Energy is the capacity of a physical system to perform work. Energy exists in several forms such as heat , kinetic or mechanical energy, light, potential energy , electrical, or other forms. Energy is the ability to do work. Energy sources could be classified as Renewable and Non-renewable.
Renewable energy is derived from natural processes that are replenished constantly such as solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen.
Sun is the primary source of energy. Sunlight is a clean, renewable source of energy. It is a sustainable resource, meaning it doesn't run out, but can be maintained because the sun shines almost every day. Coal or gas are not sustainable or renewable: once they are gone, there is none left. More and more people are wanting to use clean, renewable energy such as solar, wind, geothermal steam and others. It is called 'Green Power'. It lights our houses by day, dries our clothes and agricultural produce, keeps us warm and lots more. Its potential is however much larger
Technologies for productive use of solar energy
Solar energy can be used to generate electricity. Through Solar Photovoltaic (SPV) cells, solar radiation gets converted into DC electricity directly. The generated electricity can either be used as it is or can be stored in the battery. The stored electrical energy can be used when solar energy is not available. SPV is nowadays successfully used for home and street lighting and water pumping in villages. In hilly areas, solar water heating is also being used.
Wind is the natural movement of air across the land or sea. The wind when used to turn the blades of a wind mill turns the shaft to which they are attached. This movement of shaft through a pump or generator produces electricity. The Potential for wind power generation for grid interaction has been estimated at about 3,02,251 MW ( MW taking sites having wind power density greater than 200 W/sq. m at 80 m hub-height with 2% land availability in potential areas for setting up wind farms @ 9 MW/sq. km. India now has the 4th largest wind power installed capacity in the world which has reached 39990.10 MW (as on Oct, 2021). Private agencies own 95 % of the wind farms in India.
What is biomass?
The plants fix solar energy through the process of photosynthesis to produce biomass. This biomass passes through various cycles producing different forms of energy sources. For example, fodder for animals that in turn produce dung, agricultural waste for cooking, etc. The current availability of biomass in India is estimated at about 500 million MT per annum, with an estimated surplus biomass availability of about 120 – 150 million metric tones per annum covering agricultural and forestry residues. This corresponds to a potential of about 18,000 MW. An additional 9200.50 MWp power was generated through bagasse based cogeneration in the country’s Sugar mills.
Biomass is an important source of energy accounting for about one third of the total fuel used in our country and in about 40% of the rural households. The widespread use of biomass is for household cooking and heating. The types of biomass used are agricultural waste, wood, charcoal or dried dung.
Technologies for productive use of biomass
Technologies that enable efficient use of biomass are becoming prevalent in rural areas.The efficiency of fuel usage is increased by:
Biofuels are predominantly produced from biomass feed stocks or as a by-product from the industrial processing of agricultural or food products, or from the recovery and reprocessing of products such as cooking and vegetable oil. Biofuel contains no petroleum, but it can be blended at any level with petroleum fuel to create a biofuel blend. It can be used in conventional healing equipment or diesel engine with no major modification. Biofuel is simple to use, biodegradable, non-toxic and essentially free of Sulphur and aroma.
The flowing water and the tides in the sea are sources of energy. India is endowed with large hydropower potential of 1,45,320 MW. Heavy investments are made on large projects. In recent years, hydel energy (through mini and small hydel power plants) is also used to reach power to remote villages which are unelectrified. The estimated potential of Small Hydro Power is about 15,000 MW in the country. As on Oct. 2021, the installed capacity of Small hydro projects (upto 3MW) amounts to 4821.81 MW.
Advantages of Small Hydro Power as an energy source
Oceans cover 70 percent of the earth’s surface and represent an enormous amount of energy. Although currently under-utilised, Ocean energy is mostly exploited by just a few technologies: Wave, Tidal, Current Energy and Ocean Thermal Energy.
Geothermal Energy is heat stored in earth crust and being used for electric generation and also for direct heat application. Geothermal literally means heat generated by earth. Various resource assessment carried out by agencies established the potential 10600 MWth /1000MWe spread over 340 hot springs across seven Geothermal provinces/11 states.
The availability of geothermal power is most environment-friendly power, round the year 24x7 basis, not affected by the severity of climate during 6 to 7 winter months like hydro and like dependence on sun in solar PV.
To view the Geothermal database of India, click here.
Coal, Oil and Natural gas are the non-renewable sources of energy. They are also called fossil fuels as they are products of plants that lived thousands of years ago. Fossil fuels are the predominantly used energy sources today. India is one of the largest producer and consumer of coal in the world, with estimated reserves of around 344.02 billion tonnes (as of 2020). Coal supplies about 51.9 % of the country's total production of energy by commercial sources. The estimated reserves of crude oil in India in 2020 stood at 603.37 million tonnes. India consumes about 254 MT of crude oil annually, and more than 70% of it is imported. Burning fossil fuels cause great amount of environmental pollution.
Source : Portal content team