Green future for Bangladesh through solar power generation
Dr Masud Hasan Chowdhury
In the face of tremendous social, economic and political pressure to solve power crisis in Bangladesh it has become critically important to look for energy solutions beyond the conventional sources like domestic natural gas, coals, hydroelectricity and imported fuels. The rapid depletion of natural oil and gas reserves due to the excessive consumption is leading to severe global competition and political tensions among the powerful nations to control the remaining fossil fuel reserves. Western countries have been using fossil fuels at a much larger volume than the rest of the world since World War II. Unprecedented increase of energy consumption by rapidly developing nations like China, India and Brazil is adding tremendous pressure on the demand and supply of petroleum. Extreme competition and volatility of fuel price in the global energy market is continuously hammering small players like Bangladesh. Discounted petroleum supply from friendly countries, reliance on domestic natural gas, and subsidised fuel supply to the public and private sectors are no longer politically and economically viable options for us. Global warming and the subsequent increase of the sea level and natural calamities due to excessive carbon emission from fossil fuels are causing severe environmental and ecological havoc for low-lying countries like us. The most feasible way out of this multi-dimensional crisis is to increase our reliance on renewable energy like solar power.
Feasibility of Solar Power in Bangladesh
From the comparative analysis of the current and projected cost of electricity from conventional and renewable sources it is clear that solar power is the most expensive. Due to other compelling reasons beyond the immediate cost of production Germany, China and other developed nations are promoting and subsidizing solar power to supply more than 20 per cent of their total power usage. The question is why? Nuclear power is politically very sensitive and its technology is very difficult to obtain. By far it is the most risky in terms of damage it can cause in time of man-made or natural disasters. Recent nuclear disaster in the aftermath of earthquake and tsunami in Japan and past experience like Chernobyl accident are forcing the developed countries to reevaluate the reliability and safety of electricity generation using nuclear technology. Coal and gas reserves are continuously depleting, and these are not environmentally friendly due to the resulting green house effect. Hydropower is very good, but few countries have sufficient and suitable inland water bodies to install hydroelectric plants. Limited availability of organic waste and vegetation restricts the widespread use of biomass energy. A variety of promising technologies have been proposed to capture the tremendous amount of thermal energy and the wave motion energy of ocean water. However, the technologies and the designs are still undergoing demonstration testing at the research and development stage. Fluids drawn from the deep earth for geothermal plants carry a mixture of gases, notably carbon dioxide (CO2), hydrogen sulfide (H2S), methane (CH4) and ammonia (NH3). These pollutants contribute to global warming, acid rain, and noxious smells if released. Wind power seems to be the most viable and least expensive renewable source of energy, but still wind power is not widely recommended for countries like Bangladesh due to lack necessary wind profile. A number of researchers, organizations and Bangladesh Power Development Board (BPDB) performed series of studies to generate wind profile data in Bangladesh. It has been reported that the wind speed in Chittagong, Cox’s Bazar, Kuakata, Moheshkhali, Feni and Noakhali coastal regions are greater than 6.5 m/s. During day times (8 a.m. to 7 p.m.) wind speeds are about 30 to 40 per cent higher than the average values. These wind speeds in the coastal regions are suitable for both water pumping and electricity generation. However, inland wind plants would not be viable because of the low wind speed and variable wind profile in areas far away from the coast.
The technical feasibility of solar power in Bangladesh depends on availability of technology and sunlight profile across the country. Our public and private sectors are currently in good financial position to gather necessary expertise and technology to build commercial scale and rooftop solar plants. We just need appropriate policy undertaking.
Let us look at the sunlight profile issue in Bangladesh. Our climatic conditions and the geographical position are very favourable for solar power. Unfortunately, no formal study has been done to report accurate data on sunlight profile throughout the year in Bangladesh. For a reasonable estimate we can take sunlight data of our neighbouring states of India as the basis. National Renewable Energy Laboratory (NREL) of India reports that with about 300 clear and sunny days in a year, India’s theoretical solar power reception, on only its land area, is about five Petawatt-hours per year (PWh/yr) (i.e. 5 trillion kWh/yr). The daily average solar energy incident over Indian land varies from 4 to 7 kWh/m2 with about 1500–2000 sunshine hours per year (depending upon location), which is far more than current total energy consumption. For example, assuming only 10 per cent efficiency of solar plants, this would still be a thousand times greater than the domestic electricity demand projected for India in 2015. According to the study conducted by NREL of India, the daily direct normal solar index is around 4.5kWh/m2 in the states of West Bengal, Assam, Meghalaya and Tripura, which are the areas surrounding Bangladesh with almost identical climatic conditions and geographical location. We can reasonably predict that the average available incident solar power in Bangladesh will be close to 4.5kWh/m2, and with 15 per cent efficiency of currently available commercial solar plants we can produce 0.67kWh of electricity from a solar panel of one square meter size. If we select a 100m by 100m land, and keep 33 per cent of the area for supporting structure, equipments and connections to the solar panels we can install solar panels of total 6700 square meter on that land, which will give us 10MWh of electricity. This is a very good number compared to commercially operating solar plants in different countries. Based on the above discussion we can propose that for Bangladesh small and medium size solar power plants distributed all over the country would be a very promising solution.
High cost factors of solar electricity and favourable conditions of Bangladesh
Fuel is the most expensive item for any conventional power generation plant. The fuel of a solar plant is the sunlight, which is the primary source of energy for our ecosystem and all the living beings on earth. However, only plants and micro-organisms can harvest solar energy directly into their body, while all the animals are the secondary or tertiary consumers that collect solar energy from the plants and other animals. As human race continued its progression towards a better life by inventing new technologies, they have also learned various ways to directly harvest solar energy. One example is the production of electricity from sunlight, which is freely available and will never be exhausted as long as the earth survives. One might think why solar power is still so expensive while the fuel is free. To understand this we have to explore the underlying technology and its limitations. There are two technological options to generate electricity from sunlight. In solar thermal energy (STE) technology large concentrators are used to gather sunlight to heat water, and the resulting steam can be used to drive turbine for electricity production. In photovoltaic (PV) technology, a semiconductor device, known as solar cell, is used to directly convert sunlight into electricity. By far the PV technology is the dominant choice for solar plants.
The basic building block of PV technology is the solar ‘cell’ — the device that converts sunlight to electricity. Many cells may be wired together to produce a PV ‘module’ – the smallest PV component sold commercially. Often sets of four or more smaller modules are framed or attached together by struts in what is called a ‘panel’. The factors that influence the cost and performance of a solar cell or panel are as follows: – 1) intensity of light incident on the cell surface – higher intensity light carries more energy, 2) light absorption capacity of the cell material – more light absorption means more electricity, 3) how much of the absorbed light can actually be converted to electricity by the cell material, 4) how much of the generated electricity can actually be collected and sent outside the cell, and 5) the availability of cell material and manufacturing technology. Current PV industry is primarily based on silicon solar cell. The biggest limitation of silicon cell is its low-efficiency, which translates to very high cost of electricity production. The efficiency of solar cell is the percentage of the incident light that can be converted to electricity. A silicon cell can absorb only a tiny portion of the sunlight. Most of the remaining sunlight passes through or reflects away from the cell surface. The maximum theoretical efficiency of silicon solar cells is reported to be less than 30 per cent. The actual achievable efficiency is only around 10-15 per cent. However, it is encouraging to know that the efficiency of solar cell is going up while the cost per unit of solar electricity is going down with newer technologies. Scientists and engineers are now able to design solar cell with much higher light absorption capacity and efficiency over 40 per cent, while solar panels with 20 per cent or higher efficiency is commercially available now. The following climatic and geographical factors also favour Bangladesh for solar power.
Sunlight profile: The predicted incident solar energy (in kWh/m2) on the land of Bangladesh is more than sufficient for commercial solar plants.
Time during a day: From morning to evening sun does not shine at the same intensity. However, the variation is much less for at least eight hours in Bangladesh.
Climatic conditions: In a rainy or cloudy day sunlight may arrive on the earth’s surface with very low intensity. Over the time deposition of dust on the solar panel prevents the solar cells from getting sunlight with full intensity. In tropical countries like Bangladesh periodic rain cleans the panel surface often enough to offset this issue.
Distance from the equatorial line: Places near the equatorial line get sunlight almost perpendicularly, which means sunlight travels less distance to reach these places. As we move towards the north and the south poles sunlight falls at a larger angle and travels longer distance that lead to lower intensity of sunlight. Bangladesh is very close (23.50 North) to the equatorial line. The proximity of Bangladesh to the equatorial line benefits in two different ways: (1) the variation of the length of the day from winter to summer seasons is smaller than most of the other countries, consequently, for a commercial solar plant it would be easier to calculate the average production capacity per day over the whole year; and (2) sunlight falls almost perpendicularly on our land for a longer period during the year, which provides us sunlight with higher intensity for higher number of days in a year.
Expected socio-economic benefits for Bangladesh
The role of energy and the cost of energy services should be factored into overall national economic and social development policies, including poverty reduction strategies and our donors’ programs in order to reach millennium development goal (MDG), get carbon credits from international organisations, and fulfil long-term sustainability requirements. Energy planning must be linked to goals and priorities in other sectors. If we take the continuous rise of price and supply disruption of oil due to geopolitical conflicts and other events in consideration, it is clear that oil and gas based electricity production cannot be the only option for Bangladesh. Adoption of diversified and environmental friendly power generation technologies will benefit the people of Bangladesh in the long-term. We conclude that solar power would be a very promising and appropriate addition to our power generation portfolio. The usage of solar energy will not only provide us with a clean environment and risk free power production, but also present us a life where we will not have to constantly worry about the ever decreasing resources to provide us with the basic comforts of our life. In this section some of the expected socio-economic benefits of adopting solar power in Bangladesh are highlighted.
Employment: There will be two different fronts for job creation and poverty elimination related to solar power industry. First, the installation, maintenance and operation of solar plants will create many new jobs. Considering the worldwide growth potential of solar power sector, we can foresee a bright future for Bangladesh to build a solar power supporting industry to provide technical, material, manufacturing, and commercial services to this sector. For example, Bangladesh can immediately get into sub-sectors like making solar plant mounting system, battery for solar electricity storage, switches, wires, and other electrical components of solar plants. Only solar panels need to be imported. Installation and maintenance can be 100 per cent provided by local engineers and technicians.
Improved and reliable power distribution: Many countries are adopting distributed power generation scheme as opposed to centralised power generation and reliance on national grid to deliver the power to remote areas. In case of any failure in the national grid larger area or the entire country would be affected if the power generation is centralised. The distribution costs and losses will also be much higher in such scheme. Hundreds of interwoven rivers, low lands and periodic floods and cyclones make it much more difficult for Bangladesh to maintain a centralised power distribution system with only a handful of generation sites connected by a national grid. BPDB has moved towards a policy of localised power plants distributed all over the country. Local solar plants of 1 to 10 MW capacities will be a great addition to this distributed power generation scheme.
Institutional and sector productivity: Power generated by small solar plants in areas beyond the reach of the national grid will create limitless possibilities of productive and economic activities. Factories, industries, commercial organisations, health and education institutions, and many other entities can be set up all across the country. Equal distribution of facilities and opportunities across the country is a long-cherished goal for Bangladesh. Solar power industry can be a very effective vehicle to fulfil this goal. Some of the benefits that can be harvested from solar power in various sectors are illustrated below:
Agricultural productivity: One of our recurring problems is the interruption of power to the irrigation pumps during the cultivation seasons. Small and distributed solar plants can be the solution to this problem. Another serious problem of our agriculture sector is the manual handling, harvesting and processing of crops. People cannot afford expensive oil run machines to speed up the process. Solar plants in rural areas can open the door for many rechargeable agricultural machineries and equipments, which will dramatically increase the productivity and the efficiency of the whole cultivation, harvesting and processing chain.
Fisheries industry: Except few export oriented fisheries firms, most of the fishermen across the country do not have any means to preserve their catch for extended period due to the lack of cold storage facility, particularly in the coastal and river bank areas. As a result, if the fishermen cannot sell their catch by the end of the day, they have to suffer huge financial loss. Greedy middlemen are taking unfair advantage of these poor fishermen. Most of the coastal and river bank areas are still beyond the reach of our national grid. Small and distributed solar pants in these areas can revolutionize the fisheries industry.
Spreading Information Technology: The iv. most remarkable achievements of human race in the 21st century in the wide spread use of information technology, which changed the way we live our life and the way we do things. Mankind achieved unimaginable productivity, connectivity and facilities through the use of information technology. Unfortunately, the vast majority of Bangladesh is still unable to enjoy the fruits of this sector. In this digital age spreading the information technology and related facilities across the country from urban to rural areas is an utmost necessity. Our government has very clear plans, and we have all the experts to implement this program, but materialising it requires uninterrupted electricity supply. A solar solution to this issue seems very feasible for Bangladesh.
v. Other industries: In Bangladesh, still the major industries are concentrated in few districts mainly due to availability of electricity in these areas. For equal distribution of development and economic opportunities we need to set up industries all over the Bangladesh. This can only be done through supply of electricity.
vi. Administrative decentralisation: Since the birth of Bangladesh, a long-cherished dream is to decentralise the administration, public service entities, judiciary and other government agencies. Lack of electricity is one of the primary obstacles in fulfilling this dream.
Women empowerment: 1 to 10 MW capacity power plants can satisfy demands for vast rural territories of Bangladesh. Electricity generated by these plants would become the backbone of rural economy. The power can be used in women oriented cottage industries. This will not only solve the power crisis to a great extent, it will also open the door for economic empowerment of women and gender equality in Bangladesh.
Environmental protection and ecological balance: The sustainability of energy supply and consumption depend on the reduction of ecological and health hazards. This requires measures that increase energy efficiency of tools and machines used by human race, substitute cleaner fuels for polluting fuels, and introduce green and renewable energy technology. Protecting our nature and environment by reducing carbon foot print is one of the most important ethical and scientific goals of our time. For Bangladesh, being a low-lying coastal area, it is also a question of survival. One of the most disastrous impacts of current change in ecological balance is the increase of sea water level. Bangladesh is expected to be one of the worst sufferers of this disaster considering its geographical location and population density.
Carbon credit: International organisations, multinational corporations and industrially developed counties are expected to compete to trade carbon credits with the developing countries. By adopting solar solution to cover a significant portion of our electricity shortage Bangladesh can serve its own need, and at the same time get economic benefit by selling carbon credits to interested parties.
The energy challenge for achieving the Millennium Development Goals (MDG): The United Nation, its agencies, programs and organisations collectively have recently drafted ‘The UN-Energy Paper’ on the importance of energy for achieving the MDGs. The study concludes that, the available energy services fail to meet the needs of the poor. Worldwide, 2.4 billion people rely on traditional biomass for cooking and 1.6 billion people do not have access to electricity. This situation entrenches poverty, constrains the delivery of social services, limits opportunities for women, and erodes environmental sustainability at the local, national and global levels. Much greater access to energy services is essential to address this situation and to support the achievement of the MDGs. The World Summit on Sustainable Development (WSSD) recognised the explicit link between access to energy services and poverty reduction. The Johannesburg Plan of Implementation (JPOI) called for the international community to work together at all levels to improve access to reliable and affordable energy services for sustainable development sufficient to facilitate the achievement of the MDGs. However, governments face serious challenges for improving energy services for the poor, and they need the full financial and institutional support of other stakeholders to produce and deliver more energy. Bangladesh is a very serious and important partner of this initiative, and our government aims to take maximum benefit of UN programs like MDG. By diversifying electricity production capabilities, BPDB and Bangladesh government can move forward in making the MDG efforts successful.
Solar power at this stage can not totally replace conventional sources of energy due to economic and technological factors, but it can significantly augment the energy competence of our business, industry and residence. In due course of time with improved technology we will be able to accomplish net zero carbon emission and stop the destruction of environment by introducing a set of green energy solutions like solar power. The cost of solar electricity can be brought down only through technological development and widespread adoption of solar power. Governments around the world have declared financial incentives to promote increasing production and use of solar electricity. Considering similar geographical and socio-economic conditions we can take India as an example. India is densely populated and has high solar insolation, an ideal combination for using solar power. India is already a leader in wind power generation. In the solar energy sector, some large projects have been proposed, and a 35,000 km2 area of the Thar Desert has been set aside for solar power projects, sufficient to generate 700GW to 2,100GW. In 2009 India launched its National Solar Mission under the National Action Plan on Climate Change, and introduced plans to generate 20GW of power by 2020 from solar energy. Under the plan, the use of solar-powered equipment and applications would be made compulsory in all government buildings, as well as hospitals and hotels. In 2008, the Indian government declared subsidy of Rs10 to Rs15 for every kWh of solar electricity production. USA, Germany, China and many other European nations have similar promotional policies. Bangladesh can also adopt similar policy to establish a renewable energy portfolio.
The writer teaches at the University of Illinois at Chicago. URL: www.ece.uic.edu/~masud, Email: email@example.com