| Summary: |
The goal of the project is to develop and evaluate two different technologies for wave energy conversion using physical and numerical modeling, as well as to design efficient mooring systems for the devices when installed near the coast and offshore. To achieve these goals, numerical codes developed by the institutions, available in open-source or commercial programs, will be used, adapted to reproduce the hydrodynamic behaviors of the two technologies and include the nonlinear effects due to the mooring systems and the energy extraction system (PTO), both in time and frequency domain.
Unlike other renewable energies, where the number of technically and economically feasible technologies is limited, several technologies can coexist to extract energy from waves, depending on local conditions.
Nearshore and offshore sites are often attractive for wave energy converters (WEC) due to the high power level and potentially lower impacts, but may require mooring systems to maintain the correct position, avoid impacts with other structures, and excessive strain on the electrical cables. This key element represents a significant part of the device cost and has to be developed in a way that does not affect the performance of the WEC.
The CECO is an innovative converter, developed in such a way as to simultaneously absorb the kinetic energy and the potential energy of the waves. The experimental proof of concept was carried out at FEUP, but further studies are needed to improve its performance, as well as to develop mooring systems for deep water applications.
The FOWC is being studied at IST using numerical modeling. It has already been shown that floating oscillating water column devices have a high capture width and can be commercially installed in energy regions, however, further studies are needed to optimize energy production and reduce costs. The study will focus on the hydrodynamic characteristics of different geometries, the PTO control strategy and efficient mo  |
Summary
The goal of the project is to develop and evaluate two different technologies for wave energy conversion using physical and numerical modeling, as well as to design efficient mooring systems for the devices when installed near the coast and offshore. To achieve these goals, numerical codes developed by the institutions, available in open-source or commercial programs, will be used, adapted to reproduce the hydrodynamic behaviors of the two technologies and include the nonlinear effects due to the mooring systems and the energy extraction system (PTO), both in time and frequency domain.
Unlike other renewable energies, where the number of technically and economically feasible technologies is limited, several technologies can coexist to extract energy from waves, depending on local conditions.
Nearshore and offshore sites are often attractive for wave energy converters (WEC) due to the high power level and potentially lower impacts, but may require mooring systems to maintain the correct position, avoid impacts with other structures, and excessive strain on the electrical cables. This key element represents a significant part of the device cost and has to be developed in a way that does not affect the performance of the WEC.
The CECO is an innovative converter, developed in such a way as to simultaneously absorb the kinetic energy and the potential energy of the waves. The experimental proof of concept was carried out at FEUP, but further studies are needed to improve its performance, as well as to develop mooring systems for deep water applications.
The FOWC is being studied at IST using numerical modeling. It has already been shown that floating oscillating water column devices have a high capture width and can be commercially installed in energy regions, however, further studies are needed to optimize energy production and reduce costs. The study will focus on the hydrodynamic characteristics of different geometries, the PTO control strategy and efficient mooring systems. It will be carried out both for devices operating individually and for multi-purpose platforms. In the latter case, the FOWC, in addition to producing energy, has the mission of protecting harbors from sea agitation as a floating breakwater.
The design of mooring systems for WECs is complex and varies from case to case, due to the diversity of operating principles and system requirements. On the other hand, knowledge from the offshore industry is not sufficient, due to differences in typical water depths, design principles, safety margins, and more. Since the dynamics of a WEC and its mooring system are interconnected (i.e., the motions of the WEC depend on the history and position of the mooring cables and vice versa) a coupled dynamic analysis is required in which the PTO is also included.
The project is divided into 6 tasks. Tasks 1 and 2 aim to improve the numerical codes needed to study the performance of different geometries and components of each of the technologies. Then these models will be coupled to codes for simulating the moorings (task 3) and for reproducing the PTO (task 4), both in the time and frequency domain. In this approach, the numerical models are calibrated and validated, case by case, with experimental data obtained in Task 5. |