Wave-driven Desalination For Arid California: From Lab Test to Site Selection, Storm Waves to Economic Performance

Abstract:

This paper presents laboratory test results and findings from a multi-disciplinary feasibility study of a wave energy-driven desalination system. First, novel Fluidic Flexible Matrix Composite (F2MC) non-corroding tube pumps were built at 1/50^th scale and tested at the Aerospace Structures and Materials Lab of Virginia Polytechnic Institute and State University. These tube pumps were implemented into six different configurations by naval architects and ocean engineers at PCCI, Inc., to meet a broad range of overall system requirements.

The overall system analysis considered (1) scale-up of the test specimens to 16-cm diameter x 18-meter length tube pumps for full-scale ocean deployment, (2) site selection using the National Renewable Energy Laboratory’s Marine & Hydrokinetic Energy (MHK) Atlas, (3) wave resource assessment using methods based on the International Electro-Technical Commission’s Wave Energy Resource Assessment and Characterization guide, (4) computer modeling of six different Wave Energy Converter (WEC) buoy & mooring configurations during normal and extreme storm conditions for risk assessment, (5) total WEC system design of buoys, wave pump, mooring, and pipeline, (6) installation costs using documented ship day-rates and procedures, and (7) an economic comparison between WEC and California’s electrical prices.

This research can inform other wave energy driven pumping and compression projects for supplying seawater to reverse osmosis plants. Useful new findings were that the best system used two concentric buoyant bodies, the F2MC tube pump is a promising means to pump fluids, a valuable list of costs, and that new ORCAWAVE hydrodynamic diffraction software provides similar results as WAMIT. This was a comprehensive feasibility study funded by the U.S. Department of Energy – its findings will interest WEC researchers and energy policy makers.