It is great that you read us even in the summer period! As you know, we are located in Spain and these days the temperature is extremely high. In our city, Valencia, last Saturday 13 of August we reached 41oC, beating by far the 38.4oC record of year 2017. Luckily are we closed for summer holidays and fresh UHPC doesn’t need to flow in these difficult conditions…
Considering this situation, I thought of proposing a brief and refreshing dose of information in this post: I want to speak about offshore floating UHPC structures.
As far as I know, PREFFOR is the only company that is producing floating structures made of UHPC (please, if you are aware of other UHPC floating structures, I am extremely interested in knowing it!). Formex® is the registered brand of our highly durable concrete. Until 2021, all our floating structures were farms to harvest different types of molluscs (named “bateas” in Spanish), but this 2022 we floated for first time UHPC pontoons to protect floating PV systems from harsh environments.
Up to now we have already 39 structures floating in four different sea basins and in the largest EU lake, covering a total area that already exceeds the 20.000 m2. The first structure was floated for AZTI in 2016 in the Cantabric Sea (Atlantic Basin), and as all the others is still under operation and without any maintenance required. The figure below shows the relation between the Significant wave high (meters, return period of 50 years) and the water depth.
It is good to highlight that most of the structures are moored with one to four steel chains. The pontoons for floating PV were moored with an innovative mooring system designed by Seaflex (more information can be found in the EMFF project FRESHER).
In the case of the pontoons for floating PV systems, the application is totally novel, but In the case of the rafts the Formex® farms reached the market to replace a product that already existed: The wooden raft. Since the 60’, these rafts have been under operation, submitted to waves of up to 4 meters and moored to water depths of up to 40 m. Their problem was that their average lifespan did not exceed the 15 years, and continuous maintenance and reparation was required. Currently, with the success proven by the Formex® rafts, the trend in the market in a progressive replacement of the traditional structures by these durable UHPC farms. The figure below shows this reconciliation between tradition and innovation: A farmer moving his mussel ropes from an old wooden structure to his new and shining UHPC raft. Congratulations!