At the World Hydropower Congress, participants in the EU-funded energy innovation project XFLEX HYDRO presented the extraordinary advances in digital control and power electronics being piloted by the project.

“These technologies could make hydropower a one-stop-flexibility-shop for renewable power system security,” said Richard Taylor, who is Strategic Adviser to the project and Director at RMT Renewables Consulting Ltd.

“What is missing are the conditions to allow the investment to flow: much stronger policy and market signals are needed to motivate sector-wide interest to utilise these additional, enhancing technologies,” he explained.

The XFLEX HYDRO project is testing smart digital controls, hydro-battery-hybrids and variable-speed turbines along with other technologies.

One of the project’s main aims is to demonstrate the potential for hydropower plants to provide enhanced services to the power grid to balance electricity supply and demand. These services are increasingly important as variable renewables that are intermittent in nature, such as wind and solar, are added to national grids in ever-growing quantities.

Quentin Boucher, Senior Electricity Market Specialist at SuperGrid Institute said: “In XFLEX HYDRO we’re looking with a fresh view at all of these different benefits that we can provide on flexibility.

“Ultimately all of this comes down to business decisions by the operators… and we will try to enlighten that with the project.”

Guillaume Rudelle, Hydropower Senior Product Manager at GE Renewable Energy said: “I want to highlight the potential of the existing fleet in terms of flexibility through expanding the operating ranges of the power plant.

“It’s something that can be considered for each power plant and leveraging the whole existing fleet could generate a massive flexibility bonus for the grid.

“[Extending the operating range] is something that can be implemented quite quickly, in less than a year typically, and it is not so expensive, from a few tens of thousands of Euros to several hundred [thousand].”

Prof. François Avellan, Scientific Adviser to the project and Professor Emeritus at EPFL, explained how the project is helping to meet the challenge of a low-carbon energy mix: “We took the challenge of bringing digitalisation to the real world and to open new business use cases.

“By bringing new technology such as hydro-battery-hybrid and digitalisation we are able to provide [new] services to the grid…and the cost of that is very small with respect to the asset.”

Improving flexibility

Technologies focused on improving the flexibility of both conventional and pumped storage hydropower plants are being demonstrated by the project. These not only enable the extension of the operating range of the plant units but also the speed of the plant’s response to the electrical grid to provide balancing services.

Elena Vagnoni, Scientific Co-ordinator on the project and Scientist-Lecturer at EPFL, said: ‘Allowing this participation to the market is of great value to hydropower plant operators.

“These technologies offer unique opportunities for increasing flexibility, but it is really important to be able to have optimal management of those technologies thanks to advanced solutions such as digital tools.”

Alexander Jung, Head of Digital Hydro Solutions at Voith Hydro, said that technologies such as hydraulic short circuit allow pumped storage hydropower plants to adapt to the changing needs of the grid.

He said: “With the integration of new renewable energy sources where the excess of energy or the demand for energy can change much faster and many times during the day then you need a way to smooth out the differences and that’s where hydraulic short circuit comes in.”

It is expected that the results of the XFLEX HYDRO project in 2023 will provide important information on the cost benefit of these technologies, including consideration of enviro-social and sustainability impacts.

“It’s clear that the technologies and the money is there for modernisation and for building plants that are really equipped for the future, but there is more to do on the business case for this investment,” said Mr Taylor.

“It’s up to all stakeholders [in the sector] to create the business case and communicate that for these investments in flexibility.”

The technical knowledge gained from the project and policy and market recommendations will be shared in reports due at the end of the project in late 2023.

An on-demand recording of the World Hydropower Congress session ‘Smart hydropower: extending power system flexibility’ can be viewed online.

The Hydropower Extending Power System Flexibility (XFLEX HYDRO) project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 857832.

Source: International Hydropower Association