Design of Morring Systems for Floating Wave Energy Converters (MOORWEC)

Duration: 01.04.2010-30.09.2012 (30 months)

Coordination: Instituto Superior Técnico

Partners: Instituto Superior Técnico (IST/UTL), Faculdade de Engenharia da Universidade do Porto (FE/UP), Instituto de Engenharia Mecânica (IDMEC), Martifer Energia - Equipamentos para Energia, S.A. (Martifer Energia)

Funding Entity: Portuguese Foundation for Science and Technology

The objective of the project is to investigate the hydrodynamic problem of the mooring of floating wave energy converters (WECs) and develop methods, tools and procedures to support the design. Most of the concepts proposed and investigated over the last years can be classified as Near Shore Devices to be installed in water depths up to around 80m, but in general between 40 and 60m. These WECs are kept in station by mooring systems. One of the critical components of the floating WECs is the mooring system. On one hand the cost is significant compared to the global cost of the device (as a reference value, around 25% of the global cost). Additionally, due to shallow water, the ratio between the horizontal motions of the floater and the water depth is large, thus increasing the probability of snatch loads, as well as the complexity of the hydrodynamic problem. The mooring problem of floating WECs is different from that of existing floating offshore structures, since the later are installed in much deeper waters and also the dynamics of the platforms are different. This means that the accumulated experience in the design of mooring systems for offshore platforms, and the related design procedures, cannot be applied directly for the design of the new mooring systems of floating WECs. For this reason the design must be done by methods based on first principles accounting for the stochastic characteristics of the waves and the system responses in the local of operation. The objective of the project is to develop methods, calculation tools and procedures to support the design of mooring systems of floating near shore WECs, and analyze the mooring problem for arrays of WECs. The methods to be developed will be useful for the mooring design of other complex floating structures. The interaction between the floater, simple or articulated, and the incident waves will be calculate by a Green function higher order boundary element method.

Project Team

Associated Publications