Being an environmentally responsible technology is of high importance to Pelamis. We have identified aspects of Pelamis infrastructure that could impact local habitats and taken steps to address these, to ensure that Pelamis installations remain environmentally benign.
Power Take Off System
Pelamis has a hydraulic power take-off system with the capability to remotely isolate various parts of the system. In the unlikely event that a leak of hydraulic fluid occurs within a module, there are two levels of protection on all leak points, both of which would have to fail to allow water to ingress to a point where fluid could escape to the outside environment. A sophisticated onboard monitoring system enables us to detect the smallest changes at an early stage. Unlike the fuel tank of a passenger ship or any sort of oil and gas platform, only very small quantities of transmission fluid are carried and this does not pose a threat to the marine environment
A number of mooring system options are available to Pelamis. Currently, the system is based on a standard anchoring system based on embedment anchor, chains and tethers. This system does not currently require piling or rock pinning for installation, nor does it require heavy gravity based solutions. The components used within the Pelamis mooring system, such as chains, ropes and anchors, have been designed to have a minimal footprint and are easibly removed. More information on our offshore infrastructure can be read on the 'Wave Farm Infrastructure' page.
Unlike a vessel, where marine growth causes drag and can increase fuel costs, any increased drag to Pelamis due to marine growth is negligible. As such the system is largely tolerant of some growth. While we use localised anti-fouling protection systems to protect key areas such as the heat exchanger system, the main hull of the machine does not require any anti-fouling measures. We aim to learn more about biofoulling as the machines remain in the water for longer periods of time.
The ocean can be a noisy environment from waves, tide and existing boat noise. Pelamis may introduce some noise through movement of chains or sound of generators. Modelling of the acoustic output of the machine was undertaken by independently contracted consultants Qineteq as part of the Scottish Marine Renewables Strategic Environmental Assessment. Modelling concluded (based on limited data) that the risk of marine mammals or fish experiencing permanent or temporary loss of hearing sensitivity was insignificant. We aim to investigate and model noise impacts in more detail in the future.
Pelamis have already successfully demonstrated the complete removal of a mooring spread and decommissioning of a machine when the first full-scale prototype machine and its subsea infrastructure was removed from EMEC in 2007 over just a few days. The decommissioning process of a Pelamis machine and associated onsite infrastructure is relatively simple and has minimal environmental impact and cost. The machines themselves are removed from site under normal Operation and Maintenance processes and materials and components can be recovered for scrap, reused or disposed.
Pelamis Wave Farms
Wave farms developed in the UK using Pelamis technology will be required to carry out a full Environmental Impact Assessment (EIA) to identify potentially significant impacts on the environment and other sea users. Where potentially significant impacts on local environment are identified, measures to reduce or mitigate these will be required. More information about the site development process can be read on the 'Site Development' page.
Understanding Environmental Interactions
The wave energy sector is new, and there are some information gaps around potential impacts of various technologies on the environment. To address these gaps, Pelamis Wave Power is working with our customers and a range of academic institutes to develop an environmental work programme. We are involved in the ‘Hebridean Marine Energy Futures’ project, a consortium led by Lews Castle College, part of the University of Highlands & Islands, which has received funding for a range of activities including gathering environmental data and evaluating monitoring methods. The results will assist regulators in understanding how wave energy machines interact with the environment.