This report looks at the Pelamis P2 mooring system and the cost metrics associated with the major components therein. The P2 mooring system was a chain based catenary spread incorporating electrical export and communication components.
The catenary mooring system utilised standard embedment anchors, with chain lines on the sea bed to give the required spring force, and synthetic tethers rising up through the water column to the machine connection point. The necessary equipment to enable the rapid connection and disconnection of the Pelamis WEC to/from its moorings was located at this connection point. This connection point included a remotely operated locking system to allow both mooring and electrical connections to be made in a single unit. The Tether Latch Assembly (TLA) costs are broken down to show elements including the wet-mate connector, dynamic cable and mechanical components.
The majority of costs used in this report are those for moorings components for the P2 mooring spreads deployed at the EMEC site in Orkney in 2010 and 2011 with the actual purchases being made from 2009 onwards. Some items in the system were replaced over the course of the P2 operations programme, procured as spares, or for ongoing operations and these later costs have been included if appropriate.
Each major component in the Pelamis mooring system is considered in the document and the most appropriate cost metric for that component defined. Appropriate metrics for each of the major components are then brought together to provide example costings for three indicative systems, namely;
- Single device with passive yaw system
- Single device with active yaw system
- 10 machine farm with active yaw system