TNO and partners launch project to accelerate longduration energy storage in the Dutch energy system

Energy storage as a key enabler of a futureproof energy system

Longduration energy storage technologies make it possible to store renewable energy for 8 to 100 hours and deploy it flexibly. This helps prevent the curtailment of renewable generation and promotes a more stable energy supply.

'Long Duration Energy Storage is becoming increasingly important. We can already see that grid congestion is lasting longer in The Netherlands and that the security of energy-supply is becoming a problem, making several hours of storage necessary. It is important that we continue to develop LDES technology on the one hand, and on the other hand create market incentives to establish a functioning LDES market. ESNL is glad to be a partner to work together on these necessary conditions,' says Jeroen Neefs, Director Energy Storage NL (ESNL)

'Letting industrial energy users react dynamically and highly automated to the fluctuating supply of renewable energy as well as to the available capacity in the regional electricity network is the next key problem to solve in our energy system. As TU/e we are excited to contribute to this highly innovative project', says Koen Kok, Professor of Intelligent Energy Systems at the Eindhoven University of Technology (TU/e).

TU/e will use and further develop coordination mechanisms and analysis tools for regional energy systems integration. 'As TU/e, we strive for a standard simulation toolset, based on Digital Twins, to analyze systems-integration cases like those in RenewaFLEXNL. This project constitutes an important step towards this goal', Kok continues.

'Within RenewaFLEXNL, our collaboration with HilverdaFlorist allows us to translate system-level innovation into real operational practice. By working directly with an energy-intensive user, we demonstrate how BB One’s integrated thermal and electrical storage can relieve grid congestion while delivering reliable heat and power where it is needed most,' says Pieter Blok, CEO BB One.

Supply and demand

The growing supply of wind and solar energy in our Dutch energy system is making it increasingly difficult to keep supply and demand in balance. As one of the largest utility companies in the Netherlands, Vattenfall has a responsibility to deliver affordable energy, wherever and whenever it is needed. This is why storage is playing an increasingly important role in ensuring the affordability and reliability of the energy system.

'Current battery technology has made enormous technological progress in recent years, making it increasingly accessible. However, these batteries can only store energy economically for a few hours at most. That is why we are eager to contribute our expertise to finding solutions for long term energy storage, so that several days without wind and sun can also be bridged without using fossil fuels,' says Martijn van Berlo , Market developer onshore wind, Vattenfall.

'As a grid operator, we see Long Duration Energy Storage (LDES) as a key enabler of grid flexibility in the future energy system. LDES helps us bridge the gaps between demand and supply, integrate more renewable energy, and maintain a reliable grid. This project delivers valuable research from both market and technology perspectives, giving Stedin experience in connecting LDES to the grid and ensuring we are well prepared for the innovative energy technologies of tomorrow,' says Valerie van Hagen, Innovation advisor, Stedin

From technology to practice: three Dutch pilot projects

RenewaFLEXNL is developing three complementary solutions — electrochemical, thermal and ironair — and testing them in three use cases that reflect typical Dutch system challenges:

• Port of Rotterdam: integrating storage with offshore wind to provide green electricity and heat to energyintensive industry.
• De Kwakel: using heat and electricity from energy storage to reduce the dependency of greenhouses on gasfired CHP units.
• Altena: combining renewable generation, energy storage, charging of electric lorries, and heat supply for greenhouses and local customers.

The use cases will explore how longduration energy storage can reduce grid congestion, improve utilisation of renewable energy, and enhance regional energy security.

Three innovative Dutch storage technologies

The consortium is investigating three solutions:

• Aquabattery (electrochemical) – a scalable acid–base flow battery based on saltwater.
• ORE Energy (ironair) – multiday storage using reversible oxidation of iron, suitable for grid stability and costefficient flexibility.
• BB1 Project (thermal & electric hybrid) – heat pumps, waterbased heat storage and sodiumion batteries with smart control systems.

In addition to technology development, RenewaFLEXNL focuses on system integration: technoeconomic assessments, lifecycle analyses, business cases and recommendations for future regulation. A national system analysis will identify where longduration energy storage can deliver the greatest societal value.

Consortium

The project is being carried out by a broad partnership including:
TNO (coordinator), TU/e, DNV, Vattenfall, Vopak, Nobian, Stedin, Aquabattery, ORE Energy, BB1 Project, HilverdaFlorist, Butterfly Orchid, Emmett Green, EFS, Ecomatters, New Ground Law and Energy Storage NL.

Sounding board partners and stakeholders include TenneT, Alliander, Enexis, the Port of Rotterdam, Glastuinbouw Nederland and representatives from industry and transport .RenewaFLEXNL receives funding from the Dutch MOOI programme.