How can we make hydropower technologies sustainable?

At present, it isn’t whether we are moving towards hydroelectric power technologies, it is how are we getting there.

The International Hydropower Association (IHA) recently recognised India as an emerging hydropower giant as it overtook Japan to become the fifth-largest hydropower producer in the world in 2020 following Canada, the US, Brazil, and China.

As a country vulnerable to the effects of climate change, India is inching away from coal fire projects and moving towards renewable energy. Hydropower has been reclassified as renewable power, in order to obtain green financing. The Government of India has specifically recognized the need for boosting the hydropower sector under the non-solar Renewable Purchase Obligation (RPO). Statistically, India’s existing renewable energy capacity is 80 GW, including solar, wind, and small hydro and it is aiming to scale its capacities to 175 GW by 2022. And with the addition of large hydro to the clean energy segment, the country can scale up to 225 GW of renewable energy in the same period.

According to the draft electricity plan published by the Government of India, it forecasts that by 2027, around 44 percent of India’s total electricity capacity will come from fossil fuels, 2 percent from nuclear energy, and 54 percent from renewables. About 11 percent of this comes from hydropower. The country is in a position to meet the Paris Agreement target of 40 percent by 2050. But the path that we chart is critical and will finally decide if we can lead our way into a sustainable future.

Presently, the question is not whether we are moving towards hydropower. It is how.

The threatening impact of building large dams nearby villages as well as ecology is no secret. Even though hydropower generates clean electricity, large and small dams have a lasting impact on the environment. Dams built for hydroelectric power impact rivers and wildlife habitats, displace humans, affect fish populations, and interrupt the natural flow of sediment into river systems. Furthermore, huge amounts of concrete are a major contributor to CO2 emissions. An analysis from 100 studies of reservoir islands of 15 dams in North, Central and South America, Europe, and Asia showed that in more than 75 percent of cases, dams had an overall negative impact on reservoir island species, affecting species population density, ecological community composition, and species behaviour.

Efforts are needed to be made to minimize hydropower’s environmental footprint. This is especially necessary for India, which is ranked third in the world in terms of building large dams. In 2019 alone, India greenlit large projects including the Polavaram project in Andhra Pradesh, Etalin, and Dibang in Arunachal Pradesh, and Bodhghat in Chhattisgarh – whose total estimated cost is about ? 1.31 trillion. The damage to river ecology indirectly contributes to climate change from deforestation and the degradation of agricultural lands and forests. It affects the movement of both fish upstream and of silt downstream to fertilize fields.

Although not everything can be controlled, scientists have worked on minimizing certain risks. They are also finding ways to harness large hydropower with methods that do not cause harm to fish populations, increase the operational range of hydraulic turbines to achieve better flexibility, and digitize the way hydropower equipment operates. Many focus on improving existing and aging dams and also provide better ways for new projects. It is necessary for hydropower to adapt to opportunities and challenges based on evolving conditions.

Hydropower flexibility

Passive control methods and active control methods mitigate flow instabilities i.e. the transition from direct to indirect loading. These increase unit flexibility and operating range. This promises to be an ideal solution to the growing list of challenges faced by grid challenges. Experts highlight that in order to meet the clean energy goals, flexible, low carbon balancing resources will be required.

Hydropower digitization

The application of AI can help improve the safety and reliability of hydropower turbines and their ability to support advanced grid services. Researchers predict that an estimated 42 TWh could benefit from hydropower digitalization. Experts suggest that digitization could play a crucial role in improving the performance of hydro plants, turbines, and equipment by reducing its costs and optimizing efficiencies.

Fish-friendly hydropower technologies

With an aim to minimize turbine-induced mortality of fish populations, an eco-hydraulics approach is adopted in small hydropower plants’ design. These include Archimedes hydrodynamic screws, water wheels, and Vortex turbines for low head turbines, as well the Alden turbine and the minimum gap runner turbine for high head turbines. The Alden turbine, with only three blades, works with hydraulic efficiency of 93.6% and reduces mortality by 98% or greater for fishes less than 20?cm.

Novel small-scale hydropower technologies, fish ladders, helicoid penstocks, and more such innovations are some of the other technology trends to harness hydropower.

Such designs integrated into large dams’ designs could mitigate the risks to river ecology. It’s up to the experts to determine which technologies would work best for India.

Here’s some food for thought – Can we also look into alternative technologies as a source of renewable energy? Dams need to become more sustainable to be added to the renewable energy mix. Therefore, it’s worth looking into the innovations of the future.

Globally, a lot of innovations are being made to harness energy without causing distress to the ecosystem. In Britain, engineers are finding ways to utilize small hills to harness high-density electricity. They are using a fluid that is two and half times denser than water and generates two and half times more energy than water. This is one small example. Whether this alternative technology is scalable, entirely renewable, and sustainable remains to be seen.

What does our renewable future look like?

To meet our 2050 renewable energy goals, we must focus on pushing for technologies that can aid in sustainable development. As the most widely used and oldest form of electricity, it’s about time we find low-risk methods to make the renewable energy transition. Providing affordable, universally accessible, and low to zero-carbon electricity in the region is necessary, especially for a developing nation like ours, which is home to a large number of people living below the poverty line. But the systematic push for hydropower cannot come at environmental and social costs. Let’s find a way to make hydropower truly sustainable.

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