DESC0024022

Floating offshore wind power is poised for rapid growth in the US, where approximately 2/3 of the US offshore wind energy potential (2.8 out of 4.3 TW) exists over waters deep enough to require the use of floating platforms. However, cost remains an obstacle to extensive, rapid deployment of floating offshore wind. Anchoring floating wind installations to the sea floor is presently up to 15% of total floating offshore wind capital cost and thus presents an important opportunity for cost reduction. 3D-printed concrete torpedo anchors will reduce the cost of floating wind. Torpedo anchors are piles that are dropped passively through water bodies and embed in the bottom like large darts and have been proven effective by the oil and gas industry. They offer a number of advantages over traditional anchor designs, including relatively low-cost fabrication, fast installation (quickly dropped into place), omnidirectional loading, and high horizontal placement accuracy needed for shared anchors and semi-taut and taut mooring configurations. However, the large quantity of steel used to construct torpedo anchors results in high costs, a large carbon footprint, and foreign imports of steel or complete anchors. Innovative 3D-printed concrete torpedo anchor designs solve these issues by combining low-cost, regionally sourced concrete materials with cutting-edge automated manufacturing methods to provide lower-cost anchoring solutions for floating wind. The primary project outcome will be the advancement by two technology readiness levels (2 to 4) of a scalable, low-cost, environmentally friendly concrete torpedo anchor that is suitable for a wide variety of floating offshore wind seabed areas and mooring types. The key project objectives are to (1) generate anchor design loads for a reference deepwater floating wind plant, (2) perform preliminary front-end engineering design of four concrete torpedo anchor concepts, (3) downselect a single concrete torpedo anchor concept, (4) plan anchor qualification and large-scale structural testing of selected anchor (Phase II), (5) use 3D concrete printing to fabricate a prototype anchor at up to 1/3 scale and a section of the torpedo anchor at full-scale, and (6) disseminate project information to stakeholders. This SBIR/STTR project will develop a next generation torpedo anchor made from concrete that cuts manufacturing costs 58–82% and slashes CO2 emissions 86–96% vs. traditional steel torpedo anchors. Overall, floating wind cost will be reduced by 5.8–12%. These anchors are designed to be made quayside in US ports using low-cost automated manufacturing paired with locally sourced materials, which will increase local economic benefits and jobs for surrounding communities. The project team will also host tours for over 100 local community members of the 3D printing site in Los Angles, California.