The technology for floating photovoltaics has received great attention in recent years, and systems for lakes and reservoirs are rolled out in gigawatt-scale worldwide. However, the technology used there is not suitable for a marine environment with its strong waves, wind, and risks of corrosion and fouling. Therefore, new developments are required for a roll-out in this harsh environment. Several approaches are currently being investigated by companies around the world, including in Belgium, with some of them now approaching pilot stage.
There are distinct advantages for this technology over land-based PV installations:
- Enabling the deployment of modular large-scale photovoltaic parks which can be built efficiently even in space-constrained and densely populated countries like Belgium
- Eliminating competition with land use such as agriculture
- Increased energy yield due to the cooling effect of the nearby cold water masses and wind at open sea
- Co-utilization of space and offshore grid connections when combined with wind farms.
Over 2 years, the research consortium has conducted an independent bottom-up study to determine the potential of OFPV solutions for energy generation in the Belgian sea. In order to do so, we have performed research and simulations towards the power generation potential, assessing the impact of wave motion, reflections, temperature, wind and soiling on the power of the system. We have investigated different mechanical structures, starting with the analysis of published concepts, going through own simulations, and ending with wave tank tests on our own prototypes. Learnings about structural concepts were fed back to the energy yield simulation in order to refine the power generation analysis.
Further to the mechanical structure, the design of the electrical system was investigated. Here, the choice of components and the electrical architecture have to be optimized for maximal reliability and resilience, since any faults occurring out at sea are extremely hard to fix. Crucially, we have to decide which conventional components are fit for use, and where specific developments are required to fulfil the requirements of the harsh environment.
A big factor influencing the cost of the generated energy is the grid connection. Here, we aimed to co-utilize the infrastructure of existing wind farms in order to keep costs in check. Analysis was done to understand how much solar power can be added to the existing wind turbines without losing too much energy due to curtailment, which becomes necessary if high degrees of wind and solar generation coincide. This can potentially influence the design of offshore grids for hybrid wind/solar farms that have not yet been built.
Next to the generation, interaction with the environment needs to be taken into account. Therefore, we investigated the effect that such a system has on the environment and determine potential constraints on the size of structures or the surface coverage density. Also, the effect of organisms on the structure were considered, such that the system is kept in operating condition while being benign to the environment.
The research institutions have combined their specific expertise for the best of the project: PV module technology and performance simulation of imec, reliability, electronic design and testing capabilities of UHasselt, knowledge on marine biology of RBINS, and competencies in electrical design, grid connections, marine technology and biology of KU Leuven.
“With the existing expertise of the partners, we are well positioned to deliver multidisciplinary research in this very challenging field of energy generation, which holds huge potential for a large expansion on the scale of several gigawatts. It can help putting Belgium firmly on the map when it comes to innovative renewable energy generation.”, says Johan Driesen, Professor of Electrical Engineering at KU Leuven and affiliated with EnergyVille.