Environmental Importance of Concentrating on Renewable Energy Sources - Research Paper Example

RENEWABLE ENERGY (Degree for which this dissertation is being submitted) Submitted in part fulfillment of the Date of Submission RENEWABLE ENERGY "The earth lives. It breathes. Ours are among the cells that give it life. Like its other cells, ours take form, grow die and are replaced as part of the earth's life. If it sickens, we will be afflicted, if it dies so too will we" (Shukla, 2005 p- 7). Men made decisions are leading to transformations of the planet earth's environmental impact of such decisions and commitment actions have assumed significance concern to components of environment, including man himself. Conventionally fuel wood, cow dung lignite, hydropower, oil and natural gas and nuclear resources form part of energy sources. These conventional sources provide over 95% of total required energy and are mainly non -renewable except for hydropower, and to some extent nuclear source. Non conventional sources include solar thermal power, biogas wind energy, solar photovoltaic and tidal energy. Most of these sources are cheaper and renewable as compared to conventional sources. However in most of the countries, these sources have not yet been fully developed and commercially exploited. The overall limitations and scarcity of fossils has given rose to the urgent need for developing and exploiting these alternate energy sources. In addition, considering the cost of transportation of energy to far flung and rural areas, local available non-conventional and renewable energy sources become more important for meeting localized rural energy needs. SOURCES OF ENERGY The sources of energy are divided into three categories: Renewable Sources, Non Renewable Sources, and Nuclear Sources. In Nonrenewable sources comes the fossil fuels such as coal, natural gas and petroleum. The renewable energy sources are solar, wind, hydroelectric, biomass, and geothermal power. The nuclear-powered sources are fission and fusion. The advantages of Renewable energy is that they are sustainable energy sources and are replaced by nature after use unlike fossil fuels and petroleum which take millions of years and special conditions for their formation and are in limited supply. Various Forms of Renewable Energy Among renewable energy sources Sunlight, wind, water and biomass are mostly used all over the world. Sunlight can be transformed to electricity using photovoltaic panels. This electricity can be used to drive a multitude of electrical appliances. In addition, light, heat, and ultraviolet composure of sun's energy can also be converted into heat using solar thermal panels. The heat can be used to heat water or air for residential, commercial and industrial use. Electricity is also produced by flowing water and Wind in large scale in man parts of the world. (i) Active solar energy: The sun energy is converted used into usable heat directly to heat water for swimming pools, homes (for cooking food and boiling water) and industry, to provide space heating and to generate electricity. Active solar energy technologies transform sunlight into various other forms of energy by using water or air as energy transfer fluid. To achieve maximum benefit of solar energy in buildings, the following approaches are used. Passive solar energy: Passive solar energy is integrated into constructing energy efficient building and landscape design, e.g. window placement to heat retaining walls. In Passive Solar Architecture maximize solar gains in the building is achieved through good orientation and layout, and glazing. It helps to avoid heat losses through ensuring a high level of insulation and air-tightness of the building; (Rajaram, 2005, p 101-110). Active Solar Heating Active Solar Heating is one of the primary ways for modern architecture buildings to trap solar energy. This renewable technology uses solar energy collectors to transform sunlight into heat to water heating or other purposes. Solar Photovoltaic (PV) Systems 'Photovoltaic' means using light to produce electricity. Photovoltaic systems use daylight or direct sunlight to convert solar radiation into electricity. The rays which shines on the Photovoltaic cells causes' electricity to flow by creating an electric field. The more the intensity of the light, the more will be the flow of electricity (Shukla, 2005 p-1 7). PV systems convert solar energy into electricity by using semiconductor materials. This renewable technology is a cost-effective solution widely used in consumer items such as solar calculators, garden lights and watches. In broader application, Solar Photovoltaic (PV) Systems is used to provide free solar electricity to houses as well as for commercial and industrial applications. (ii) Biomass energy: Biomass is matter usually thought of as garbage. The sun's energy is stored in organic materials such as dead trees, tree branches, yard clippings, left-over crops, wood chips and wood peat. Wood and peat which are both burned to provide heat. Grains are also biomass energy which can be fermented into ethanol and used as a liquid fuel. The waste wood, dead trees, tree branches, yard clippings, left-over crops, wood chips and wood peat and other scraps from factories and farms are gathered together in big trucks to a biomass power plant. The biomass is dumped into huge hoppers which is then it is burned using a furnace. The heat generated is used to boil water in the boiler. The steam energy thus produced I is used to turn turbines and generators (Shukla, 2005 p- 32). The widespread use of Biomass energy brings various environmental benefits. Among them are reducing air and water pollution reducing erosion, and increasing soil quality and improving wildlife environment. (iii) Hydro energy: Hydro energy is taken from water and converted to electricity. Small hydro projects will generate power by using kinetic energy of falling water by directing water to the turbine using pipes. This energy is captured to run a generator. Power can also be generated from the energy of tidal forces or wave power, which uses the energy created by waves The reason to use hydro energy is that it is reliable, cheaper than using other methods to convert energy to electricity. (iv) Wave or tidal energy The movement of waves and tides, particularly in shallow water, can be harnessed and converted to electricity. Wave or tidal energy uses the power of ocean currents, waves, and tides to create energy. Using tidal energy Electricity can be produced from several existing and emerging technologies as they show much promise for future development (v) Wind Energy: Wind power is the conversion of wind energy into useful form and can be harnessed by wind turbines and windmills to generate electricity and for pumping water. Wind energy is plentiful and best form of renewable energy. It is clean, reduces toxic atmospheric and greenhouse gas emissions (vi) Geothermal energy: This is to capture Heat from the earth's core used directly with the help of devices called heat pumps to heat and cool buildings. The steam and hot water produced inside the earth is used to heat buildings or generate electricity. The water is replenished by rainfall and the heat is continuously produced inside the earth (Shukla, 2005 p- 45). Reason for Concentrating On Renewable Energy Everything has a cost and so has environment. The cost of development is environmental degradation. At present, techno rich north is exploiting both the gene-rich south and the environment for their accelerated economic growth. There appears no solution to the environmental degradation as long as development process remains resource intensive. Solution to the problem is utopian. The main concern for consumers to use renewable sourest are global warming, depletion of the earth's available resources (which are irreversible) and cost considerations of energy sources. Global warming is caused when the atmospheric consideration of greenhouse gases like carbon dioxide increases. Excessive burning of fossil fuels like petroleum is the main cause. The industrialization all over the world puts a strain on already limited energy resources and to the ongoing deterioration of the global environment. Although renewable energy sources cannot completely replace existing energy demands, but they can highly supplement power generated by utilities and increase the diversity of our energy supply. Thus, searching for alternative sources of energy is crucial. Benefit to Environment Renewable sources and Global Warming Coal, oil and natural gas increase the amount of carbon dioxide in the atmosphere and the earth's average temperature is raised. According to scientists due to global warming in coming decades: -Sea levels will rise 40 cm higher by 2100 and 50 million people in coastal regions around the world would be displaced by flooding (World Today, June 2007) -On the plain, winter precipitation will decline causing water shortages, shrinking grasslands and triggering a fodder crisis - Warmer ocean temperatures would lead to bleaching and destroy vast tracks of oral reefs. Ocean acidification would lead to shell dissolution, severely impacting marine life and fisheries. -With erratic rainfall and decrease in precipitation levels, forest would delete rapidly (World Today, June 2007) Renewable energy sources will take the burden from fossil-fuelled electricity generation, thereby reducing greenhouse gas emissions. It provides affordable and clean sources of electricity to remote populations in developing countries. Comparison of Energy Produced By a Wind Turbine System to That of a Photovoltaic (PV) Solar System Energy from the Wind: Wind is the reaction of the atmosphere to uneven heating conditions and increases or restrict by local area topography. Wind is indeed a erratic renewable energy source Equipment used for Wind System: Let's take a 1KW power produced by Bergey XL.1 turbine is used, which is mounted on a tower height of approximately 100 feet above the surface of the earth. The height of trees in neighboring area has of approximately 30 feet and thus effective tower height becomes 70 feet above obstructions. The wind speed is around 25.6 mph. A 1,500 ah battery bank is situated at a distance of 300 feet from he base of the tower which is linked with #2 gauge copper buried cable (Puri, 2005 38) The structure itself impedes the flow of the wind, thus Windmills can not operate at 100% efficiency Equipment used for Solar System: Let's take the photovoltaic system with a total power of 750 watts and consists of ten Shell SQ75 modules, which are joined in two parallel strings of five modules in series. For switch the incoming higher voltage to a system voltage of 24 volts n Outback MX-60 charge controller is used. A 1,500 ah battery bank is situated at a distance of 200 feet from he array which is linked with #2 gauge copper buried cable (Puri, 2005 p 41) Equipment Costs Wind Energy System Solar PV Energy System: Turbine $3,210.00 Modules x 10 $6,300.00 Tower $3,100.00 Fixed Rack $1,470.00 Cable $ 705.00 Charge Controller $ 941.00 Cable (200 feet) $ 470.00 Total $7,015.00 Total $9,181.00 [Taken from: Puri, 2005 p 42-43] The true value of both devices can only be made with the Price per Rated Watt. This is the comparison to the price per produced KWh. Comparison 1. Purchase Cost VS Cost per Rated Watts: Wind System: Total cost $7015.00 divided by the factory rating of 1,000 watts equals $7.015 per rated watt. Solar System: Total cost $9181.00 divided by the factory rating of 750 watts equals $9.181 per rated watt. Average system costs = $100 per square foot Average solar panel output = 10 watts per square foot (approx) Average solar energy system costs = $9.18 per watt [Taken from: Puri, 2005 p 49-50] 2. Resource Assessment Wind maps provide a rough indication of wind speed in an area and thus very difficult in calculating the potential energy output of a turbine. Correct information can only be provided using a data logger. Clearly, wind power is a highly variable source and hence energy storage is crucial. For solar energy, Solar isolation maps are available for determining the potential output of a PV array it is essential to calculate the average number of productive sun hours per day an array will collect and called Solar Isolation for the area. The solar energy depends on latitude, climate, and ability to tilt panels towards the sun, seasonality, and temperature. The array should be located for clear from any obstruction and so as to receive maximum exposure to the sun. Solar is far less site specific than wind 3. Service Life and Maintenance Wind turbines constitute of mechanical devices and thus require maintenance throughout their lifetime. Combined On-site Solar and Wind Power Systems Both sources provide clean renewable power. Both of these devices should perform for a number of years so the purchase cost can be minimized over a long term. Combining them provides permits somewhat less on-site power storage need and will have environmental benefits. Conclusion Due to constantly improving performance and cost, and growing acknowledgment of their environmental, economic and social benefits, renewable energy technologies will grow increasingly competitive with traditional energy technologies in years to come. On next 25 years, various forms of renewable energy should be supplying 80% of the world's energy needs. .. References Puri Aroon, (2005) Renewable energy comparison, Today group. New Delhi, p.38-75 Shukla S P, Sharma N & Sabata B C, (2005), Planet Protection, Mittal Publicaions, New Delhi, p-7-55 Rajaram K,( 2005) Global warming, What we can do to save World, Spectrum Publishing, Luknow, p-101-132 World Today: The India Group Journal, World Commission on Environment and Development, Our Common Future, published in June 2007 Read More