. Here are a fewwood soy beans vegetable oilwoodchips grains algaepaper linseed silage
    • trash, animal bagasse waste(slaughtering),corn, maize manure, wheysugar cane hemp rice huskscanola sewage and many moresunflower food scraps wheat strawWe hope that all the conventional sources will become rare, endangered and extinct, as theyproduce lots of carbon dioxide that adds to the greenhouse effect in the atmosphere (uraniumleaves different dangerous byproducts).And we similarly hope that all the non-conventional sources will become conventional, common,and everyday, as they are all free, green and emit no carbon dioxide (well, biomass does, but itprevents the production of methane which is a greenhouse gas 21 times more dangerous thatCO2).
    • ENERGY RESOURCES OF BANGLADESHDifferent types of energy sources have been used and may be used in future in meeting energyneeds of the country are presented below.Coal ReservesIn Bangladesh, the total in-place reserve of coal in three locations (Jamalgonj 1000 million tons,Barapukuria 390 million tons, Khalaspir 450 million tons) is about 1,840 million tons.Extraction 1000 million tons of coal discovered at Jalmalgonj at a depth of 1000 metres was notfound techno-economically feasible. A coal mining project is under implementation to extractBarapukuria coal (in place reserve of 390 million tons). It is expected to produce 1 million ton ofcoal per year from the year 2004 for a period of 64 years. Total extractable coal fromBarapukuria coal mine is 64 million (16.4% of in place reserve).In place reserves of Barapukuria and Khalaspir coal deposits have been reported as 390 milliontons and 685 million tons respectively. Two more coal deposits have been discovered atDigliipara and Phulbari; in place deposits have not been assessed (Karim 2003). By adding inplace coal deposit of Jamalgonj (1000 million tons) with the above two deposits, LoLal coaldeposits in three locations (Jalmalgonj, Barapukuria, Khalaspir) may be computed as 2,075million tons. Karim (2003) further reported that heat equivalent of Barapukuria coal deposit is30.44 TCP of natural gas. It may be mentioned that in heat equivalent term 1 TCF naturalgas=990 Peta Jule and 1 ton of Barapukuria coal=25.6 Giga Joule. Therefore, in heat equivalentterm 1 TCF natural gas is equivalent to 38.67 million tons coal. The heat equivalent ofBarapukuria in place coal deposit of 390 million tons coal is equivalent to 10 TCF of natural gas(390/38.6). Heat equivalent of 64 million extractable coal is equal 1.66 TCF of natural gas. Itwas a gross error to claim (Karim 2003) thai Barapukuria coal deposit is equivalent to 30.44TCF natural gas (1,177 million tons of coal). It is rational to consider only extraetable quantityof coal (64 million tons) for energy planning purpose.Without mentioning the number of discovered coal deposits the total coal deposits of the country(including 390 million tons Barapukuria deposit) has been reported as 2,525 million tons, of thetotal deposits 490 million tons (19.4%) of coal has been reported as extractable. The heatequivalent of extractable coal has been reported as 14 TCFF of natural gas (Hossain 2003). Onthe basis of 1 TCF natural gas equivalent to 38.67 million tons coal, heat equivalent of 490million tons coal is 12.67 TCF natural gas. No explanation has been given how the extractablecoal has been estimated as 490 million tons. As it is not be feasible to extract 1000 million conscoal at Jamalganj, this amount should be deducted from total in place reserves (2,525-1000=1,525 million tons), then cxtractablc factor of Barapukuria coal (0.164) may be used to computethe quantity of extractable coal (1.524x0.164=250 million tons)Peat ReservesThe total peat deposit of the country is 170 million tons. A pilot project was implemented byPetrobangla for commercial extraction of peat at Madaripur. It has not been possible to extractpeat due to techno-economic reasons (possible negative effects on agriculture land).Hydropower Potential
    • The total hydropower potential of the country in three locations (Kaptai, Sangu andMatamuhuri) is 1500 GWh/year {755 MW) (BPDP 1995) of which about 1000 GWh/year (230MW) has been harnessed at Kaptai through 5 units of hydropower plants. BPDP has planned toinstall two additional hydropower units (2x50 MW=100 ,V1W). Further expansion ofhydropower may not be feasible due to socio-political and environmental reasons. Without anyreference an exaggerated potential of hydropower resources of Bangladesh was reported as52.000 MW (Sadler and Sahai 2000). This type baseless news creates confusion among thepolicy planners and decision makers.Crude Oil ReserveOne oil field was discovered at Haripur, Sylhet in 1986 with total deposit of 8.2 million barrels.Production was discontinued in 1994 after extraction of 0.64 million barrels due ro technicalreasons.A news item was published in a national daily that a Texas based geological survey companyreported that in Bangladesh there is crude oil reserve of 2 trillion barrels (The Daily Ittefaq. 9February, 2001). The total oil reserve of the whole world in 1996 was I trillion barrel (Simpson1998). This type of baseless news creates confusion in peoples miles.Natural Gas ReservesTotal number of natural gas fields discovered up to June 2003 is 22. Total proved and probablereserves of natural gas in 22 gas fields were reported by Nagorik Committee (Anon 2002c) as10.82 TCP and 5.8 GCF respectively. Proved reserve is recognized as bankable assets byinternational financing institutions. In Bangladesh the practice of using recoverable. reserve(proved + probable) has been introduced since 1980s. Total recoverable reserves (proven reserve+ probable reserve) of 22 Gas fields estimated by different studies arc shown in Table 2.1.Cumulative consumption of natural gas up to April 2002 was 4.6 TCF. Remaining proved andrecoverable reserves of natural gas it) 22 gas fields of May 2002 is shown in Table. 2.1. Theamount of natural gas consumed in 2000 was 0.331 TCF.Table: Proved and Recoverable Reserve on Natural Gas in 22 Fields Particulars Proved Recoverable Remaining Remaining Reserve Reserve Proved Recoverable Reserve Reserve TCF TCF TCF TCF Annon(2002c) 10.82 6.22 Petrobangla (2001) 15.51 10.91 HCU/NPD <2001) 20.40 15.80 GDRC-1 (Annon 2002a) 16.64 12.04 1 GDRC-2 (Annon 2002a) 20.15 15.55* Remaining Reserves on Mav 2002aGDRC-Gas Demand & Reserve Committee (Annon 2002a)Undiscovered Natural Gas ResourcesUndiscovered natural gas resources of Bangladesh reported by two recent studies(USGS/Petrobangla 2001, NPD/HCU 2001) arc shown in Table 2.2.Table: Undiscovered Gas Resources (In TCF) P95 P90 Mean P50 P10 P05 USGS/Petrobangla 9 32 31 - 66 HCU/NPD 19 42 42 64Undiscovered gas resources arc hypothetical and speculative numbers used only for explorationplanning. These numbers are not comparable with recoverable reserves of considered for
    • commercial decisions (Table 2.1) Recoverable reserve of gas in undiscovered areas is to beascertained and assessed through exploration activities.Beyond accepted norm and standard practice some people add different values of totalrecoverable reserves of gas shown in tabic 2.1 with different values of undiscovered gasresources shown in Table 2.2 and generate different values of total gas reserves/ resources (asshown below).*15.51 TCF (recov. Reserve) + 32.0 TCF (undiscovered resources) = 47.51 TCF*15.51 TCF (recov. Reserve) + 66.0 TCF (undiscovered resources) = 81.51 TCF*20.4 TCF (recov. Reserve) + 42.0 TCF (undiscovered resources) = 62.4 TCF*20.4 TCF (recov. Reserve) + 64.0 TCF (undiscovered resources) = 84.4 TCFThen it is argued that Bangladesh has large reserves of natural gas ranging from 47.5 TCF to84.4 TCF and should consider it for export.Without considering the increase in gas demand in future years sometimes the computed valuesof total gas reserves/resources are divided by the current years use of gas (0.331 TCF in 2000)and then it claimed that existing gas reserve/resources would meet the gas requirement ofBangladesh for many years (example is shown below).*47.51 TCF for 143 years (47.51 TCF/0.331 TCF)*81.51 TCF for 246 years (81.51 TCF/0.331 TCF) *62.41TCF for 188 years (62.41 TCF/0.331 TCF)*84.41 TCF for 255 years (84.4 TCF/0.331 TCF)The motive behind this publicity is to create public opinion in favor of gas export. This type ofpropaganda has created lot of confusion among the concerned people about the reliability of dataon gas reserves and future use of gas.Imported Commercial EnergyEvery year Bangladesh is to spend a substantial amount of foreign currency to import petroleumfuels and coal. During last decade (1990-200) the growth rate of consumption of importedpetroleum fuels was1.1% and the amount consumed in 2000 was 3.23 million tons. Averageyearly consumption of imported coal was 0.5 million ions, mostly used in brick kilns.Indigenous Biomass fuelsBiomass fuels (e.g. wood fuels, agricultural residues, animal dung) available from limited treecovered lands (reserve forests, un-classed state forests, plantation village woodlots), agriculturallands and cattle population are the major sources of energy consumed in the country. Overexploitation of biomass fuels have been contributing in environmental degradation (e.g.deforestation, soil degradation).Animal PowerTotal cattle population of the country in 1989 was estimated as 20.39 million of which 12.33million heads provided draught power required for cultivation. During peak agricultural season,mechanized tillage devices (e.g. tractors, power tillers) consuming petroleum fuels are used tomeet shortage of draught animal power.Prospect of Nuclear PowerSince 1960s government has been tying to establish a nuclear power plant Lit Rooppur. A numberof feasibility .studies have been carried out to achieve the objective; it was not possible toachieve any success. In the present geo-political situation it may not be possible for a developing(Muslim) country like Bangladesh to mobilize necessary funds to establish a nuclear powerplant.
    • Prospect of Solar PowerIn Bangladesh during last twenty years (1980-2000) different type of Solar PV System (e.g.lighting, pumping etc.) installed by different organizations (BAEC: 10 kW, REB: 62.5 kW,Grameen Shakli: 245 kW, Rahim Afroz: 12 kW, LGED:66.3 kW, BRAC: 24.4 kW) were about420 kV= 0.42MW. Total installed solar power was only 0.01% of total installed power plants ofBangladesh (4.000 MW).India is one of the largest market and manufacturers of Solar PV modules in the world. India hasinstalled 58 MW. Total installed solar power was only 0.06% of total installed power plants ofIndia (97.837 MW). Annual production capacity of Solar PV System is 10 MW. India alsoexports solar PV modules. Total, installed Solar PV in the world in 2000 wax about 1.200 MW.Solar electricity is at least 10 limes more costly than electricity form fossil fuels and nuclearpower (The Shell Report 2002). Because of high cost solar power has very limited prospect inmeeting total energy need of Bangladesh.A news item was published during President Bill Clintons visit to Bangladesh in March 2000that the way solar PV technology is progressing, natural gas of Bangladesh may become uselesswithin next 20-25 years (The Banglar Bani. 22 March. 2000, Islam 2001). Subsequently thisobservation was repeated by some political leaders of Bangladesh to argue for the export of gas.There is no prospect of solar PV substituting natural gas within 40-50 years.Prospect of Wind PowerTotal wind power generation in Bangladesh was reported as 50 kW. Ii was 0.00125% of totalinstalled power plants of Bangladesh (4000 MW). Because of high cost there is limited prospectof wind power in meeting total energy need of Bangladesh.Total installed wind power in India was 1.175 MW and it ranked fifth in wind power generationill the world. Total installed wind power plants in the world in 2002 was about 30.000 MWGermany has installed 12,000 MW which was highest in the world.Observations on Energy Resources of BangladeshIt may be observed from the presentation in this section that number of attempts have been madeto distort the energy data of Bangladesh. Some of these attempts are due to ignorance about theenergy data and some are to create public opinion in favor of export o countrys limited reserveof natural gas. Policy planners, decision makers, national energy planners, concerned citizenswill have to be aware about the misinformation and propaganda. Various issues need lo beconsidered in deciding appropriate energy strategies for Bangladesh are presented below.Energy Strategies for Future* No prospect o increasing biomass fuels supply. Share of biomass fuels in total energy will decline. Supply of biomass fuels will have of be maintained within regenerative limits.* Limited prospect of expansion of hydropower.* Limited contribution of indigenous coal [@ 1 million tones per year from 2004. Total 64 million tons (equivalent 1.66 TCF of natural gas) over a period of 64 years. Sudden increase of yearly supply of coal will not be possible to meet increased demand.* Very limited prospect of power generation by new-renewable energy technologies (e.g. solar PV. Wind power).* Efficient use of energy will have lo be given due consideration.* Consumption of oil will increase. Dependence on imported oil will have to be minimized to save foreign exchange. Wherever possible oil will have to substituted by indigenous natural gas (e.g. use of CNG in transport).* Indigenous natural gas in the only reliable source of energy to meet future energy needs.
    • ENERGY OVERVIEW OF BANGLADESHEnergy Resources and ConsumptionThe main energy sources of Bangladesh are biomass and natural gas. Biomass energy sources aretraditionally used for domestic cooking and in small rural industries. Biomass fuels are estimatedto account for about 73% of the countrys primary energy supply. Bangladesh have provednatural gas reserves of 301 billion m that would last for 32 years at the current rate of production.The remainder of energy supply is from oil, mostly imported and limited amount of hydropower.Bangladesh has an installed electric generating capacity of 4005 MW, of which 94 % is thermal,mainly natural - gas - fired (BPDB, 2002).Natural GasNatural gas is today recognized as an important indigenous hydrocarbon resource in Bangladesh.It use as a fuel in Chhatak Cement Factory in 1960 from the Chhatak gas field marked its firstcommercial exploitation. Since then over the years the consumption of natural gas has beenincreasing and it has contributed to the national development significantly.Uses of Natural GasThe uses of Natural gas in Bangladesh can be broadly divided into the following five categories:1. Power: Gas is now the major fuel for power generation in Bangladesh. There are today ninemajor installations where electric power is generated using natural gas as fuel under PDB. Someindependent power producers are also engaged in electric power generation and they have beenoperating some gas fueled power plants. Power sector consumes approximately 45% of the totalgas. 2. Fertilizer: Gas is the feedstock and fuel for production of urea fertilizer andammonia. CUFL and KAFCO is the major fertilizer factory in Bangladesh. Totalseven grass roots urea complexes now in operation have a combined connected demand ofapproximately 35% of the total gas consumed.3. Industrial: The industry sector during the current decade has been consuming8 to 12% of the total gas consumption. Major application areas include: steamgeneration, captive power and process (heating media and heat source/fuel).4. Domestic: The domestic consumers use gas a fuel for cooking mainly. In recentyears some affluent customers have been using gas for stand-by generators andraising hot water.5. Commercial and Seasonal: The commercial sectors accounts for less than 1.5% of total gasconsumption and this has not shown significant growth during current decade. The seasonalusers mainly the brick field, consume a small quantity of gas during the brick manufacturingseason.
    • Biomass"Around 65% of the biomass energy used in Bangladesh is from wood fuels while the rest isfrom agricultural residues (27%) and animal dung (8%). Biomass is mainly utilised for domesticcooking. Traditional stoves in Bangladesh are inefficient and emit significant amount of smoke,which is a health hazard. Agricultural residues such as rice husk, wheat husk, bagasse, corncob,peanut shells, rice and wheat straw, are abundantly available in most part of the country.However, their utilisation of energy production is limited and inefficient due to their uneven andtroublesome characteristics. Many of these undiserable characteristics can be overcome if theresidues are compacted to from briquettes. Regular size and shape of briquettes make them easyto transport, store and utilise.Biomass briquetting technology appears to have been originally developed by localentrepreneurs without any support from the government or donor agencies. Later, BIT and BRRIdeveloped this technology further to suit local conditions. Currently, over 900 briquettingmachines, mainly using rice husk, are operating in the country.Another promising renewable energy technology in Bangladesh is biogas. Biogas obtained byanaerobic fermentation of cow dung and other organic matters can be used for cooking, lightingand other purpose. Bangladesh has a potential to produce 2.97 billion m3 of biogas per yearfrom cattle dug, which is equivalent to 1.52 million tons of kerosene.Renewable EnergyBangladesh is endowed with vast renewable energy resources. Harnessing these resourcesappears to be a promising solution for improving the quality of life of rural villagers, who areunlikely to have access to conventional electricity supply in the foreseeable future.Solar EnergyAll substances, solid, liquids and gases at temperatures above absolute zero emit energy in thefrom of electromagnetic waves. This energy is called radiation. The radiation which is mostimportant to us is that emitted from sun, the earth and the atmosphere lying within the ultraviolet,visible and infrared spectral region.Bangladesh received an average daily solar radiation of 4 - 6.5 kWh/m . Despite large potential,utilization of solar energy has been limited to traditional uses such as crop drying in the opensun. Solar photovoltaic (PV) systems are gaining acceptance for providing electricity to households and small business in rural areas. In 1988 Bangladesh Atomic Energy Center (BAEC)installed several pilot PV systems. The first significant PV- based rural electrification programwas the Narshingdi project installed with financial support from France. Since 1996, penetrationof Solar home systems (SHSs) increased rapidly, mainly due to the efforts of Grameen Sakti,which sells PV systems on credit to rural households through its extensive network. Severalother NGOs such as CMES and BRAC are also engaged in promoting PV technology. PVmodules are generally imported, while there are a few private companies manufacturing PVaccessories.HydropowerThe potential of hydropower is very limited in Bangladesh due to the countrys topography. Atpresent only 230 MW of hydropower is utilised in Karnafuli hydropower station operated byBangladesh Power Development Board (BPDB). BPDB is considering extension of Karnafulihydro station to add another 100 MW capacity. Only a few locations in the southeast andnortheast hilly region can be suitable for mini or micro hydro power plants.WindPreliminary studies indicate that wind energy will be viable in the coastal Bangladesh, offsoreisland, riversides, and some inland open areas. Several years of wind data isessential for actual assessment of wind energy application, a wind monitoringsystem has recently been set up at St. Martins island. Two systematic wind datamonitoring projects were carried out by BCAS and LGED at seven locations andby GTZ and REB at four other locations. Grameen Sakti has installed severalsmall wind turbines (0.3 to 10 kW) on experimental basis.