Table of Contents
- I Executive Summary
- II Introduction
- III Need for Renewable Energy Supply
- IV Consideration of Article
- V Other Options
- 1 Solar
- 2 Geothermal
- 3 Biofuels
- 4 Hydro-electric Power
- 5 Tidal or Wave Power
- VI Recommendations to Government
- VII Conclusion
- VIII References
- IX Appendix
I Executive Summary
Since ancient times, early man had utilised renewable sources of energy such as animal dung and wood to provide his energy needs. The onset of industrialisation saw the emergence of the importance of coal as man’s major supplier of his energy needs. This is replaced by petroleum, which has become the mainstay of industry and civilisation in the 20th century. But the realisation that oil has generated international conflict, caused damage to the environment and that its global reserves are fast depleting has caused nations to fast-track the development of renewable energy measures that promote the expansion of sustainable energy sources that are cleaner and as efficient as well. To do this, it is imperative that nations must enact and implement an energy policy that is workable and doable.
Since time immemorial, ancient man had made use of animal dung and wood to provide his energy needs but the discovery that peat found in swamps provided better energy supply caused a transition of preference to coal in all its forms i.e. peat, lignite, bituminous, anthracite and coke. Coal mining was practiced throughout Europe by 13th century although it had been known in China and the Roman Empire as early as 1 AD (Kranzberg & Pursell 1967,p.83). The Industrial Revolution created an even keener demand for it although petroleum in the form of liquid gas and natural gas took over as the mode of preference because it is more abundant, cleaner and cheaper than coal. Petroleum eventually became the mainstay of industry and civilisation in the 20th century. After the first oil well was drilled in Pennsylvania, USA in 1859 (Jenkins 1986,p.345), the petroleum industry has rapidly grown that in 2006, it now comprises 2 60% of the world’s energy consumption with oil having 37% and natural gas 23%. Coal meanwhile supplies about 27% of the world’s energy. The rest is provided by nuclear energy, where 439 nuclear plants in operation by 2007 provide about 6% of the world’s energy needs and the so-called renewable energy sources with 7% (US Energy Information Administration,2008).
III Need for Renewable Energy Supply
While coal, petroleum and nuclear energy have provided the world with its energy needs yet they simultaneously cause catastrophic perils to the world which some doomsayers opine might bring humanity to the brink of extinction. First, it had been proven that there is an alarming depletion of the earth’s ozone layer resulting to a yawning hole over Antarctica. Then, it had been noticed that the earth is getting warmer and in fact has warmed by “0.76 degC on average and the rate of warming has further increased” (IPCC WGI Report,2007) resulting to the thawing of glaciers, the rising of sea levels, emergence of freaky weather conditions that result to drought and famine, floods, landslides, forest fires, desertification and deaths of animals, plants and people (Suplee 1998,pp.38-58). Pinpointed as the culprit is man’s total addiction and dependence on fossil fuels i.e. coal and petroleum which has caused the emission to the atmosphere of toxic pollutants such as mercury, lead, arsenic, nitrous oxide and especially of the “greenhouse gases” mainly CO2 which result to global warming or climate change. These fossil fuels are also fast depleting and if they do deplete, the world will be faced with a crippling energy crisis. World coal reserves are estimated to be at around 607 gigatonnes but at the present rate of burning, these coal deposits would be depleted at around 133 more years. World oil reserves, 65% of which are in the Middle East, meanwhile are estimated at about 165 3 gigatonnes and expected to be depleted for 41.6 years while natural gas has known reserves of 162 gigatonnes and expected to deplete in 60.3 years (WCI, 2007 and UN & UNCTAD 2009,p.12). However, oil discoveries especially in the Athabasca tar sands of Alberta, Canada will change this figure. 696 billion barrels of very heavy crude oil have been known to be trapped in these sands which measure 150 miles long and 75 miles wide (Snook 2008,p.148). These estimates are even more alarming considering the fact that North America, Europe and Asia are inextricably dependent on petroleum and consume more oil than they produce. In the 1990’s USA produced only 7 million barrels a day but consumed 19.5 million barrels a day, forcing it to import 11.8 million barrels of petroleum per day (Wright 2001,p.493). When the time of depletion comes, life in those areas of the world will be at a stand-still as people will be freezing in the dark.
The world economies are also wracked by the swelling global prices of these fossil fuels. 2007 and 2008 particularly saw the prices of oil madly and relentlessly rising. The spot price of a barrel of Brent stayed at an average of $72.54 per barrel (pb) for the first months but rose steeply to $96.68 pb in November and closed the year with prices that were 60% more as compared with the start of the year. By 2008, prices hit the $100 pb mark and increased some more to over $145 pb in July and the prices were unstoppable thereafter (UN, UNCTAD 2009,p.11).
While struggling with surging oil global prices, the world has to contend with enmities and conflicts generated by petroleum. Petroleum had also been used as weapon to achieve political ends. With oil politics rearing its ugly head, international relations have become drastically affected. During the Yom Kippur War in 1973, OPEC jolted the world by raising oil prices, an inevitable outcome of its cutting oil production by about 20%. Together with its declaration of 4 an oil embargo against USA, this production cutback was done to pressure the USA and its allies who were supporting Israel against Egypt and Syria (Carafano & Weitz 2008,p.119). In fact, oil price manipulation by OPEC for political reasons has strained the economies of many oil-importing nations, caused severe inflation and caused fuel shortages. Worse, petroleum and its production caused Iraq to invade Kuwait in August 1990 claiming that Kuwait had been siphoning oil that rightfully belonged to Iraq and had been flouting its oil production quotas (Europa Regional Surveys 2004,p.456). It has also been a known fact that petroleum money has been used to support Arab nations in their wars against non-Arab states.
Nuclear energy cannot be relied upon as an alternative because nuclear plants pose danger as exemplified by nuclear plant disasters in Chernobyl and elsewhere. Disposal of hazardous nuclear wastes has not been resolved although there is a move to use Thorium instead of Uranium as nuclear fuel that may mitigate the problem of waste disposal on the basis that the Thorium fuel cycle is more proliferation-resistant. However, this has been believed to be not commercially feasible (Metz & IPCC 2007,p.271). Also feared as not commercially feasible because of the high costs involved in the technology is the step to produce pollution-free, environment-friendly coal through technologies involving carbon capture such as pressurised fluidised bed combustion, selective catalytic reducer and integrated gasification combined cycle (Committee on Science, Engineering & Public Policy 1992,p.336-8).
It is imperative that the world must avoid serious economic damage as well as catastrophic disasters caused by the use of fossil fuels and nuclear power. Mankind must take the right actions right now by improving energy efficiency, by using less fossil fuels and by harnessing 5 and heavily investing in clean, alternative energy sources. The latter can only be renewable energy sources that contribute no carbon emissions and thus promote a “green” environment and are cheaper, cleaner and available abundantly to humanity. These are solar, wind, geothermal, hydro-electric power, tidal or wave energies and biofuels.
IV Consideration of Article
All evidences point to the fact that the world is on the brink of extinction and that humanity’s overdependence on fossil fuels is the culprit of man’s impending self-annihilation.
Climate change is a real threat not to mention possible catastrophic wars as petroleum money is being used to buttress and fortify certain nations in their strife against their enemies. We also must not forget that many oil-importing nations are becoming economically strangled by rising global prices of fuel and other petroleum products. The only solution to these ponderous problems is to develop, explore and utilise clean and renewable sources of energy for sustainable development. A clear energy policy that pushes for a shift in the energy mix towards cleaner, cheaper and safer energy sources, particularly geothermal, hydropower, solar, wind and biofuels is the only way out to achieve energy security, to avert an impending world oil crisis and a catastrophic disaster due to global warming. In other words, to save the world, nations must focus their efforts on renewable energy development.
V Other Options
1 Solar Energy
It is a reality that the sun is the powerhouse of the earth and that solar power impinging on earth is enough to satisfy the energy needs of the world. Although only 50% of solar 6 radiation makes it through the earth’s surface, 30% of which is reflected by the atmosphere while 20% is absorbed, yet this radiation is equivalent to the output of about 170 million of the world’s largest power stations (Taylor 2005,p.36) and is “about 10,000 times the world’s current annual energy consumption” (Ahmed & Anderson 1994,p.31). The problem is how to harness this solar power to the fullest and make it available to everybody but its potential to take the place of fossil fuels as man’s primary source of energy is always there waiting to be availed of to the full.
The earliest technology to harness solar power was used by the Greeks who in 400 BC concentrated the sun’s rays to effectuate the kindling of fires by allowing the sun’s rays to pass through glass spheres filled with water. The Chinese and the Greeks then in 200 BC made use of curved mirrors to focus the sun’s rays (World Book, Inc. 1994,p.579). Henceforth, humanity discovered the principle that solar power can be generated by concentrating and reflecting the sun’s rays through mirrors or lenses. The reflected sunlight heats up any object and its container and the produced energy may be converted to “useful heat, to electricity, or used to create fuel” (Cassedy 2000,p.19).
Engineers have devised technologies to capture and collect solar radiation and store it to serve humanity’s needs. The first involves a parabolic-trough system wherein solar energy is focused into a receiver pipe. The second makes use of a central-receiver system wherein sun-tracking mirrors called heliostats reflect solar energy into a receiver-heat exchanger situated on top of a tower and the third utilises a parabolic-dish system wherein tracking dish reflector concentrates sunlight into a receiver-engine or a receiver-heat exchanger mounted at a focal point of the dish” (Johansson & Burnham 1993,p.214). These technologies have opened the floodgates of several uses of solar energy as well as various trends in the use of solar power. 7
Today, solar energy is being used for domestic water heating. Flat collecting panels are mounted on top of the roof and cold water is pumped through the panels where it absorbs solar radiation. Heated water is thus generated to supply hot water for the homes or to warm the water in swimming pools. There are now more than half a million of such system installed in USA alone since 1970 (Cassedy 2000,p.20). It is even more acceptable in Israel and Japan. In Israel, the government requires all new homes to install this system (Cassedy 2000,p.26). Gaining wide acceptability are also solar active space heating and cooling systems for solar-heated or cooled homes. The latest trend is a combination of both where a right-hand valve is manipulated to switch from summer active solar cooling to winter space heating systems. Here flat plate collectors are mounted in the rooftops of homes and commercial buildings. “For winter’s heat, the valve is set to let the hot water flow through the heating coil while the valve set for summer cooling allows flow through the absorption air conditioning unit” (Cassedy 2000,p.28). The problems for the first two systems are cost of technologies, intermittency and efficiency of storage systems. Contrapuntal to this is the concept of passive solar designed homes or buildings where the architecture for windows, walls and floors is designed so that these are enabled to collect, store and distribute solar energy in the form of heat in winter while rejecting solar heat in summer. One such trend is to design shutters made from heat-insulating material which when closed at night will allow much of the heat that entered during the day to be retained (Crosbie & Steven Winters Associates 1998,pp.12-28).
Another useful trend is the use of series of solar cells made of semiconductor silicon or gallium arsenide which utilise the photovoltaic effect of solar radiation to turn light into an electrical voltage. Thus, we now have solar calculators and watches, solar batteries, solar-powered communication satellites, aircraft (like the Solar Challenger that crossed the English 8 Channel in 1981 with sunlight as its only source of power), solar public telephone booths, solar automobile (like the Sunraycer that won the World Solar Challenge in 1987), and solar homes.
These solar cells provide a bright future for humanity as they have the potential to provide electricity to homes thus the potential to replace the role of petroleum. These have advantages of reliability and safety. Because solar cells depend not on heat but on light, they are not combustible and flammable like petroleum and the solar energy can be stored in batteries so that electrical supply generated can be available at any time of the day. It is very reliable because when installed, they can be left running unsupervised for years. Thus we hear of unmanned lighthouses in UK powered or unattended weather stations powered by solar cells. The most ambitious project involving power cells is the 40 Solar Power Satellites equipped with huge arrays of solar cells to be put in orbit around the earth that have the potential to solve the world’s energy needs. Conceptualised by Dr. Peter Glaser, the resulting electricity will be converted into microwaves and beamed down to receiving stations on earth where they will be reconverted into electricity. It is expected that 40 of such satellites can provide Europe with a quarter of its electricity requirements by 2040. Of course, the costs of installing such power stations in space are prohibitive (O’Leary 1982,pp.39-48). The major drawback of such solar cell technology is that “this labor intensive production process leaves the modules too costly- maybe 4 to 6 dollars per peak watt- to compete with cheap fossil fuels”. But then it has advantages of having “no fuel to burn, few parts to fix, little supervision required” (Ashley 1989,p.118). It’s hope lies in finding ways to make inexpensive materials that lower the costs yet still work efficiently.
Last but not the least solar radiation has been used to generate electricity using the solar-thermal steam or industrial process heat technology. Because this provides thermal energy with 9 temperatures from 80-250degC, then its use is ideal mainly for industrial uses where it has potential to displace fossil fuels as source of energy. The fact that it has so far failed to do so can be traced to drawbacks such as its high investment costs, it’s being considered as unconventional and not a long-term proven technology, a lack of suitable planning guidelines and tools and only a few professionals have the expertise on this. That it can be a successful undertaking was proven when a clothing factory in Shenandoah, Georgia using this technology which utilized 114 parabolic dishes and an energy storage system was able to generate 400kW of electricity and 401kW steam as well as 401 kW chilled water to provide 50% of the industry’s electrical, heating and air conditioning requirements (Stine & Harrigan 2008,p.1). The future holds bright prospects for this technology if engineers be able to devise much improved flat plate collectors that mitigate thermal losses, more highly concentrating collectors that provide more efficiency and better heat storage systems (ESTIF 2009,pp.5-6). At the moment scientists are trying to develop 7 of this kind using the Fresnel principle and parabolic mirrors.
2 Wind Energy
Early Persians found that wind energy can convert their grain into flour. As early as the 7th century, Persians invented and constructed windmills where millstones are attached at the lower end of the shaft and the wind energy generated move these millstones to grind the grain into flour (Encyclopedia Americana 1989,p.355). Wind energy must thus rightly be considered the oldest form of renewable energy. Since ancient times too, agrarian communities in Crete erected hundreds of sail-rotor windmills to pump water for crops and livestock ( Riley & McLaughlin 2001,p.115). After windmills were introduced in England in the latter half of the 12th century (Town & Country Planning Association 1955,p.100), windmills became a popular 10 source of energy in Europe as they are used to hoist sacks of grain, pump water from wells and used to irrigate agricultural lands.
Then the ingenious Dutch thought of using windmills to drain water from their low-lying land. The Dutch devised a system whereby a windmill drives a device resembling a waterwheel which scoops up water from below. To reclaim land from the sea, the Dutch bundled several turbines for driving one or several well pumps. This is called high volume wind pumping. But with the advent of coal and petroleum fired industries, wind energy use fell into disuse and became virtually extinct by the middle of the 20th century. But problems of climate change and the energy crisis of the 1970’s resurrected the use of wind energy as this causes no air or water pollution. Besides being clean, it uses no fuel, is reliable when the site is forever windy and is relatively safe.
Today, wind generators are devised to produce electricity. “The modern wind turbine consists of a set of ‘impellers’, much like aircraft propellers, which drive the shaft of an electric generator” (Cassedy 2000,p.113). It is designed on the aerodynamic principle of lift. Latest trends of wind power include the erection of a windmill showcasing a Darrieus vertical axis wind turbine which allows no adjustment when wind changes power and direction, the use of many medium-sized machines instead of a few large ones such as the ones used in the California wind farms and the use of three-bladed machine which blades are heavier and more rigid such as those of the Danish Vesta and Nordtank machines which have captured 50% of the world market. Unlike the others, wind energy machines are not costly. In fact, by the early 1990’s wind turbines had a unit capacity cost of $1,000/kW which is comparable to that of conventional electric plants (Cassedy 2000,p.120). And the cost of wind generation continues to spiral down 11 largely because of incentive schemes for renewable energy utilities as enacted by the National Energy Policy Act of 1992 and state tax credits. In 1997, wind generation cost had gone below $0.05/kW/hr (Cassedy 2000,p.120).
Wind energy however, has its limitations. Essential is a good wind area with high wind velocity and wind-power densities. When the wind stops, the machines also stop. Another drawback is that wind turbines may be subject to mechanical fatigue failures specifically fatigue failure of blades which are subject to twists and flexing stresses in ever recurring wind gusts. However, quality and design of blades had been improved and continue to be improved in the future as scientists are looking for lighter and stronger materials of blades and the perfect rotor diameter which would bring the least stress and fatigue to the machine (Cassedy 2000,p.115).
3 Geothermal Energy
Since time immemorial both Iceland and the North Island of New Zealand took advantage of their volcanic lands which feature so many geysers and hot springs. Both used the steam from these to heat their homes and offices and to provide them with electricity for domestic and industrial uses. These natural concentrations of hot water seem inexhaustible, are clean and sustainable, does not emit carbon dioxide or any of the greenhouse gases, need no fuel, do not take much land space unlike most renewable energy sources i.e. only 400sq. meters, very safe because it does not involve combustion and once the geothermal power station is constructed, the energy is almost free.
The experiences of both countries show that the earth’s internal temperature can provide a useful source of energy and with the energy crisis and climate change problems, such geothermal 12 energy can be tapped to replace the role of fossilised fuels. In volcanic areas, molten rock with temperatures above 250 degC can be just meters below the earth’s crust and it heats the deep-lying circulating water to produce steam and through diffusion and convection, the steam and hot water are spurted above the earth’s surface to produce geysers and hot springs. It is possible too to drill holes in the ground at depths of up to 3000 meters, pump down cold water into the hot upper mantle of the earth forcing steam to be ejected out. When this is done, the ejected water is purified at the wellhead and used to drive turbines to drive electric generators or turbo-generators or passed through a heat exchanger to provide hot water to warm homes and commercial buildings. Purification of hot water is a necessity in order to avoid the turbine blades of being “furred up” and destroyed.
The first geothermal power station that generated electric power was first developed in Tuscany, Italy in 1904. Almost a century after, the world’s largest geothermal power complex in northern California called The Geysers was established. The Geysers “produces more power than any other geothermal field in the world” (National Research Council 1996,p.26). The Geysers “has produced over 150,000 gigawatt-hours of electricity and is expected to produce at least as much more power during its operating life” (Berger 1998,p.220). The Geysers is a powerful testament to the reality that geothermal energy when exploited to the full can supply the world with its needed energy needs. It’s known reserves if fully exploited are forecasted to generate 12 billion tonnes of oil-equivalent energy within the next 10 to 20 years (Johansson & Burnham 1993,p.549). In USA alone, capacity of all US geothermal power plants in 1990 totaled some 2800 megawatts. USA also has a potential to generate 23,000 megawatts a year for 13 30 years. Other foreign countries meanwhile are forecasted to add geothermal capacity of 4000 to 6000 megawatts at a cost of $10-15 billion for the next 20 years (Berger 1998,p.231). With the use of binary geothermal technology, USA is confident that it can produce at least 40,000 megawatts of geothermal electricity at a cost of 4.5-6.5 cents per kilowatt hour. There is so much hope for geothermal energy because it has been proven that “worldwide hot dry rock geothermal resources are enormous, at more than 10 million quads” (Berger 1998,p.235). A new technique has been developed to tap these resources. In New Mexico, scientists have drilled into hot, dry rock beneath a quiescent volcanic system and have injected surface water which did return as superheated steam. This is called LASL hot-dry rock technique and when applied elsewhere geothermal energy might end up as the fuel of the future (Meyers 1987,p.192).
In response to overall efforts of countries to adhere to the Kyoto Protocol on greenhouse gas emissions and also because of the energy crisis, many countries have decided to reduce the share of oil and coal in these countries’ energy mix. One step to guarantee energy security without raising the volume of carbon emissions is resorting to biofuels as source of energy. Biofuels and biomass together comprise bio-energy. Biofuels, a discovery of Sir Darius Savory refers to liquid fuels derived from plant materials, the latter of which may be corn, sugarcane, soy, palm and other vegetable oils and an inedible but oil-laden nut called jatropha. Surprisingly, biofuels had been used as fuels as early as 18th century when Nikolaus August Otto invented a combustion engine fueled by ethanol and Rudolf Diesel powered diesel engines using peanut oil (Tickell 2006,p.66). The advent of petroleum relegated these inventions to the back seat. But with problems involving fossil fuels, biofuel use is speedily resurrected. 14
The European Union has recently proposed that 10% of all fuel used in transport should come from biofuels by 2020 (EurActiv.com). It is thus expected that the emerging global market for biofuels may be worth billions of dollar a year. More investments in biofuel have been pouring in and in 2007 alone, the world biofuel production capacity has reached more than $4 billion. In 2008, biofuels comprised 1.8% of the world’s transport fuel. The most common forms of biofuels are bioethanol, which is a product from fermentation of sugar and starch crops mainly used in Brazil and USA as substitute for gasoline as vehicle fuel or as gasoline additive to increase octane and improve vehicle emissions. The latest trend is to make use of ordinary grasses and tree leaves in lieu of sugar; biodiesel, which is a product of the transesterification of palm oil and other vegetable oils, animal fats and recycled greases mainly preferred in Europe also as replacement for gasoline as vehicle fuel and as diesel additive to mitigate the levels of carbon monoxide and other undesirable byproducts in diesel-powered vehicles; green diesel or renewable diesel, which is a product of the fractional distillation of tallow, jatropha seeds, canola, algae and salicornia with uses similar to biodiesel; and biogas, which is product of the anaerobic digestion of organic biodegradable waste materials or crops fed into an anaerobic digesters used in UK as biofuel and fertilizer (Soetaert & Vandamme 2009,pp.2-7).
There is no doubt that biofuels have the potential to reduce dependence on fossil fuels as sources of energy for domestic and industrial uses. But biofuels usage has been under attack from some sectors who claim that biofuels are environmentally worse than oil and coal because reforestation is engendered when carbon-rich tropical forests are razed to make the sugarcane, corn and other crop fields thus causing vast greenhouse gas emission increases. Biofuels also preclude the food versus fuel dilemma. The UN has estimated that 25 million hectares once 15
devoted to food suddenly have been converted to fuel crops resulting to increase of food prices by as much as 75% since 2005. Other problems include impacts on water resources, specifically effects on water quality and quantity, soil erosion, sedimentation and infiltration into groundwater from increased fertilizer application (Bernan 2008,pp.63-64).
The latest trends in biofuel production that address the aforesaid issues include the use of ordinary grasses and tree leaves in lieu of sugar. Because these cellulosic materials have minimal food value, it is less costly to produce. Another trend is adaptation of technology. Technologies that involve simultaneous fermentation and saccharification of cellulosic crops into ethanol have succeeded to lower the cost of ethanol from $0.95 per liter 10 years ago to only $0.28 per liter today and the selling price of methanol from $0.27 to less than $0.25. There are efforts to further hone these technologies that would in the future bring down the cost of ethanol and methanol to the level of gasoline i.e. $0.21 per liter or $25 per barrel (Johansson & Burnham 1993,p.865).
Included within the concept of biofuels is the latest technology that has caught the attention of the world i.e. the burning of rubbish or waste materials in incinerators to generate electricity. A good example of this technology is the one used in London, UK where 1,300 tons of garbage is incinerated each day and the energy generated is sold as electricity. A 395 million pound incinerator plant in Deptford is in construction stage and this “will handle 400,000 tonnes of municipal waste a year” and the energy product has been contracted for sale to London Electricity (Gandy 1994,p.67). Previous to this, UK has also pioneered the production of biogas energy from landfill putrescent materials. Technology has been discovered to systematically extract gas as fuel source in landfill sites. This is in line with UK’s determination “to raise the proportion of electricity generated from non-fossil sources to 24% by year 2025” (Gandy 1994,p.66).
5 Hydro-Electric Power
Hydro-electric power, which is the generation of electricity by using the force of falling water to turn turbines and thus drive a generator is next to fossil fuels, the world’s most important and relied upon source of power. It now accounts for 20% of the world’s electricity. It has built in advantages of having a fuel i.e. water, which is free and inexhaustible, safe, cheap, reliable and dependable, non-polluting to the atmosphere and is definitely a “long-lasting solution to the world’s energy problems” (Gonzalez & Sherer 2004,p.384). It is also the world’s oldest source of power being used more than 2000 years ago as river-driven water wheels and reached its apogee during the Industrial Revolution (Smith 1975,pp.103,138). Instead of clumsy water wheels, today’s hydro-electric plants make use of hydraulic turbines that convert the potential energy of an elevated water supply stored in a dam or flowing stream into mechanical energy. When such dammed water is released, its pressure or kinetic energy is converted to rotational kinetic energy when the water hits the water turbines’ rotating shaft located at the foot of the dam. The shaft then drives the electric generator coupled to it, which then transforms mechanical energy to electrical energy. Transmission facilities then convey the electricity to the market terminal and finally to the end users. The three most common types of turbines used in hydroelectric power stations are a Pelton wheel, Kaplan turbine and Francis turbine (Johansson & Burnham 1993,p.74). The Pelton wheel has buckets about its edge, into which jets of water are aimed and thus turning the wheel. The Kaplan wheel looks like a giant propeller immersed in water while a Francis wheel showcases spiral vanes from where water enters. This technology 17 has been considered a reliable one and has been proven over time. It is also safe because the fuel is water and because the process can be stopped when problems arise. It is also totally controlled by the power station engineers. However, dams may pose problems as they may cause inundation of lands and displacement of wildlife habitat as well as possible ecological damage, as was the case in the Hydro-Quebec projects in northern Canada where the Cree natives were not only displaced but their primary food resources were poisoned by mercury (Gonzalez & Sherer 2004,p.384).
It has been estimated that if all hydroelectric power sources in the world are used, 2.25 billion KW could be generated. Today, only 675,000 megawatts of electricity has been produced by hydroelectric plants all over the world, an energy equivalent to 3.6 billion barrels of oil and this comprises only 19% of world electricity with China being the main contributor with 4,279 trillion BTUs followed by Canada, Brazil and the USA. There are also 80,000 dams in USA alone but sadly only 2,400 of these are used for electricity generation (Stringer 2006,p.24). Thus, there is still so much potential as untapped hydro resources are still abundant in Latin America, Central Africa, Brazil and USA (USGS, usgs.gov). In fact, it has been estimated that the world’s economic hydroelectric potential is in the range of 6,000 to 10,000 terawatt-hours or TWh, of which only about 2,000 TWh has been developed so far. Tapping this undeveloped potential mainly in Russia and the developing nations means a bright future for hydroelectric power (Johansson & Burnham 1993,p.77). China has made moves to tap its huge reservoir of hydroelectric power by building a dam across the Yangtze River, the Three Gorges Dam.
Construction of the dam is the costliest part in hydroelectric power generation although maintenance and operation costs are relatively low. But today’s dams have a finite economic life 18 ranging from 50 to 100 years while the dams’ mechanical and electrical components may last for only 60 years. Thus, there must be a costly refurbishing, upgrading and retrofitting to provide continued safety, efficiency and reliability which may cost as much as $ 212 million (Johansson & Burnham 1993, pp.83-84). To avoid such refurbishing and its costs, there is a technological trend to construct roller compacted concrete or RCC dams instead of the conventional immersion-vibrated concrete gravity dam. RCC dams use a “large portion of Pozzolan-rich cement and is compacted with conventional earth-moving equipment”. The speed of their construction “contributes to cost savings on the order of 66% compared to ordinary cement”. Another trend is the use of geosynthetic materials such as polyamide, geotextiles and propylene to fortify the dam and make it leak-free. Another innovation is the use of inflatable weirs for regulation of water level and for elevation of the dam’s crest.
6 Tidal or Wave Power
Related to hydroelectric power is tidal or wave power. Both are designed to generate electricity and both take advantage of potential energy trapped in water. There are places where the rivers are too mellifluous that they become unsuitable for hydroelectric power usage, thus the power of tides and waves of the sea is harnessed. However, usually the power generated is relatively minimal compared to power generated by a hydroelectric power plant. Huge ocean waves, however, have the potential to generate massive amounts of energy but then such are difficult to harness in a cheap and efficient way. Yet, scientists are finding means to actuate its vast potentials. In one experimental scheme, floats called ‘nodding ducks’ are set in place and when waves pass by, these bob up and down, absorb wave energy and the movement operates a pump which impels water through a turbine that then turns a generator and eventually generates 19 electricity. The latest invention is the ‘Salter’s Duck’ by Stephen Salter which showcases a‘nodding duck’ with edges that are responsible for almost total absorption of wave energy. Upon absorption of the wave energy, there is produced a back and forth turning motion about the duck’s submerged ankle pushing dozens of pistons in and out resulting to conversion by the double acting dynamo of this movement to electricity.
Another experiment on wave power has been attempted in Scotland in the Islay Isle. It tries to utilise the oscillating water column principle. Here, a submerged chamber with an open bottom and containing columns of water with air above it is exposed to ocean waves. When waves pass through it, the water column bobs up and down, thus driving the air in and out of an attached turbine which is likewise linked to an electricity generator. The experiment attempts to generate 180,000 watts of electricity. Similar to this is the Mighty Whale stationed off the coast of Japan. It is not submerged however, and the waves press on the side of the wave device (Stringer 2006,p.26).
Yet another experiment off the coast of Scotland involves a raft converter called the Pelamis. It looks like four railway carriages connected to each other flexibly, each carriage rising and falling with the waves and the energy absorbed is converted to electricity by 3 power conversion modules. Each of these modules has produced 250 kilowatts of electricity, enough to provide electricity needs to 500 homes (Stringer 2006,p.27).
As to tidal power, there are minimal attempts to set up tidal power stations mainly because the power generated hardly justifies the costs of construction of the infrastructure. Thus, besides France, there are “only very modest stations built in Russia, Canada and China”. In fact, in the world’s only major tidal power station which is in the estuary of Rance River in France, 20 the energy output is 500,000 kilowatts at its maximum while the cost of the construction is $100 million. Despite the “capital intensive aspect of the undertaking and the high cost of the delivered kilowatt”, the Rance station is doing very well, has caused minor environmental impacts and has proved its reliability, safety and energy dependability to the populace in the region (Charlier & Finkl 2009,p.108). The station relies on the rising and falling of tides which energy is captured by turbines set in the barrage (Charlier & Finkl 2009,p.105). There is still so much hope for this kind of energy because of attempts to improve its technology. Other than the float method and the rotating paddle wheel method, there is devised a more sophisticated method which consists of compression by incoming tide of air contained in a conduit of metal or concrete. The compressed air can be called upon at any time and the system thus frees the plant from the constraints of the lunar cycle” (Charlier & Finkl 2009,p.105).
7 Recommendations to Government
In view of the energy crisis, UK’s dependence on foreign oil and the compelling energy security as well as the demands to address climate change problems, UK must make strategic moves to resort to renewable sources of energy. The first step therefore is to make an energy policy that is contained in legislations that would favour unhampered harnessing of such energies. The main legislation with energy policy could be entitled as Renewable Energy Bill or Renewable and Alternative Energy Act or even as Magna Carta For Renewable and Alternative Energy. Other specific legislations could be Biofuels Act, Solar Energy Act, Geothermal Energy Act etc. The aims of such renewable energy bill should be: to set the right policy environment and programs and decisive policy actions for the development, exploration and use of clean and renewable sources of energy for sustainable development; to search for cost-effective policies 21 and current and emerging technologies that can facilitate and make viable any industrial development of such renewable energy resources; to facilitate the massive uptake of renewable energy in the country by promoting the expansion of sustainable energy sources and by setting time-bound renewable energy targets; to establish a fund to finance research and development, promotion and utilization of renewable energy resources which fund shall be administered by the Department of Energy as a special account in any government financial institution; and lastly to grant fiscal and non-fiscal incentives to developers or individuals engaged in the production of renewable energy sources as well as to consumers involved in the promotion , commercialisation and utilisation of renewable energy resources to accelerate its development. Without a good incentive scheme, developers and consumers are not likely to buy the renewable energy concept. Under this Renewable Energy Bill, developers, manufacturers, fabricators and suppliers of locally produced renewable energy equipment will be afforded tax and duty-free importation of components, parts and materials, tax credit on domestic capital components and income tax holiday and exemption. Giving tax breaks and incentives to producers will encourage participation of the private sector in renewable energy activities. Moreover, it is imperative that there be established a government agency with the responsibility to assist, advise, protect, educate the developers and producers of renewable energy resources and to assist them through financing, training and technology transfer and business incubation as well as to identify the ideal energy mix between the traditional fossil fuels and the renewable energy resources and determine how to reduce the share of oil and coal in that energy mix.
Today, fossil fuels i.e. oil, natural gas and coal supply supply 87% of the world’s energy needs while nuclear energy supplies 6% and renewable energy sources only 7%. There is also a 22 total dependence and addiction by industrialised nations to these fossil fuels as they consume or burn with harmful emissions so much of these fuels than they could produce. But it had been proven that these fossil fuels cause climate change which may signal the annihilation of the human race in the near future. These fossil fuels also cause an alarming energy crisis with these finite fossil fuels nearing its depletion period not to mention that their prices are spiraling up to perilous proportions. Petroleum or its production is also used in the so called oil politics where money generated by petroleum sales are used to drive a wedge between Arab states and their non-Arab states which may even result to a dangerous world war involving weapons of mass destruction and thus signal the end of the human race. But all is not lost because the world is blessed with inexhaustible, free, non-polluting and clean, safe, relatively cheaper to process and reliable renewable sources of energy which is God’s gift to humanity but which mankind has not tapped to the fullest. To avert world disaster, it is imperative that these renewable sources of energy i.e. solar, wind, geothermal, biofuels, hydroelectric and tidal or wave power must be explored, developed and utilised to the full and the soonest the better. For UK and other industrialised nations, it is also imperative that legislations such as a Renewable Energy Act which contain the country’s renewable energy policy and which provide incentive schemes to developers and consumers involved in the promotion, commercialisation and utilisation of renewable energy resources be instituted to accelerate their development. If the aims are fulfilled, there will be hope for humanity. 23
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1.When the subject matter of biofuels is discussed, biomass is also included because biomass is the general topic which includes in its ambit the subject matter of biofuels.
- There are other renewable energy sources but because they have no capacity to address the problems presently bedeviling the world, it is prudent not to include their discussion. These include burning of wood, animal dung, and garbage refuse which happen to be included under the heading biomass.
- To answer the complaint that biofuels cause a food versus fuel dilemma i.e., hectarages of land devoted to food production have been converted for fuel crop planting, some analysts have come up with a solution. They suggest that fuel crop planting should only be done in idle lands and hillsides and other lands growing grasses and other ‘non-productive’ vegetation.
- A QUAD is a unit of energy that is an abbreviation of quadrillion and is defined as 10 raised to the power of 15 British thermal units.
- BTU means British thermal unit.
- Transesterification is a chemical process of exchanging the organic group R” of an ester with the organic group R of an alcohol. It is the main reaction for converting oil to biodiesel.
- A terawatt is a unit of power equal to one trillion watts.
- Saccharification is a process of breaking a complex carbohydrate such as starch or cellulose into its monosaccharide components.