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Use of sunlight to solve energy crisis

By Sohel Manzur
Extensive use of sunlight In a tropical region like Bangladesh may bring a revolu tion In resolving the severe crisis of energy, researchers W-
The heats and electricity that can be collected from the solar energy can very well fulfil tire enormous energy require ments of our country.
It was found by the researchers of the Renewable Energy Research Centre (RERC) of Dhaka University
The Centre conducted a survey recently to sort out the prospects of solar energy in our country along with some other unconventional energy resources, which include airflow. biomas waterflow and geo-thermal energy.
The Centre, at present, has concentrated its effort mainly on the solar energy to collect extensive heat and electricity from it by thermal conversion and photovoltaic conversion system respectively.
Its efforts also Include switching over the conversion system to be more feasible for our country by increasing its capacity of energy collection and reducing its instalment coat as well
The concept of photovoltaic conversion, on which the Re newabfe Energy Research Centre Is launching quite a size able number of research stud les in order to provide electricity from solar energy, is the simp Heat one.
Some unit cells become ex clustvely sensitive under sunlight and produce electron flows. Thus the electric currents are produced by transmitting the electron flows.
The electric current produced from the unit cells are DC current, which are converted into AC current by using Inverter.
Thirty three unit cells form a module and a series of modules form a panel Extensive elect ricity can be produces by
a series of parallel panels.
The unit cells are Imported from USA at a cost of 2.5 US dollar which can produce 1.7 ampler electric current. A single module Is empowered with 24 voltage of electricity.
The panel or module can function only under sunlight. But the electricity can be preserved In solar battery or in storage battery for Its later use.
The centre estimated that it will cost only Tk. 23.000 to Install a photovoltaic con ver ston system on a roof of a house containing all sorts of modern electronic machineries including refrigerator, air cooler and others. Moreover It Is guaranteed to function till one hundred years or more.
It is gathered that two Rangpur villages were brought under electric facilities 1n 1989 by using solar energy It was also Implemented tn Swandip upazila and in Shallkupa-tea -garden
Researchers found that If
the photovoltaic panels arc laid over only five per cent land of the desert Sahara, the electricity produced from the panels will be able to fulfil the requirements of ten days of the whole world.
The centre also prepared a number of various heat producing machines/panels by using the thermal conversion system. Those include. Linear Panel Microtype Concentrating Collector, Liquid Flatplate Collector. Chowgram Programme. Solar Water Heater. Solar Cooker. Paraboloid Dishtype Concentrating Collector. Hot-box Solar Cooker. Solar Dryer and Solar Pond
The concept of the system is simple. It containes simply a heat absorber, which can absorb maximum heats from the sunlight and a receiver, where the heats are concentrated for its use
The Unear Mocrotype con centrating Collector can be used In producing distilled
water from the polluted one and sugar or molasses from the Juice of sugarcane and date
Liquid Flatplate CoHector may be used to get germless fresh water for drinking and homestead use. Chowgram programme is another system to produce germless water and the system has already been Implemented on a maternity hospital In Sreepur.
Hot-box solar cooker Is a system which can preserve heats for its use In cooking even after a long spam of time. Solar Pond is another system to preserve heats for its use in any other purpose later. It may be pointed out that Australia and Israel at present collect 90 per cent of their required energy from the solar power.
The primary energy supply in Bangladesh is largely dependent on agricultural residues, wood fuel and dung. The amounts are. 312.4 pico Joul (PJ). 82.1 PJ and 77.3 PJ. respectively out of total 598.2
P J energy supply. Thus the percentage of traditional energy consumption tn Bangladesh Is 86 while the percentage is 48 in India.
The extensive use of wood fuel to affecting our environ mental balance. Besides, the appropriate use of dung and agricultural residues may bring several times more energy, than the present production.
Per capita energy preservation to Bangladesh to one per cent of the per capita energy preservation In the whole world.
fhe centre estimated that the energy supply In Bangladesh will have to be tn creased in 100 or 150 per cent If the Gross National Product (GNP) Is aimed at in creasing tn one per cent more Under this circumstances the concentration on the natural resources of energy like solar energy to no doubt essential for our country, the researchers opined.