Presentations

Abstract

Floating offshore wind (FLOW) requires anchoring systems that combine high load capacity, omnidirectional stability, seismic resilience, and environmental sustainability at competitive cost. Anchors are among the most capital-intensive and environmentally sensitive components of FLOW, and conventional steel anchors pose challenges due to high embodied carbon, supply-chain dependence, corrosion, and installation vessel requirements. Under California Energy Commission award EPC-23-003, Sperra and its partners are developing reinforced concrete suction and torpedo anchors manufactured with automated 3D concrete printing, sprayed concrete, and cast-in-place methods. By replacing imported steel with locally sourced materials and portside fabrication, these anchors can reduce manufacturing costs by 37–82% and lifecycle CO₂ emissions by 71–78%, while creating ~25% more jobs through regionalized supply chains. The project brings together expertise in structural and geotechnical engineering, lifecycle and economic assessment, and environmental planning to establish the technical and commercial basis for these anchors. The project has advanced front-end engineering design (FEED), port-based manufacturing planning, lifecycle and environmental assessments, and geotechnical modeling for 15 MW platforms in California’s Humboldt and Morro Bay Wind Energy Areas. Although rooted in U.S. conditions, the findings are directly transferable to Europe. Ultra-deep Atlantic waters off Portugal, Ireland, and Norway present similar hydrodynamic and soil challenges, while seismicity in the Mediterranean mirrors California’s risks. Europe also faces port infrastructure bottlenecks that concrete anchors, fabricated at scale in-port, are designed to overcome.