Delta21
Delta21 is an innovative project that combines flood protection, large-scale energy storage, and nature conservation. With a unique reservoir serving as a natural hydroelectric battery, the project offers a sustainable solution to the challenges of tomorrow. GreenTrust plays an important role in the project’s development: Tijmen Keesmaat is the project director, and Lisa Hoffard supports the team with her legal expertise.
The Power of Water for a Sustainable Future
How can we ensure that the Netherlands remains safe, sustainable, and livable in the future? Delta21 offers an innovative solution that combines flood protection, large-scale energy storage, and nature conservation.
At the mouth of the Haringvliet, a unique system is to be created featuring a large drop lake that functions as a natural hydroelectric battery. This will allow renewable energy to be stored and released during periods of high demand. At the same time, the system will help protect against flooding and provide opportunities for ecological restoration.
A Unique Collaboration Among 24 Partners
Delta21 is not only technically innovative, but also unique due to the collaboration between 24 companies, energy cooperatives, and civic organizations. Together, they are working to create a future-proof Dutch delta.

I’ve been working in the renewable energy sector for a long time and have always been focused on the question of how to make the energy system smarter and more sustainable. It was against this backdrop that Delta21 came my way. This project brings together everything I’ve been working on for years: energy, system integration, and social impact. That made the move a very logical one for me. This is the most wonderful project in the energy transition.
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Ambitious Project
GreenTrust is closely involved in this ambitious project. Tijmen Keesmaat serves as project director and is leading the further development of Delta21. Lisa Hoffard supports the project team with her legal expertise, including in formalizing agreements between the parties involved.
Through Delta21, GreenTrust is contributing to an innovative project that harnesses the power of water for the sustainable future of the Netherlands.
Read more on the website and watch the animation
Group photo: Anna den Hartog
Team Delta21
The founders of a green future

