Restoration of the Kakhovka HPP: What can be built in the place of the ruined dam

In the night against June 6, ruscists committed a stunning act of terror and ecocide, blewing up the Kakhovka Hydro Power Plant. The occupiers had mined the station as early as 2022, in October President Volodymyr Zelensky in his address to the European Council emphasised that the consequences of undermining the dam would be catastrophic. "Russia is consciously creating a breeding ground for a massive disaster in the South of Ukraine," he said. "We have information that russian terrorists have mined the dam and the Kakhovka Hydroplant units."

The scale of the consequences of this crime is hard to fully estimate yet. Kakhovka HPP provided light and water to a vast number of people and enterprises, it fed the North-Crimean canal. Not to mention how many millions of living creatures the natural ecosystem it housed served... On the morning of June 6, Ukrhydroenergo operating company announced that the station was completely destroyed and could not be restored. Later, the head of Ukrhydroenergo, Igor Syrota, said that the restoration of the Kakhovka HPP would cost $1 billion and could take five years.

In any case, a powerful energy infrastructure in this region is needed. The reconstruction of the hydroplant or the construction of a new energy object in its place will sooner or later be on the agenda. And it's an opportunity for Ukraine to get a new, modern, ecological, powerful hydroelectric station, equipped with the latest technological trends. Mind found out exactly which ones.

What's unique about the Kakhovka HPP? Kakhovka HPP was innovative from its "birth": a number of advanced technological solutions were introduced during its construction. For example, it was the first in the world hydraulic engineering practice to be erected on fine-granular silt soil. Its earthen dam with very gentle slopes majestically laid on a large area of quicksand. And in 2019, for the first time in Ukraine, an experiment with water aeration was conducted here, which was successful and proved that it is technically possible to increase the concentration of oxygen dissolved in water at the station.

Photo: UNIAN

Why is global hydropower still more relevant than ever? Today, hydropower is experiencing a rise, as it answers two relevant questions of modernity: an unchangeable and accessible resource and environmental friendliness. It is the most powerful and widely used source of renewable energy. According to a recent report by the International Renewable Energy Agency (IRENA), hydroelectric power plants in 2022 produced 1.4 gigawatts of energy – 41.3% of the total global renewable generation capacity. The number of hydroelectric power stations in the world and the amount of energy they generate is growing every year.

What are the most significant projects that have emerged recently? China holds the world record in hydroelectric power production. It's no surprise: since 2012, the world's largest dam, "Three Gorges", has been operating on the Yangtze River. About 100 years passed from the idea to its implementation: almost 40 years of ideation, the same amount for planning, construction took 20 years. The planned capacity of the station is 22,500 megawatts. Compare this to our Kakhovka, which produced 334.8 MW.

The Three Gorges dam

Based on previous estimates, Three Gorges cost China $29 billion, of which over $10 billion was spent on relocating people. But by 2018, the total income from the dam amounted to $43.7 billion – and that's without considering tourism revenue. This station became the site of implementation for a large number of technological innovations, the most famous of which was the lift for small and medium vessels with a tonnage up to 3000 tonnes. A ship sails into the lift chamber and rises to a height of 113 metres. Thanks to the lift, the passage of vessels through the dam takes 40 minutes. For comparison: overcoming all five chambers of the Three Gorges lock takes four hours.

Are there any environmental risks in such projects? The construction of monster dams also has its downside, loudly spoken about by ecologists. While hydroelectric power production is more or less environmentally friendly, the construction of stations carries significant risks to the environment. For example, the construction of the Brazilian HPP Belo Monte (commissioned in 2016) slowed the flow of the Xingu River within five municipalities of Brazil, affecting human activity and local flora and fauna. The Norte Energia consortium, which operates the station – the fourth largest hydroelectric plant in the world – continues to carry out compensatory measures and has already spent 6.3 billion Brazilian reais ($1.25 billion) on this.

What alternatives exist? One of the persistent trends is the development of small hydropower (capacity up to 10 MW) – micro-, mini-, even pico-stations, capable of powering up to five houses. They are perfectly suited for supplying renewable energy to small communities. Their operation doesn't require a dam or reservoir, minimising the impact on natural ecosystems. However, their output power is lower, and seasonal phenomena can lead to fluctuations in energy production. Ukraine has significant potential for development in this direction: according to the UN report on global development of small hydropower in 2022, the potential capacity of our small HPPs is estimated at 280 MW at the current level of 119.6 MW.

What trends in modern hydropower can be seen in the future? Recently, the StartUs Insights portal published the 10 most relevant hydro energy trends in 2023, based on research from 487 startups and scale-ups from around the world working in this field. Analysts believe that this data will help energy industry players, municipalities, and governments to better prepare for making strategic decisions.

1. Modernising existing technologies – upgrading hydroelectric power plants by implementing the latest advancements in turbine technology. Generators with permanent magnets and fish-friendly turbines increase the production capacity and efficiency of the plants. Solutions for storage and hybrid batteries enable efficient utilisation and transportation of generated electricity. Modular power generation systems facilitate easy deployment and expansion of hydroelectric power plants. Startups utilise solutions such as gravitational hydraulic machines, water wheels, Archimedean screws, current-controlled rotors, and dual-fed asynchronous machines in their developments. Modular solutions help maintain stable grid and provide precise control over energy production.
2. Marine and hydrokinetic technologies. The energy from ocean currents, waves, and tides opens up tremendous opportunities for creating reliable and clean energy. Barrage technologies, tidal flow generators, and hydrokinetic flow technologies are among the latest advancements in this field.
3. Cutting-edge turbines. Innovative designs such as low-head turbines, vortex turbines, Alden turbines, and turbines with minimal clearance allow power stations to generate more energy without altering water consumption.
4. Power injectors. Pressure and water flow rates are two critical factors that determine turbine power. Power injectors work by introducing a high-pressure water jet into the turbine's inlet orifice. They are used in hydroelectric systems to increase the overall output power of the plant.
5. Data analysis. Technologies such as hydroefficiency analysis and optimisation of combined curves help analyse the performance and utilisation of facility capacities. Solutions like numerical cloning enable HPPs to create digital copies and study their behaviour under different operating conditions.
6. Preserving aquatic life. Advancements in turbine designs, such as hydrokinetic turbines with very low heating and minimal clearance, aid the safe migration of aquatic organisms through hydropower stations. This supports ecological balance and the increasing use of fish ladders and pumps as turbines.
7. Simulations. Through intelligent modelling, digital twins, and control systems, startups minimise the operational costs of run-of-river plants. These technologies enable predictive real-time maintenance and help facility operators increase their uninterrupted operation time.
8. Pumped hydro energy. This is when two reservoirs at different elevations are connected to generate electricity, and water is moved from one reservoir to another. Innovations in pump designs and materials enhance the efficiency of pumped hydro energy systems, reducing the amount of energy required for water pumping.
9. Artificial canalisation utilises man-made channels to redirect water flow for optimising energy production potential. Aqueducts, underground air cushion reservoirs, pipes, and spillways are among the technologies that stimulate electricity generation in areas where large water bodies are not readily available.

What do startups offer? In the trends description, you can learn which startups are working in each direction and what developments they have. For example, generators with permanent magnets developed by the British startup Hydrosyst can be used in both new and existing stations. The Energyfish device by the Energyminer team generates electricity using natural water movement without any negative impact on the environment. Finnish startup Finnrunner offers resource-saving solutions such as composite materials and additive manufacturing for turbine and equipment production. The team at Motrhys from France provides a comprehensive set of solutions for monitoring the performance and safety of hydro equipment. And the Austrian startup Hydrogrid "digitises" hydroelectric power plants.

The best approach to the reconstruction of the Kakhovka Hydroelectric Power Plant will be decided by experts. We hope that the restored plant will implement the best and most advanced technological solutions in the field of hydroenergy.