Platform for Ocean Energy (PLAT-O) is a submerged taut moored, buoyant, subsea reaction sub-system, which acts as a support structure for tidal turbines. When in operation, the platform positions the turbines in the optimum high flow, low wave region of the water column for the extraction of energy from the tidal stream. PLAT-O has been designed to maximize power capture while minimizing operational costs and operations and maintenance (O&M) requirements.
PLAT-O relies on the buoyancy of the installed structure acting against a taut mooring system. The interaction of these elements produces a stable platform capable of supporting two turbines in normal operating conditions. The platform also has the ability to comply with the tidal stream, current and waves in extreme conditions reducing the loads produced. Since the load is transferred to the seabed in a straight line via the mooring lines, which act in tension, the weight of all system components is easily optimised in comparison to traditional seabed mounted structures. In addition, the turbines can be positioned in the optimum position to balance the loading caused by wave action against the increased power available in the tidal flow with separation from the seabed boundary layer.
SME has been developing the PLAT-O concept since its inception in 2012. In order to achieve a step change in the cost of tidal energy SME has pursued the development of small generation installations with matching diminutive capital expenditure and O&M costs. SCHOTTEL Hydro has supplied SCHOTTEL Instream Turbines (SITs) for the PLAT-O project.
For specific information related to the EMEC Fall of Warness site see: https://tethys.pnnl.gov/annex-iv-sites/emec-fall-warness-grid-connected-...
This document details information specific to SMEs PLAT-O#1 device.
The proposed device will be installed at a minimum clearance to surface of 11m within EMEC’s Fall of Warness tidal test site. The location of the rock anchors will be in the northwest of the EMEC test site, connecting to EMEC Berth 7.
Rock anchors were installed on site in May 2016 with the device planned for instalment in September 2016. However, following this preparation the PLAT-O#1 device was not installed at the Fall of Warness test site and there are no plans to deploy anything in its place at present.
SME has since progressed onto development of the PLAT-I tidal energy platform in Grand Passage, Nova Scotia, which was installed in September 2018 and began generating power in February 2019.
The European Marine Energy Centre (EMEC) has been accredited with the UK Accreditation Service (ISO 17025) since 2005. EMEC has been granted the consents required to install an agreed ‘envelope’ of device types at these sites.
Each developer deploying at EMEC is required to submit device-specific information to support amendment of these consents to allow installation of their device. This information includes a project summary and details on how the specific device details align with the EMEC environmental description and navigational risk assessment. The following licence applications have been submitted by SME:
· Marine Licence under Marine (Scotland) Act 2010, Part 4 Marine Licensing
· Licence to disturb marine species (EPS licence) under The Conservation (Natural Habitats) Regulations 1994
· Licence to disturb basking sharks (Cetorhinus maximus) under The Wildlife and Countryside Act 1981 and the Nature Conservation (Scotland) Act 2004 (W&CA)
The Fall of Warness site’s seabed ranges from eroding sub-littoral sandbanks in the east to smooth scoured bedrock ridges and platforms with occasional boulders towards the center of the site. Fall of Warness is not a protected area; however, there are protected sites in close proximity. These include:
- Faray and Holm of Faray SAC – protected for its grey seal populations.
- Sanday SAC – Protected for its harbor seal populations, intertidal mudflats and sandflats, inshore sublittoal rock and subtidal sandbanks.
- Muckle and Little Green Holm SSSI – Nationally important grey seal breeding colony (Around 3% of the national breeding population).
EMEC has produced a specific Environmental Appraisal (EA) for the Fall of Warness site which can be downloaded from here.
Potential disturbance to marine mammals and birds as a result of vessel activity during installation and during O&M procedures, installation of the rock anchors resulting in noise impacts and the potential for collision with marine mammals and birds are considered the key environmental issues for the Project.