A legend goes like that Archimedes, an ancient Greek mathematician and physicist, destroyed enemy ships with fire during the siege of Syracuse (c. 214–212 BC). It is known that he used his ‘burning glasses’ as his weapon to concentrate sun’s rays on the approaching ships of the Roman soldiers coming to invade Syracuse of Greece. By using glasses, Archimedes focused sunlight on the wooden ships of the attackers which caused them to catch fire and repelled the soldiers.
The story indicates that it is since the ancient time that solar energy has drawn the attention of the scientists and they had begun to realize the fact that sunlight can be a great source of energy. With the passage of time, scientists have been able to invent the technology of converting energy of sunlight into electricity, which is an affordable, renewable and inexhaustible source of energy and a reliable alternative to the energy generated from natural gas or fossil fuels.
Solar energy is radiant light and heat from the sun that is harnessed using a range of energy evolving technologies such as solar heating, photovoltaic, solar thermal energy, solar architecture, molten salt power plants and artificial photosynthesis. It is an important source of renewable energy and its technologies are broadly characterized as either passive solar or active solar depending upon how they capture and distribute solar energy or convert it into the solar panel.
The facts that solar energy is available in large magnitude and it is inexhaustible and renewable make it a highly appealing source of electricity.
The invention of the solar energy technology has opened a door of huge possibility for the countries around the world. In 2000 World Energy Assessment, the United Nation Development Programme found that the annual potential of solar energy was 1,575–49,837 exajoules (EJ), which was several times larger than the total world energy consumption per year (559.8 EJ in 2012).
Solar energy offers a clean, climate-friendly, very abundant and inexhaustible energy. The International Energy Agency has recognized the efficacy of solar energy and opined that it can play a vital role in solving some of the most urgent crisis that the world is currently undergoing. In 2011, the agency described the advantages of solar power to the world, predicting its possibilities and advocating the use of solar power globally. It said that the development of affordable, inexhaustible and clean solar energy technologies would have huge longer-term benefits. It would increase countries’ energy security through reliance on an indigenous, inexhaustible and mostly import-independent resource, enhance sustainability, reduce pollution, lower the costs of mitigating global warming, and keep fossil fuel at low price.
In the meantime, a number of industrialized countries including United Kingdom, Italy, Japan, China, United States, India and some others have already installed solar power capacity into their main electrical grids, supplementing or providing an alternative to conventional energy sources. On the other hand, an increasing number of less-developed nations have been turning to the use of solar energy in order to lessen their dependence on imported fuels for generating electricity, which is rather expensive.
It is to say that the technology of generating electricity using solar power has really opened a door of possibility for the developing countries like Bangladesh which have to depend largely on imported fossil fuels or natural gas for generating power. Our country has lagged behind in generating electricity and failed to cope with the demand of electricity in the country for decades. It is reported that about seventy two percent of our population has an access to electricity while the rest of them cannot avail themselves of electricity. Many houses are located in the off-grid areas which do not have electricity. Moreover, it is also true that the electricity supply in many areas of our country is not adequately reliable till now.
Hence, the best source of energy Bangladesh can now turn to is solar power in order to ensure its energy security. Well, the current government has made some sincere efforts to enhance the generation of electricity in the country and has succeeded to a commendable extent, however, a considerable number of our people do not have an access to electricity yet.
In order to provide electricity to households in the off-grid areas and increase the country’s efforts for off-grid rural electrification, Bangladesh government launched its Solar Home System (SHS) program in 2003 with the assistance of the World Bank. Since then Bangladesh has made considerable progress in the rural renewable energy development and recently, it has topped a global list of countries that have installed the highest number of Solar Home Systems (SHS). The program reached about three million households within 2014 by adding more than 50,000 systems per month since 2009. Apart from that, 617 solar irrigation pumps (SIP) have already been installed with a view to replacing diesel-run irrigation pumps while solar street lights in some districts, 7 solar mini-grids in remote islands, urban rooftop solar program, and solar-powered arsenic water treatment plants are also contributing to country’s overall effort to use renewable energy. And it is also mentionable that Bangladesh has set a goal to provide electricity to six million more households by 2017 while it aims also at ensuring a universal electricity access for the countrymen with the SHS program by 2021. World Bank has recognized the program as "the fastest growing solar home system program in the world”.
Gradually, the use of solar power is gaining more and more popularity among the common people of our country. Solar panels which transforms sunlight into electricity, is gaining its importance in our day to day life as a replacement for conventional electricity. Nowadays, people living both in rural and urban areas have started using solar power by setting up solar panels on their rooftops. People having grid connection can get electricity at the time of load-shedding. On the other hand, people living in the off-grid areas can use fans and electric lights, charge their cell phones, watch television, the children can study in a better environment and people can perform their household activities at night by using solar power.
Apart from all these facilities that the people can get by using solar power, they can also be benefitted from this by using net-metering system, which can transform the electricity consumer into electricity generators. It allows the customers to generate their own electricity from solar power while they can feed extra units of electricity back to the grid connection. This system uses a bidirectional meter, measuring and recording electricity flow in two directions—from utility to the customer (import) and from customer to the utility (export). The users have to pay their bill on the basis of net metered calculation, which is, imported units minus exported unit. The developed countries like US, Australia, Canada, Italy, Spain, and Denmark have adopted the system because of its multiple benefits. However, our country can also introduce this system to the people in order to encourage the use of solar power technology in the country.
And most importantly, the future economic development of our country largely depends on the availability of electricity as it is the most widely used form of energy. This is why the use of solar energy in the country should be encouraged while solar panels should be set up at schools, colleges, universities, mosques, temples, government buildings, factories, bus stations, train stations and unused lands so that we can make our country an energy-independent country. Of late, Bangladesh has aimed at attaining 17 Sustainable Development Goals by 2030; one of them is to combat climate change and another is to attain energy development and energy security by increasing its use of renewable energy sources. And it will be possible only if we can generate power by using a clean, renewable, inexhaustible source of energy like solar energy.