Removal of the Need for Boreholes for Micropile Design and Installation

Subsea micropile foundation and anchoring technology is currently under development in support of the growing US marine wind energy industry. Subsea micropiles allow for marine anchors to be installed at significantly reduced cost and with a smaller environmental impact. Deep Reach Technology proposes to develop technology that will further reduce cost and environmental impact by eliminating the need for boreholes in the micropile design process. The boreholes will be eliminated by adding sensors to the subsea micropile installation system and collecting geotechnical data during the installation process. These data can be correlated to geotechnical design parameters, which will allow the pile design to be modified in real-time and in response to actual subsurface conditions. This eliminates the need for an anchor design phase and the associated geotechnical boreholes. The Phase I work established the overall technical feasibility of the concept. The Phase II work developed a prototype system to be tested on land to prove that the data collected is suitable for micropile design. Phase II is still underway, with the prototype test scheduled for June 2023. The Phase IIB work will adapt the prototype for testing offshore and then conduct an at-sea test demonstrating its operation. The result of the Phase II work will be a proven system ready to go to the private investment market for final commercialization funding. Subsea micropiles have the potential to expand the wind and wave resources available for energy generation in the United States. Anchoring systems make up a significant amount of the overall project cost for such systems, and cost savings will enable more systems to be economically feasible. At a price ranging from $500,000 - $1,000,000 each, boreholes represent a significant portion of the anchoring system cost. This effect is magnified by the fact that up to three boreholes are required per turbine. By further reducing costs, DRT’s proposed technology can accelerate adoption of subsea micropile anchors. It can also continue to drive offshore renewable energy costs down, with an ultimate objective of getting them cost-competitive with fossil fuels without the need for government subsidies.