RENEABLE ENERGY SOURCES FOR DEVELOPMENT OF BANGLADESH

Transcription

1 RENEABLE ENERGY SOURCES FOR DEVELOPMENT OF BANGLADESH Fazle Rabbi Sabbir Ahmed Hasan Md. Ashiqur Rahman Abstract Energy is one of the main rudiment to ensure socio economic development. The proper utilization of energy should e the prime concern to any development country. Day by day the demand of energy increasing in an alarming rate and assuming that by 2035 energy demand in Bangladesh will be doubled. In rural Bangladesh, energy demand is mostly for household cooking which is almost completely supplied from biomass resources. Bangladesh has good potential for harnessing renewable energy sources such as solar, biomass, wind, tidal, ocean heat etc. Some projects have been already taken by some public and private organizations to develop renewable energies. Renewable Energy Policy has been adopted and plans have been made to implement the policy obtain a fare share of renewable energy at the earliest possible time.it has been proved that development in rural areas can be much benefitted with the proper utilization of our renewable energy sources. However in Bangladesh efficient utilization of renewable energy resources yet to assume roper commercial dimensions. Index Terms Renewable energy, Pyrolysis, Social development, Proper utilization. I. INTRODUCTION Converting energy from one form to another is the most important phenomena in our daily life. For any developing country including Bangladesh uninterrupted electricity supply is our topmost priority. Which can be only possible by proper utilization of energy resources. Energy crisis and environmental degradation are the main problems of mankind now-a-days. As a third world country Bangladesh is facing the problem more. The per capita energy consumption of Bangladeshi people is 227 kg oil equivalent where the standard is 1178 kg oil equivalent[1]. So, we should think about non conventional way to mitigate this difference. In this paper we will mainly focused on available renewable energy sources and their uses in Bangladesh. II. ENERGY: Energy is the key factor for human development. The standard of living and quality of life extensively depends on energy use in industry, transportation, residential, commercial and agricultural. The world primary energy share about 85%. The world reserve to production ratio of primary energy is very low. The rate of energy consumption increasing significantly day by day. The world will not be able to sustain so longer based on current reserves of primary energy. Under such circumstance, the world community needs to search new sources of energy which is sustainable and be able to meet the demand. III. POTENTIALITY OF RENEWABLE RESOURCES: Pyrolysis: Agricultural waste is one of the members of biomass, which is an attractive renewable energy resource because it is widely dispersed and could contribute zero net carbon dioxide emission to the atmosphere [2]. Biomass can be used as raw material for pyrolysis to generate liquid, gaseous, and solid fuels. Pyrolysis conversion technology for biomass has been investigated over the last three decades and is used commercially [3]. Pyrolysis produces gas, vapour that can be collected as liquid and solid char. The yields of each of these products depend on process conditions [4]. Solid char has a good gross calorific value (GCV) of MJ/kg [5] and may be used to provide heat for pyrolysis process itself.

2 Fig. 1. A possible pathway of pyrolysis of organic solid waste A statistic shows that about 90,000 metric tons tires become scrap and are disposed of every year in Bangladesh[6]. If we able to make proper use of two third of this amount, more than 25,000 metric tons of liquid fuel can be obtained. This fuel can be used as Bio-diesel. Agricultural waste is one of the members of biomass, which is an attractive renewable energy resource because it is widely dispersed and could contribute zero net carbon dioxide emission to the atmosphere. Biomass can be used as raw material for pyrolysis to generate liquid, gaseous, and solid fuel. Every year more than 30 million metric tons agricultural bi product such as rice straw, jute stick and bagasse are produced. These bi products contains sufficient amount of volatile material. Below Table 1 shows the percentage of different particles of solid waste. Solid Waste TABLE I. Different particles of solid waste. Moisture Ash Volatile content content matter %wt %wt %wt Fixed carbon %wt Rice starw Jute stick Bagasse So these products can be used as pyrolysis feed. Every year Bangladesh govt. spends 3000 billion taka for importing crude oil. If we able to use 10 percent bio diesel, huge amount of money will be saved. A good number of organizations and departments are doing research, development, demonstration, diffusion and commercialization of solar energy technology. Diffusion aspects of the solar energy technologies are using mostly in Bangladesh specially solar Photovoltaic (PV) systems, solar cooker, solar oven, solar water heater and solar dryer. Solar energy technology in Bangladesh: Solar PV System: Rural electrification Board (REB), Atomic Energy Commission (AEC), Local Government Engineering Department (LGED), and Grameen Shakti (GS) have installed (are in the process of installation of ) a number of solar PV systems in different parts of the country. Solar Cookers: Institute of fuel Research and Development (IFRD) of BCSIR and Centre for mass Education in Science (CMES) are engaged in the development and dissemination of solar cookers. A low cost reflector type cooker developed by IFRD is a spun-aluminium parabolic reflector. It is light weight (2-3 Kgs), cheap and simple to construct, but the disadvantages are that it needs manual sun tracking frequently and the reflectivity deteriorates rather rapidly and cooking is interrupted by cloudy and hazy conditions. On a bright sunny day a 42 inch aperture spun aluminium cooker takes about three hours for cooking three items (rice, fish or meat, pulses) for a family of 5-6 members in Bangladesh. Solar Oven and Dryer: Different models of solar ovens have been designed and constructed with locally available raw materials. The institute of Food Science and Technology (IFST) has developed a cabinet dryer for drying fruits, vegetables etc. by simply spreading a transparent cover over a box. These dryers are made of bamboo and polythene sheet. Solar Water Heater: This heater is designed and constructed by IFRD. It consists of coated flat plate which absorbs solar Output radiation, convert into heat and transfers the resulting heat to circulating water. This type of heater is useful for supplying low grade thermal energy at temperatures below 90 0C. Ocean thermal energy conversion (OTEC): Ocean thermal energy conversion (OTEC) uses the temperature difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity. OTEC is a base load electricity generation system, i.e. 24hrs/day all year long. However, the temperature differential is small and this impacts the economic feasibility of ocean thermal energy for electricity generation. Solar energy: Solar energy is one of the oldest renewable sources in the world. This energy is taken from the sun in the form of solar radiation. Solar energy is radiant light and heat from the sun harnessed using a range of ever-evolving technologies such as solar heating, solar photovoltaics, solar thermal electricity, solar architecture and artificial photosynthesis.

3 Fig. 2. Ocean thermal energy conversion system We have Bay of Bengal. This bay is huge solar collector. So, this solar energy can be converted into electricity by taking some actions. The average depth of bay of bangle is about 2.6 km[7]. Ocean thermal energy makes use of the difference in temperatures of warm surface water (22 27 C) and very cold water at a depth of 1 km (4 7 C). So, this ocean thermal energy conservation can be implemented easily. Geothermal energy: Geothermal energy is also a huge source of energy. it is contained in the heated rocks and fluid that fills the fractures and pores within the earth's crust. It originates from radioactive decay deep within the Earth and can exist as hot water, steam, or hot dry rocks. Some special area of Bangladesh such as sylhet, thakurgaon, rajshahi, have geothermal energy resource. So we can use this geothermal energy for producing electricity. It is evident from the BHT that the geothermal temperature is sufficiently high, 100 to 180 o C, to generate electricity at depth from 3 to 4.5 km when the geothermal water is taken to the surface through drill holes. Fig. 3. Geothermal map of Bamgladesh Hydropower: Water is about 800 times denser than air and therefore even a small stream of water can produce a reasonable amount of energy. Water energy can be in many different forms such as hydroelectric energy, micro hydro, hydro power without dams, and ocean energy. Today there are many hydroelectric power stations in the world and together they are providing about 20% electricity across the globe. Bangladesh has a long coastal area (710 km) with 2~8 m tidal height/head rise and fall [8]. It also has some large tidal sites and many channels of low tidal range in a large number of deltaic islands, where barrages and sluice gates already exist. Therefore, the potential for tidal power to be harnessed is significant, because the barrages necessary for creating controlled flow through turbines (to tap tidal power) are also needed for flood control. This avoids the problem of high capital cost as the engineering is either already there or is needed for cyclone protection. Analysis of the following table [9] indicates that Bangladesh has very good prospects for tidal energy, particularly in Sandwip. The island of Sandwip is located in the Bay of Bengal, adjacent to Chittagong and is a mere 15 km from the mainland. The entire island is 50 kilometers long and 5-15 kilometers wide The population is around (as of 2009) on an area of 357 km2. The entire island is a mudflat created from the Ganges delta. The 5 m tides experienced at Sandwip results in poor accessibility, with the island constantly surrounded by mud flats, except during high tides.

4 Wave power plants: Wave power plants can set up in coastal areas of our country like cox Bazar, St. martin etc. These types of plats can produce electricity 24 hour depending on the speed of wave. Facilities- It is more useful than wind turbines. In Bangladesh wind turbines produce electricity in mainly winter seasons. So wind plants almost shut down for 6 months per year. But in wave power plants we can use it all the time of a year. Set up: It doesn t depend on tower height. It can produce.04 to 2 MW power TABLE II. Velocity in Bangladesh Month C(m/s) V mean (m/s) January February March April May June July August Wind turbines can be set in different heights and also the diameter of the rotor can be different. For different height and rotor the output will also vary. A variation is given belox in Fig. 5. Fig. 4. Wave power plant Wind Energy: The wind resource is one of the potential energy. sources specially for the coastal and off-shore islands of Bangladesh, most of them having no access to electricity or gas supply system. However, application of wind energy technologies needs a systematic and proper assessment so far been the major obstacle towards wind energy projects. The average speed of air of costal area of Bangladesh is given in table 1. In recent years GOB has taken interest to assess the potential of wind energy in the south-eastern coastal areas of the country. It appears from one of the studies that, wind pumps can be commercially used for irrigation by replacing the existing diesel pumps. It may further enhance the future extension of shrimp hatcheries and shrimp processing units in those areas, where fishery is the main occupation of the local community. Fig. 5. power for different rotors IV. BARRIERS FOR SUSTAINABILITY OF ALTERNATIVE ENERGY TECHNOLOGIES Some of the main barriers for sustainability of alternative energy technology is given below: 1. High initial cost 2. Dependence on the weather 3. lack of awareness 4. Lack of established high-volume supplier-dealer chains. 5. High prices of the components. 6. Lack of fund. Under the circumstances sustainability depends on the correct design of the instalment payment mechanism that takes into consideration recipients cash constraints and the upper limit of the amortization period.

5 V. CONCLUSION In respect to recent forecasts of world energy consumption and global climate change, it is suggested that developing countries such as Bangladesh are particularly vulnerable. This is primarily due to their location in the middle of a growth and sustainability nexus. Where the need to foster large growth rates in energy supply just to meet basic human needs is only too obvious. It is therefore maintained that developing countries, such as Bangladesh, are best served by attempting to identify strategies for the sustainable development of its energy service provision. In this regard, it has been attempted to identify the specific contexts at play within the energy sector of Bangladesh, using this as a basis to formulate policy interventions to address the issue of energy supply and energy sustainability. These strategies for policy reform within the energy sector are then to be trailed through the implementation of specific pilot projects, in order to evaluate their validity. The primary energy needs of rural Bangladesh can be sustainability met with locally available renewable resources. Small community based energy enterprises, with financial assistance from GOB or local NGO s or international development agencies can be established as community based micro power company which will provide energy for: (a) household cooking with biogas generated from the anaerobic digestion of dung and agricultural residues and (b) household lighting electricity produced from low power DC batteries, charged in local PV based battery charging stations run on commercial basis. However, in its full context, energy cannot be viewed as an isolated entity, but rather in contexts of energy and life-style, energy and the environment, energy and technology, energy and poverty, energy and geopolitics. The issue of energy and development must be placed in a holistic context where energy, and energy sustainability, must be addressed as one component of a broader transition towards economic, social, political and environmental sustainability of a country REFERENCES [1] M.H. Ullah, T. Haque, M.M. Hasib, "Current Status of Renewable Energy Sector in Bangladesh and a Proposed Grid Connected Hybrid Renewable Energy System", International Journal of Advanced Renewable Energy Research- Vol. 1, Issue. 11, pp , 2012 [2] A. Demirbas, Effects of temperature and particle size on biochar yield from pyrolysis of agricultural residues, Journal of Analytical and Applied Pyrolysis, vol. 72, no. [3] A. V. Bridgwater, A. J. Toft, and J. G. Brammer, A technoeconomic comparison of power production by biomass fast pyrolysis with gasification and combustion, Renewable and Sustainable Energy Reviews, vol. 6, no. 3, pp , [4] A. V. Bridgewater and G. Grassi, Biomass Pyrolysis Liquids Upgrading and Utilization, Elsevier, Oxford, UK, [5] S. H. Jung, B. S. Kang, and J. S. Kim, Production of biooilfrom rice straw and bamboo sawdust under Reaction conditions in a fast pyrolysis plant equipped with a fluidized bed and char separation system, Journal of Analytical and Applied Pyrolysis, vol. 82, no. 2, pp. 240, [6] Bangladesh Bureau of Statistics, Government of Peoples Republic of Bangladesh. Statistical Year Book of Bangladesh th ed.; Dhaka, [7] Das, S.C., Adhunik samudra Bughan (In Bangla). Bangla Academy. 396pp. [8] HM Treasury and DETR press release (2000) Protecting the Environment and Supporting Britain's Road Transport, UK Parliament, 7th March 2001 [9] Ltd.,(Nova Scotia)IEEE Standard , Recommended practices and requirements for harmonic control in electrical power systems, The Institute of Electrical and Electronics Engineers, (Standards and Reports)