DON27TZ02-NV005 — Self-Sustaining Wave Energy Capture for Persistent Autonomous Ocean-Going Systems

Develop a human-portable wave energy capture device able to deploy autonomously and generate sufficient power to effectively recharge autonomous vehicles.

Unmanned surface and undersea vehicles need regular recharging, and since they often operate far from human contact, their charging systems require a reliable, self-sustaining power source. The Office of Naval Research (ONR) believes the ideal power source will be a wave energy capture device (WECD). WECDs capture kinetic and potential energy generated by the movement of ocean waves on or near the surface of open water. The desired WECD must be portable, specifically, designed as a set of components that can each be carried by one or two people who must be able to quickly assemble and disassemble those components. Components designed for one-person carry should weigh no more than 14 kg with largest dimension no greater than 1.9 m, while components designed for two-person carry should weigh no more than 45.4 kg with largest dimension no greater than 2.3 m. The WECD must be able to be relocated to areas of very different depths, including full ocean depth so the WECD’s design cannot require placement or anchoring on the sea floor. And since the WECD may need to deploy near the shore, its design must allow it to function in waters as shallow as 100 meters. Ocean weather conditions can be challenging. The WECD should function reliably at Sea State 6 or less (very rough seas, with wave heights of 4 to 6 meters), and it should be able to survive conditions up to Sea State 8 (very high seas, with wave heights of 9 to 14 meters). ONR assumes the WECD will be tethered to some device at or near the surface of the water. That tethered system may be an autonomous vehicle in loiter mode, and since loitering involves continuous vehicle movement, the WECD should operate reliably while in motion, and its design should leverage such motion to increase energy capture. The WECD should produce a minimum of 20 kilowatt-hours (kWh) per day, but more is highly desirable. ONR believes 100+ kWh per day is achievable. Even in calm seas, the ideal WECD should produce sufficient electricity to charge a 2-kWh battery in 6 hours or less. Vehicle movement may be considered when ensuring this minimum level of power generation. The desired WECD may be needed in areas where human assembly is impractical. Thus, the deliverables must include a prototype device capable of deploying the assembled WECD from the deck of a medium or large autonomous surface vessel. Like the WECD itself, the deployment device (DD) should function reliably in challenging weather conditions: Sea State 4 or less (moderate seas with wave heights of 1.25 to 2.5 meters). Once deployed, very little of the WECD itself should be visible at the surface of the water. The WECD should minimize any increase in the visibility of the vehicle it is tethered to. This includes surface and airborne observation, both optically and by radar. Acoustic noise generated by the WECD should either be minimized or disguised to seem environmental or biological. Cost for the WECD and associated DD should be minimized. ONR expects that under certain environmental conditions or mission requirements, WECDs may not be recoverable. At full-rate production, the ideal price will allow for multiple units per million dollars. Under normal operating conditions, including Sea States of 6 or less, the expected operational duration of the deployed WECD should be at least one month, with three months or more expected if Sea State 4 or less is maintained.

Develop a concept for a WECD and DD capable of satisfying the listed requirements. Evaluate feasibility of the conceptual design by performing modeling and simulation, supplemented by component-level laboratory tests and water tank tests as appropriate. Provide required Phase I deliverables to include design plans and schematics for the WECD and DD, along with test and evaluation reports that are sufficiently detailed to enable ONR to assess the feasibility of the contractor’s proposed approach; and a Phase II plan.

Complete design and perform fabrication, verification, and testing of a prototype WECD and prototype DD based on the designs completed in Phase I. Perform testing that can include modeling and simulation (M&S); any such M&S must be validated and supplemented by in-water tests and must include at least one end-to-end sea test. Evaluate the performance of the WECD and DD during tests against the objectives expressed in the Description. Provide deliverables that include the prototype WECD and DD, along with an evaluation report that is sufficiently detailed to enable ONR to assess the performance of the contractor’s prototypes with respect to all objectives. Develop a plan for production of WECD and DD devices, making whatever improvements are appropriate based on the results of testing and evaluation in Phase II.

Validate the production plan with low-rate initial production (LRIP) of WECD and DD devices, and tests of those devices using a combination of M&S and in-water tests, including sea tests. Deliver at least one set of WECD and DD from LRIP to Navy operators for extended testing. (Note: All test data generated by the Navy will be shared with the contractor.) Evaluate the LRIP units for consistent performance and reliability based on the objectives expressed in the Description. Deliver LRIP WECD and DD units and evaluation reports that are sufficiently detailed to enable ONR to assess the units’ performance with respect to all objectives.