Testing is extremely important to the development of Pelamis technology, and Pelamis Wave Power continues to test concept of design in parallel with real sea testing of commercial machines operating at the European Marine Energy Centre.
Numerical Modelling & Analysis
Pelamis have developed an in-house software programme specifically for analysing the machine and mooring dynamics including non-linear hydrodynamics, measured fully directional spectra, detailed control and power take-off modelling, and structural load & fatigue analysis.
Numerical modelling is a vital part of the design process, as it allows rapid design evaluations and optimisations to be made. However, numerical work can be misleading if used in isolation. At every stage of the development programme, experimental models have been built and tested to validate simulation results.
Experimental Model Testing
Pelamis continues to place high importance on laboratory tank testing and qualification in parallel with at sea operations.
During the first phase of the Pelamis machines' development prior to full-scale operations in 2004, a range of scales and technology demonstration models were used to understand survival characteristics in extreme waves and verify the accuracy of our simulations.
The latest generation of tank test model in use today uses electronic joint control under computer control. This is the primary tool for the analysis of machine response in the very largest seas where no numerical simulations can yet capture the full dynamics of extreme waves. Pelamis Wave Power is active in pushing the boundaries of simulations into this extreme regime.
Pelamis Wave Power work in conjunction with our suppliers to test machine components under representative conditions and over extended duty. These tests include; impact testing, accelerated cycle and load tests to confirm component life, and extreme load tests.
The design of the Pelamis machine and its mooring system are independently verified to meet applicable offshore oil & gas standards and codes.
The successful verification of the design has allowed Pelamis Wave Power to secure commercial insurance for all Pelamis machines.
Real sea testing
The E.ON Pelamis P2 machine, which was first installed at the European Marine Energy Centre (EMEC) in Orkney in October 2010, is currently undergoing a progressive testing programme, putting the machine through its paces in increasingly energetic sea conditions and progressing through a rigorous inspection regime. During each installation period the E.ON machine has been generating electricity into the national grid.
The ScottishPower Renewables machine will likewise be tested in parallel with the E.ON machine in a similarly progressive work-up programme.
This approach to testing allows Pelamis to verify expected behaviour and energy outputs in a controlled manner, with the ability to find and address any technical problems as they occur. Our testing strategy is enabled by the quick connect and disconnect system that allows the machine to be rapidly and remotely removed from its electrical and anchoring systems, in contrast to the 'deploy and hope' approach necessitated by one that requires a machine to be fixed to the sea bed permanently.