With rapid progress in its industrial and socio-economic development, India needs more energy. The country’s energy demand is constantly increasing and at present, fossil fuels like coal, oil, petrol, diesel etc. are meeting most of this.
Nearly 62.7% of electricity is obtained from fossil fuels and it is expected that the energy demand of the country will be more than double by 2030. With limited reserves of fossil fuels and increasing costs, every year, India spends a large amount of foreign exchange to purchase these. At the same time, due to the burning of these fossil fuels, a large amount of greenhouse gases like carbon dioxide, oxides of nitrogen and sulphur are being released into the atmosphere causing a lot of pollution problems and global warming.
According to key world energy statistics, in 2019, India generated 1561 trillion watt-hours (TWh) of electricity and is the third-largest producer of electricity in the world after China and the USA. With limited resources of fossil fuels, along with the increasing demand for electricity, the government of India has targeted to increase the generation of renewable energy by 175 GW by 2022 from hydropower, solar, wind and bio-products.
In this context, the generation of electricity from hydropower which is quite abundant in the country is necessary. At present, India is the fifth-largest producer of hydropower in the world with an installed capacity of 45,699 MW in 2020. However, hydropower contributes only a small fraction (12.4%) of the total installed capacity in the country, indicating that there is a great scope to produce a large amount of electricity from this.
At present, the tendency all over the world is to avoid large hydropower in view of high cost in construction, opposition by people living in the area and having cultivable lands, frequent silting and flooding of the dam, desertification, rehabilitation of displaced families, adverse effect on environment etc. Therefore, in recent years, efforts are being made to develop small hydropower for electricity generation as these are usually much less costly to construct, free from frequent maintenance, sustainable and environment friendly.
Unlike large hydro powers, these are long-lasting and also exempted from forest and land clearance and rehabilitation problems. Further, small hydro powers are ideal to power villages and isolated places including mine areas. As a result, accessibility to electricity results in boosting the socio-economic developments of the region.
A recent survey indicates that there are 7133 hydropower sites on various rivers in different parts of India with an approximate potential of 21.13 GW. Out of these, by 2019, only 1127 small hydropower units contributing 4672 MW are functioning and another 109 small hydropower units are in process of completion with a capacity of 529 MW. These figures indicate that presently, only 17% of the potential of small hydropower is being harnessed and thus there is a large scope to develop the rest hydropower units.
However, past experience showed that, because of faulty decision to select the proper site, size of the unit, purchase of generating equipment, many small hydropower units in India have been scrapped. Many small hydropower units have also been scrapped due to low consumption of electricity and limited funding from the government in terms of maintenance cost. To make the functioning of small hydropower units successful, besides proper planning, the best available technology has to be utilised and well-trained personnel to be employed. In India, small hydropower units have been classified into four subgroups.
- Hydropower up to 5 KW is called Pico
- Up to 100 KW is Micro
- Up to 101 – 2000 KW is Mini and
- 2001 to 2500 KW is Small
There are more than 400 rivers in India. The total length of India’s coastline is 4517 Km. In addition to these, the country has got a good number of waterfalls and 46 wetlands as recognised under the 1971 Ramsar Convention. In these water bodies, a detailed survey should be made to locate suitable sites for setting up more small hydropower units.
At present, Karnataka has the highest installed capacity of 1281 MW followed by Himachal Pradesh and Maharashtra with 907 and 380 MW electricity respectively. The states in the north and eastern region of India have a high potential for installing small hydropower units. In addition, efforts should be made to develop and standardise harnessing hydropower from sea tides and waterfalls. At the same time, the four types of hydropower systems namely run-off river hydropower, storage hydropower, pumped storage hydropower and offshore hydropower have to be taken into consideration so that at different water bodies appropriate hydropower systems can be identified and installed.
Out of all renewable sources of energy, small hydropower is most efficient, practically free from environmental pollution and socio-economic obstacles. Because of better available technology, India should put up more small hydropower units as large hydropower units have got many socio-economic problems. With huge hydropower potential in the country, especially in the Himalayan states as well as in the coastal region, selection of proper sites and setting up small hydropower units using the best available technology should receive high priority. In this way, it would be possible to meet the increasing energy demand in the country in an environment-friendly manner.
