IMPROVED SEABED ANCHORING TECHNOLOGY Innovation Opportunity Identified at PROTTEC Retreat 26/28 October 2010 Jonathan Williams, Marine South East

Basic Ideas Permanent seabed anchors are expensive, eg for: –Offshore platforms –Renewable energy arrays Conventional installation is based on techniques developed on land –Piling/drilling –Require expensive vessels Can we envisage a novel approach, particularly for renewable energy arrays? –Using subsea tooling, based on experience with similar seabed vehicles (at SuperCAT)? MSE has performed further analysis to explore this possibility

Current Practice - Shallow Piled from jack-up barge: –Expensive (>€100k/day) –Depth limited (~35m) –Subject to weather & scheduling delays Gravity base: –Mainly for moored devices –Limited load capacity –No ‘pull-out’ capacity

Current Practice - Deep Torpedo pile: –Developed to moor FPSOs –Avoids use of expensive rig –Depends on seabed type & sufficient water depth Drill & grout –Requires very expensive drill ship Gravity base: –As for shallow water

Concept Remote tooling to deploy on seabed Explosive anchors pinning an anchor plate? –Marinise techniques used successfully on land Horizontal & vertical load capacity –Increased mooring flexibility

Market Analysis Offshore wind (deeper water >35m) –Floating turbines (eg Hywind) with mooring –Tripod/quadripod –€0.5M per installed MW (Gifford) for 15GW equals €7.5B market (but cost reduction will be essential!) Wave & tidal (floating devices) –Mooring systems need lots of anchors Eg Pelamis = 1 anchor per 250kW –Moored devices for 40% of EU target (5GW by 2020) equals 8,000 anchors –€125k per anchor (estimate) equals €1B market 35-50m water depth is priority for continental shelf renewable energy arrays

Potential Concerns Environmental noise impacts –Need risk assessment –Faster installation = less duration of impact –Easier limiting to less sensitive seasons

Science & Engineering Status Foundations & moorings identified as priority by Energy Research Centre (Edinburgh) Substantial modelling capability in foundation geotechnics Extensive engineering capability in seabed remote operations & tooling Strong scientific competence in ecosystem risk assessment