Nereus™ – Powering AUVs using Ocean Waves

Autonomous underwater vehicles (AUVs) and unmanned underwater vehicles (UUVs) are devices that perform underwater tasks without a connection to a surface vessel and that carry instruments and sensors that monitor, inspect and survey underwater environments. Although they are a less expensive and safer alternative to traditional means of conducting such tasks, the power capacity of batteries remains a constraint that keeps their missions limited in range and duration, often to as little as a few hours. Docking and recharge stations can extend the range and duration of AUV missions by recharging their batteries at sea, as well as providing a secure platform for docking between missions. Underwater recharging of AUVs would reduce the need to recall vehicles to the surface as frequently; save time and resources; improve human safety on ships at sea; increase mission duration, range, and stealth; and lower carbon emissions. However, underwater docking stations are not widely used because they lack a practical power generation source. Resolute Marine is developing an innovative wave-driven powering system called Nereus™ that can provide a locally generated, reliable power source for underwater docking and recharge stations. Nereus™ is a novel combination of wave energy conversion and piezoelectric technologies that consists of a Single Point Absorber (SPA) that produces electricity using a piezoelectric generator with a targeted 10 kW power rating to meet the needs of our first customer and project partner, Marauder Robotics. The goal of this project is to design, build and test a compact and self-contained wave energy converter that is easy to deploy and requires minimum maintenance to provide power for AUVs. In Phase I, the project will focus on; a) the design of a proof-of-concept Nereus™ system through modeling and optimization of the wave energy converter for operation in a broad range of sea- states; b) focused design on the piezo-electric power take-off; and c) system modeling to demonstrate the compatibility of the Nereus™ system with Marauder Robotics’ requirements. Globally, the AUV market is estimated at $2.6 billion and is expected to double by 2022. The market for underwater AUV charging stations, which includes the charging stations and associated infrastructure, is not well developed and has an unknown value but is expected to grow at a similar rate as the AUV market. Looking beyond its application for AUVs, Nereus™’s addressable market also includes powering ocean observation and navigation systems where battery life severely limits endurance and increases mission costs. The world market for navigational and survey instruments more than doubled between 2001 and 2011, from $7.5 billion to $16 billion suggesting that this is an attractive market opportunity for Nereus™ systems.