Delta Plan 2100
Green energy resources in coast belts
�The Delta Plan 2100' emphasises to develop a long-term renewable energy policy, as well as to formulate a master plan for 50-100 years to harness the potentiality of renewable energy involving public and private sectors. The best utilization of resources in ocean (called the "blue economy) in relation with renewable resource exploitation could be emphasized for the development of Bangladesh.
The effect of climate change is much pronounced in coastal areas. Natural disasters, cyclones, salinity intrusion and climate change are great challenges. However, 'Dalta Plan 2100' emphasises to reduce environmental risks and to promote ocean based 'green energy' resources.
'Green energy' comes from natural sources such as sunlight, wind, rain, tides, plants biomass, algae, geothermal heat and hydro projects etc. These energy resources are renewable, meaning they're naturally replenished. They are called green energy as they are produced from renewable sources and produce very less impact on environment. By using more green energy sources, we could reduce coal and oil import.
Most of the coastal regions of Bangladesh is less developed, but have a good renewable energy potential. In this context, one of these sources is ocean energy. Most ocean energy technologies fall under two categories: thermal energy from the sun's heat and energy from the air, tides and waves. However, enhancing green growth through development of renewable technologies, as well as building capacity for its application could be emphasized.
The government targeted that at least 30 per cent of total energy should come from renewable sources by 2041. Intensive research could be started in all science and technology universities on developing 'solar panel, hydro power and wind power' etc. 'The Delta Plan 2100' should give us a guide line- how to best use of renewable technologies and how to reduce environmental risks for sustainable development.
In the Bay of Bengal wind, wave and tidal range and currents offer a significant potential to 'renewable energy'. Researchers are developing new technologies that can extract energy from ocean currents and convert it into usable power. The waves, tides and currents are not the same--those potential energy could be used by nearby communities and recreational users.
Tides are caused by gravitational forces from the moon and sun--can be captured. It must be connected with a turbine inside a protected tidal barrage (as like river dam) to capture the energy from the power of tides. Tidal energy is created by difference in head between high and low tides. With the receding tide through large turbine generator, this energy is then converted into mechanical energy. We could start strategic research on 'tidal range technologies'.
The characteristics of waves are determined by the strength of the wind, its duration. The stronger the winds are- the bigger the wave- used for more electricity generation. A machine that exploits wave power for electricity generation is a 'wave energy converter'. 'Wave- power generation' is not a widely employed, but research could be conducted.
Water is a most common element on earth- hydrogen is a part of water (H2O). Water contains two-thirds of hydrogen. When hydrogen is separated from water, enables hydrogen to act as a fuel for generating electricity. Hydrogen fuel is a zero emission fuel- when burned with oxygen. It can be used in fuel electro-chemical cells or in engines to power a vehicle. It may be treated as renewable energy, as it does not have any adverse effect on environment.
A wind turbine is a machine that converts the wind's kinetic energy into electrical energy in sea side areas. Wind mills achieved its most prominence in Europe. Wind power is a renewable alternative to 'burning fossil fuels'. One constraint is that its capacity is lower- when there is low wind flow. Delta Plan 2100 has proposed for best use of wind mill in Bangladesh conditions.
Entire deltaic coastal zones have much more wind flow. However, suitable locations could be identified for 'wind mill parks' to be connected with main transmission grid. For expending the use of wind mills - it is proposed to build a 'wind mill industry'. In a wind turbine, a rotor is connected to the main shaft, which spins a generator to create electricity. Research could be conducted to increase efficiency of wind mill through modifying 'rotating wheels'.
'Solar thermal power' is widely used in a sunniest country like Bangladesh. It is an enormous promising devise- which generates electricity from a solar panel. Installation of solar panels in coastal embankments and other fallow lands has much scope. It could be used in mechanical dredgers, boats, ships, homes, offices and industries- could be used widely in surface and ground water irrigation.
'Solar or photovoltaic cells' could convert sun light directly into electricity by the photovoltaic effect. The majority of solar panels are made of 'crystalline silicon wafers' -when the sun shines on wafers, electrons start to move- this flow of electrons is an electrical current. Very pure silicon is needed for high efficiency. To build our own "Crystalline Silicon Solar Cells" intensive research is needed.
'Geothermal energy' originates from heated rocks and fluid that fills the fractures within the earth's crust. The energy within the earth can stay as hot water or hot dry rocks. By using drill-holes, hot water is soaked- steam is then help to move turbine to generate electricity. Bangladesh has many abandoned gas wells having temperature more than 100�C. Below the seabed, gas can be located at 10 kilometres depths, where temperatures can be 150 degrees Celsius.
'Geothermal plant' is clean, sustainable and environment friendly- does not need fuel. The first geothermal power plant of Bangladesh has been planned to set up in Thakurgaon. Geothermal energy is one of the most promising renewable energy sources. It could play an important role to minimize power crisis of Bangladesh. More emphasis could be given on geothermal exploration.
'Plant-e Company' in the Netherlands- developed a new system for 'energy harvesting' from water lodged paddy field. The technology harnesses excess organic matter produced by the rice plants during photosynthesis, which is expelled through the rice plant's roots and consumed by micro-organisms in the field. 'Microbial fuel cells' or micro-organisms make free electrons, that electrons could be harvested by placing carbon electrodes in roots zone of paddy field to generate electricity.
The system generates electricity from water-logged paddy fields having advantage over wind or solar system, that works at night and when there's no wind. These are just the beginning- we must have to start collaborative research to generate electricity from organic wastes and to identify rice paddy field microbial species.
'The Delta Plan 2100' has proposed a holistic approach to fulfil at least 30 per cent of the energy from renewable sources by 2041. To fulfil this target, basic and applied research on 'all sectors of green energy resources' could be conducted. Different green energy resources based large investment and research friendly environments could be built up emphasizing innovation, research facilities development and international cooperation.
Designing our own "research plan"--involving talented scientists/engineers will provide higher outputs in renewable energy sector of Bangladesh.
The writer is chief scientific officer, Bangladesh Rice Research Institute, Gazipur