Energy and powered devices are an integral part of society. Humanity’s earliest days saw the discovery of fire through wood combustion, and the use of charcoal for smelting metals dates back to as early as 500 BC. Powered devices using natural energy sources such as water and wind were introduced by the Ancient Greeks and were commonly used until the 18th century steam engine revolutionized the way devices could be powered. Various natural oils were used for a range of purposes, such as whale oil for lamps. The Industrial Revolution led to the massive use of coal as fuel, and the extraction of petroleum and various other oils became extremely important with the advent of internal combustion engines. Electrical power based on fossil fuels became widespread at the end of the 19th century and the production of cleaner electrical energy through nuclear, hydropower, geothermal, and solar means is a topic even more relevant to today’s world.
Renewable energy system is a noiseless, non-corrosive and environment-friendly energy conversion system. It is an attractive alternative to the traditional CFC or HCFC-based vapor-compression energy system as it employs safe and natural energy. So, many researchers around the world have made significant efforts to study such a renewable energy system in order to commercialize itworldwide. Renewable energies are ways to generate energy from unlimited natural resources. Renewable energies are often referred to “green energies” or “clean energies”. Renewable energies are generally spoken of as opposed to fossil fuel energies. The fossil fuels’ stocks are limited and non-renewable in the human timescale. The most known examples of these resources are coal, oil or natural gas. On the contrary, renewable energies are produced from renewable sources and have no time limit. Still, this doesn’t mean that these energies aren’t harmful to the environment and have zero impact. Nonetheless, they have a low environmental impact compared to fossil fuels. That’s why they’re increasingly becoming important elements in the world day by day.
Electricity generation is the second leading cause of industrial air pollution in theworld. Most of our electricity comes from coal, nuclear, and other non-renewable power plants. Producing energy from these resources takes a severe toll on our environment, polluting our air, land, and water.
Being aware of the finite stock of fossil fuels and their negative impact on the environment, countries across the world are now leaning towards renewable energies like solar energy, wind energy, biomass energy, hydro energy, geothermal and ocean energy in an effort to ensure energy security. The use of renewable energy has risen considerably in recent times, both in developed and in developing countries.
Technologies such as solar, wind and hydro energy are at the heart of transformations taking place across the global energy system. Their increasing deployment is crucial for the greenhouse gas emissions, reduced air pollution, and expanded energy access. Sunlight is one of our planet’s most abundant and freely available energy resource. The amount of solar energy that reaches the earth’s surface in one hour is more than the planet’s total energy requirements for a whole year. The Kurnool Ultra Solar Park in India has a total generation capacity of 1000MW where over 4 million solar panels are installed. Wind is a great source of clean energy. Wind farms are an increasingly familiar sight in the UK and USAwith wind power making an ever-increasing contribution to the National Grid. For example, the Alta Wind Energy Center in the U.S. with a total capacity of 1,548MW which is expected to reach 3,000MW by 2040.Hydropower is the largest renewable energy source for electricity in the United States and China though wind energy is soon expected to take over. The Three Gorges Dam in China is the world’s largest power station in terms of installed capacity (22,500 MW).
REN21’s Renewables 2014 Global Status Report indicates that renewable energy provided an estimated 19% of global energy consumption in 2012 compared to 16.7 % in 2010. More than hundred countries now have renewable energy policy of one kind or the other.The renewable energy communities have provided 8% of the world’s electricity in 2017 and they now cover 1/3 of the power mix in Europe. At the same time, the energy grid gets 1/4 of the total energy in China and 1/6 in the United States, India, and Japan. In 2020, the UK hit a new amazing renewable energy milestone. On Wednesday 10th June, the country ran purely on renewable energy for the first time ever. This is a great step in the right direction for renewable energies.
“Renewable Energy Policy of Bangladesh, has been in force since 2009, which envisions having 5% power from renewable energy sources by 2015 and 10% by 2020. The government has established Sustainable and Renewable Energy Development Authority (SREDA) to promote renewable energy and energy efficiency.The national capacity of solar power development currently exceeds 150 MW.Today, hydropower makes up the largest share of electricity generated from renewable sources as the global capacity reaches 1,000 GW. The only hydroelectric power plant was established at Kaptai with present installed capacity of 230 MW. Bangladesh Power Development Board (BPDB) identified two other sites at Sangu (140 MW) and Matamuhuri (75 MW) for large hydropower plants.Bio-energy is energy derived from any form of biomass, including bio-heat, bio-power, and bio-fuel. Bangladesh Agricultural University and Bangladesh Council of Scientific and Industrial Research (BCSIR) launched biogas technology in the country in early 1970s. Against an estimated potential of 4 million biogas plants about 70,000 plants have been established so far throughout the country. Tapping potential of biomass, two rice husk-based power plants of 250 kW at Gazipur and 400 kW at Thakurgaon, and seven poultry waste-based power plants at different sites with aggregated capacities exceeding 1 MW, have been established at the initiative of private sector with support from IDCOL”. (Source: The Daily Star, November 29, 2020)
As world population rises, so does the demand for energy in order to power our homes, businesses and communities. Innovation and expansion of renewable sources of energy is key to maintaining a sustainable level of energy and protect our planet from climate change.
Renewable energy sources make up 26% of the world’s electricity today, but according to the International Energy Agency (IEA) its share is expected to reach 30% by 2024. “This is a pivotal time for renewable energy,” said the IEA’s executive director, FatihBirol.“Newly electedUS president Joe Biden said his electoral promisethat if elected, his administration would gradually shift its focus from fossil fuels to renewable energy, such as solar and wind. Biden has long proposed to reduce the use of oil and gas as part of a green economy. The United States will be completely carbon-free by 2050 which is the part of his plan”. (Source: The Daily Prothom-Alo, October 25, 2020)
Renewable energy is ideal for the future growth and development for it reduce global warming. The objective in using renewable energy sources is to reduce the pessimistic environmental effects associated with non-renewable energy sources such as coal, oil and natural gas. Choosing to use a renewable energy source will not only translate into cost savings over the long-term, but will also help protect the environment from the risks of fossil fuel emissions. Energy conservation awareness campaigns must be initiated at government level to make people aware of the importance of conserving renewable energy. Moreover, power companies should gradually resort to the use of renewable resources as they are abundant sources of renewable energy which will never deplete. Social media can play a key role in this regard by educating people about renewable energy sources and their utilization. Colleges and universities should teach a compulsory subject on renewable energy conservation and application.
Ph.D. (Fellow) BUET, M.Phil. (BUET)
Assistant Professor of Mathematics
Asian University of Bangladesh