The interaction between hydropower and the environment is a controversial topic. Hydropower companies and energy agencies promote the use of hydropower, especially in light of the renewable energy targets and thanks to its multi-purpose benefits. Indeed, hydropower plays the most significant role in terms of energy generation and flexibility (620 TWh/y in Europe). On the other side, environmental agencies perceive hydropower plants as a main factor of environment degradation, due to its impacts on rivers. Hence there is the need of better understanding which is the optimal compromise between hydropower benefits and environment protection, in order to develop hydropower in a sustainable way.
In Quaranta et al., (2020) a collection of innovative case studies is presented, covering (1) ecologically improved turbines, low head hydropower converters (Vortex turbine, Hydrostatic Pressure Machine, Very Low Head turbine, Girard-optimized turbines, hydrokinetic turbines) and hydropeaking reduction, (2) new control systems, governors and digitalization, (3) hydropower as a strategy for local sustainable development, and (4) energy recovery in existing hydraulic infrastructures and aqueducts. The described case studies show as hydropower can generate several benefits if developed in a sustainable way and exploiting the existing structures. New sustainable practices and turbines with better ecological behavior can minimize environmental impacts, like the reduction of fish mortality, improvement of fish habitat availability, reduction of lubricant oil and generation of economic incomes for local development. The use of existing structures reduces the total installation cost: one example in Italy reports a total saving of 277 €/kW by reusing irrigation pipes and reservoirs. Innovative low head hydropower converters can exhibit good ecological behavior, with reduced costs (< 5,000 €/kW) especially when installed in existing weirs.
Quaranta et al., (2021), assessed the opportunities of modernizing the European hydropower fleet. Hydropower modernization allows to increase generation and flexibility, but also to improve water management (e.g., flood control and water storage). By the dam heightening, the head loss reduction in waterways, the increase of the weighted efficiency of electro-mechanical equipment, and digitalization, the overall energy generation could be increased by 8% for European Union and 9% for the whole Europe. Additional strategies, that were not discussed because they are very site-specific, can further improve the expected energy benefits. For example, floating PV potential on hydropower reservoir in Europe is 729 GW, new waterways can double the peak power in certain plants, and a better inflow forecast (spill reduction) can increase annual generation by 11% in certain cases. The additional energy storage achievable by reservoir interconnection within 20 km and coordinated operation within 3000 km has been estimated in literature as 169 TWh. Novel materials are also being developed to improve efficiency, lifespan and durability of hydropower equipment. The modernization of hydropower plants can generate significant benefits in terms of energy, and should be considered as an important element of energy policy, also considering the additional benefits in terms of reliability and flexibility of the energy system that it may deliver.
In Quaranta et al., (2022), micro hydropower plants installed in existing barriers and in water networks would allow to optimize the existing structures, providing decentralized electricity and supporting R&D and market development. The retrofitting of old water mills would also promote the valorization of the cultural heritage, generating income due to the promotion of cultural and social activities. In the European Union, the potential in water mills, water and wastewater network was estimated at around 5 TWh/y.
The discussed strategies, insofar as not entailing a worsening of the hydro-morphological alterations, are also expected to cause limited or no conflict with the environmental objectives of water policies in Europe.
“Hydropower plays the most significant role in terms of energy generation and flexibility.”
Expert Bio:
Expert is an expert on unconventional energies like tidal, nuclear, hydro, geothermal and bio energies.
Key roles and experiences include:
– Over 5 years experience in research and development for hydropower in topics like efficiency of water wheels and optimization of hydraulic structures.
– Held titles such as scientific consultant in hydropower innovation, hydropower scientific expert for the IEA, and scientific officer of a joint research centre.
– Worked as a consultant on the efficiency of the new patent of an air wheel.
Expert has extended knowledge on:
– Hydropower
– Hydraulics
– Urban greening