Renewables
Hydropower is the oldest renewable source and, by building on the experience of the past, it never stops innovating. Indeed, technology is always offering new solutions for improving efficiency, increasing production and meeting the challenges posed by the new global context and the energy transition in particular.
Our Group, which is at the forefront of innovation globally, focuses on the development of hydropower with major investments and adopts new solutions with wide-ranging projects in various fields.
Flexibility, efficiency and hybridization
"The common thread linking these projects can be summed up in three words: efficiency, flexibility and hybridization," says Alessandra Carota, Head of Hydro Innovation at Enel Green Power.
Efficiency is the optimization of the use of water resources even in situations of scarcity, while flexibility is the adaptation of the production profile to changing demand conditions, and, last but not least, hybridization is the ability to generate value for our company through integration with other renewable sources and technologies.
Engaging suppliers in order to innovate
Efficiency and flexibility are the directions in which we are heading in the mini-hydro sector, which includes small-scale hydropower below 3 MW capacity: this is now an integral part of our 2025-2027 strategic investment plan. It is precisely small-scale hydropower that has been included in one of our most original projects as part of our "Open Innovation" approach: we have launched an initiative called "Innovation by Vendors" in order to find the most innovative solutions in the market and bring them into our Group.
As part of this initiative, in October 2024 we organized a workshop in Rome, attended by more than 14 international turbine manufacturers, including both our suppliers and new companies with whom we had never collaborated. This was in order to expand the range of possible solutions for this sector.
On that occasion, we invited manufacturers to submit proposals aimed at both the optimization of existing systems and the construction of new systems for Ecological Runoff: we wanted solutions that are flexible, sustainable, economically competitive, easy to install, and with high performance and reliability.
Optimizing water scarcity in run-of -river hydropower plants
Moving on to slightly larger plants, for run-of-river plants of up to 10 MW capacity, we have adopted a new technological solution, again in the name of efficiency. To meet the challenge posed by climate change, which requires increasing production more efficiently even with reduced water flow, we opted for a device known as the Variable Speed Generator (VSG).
Normally, when there is low water flow in a hydropower plant, below a certain critical threshold called the "technical minimum," the turbines do not come into action. VSG enables the technical minimum to be lowered, meaning that the plant can be activated even with low water flow.
VSG has been tested with positive results at the Les Illes power plant (Catalonia, Spain), and such was its success that we will implement it at other Spanish plants.
Increasing the efficiency of turbines
The fundamental challenge for all hydropower plants, regardless of their size, is turbine efficiency: innovation offers considerable room for improvement especially for Kaplan turbines, particularly in plants with low and variable jumps. In this context, KOOS (the Kaplan Online Optimization System), which grew out of our patented solution, has been proposed as advanced software technology to optimize turbine efficiency in real time, thus increasing energy production and reducing operating costs.
The distinguishing feature of KOOS is the real-time monitoring of turbine operating variables such as water flow rate, power generated, and jump. This data is used to optimally adjust the position of the distributor blades and turbine rotor in real time, thereby maximizing energy production and minimizing energy losses.
Trials have been conducted at the Isamu Ikeda plant (Brazil) and soon the new system will also be adopted at the Pontecorvo power plant (Lazio, Italy).
Run-of-river power plants become programmable
In addition to improving efficiency, we are also creating greater flexibility, thanks to a simple but effective idea: making run-of-river power plants programmable (such is their nature that normally they are not).
The Regulating Canal project (ELENA, or nEw modeL rEgulatiNg cAnals), which was initiated at Narzole (Piedmont, Italy), entails considering the hydroelectric canal as if it were a reservoir: a portion of the canal water (a layer only a few centimeters thick, but tens of kilometers long) is allocated for planned use.
In this way, thanks in part to sensors and digital technologies for real-time monitoring of the volume of water that has accumulated in the canal, the production of the plant becomes modulable. This makes it flexible, and at the same time the use of the water resource is optimized, with an increase in efficiency.
Integration of batteries with reservoir hydropower plants
Flexibility and efficiency meet again through hybridization in the BESS4HYDRO innovation project. At the Dossi power plant (Lombardy, Italy), a lithium-ion battery has been integrated into a programmable reservoir hydroelectric plant for the first time.
It is a combination that can significantly improve operational efficiency and turbine life, increasing output and providing greater grid flexibility. Furthermore, the battery will also act as a virtual "second reservoir," improving the scheduling and utilization of the water resource.
The project's innovation was also recognized by the European Union. It received the support of the Innovation Fund in the "small-scale" category and was awarded the "STEP" (Strategic Technologies for Europe Platform) seal of approval. This initiative was set up by the European Commission in order to stimulate investment in innovative technologies that are considered critical for Europe.
Double synergy with photovoltaics
A different, but equally innovative and promising type of hybridization comes in the form of combining hydropower and solar plants: for example, photovoltaic panels can be installed to cover hydroelectric canals and on floating platforms in reservoirs.
At Venaus (Piedmont, Italy), the location of our Group’s first floating photovoltaic plant, we are taking a step further: we are designing a desedimentation system integrated with the floating platform to continuously and sustainably manage the sediment in the reservoir.
The system consists of a series of propellers integrated into the platform anchors, which set the sediment deposited on the bottom in motion and operate in synergy with a raft equipped with a suction pump, all powered by solar panels. Thanks to this innovative procedure, sediment is removed and released in controlled and continuous concentration in the turbine, during normal plant operation, without the need to empty the reservoir. It’s a dual synergy between the photovoltaic and hydropower plants.
Measuring snow with the help of the ESA
If hybridization is one of the most advanced frontiers of innovation, then one of our most futuristic, efficiency-oriented hydropower projects looks to space technologies and involves a prestigious international partner: we’re talking about the European Space Agency (ESA).
The project involves using satellite data and images to study snow accumulation in the Alps and Apennines to calculate how much water will result from them as they melt in the warm months: this is the parameter known as "snow water equivalent" (SWE).
In this way, with data acquired with a certain frequency, we will be able to estimate the amount of water available to our hydropower plants more accurately and more economically than with measurements taken periodically in the field. We will thus be able to better predict production, optimize the use of water resources, and increase plant efficiency.
The collaboration with the ESA is representative of the main lines of our innovation strategy: to collaborate with excellent organizations globally, to explore all frontiers of science and technology and, above all, to put this at the service of sustainability.
