THE government has fixed a target to generate 10 per cent of total electricity from renewable energy by 2020. It is exploring all possible options for increasing power generation. Use of renewable energy will have to be increased to meet huge shortage of power and for the sake of sustainable development. The sustainable development is one of the greatest challenges today the country is facing.
Bangladesh is now poised to depend on renewable energy sources — solar, wind, biomass and biogas — amid growing concerns over a steady decline of non-renewable resources such as fossil fuel, which has prompted many countries to seek alternative sources of energy to meet the future needs. It is anticipated that the renewable energy will take a vital role in future for off-grid electrification in the country.
The country is now reeling under acute energy crisis with the electricity generation hovering around 3,800 megawatt (mw) against the demand for over 6,000 mw. Renewable energy sources contribute less than 1.0 per cent of the total electricity generation. But the government has targeted to augment contribution of the renewable energy sources to 5.0 per cent by 2015 to generate around 450 mw from renewable sources. By installing wind turbines, the government has planned to generate at least 200 mw of electricity by 2013. It has targeted to generate around 100 mw of electricity from solar power projects by 2013 next.
The country’s electricity demand has been growing by 7.50 per cent annually since 1990. Around 40 per cent of its population has access to electricity — one of the lowest in the world, according to the power division statistics.
The main renewable energy resources in Bangladesh are biomass, solar, wind and hydropower. The hydropower potential of Bangladesh is low due to the relative flatness of the country. Wind power generation in Bangladesh has certain limitations due to the lack of reliable wind speed data and the remarkable seasonal variation of wind speed. The country has good prospects of utilizing solar photovoltaic (PV) systems for electricity generation, but the high capital investment cost is a big barrier for adopting such systems. Biomass is the major energy source in Bangladesh and its utilisation systems represent a proven environment-friendly option for small- to medium-scale decentralised electricity generation.
Biomass resources are potentially the country’s largest renewable energy source — annual terrestrial biomass amounting thousands of dry tonnes. Biomass conversion to fuel and chemicals is an important alternative to replace oil and coal. The challenge is to develop a process of technology which can cope with our needs and ability. Biomass gasification process has already developed and the system consists of an auxiliary set-up coupled with a prime mover. The auxiliary attachment includes a gasifier coupled with cooling system at the bottom or side end and with a series of filters to absorb moisture along with unwanted/unburnt part/ash before the flue gas reaching the generation system. Hopper is used above the gasifier to insert fuel to the gasifier where fuel is fired through a chimney. A rotating cutter is used at the bottom of the gasifier to pulverise the fuel into fine particles.
Since the annual production of biomass is set to be of significant amount, this energy can be produced and used in an environmentally suitable manner while mitigating net CO2 emission. There can be little doubt that the potential source of stored energy should be carefully considered for future energy need. Small units of biomass power generation system can be installed in every village to meet its demand or a part of its demand so that pressure on the national grid will be low. In this regard, one point should be kept in mind that the auxiliary attachment of biomass for generator is cheap and Indian attachments can be easily used and they are exporting the system all over the world. Per unit electricity production rate will also be less than that of a diesel generator.
As of now, the country is dependent on non-renewable resources such as petroleum and natural gas to meet ever-growing energy needs. The contribution of renewable sources to power generation remains negligible. In Bangladesh, efficient utilisation of renewable energy resources is yet to assume commercial dimensions and hence rational policy dissemination on renewable energy usage is essential. To increase their contribution, the government had earlier taken steps to finance installation of the Solar Home System (SHS) in the off-grid rural areas under a project named ‘Rural Electrification and Renewable Energy Development Project’, financed by global lending agencies.
With a view to encouraging renewable energy, the government had prepared a policy, which recommended establishment of an institution named Sustainable Energy Development Agency (SEDA). SEDA is scheduled to support establishment of small and medium renewable energy enterprises and providers, create market opportunity and start-up business models, the draft says. To encourage private sector investment, the policy favoured providing appropriate subsidy for installation of solar, wind and biomass utilities.
Contribution of biomass in total primary energy consumption of Bangladesh is around 60 per cent. The major sources of traditional biomass are agricultural residues, wood and wood wastes, and animal dung, and their shares in energy supply are approximately 45 per cent, 35 per cent and 20 per cent, respectively. Industrial and commercial use of biomass accounts for 14 per cent of total energy consumption. 63 per cent of energy required in the industrial sector comes from biomass fuel. Natural gas, Liquefied petroleum gas (LPG), electricity, kerosene and biomass fuels are used for cooking. In areas without natural gas and electricity, biomass is used to meet the household cooking needs.
Agricultural crops generate large quantities of residues. Such residues represent an important source of energy both for domestic as well as industrial purposes. Other sources of biomass in the country are farm-animal waste and poultry droppings produced by the national herds, fuel wood from existing forests, tree residues and saw dust from the forestry industry. Considering that the consumption of biomass for non-energy purposes is negligible, the annual available biomass energy potential for electricity generation in Bangladesh is in the range of between 216 and 250 TWh.
According to Infrastructure Development Company Limited (IDCOL), a government agency, Bangladesh has 215,000 poultry farms and 15,000 cattle farms. By establishing biogas plants in these farms, electricity could be generated. So far 35,000 biogas plants have been established across the country and these plants are producing gas, which is being used for cooking purposes in the rural areas. As such, there is a huge possibility to produce electricity using biogas in Bangladesh, if proper research is carried out by research agencies, professionals and the implementing authority, i.e., the government.
