Wave Energy Converter Layout for Maintainable RO Desalination

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Solution Overview

Problem

Existing wave-actuated desalination systems face challenges in maintenance and repair due to underwater components, making access difficult and inefficient.

Innovation Solution

A wave energy converter subsystem connected to a reverse osmosis desalination system with a horizontally disposed hydraulic cylinder and line management system, allowing for above-water access and maintenance, utilizing a catamaran-type float with expandable hulls and a line management system to facilitate efficient energy harvesting and desalination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the hydraulic cylinder and other components are placed underwater to enable wave energy harvesting, then the system can effectively convert wave energy for desalination, but maintenance and repair operations become difficult due to poor underwater visibility and accessibility

Engineering Contradiction:
Improvewave energy conversion efficiencyVSAvoidmaintenance accessibility
Core Design Contradiction:
PowerVSEase of repair

Solution Approach 1:

The system is divided into two distinct segments: an underwater wave energy conversion subsystem (float, hydraulic cylinder, pulleys) and an above-water desalination subsystem (RO membranes, processing equipment). This segmentation allows the energy conversion components to remain underwater for effective wave energy harvesting while the desalination components are accessible for maintenance on the float surface or onshore.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A hydraulic transmission system acts as an intermediary, transmitting mechanical energy from the underwater hydraulic cylinder through hydraulic fluid to the desalination subsystem. This intermediary mechanism enables the separation of power generation (underwater) and power utilization (above-water), resolving the contradiction between underwater component placement and maintenance accessibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If the hydraulic cylinder is disposed horizontally to optimize wave energy harvesting, then energy conversion efficiency improves, but the complexity of the line management system increases due to the need for proper line engagement and tension control

Engineering Contradiction:
Improveenergy harvesting efficiencyVSAvoidline management system complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The line management system is designed to be self-regulating through the natural buoyancy and weight distribution of the float and anchor assembly. The vertical line segment automatically maintains tension and proper engagement with the horizontal hydraulic cylinder rod, eliminating the need for complex active tension control mechanisms while preserving energy harvesting efficiency.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the connecting member length is made variable and controllable to adapt to sea level changes, then the system can maintain optimal operation under varying sea conditions, but the device complexity increases due to additional control mechanisms

Engineering Contradiction:
Improveadaptation to sea level changesVSAvoidcontrollability mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connecting member length is made dynamically adjustable through a telescopic or extendable mechanism that can be modified based on sea level conditions. This dynamic adaptation allows the system to maintain optimal geometry for wave energy harvesting across varying sea levels without requiring complex active control systems, as the adjustment can be performed passively or with simple mechanical means.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4251873B1Wave-actuated system, wave energy converter subsystem, and method for operating a reverse-osmosis desalination subsystem
Publication Date: 2026.03.18 ONEKA TECH
  • EP4251873B1 patent drawingFigure 1
  • EP4251873B1 patent drawingFigure 2
  • EP4251873B1 patent drawingFigure 3

AI summary

A wave-actuated system for desalination of water by reverse osmosis (RO) has at least one offshore wave energy converter subsystem for pumping salt water and supplying the pumped salt water via a water outlet, a pretreatment subsystem hydraulically connected to the water outlet of the at least one offshore wave energy converter subsystem, and a RO desalination subsystem receiving filtered water from the pretreatment subsystem. The at least one wave-energy converter has a float and a hydraulic cylinder pumping salt water to the RO desalination subsystem. A method for operating a reverse-osmosis desalination subsystem using pressurized salt water supplied by at least one wave energy converter subsystem is described. A method for making a hull is also described.