As India gears up to augment its electricity generation capacities, it is becoming quite clear that overdependence on any one technology is not going to be enough. While coal-fired thermal plants will continue to play an anchoring role, concerted efforts would need to be made to ramp up the share of renewable energies over the coming years.
Technically speaking, hydel power accounts for only a small portion of renewable energy in India, as only plants up to 25 MW capacities are put under the category. The overall hydroelectricity capacity accounts for around 15 percent of the country's total power generation capacity. However, less than half of the hydel energy potential has been harnessed, and there are plenty of reasons why it must be done at the soonest.
First and foremost, the power generated by these plants itself is clean and green as it is not accompanied with any emissions. More importantly, hydel energy is probably the only form of energy that could enable just-in-time electricity generation for peak requirements and as such could complement other technologies even in cases where hydel energy is not being used as the primary power generation technology. Using pumped-storage technology, water is stored at an elevation higher than the turbines and is released during periods of peak demand to generate electricity as instantaneously as in a matter of a minute or two. As such, co-existence of these plants along with other technologies could do away with the need to build redundancies in thermal power plants, and in turn, make those plants greener as well.
Despite these benefits, there are various reasons why large hydel plants were historically not identified as part of the renewable energy sector. They involve huge bodies of civil and other engineering works, which could have considerable carbon footprint during the development phase. Also, any flooding of the surrounding areas caused due to the construction of dams could lead to CO2 emissions arising from decomposition of vegetation in the area.
Many of these concerns could be a little far-fetched, particularly if viewed in the context of a hydel plant's lifespan, which could easily range anywhere between 50 to 100 years. With proper maintenance, the equipment could last much longer when compared to thermal plants while the water reservoirs could meaningfully last as long as they continue getting water from the sources, say, a river.
So what could be the action points? Well, as a first step, by doing away with the technical clause that classifies only hydel plants of capacities under 25 MW as renewable energy plants, India could potentially kick-start a new phase of hydroelectric capacity augmentation. A maturing of both the reservoir and turbine technologies over the past several decades has anyways helped to mitigate the apprehensions about the hydel power projects, but yes, environmental and ecological concerns as well as rehabilitation needs would need to be duly addressed.
A renewable energy classification could give the larger hydel power plants the boost they have been in need of. Not only the clearance-related processes could be fast-tracked through accelerated coordination between the various stakeholders, but also the flow of investments into the sector could become more steady and predictable, on the back of entitlement for incentives typically associated with the renewable energy sector.
Meanwhile, there is much scope to augment the hydel power generation capacities of the existing plants, say, by way of replacing some of the older turbines with more efficient ones. The reservoir areas could also be utilized to install photovoltaic panels so as to generate a supplementary amount of solar energy from the same plant. This could also reduce the evaporation of reservoir water, thus making it more sustainable.
Greater use of run-of-the-river technologies so that environmental and ecological issues are better addressed.