CalWave Spring and Pre-Tension Systems for Wave Energy Converters

Statement of problem or situation that is being addressed in your application: Despite the vast resource potential, no ocean wave energy converter (WEC) design has yet proven a levelized cost of energy (LCoE) competitive with established forms of renewable energy. One key subsystem for enabling WECs is the pre-tensioning system that is part of a rotary power take-off (PTO). To effectively extract energy from ocean waves and keep the device on station, any type of WEC system that is taut moored with an integrated PTO/mooring requires a pre-tension subsystem. To produce commercially viable WECs, the pre-tensioning system needs to be cost competitive while also meeting various functional requirements. General statement of how this problem will be addressed in the project: A systematic analysis of existing and promising alternative spring and pre-tensioning subsystems for PTO subsystems for WECs will be conducted. The study of pre-tensioning systems will be validated by experimental testing and compared with an existing, technically viable hydraulic gas spring pre-tension system. What is to be done in Phase I? CalWave will conduct a detailed pre-tension system scoping study, evaluate currently available options, and down selecting to the most promising alternatives. These most promising alternatives will then have scaled prototypes be designed and manufactured. The scaled prototypes will then be tested on a test apparatus and have their performance compared against each other. Commercial Applications and Other Benefits: This project will put CalWave on a path to ensuring the best industry available pre-tensioning system is included in its successful xWave architecture, improving the odds of successful commercialization. The ideal outcome is to improve the design of the pre-tension mechanism such that it is more suitable for utility scale WEC devices than the existing design. This could provide big dividends for both the capital and operating expenditures required for utility scale WEC devices.