On the annual wave energy absorption by two-body heaving WECs with latching control

Although the latching control strategy has been recognized as an important mean of increasing the efficiency of one-body point-absorbing wave energy converters (WECs), its effectiveness in two-body floating point-absorbers has been questioned in some studies. The current work investigates the increase in annual absorbed energy achieved with a simple threshold unlatching control strategy when applied to a generic two-body heaving WEC. The WEC performance is evaluated for a set of sea-states characteristic of the wave climate off the Portuguese west coast. To achieve this computationally intensive task, a new high-order numerical method for the solution of the Cummins equations is presented and used. This approach is based on a polynomial representation of the solution, whose coefficients are computed using a continuous least-squares approximation. The code has been parallelized and computations were performed at the IST cluster. (C) 2012 Elsevier Ltd. All rights reserved.