Using a special type of concrete, researches Branko Šavija and Yading Xu from TU Delft in the Netherlands aim to generate energy using waves battering the coast.

Often, when talking about green or renewable energy, the focus lies on wind turbines and solar panels. However, with water, it is also possible to generate green energy, especially when waves batter the coast.

Šavija works with materials with unexpected behaviour. These include auxetic concrete, which is a flexible concrete with a special property. When loaded, it contracts, but when the load disappears, it expands like a sponge.

Breakwaters consist of large pieces of concrete. When waves hit the blocks, vibrations arise, which could be turned into electricity. The Netherlands has 450 km of coastline. If blocks of several metres of auxetic concrete are used, these could generate a lot of energy.

Šavija and Xu are currently working on linking piezoelectric polymer films to the concrete. This soft and flexible film is capable of converting the movement from the concrete into electronic resistance. Eventually, they will develop a proof-of-concept at laboratory scale.

Photo: TU Delft