Marine Energy

Cable installation to begin for PacWave South wave energy test site

Cable installation to begin for PacWave South wave energy test site

Crews are preparing to begin installing the power and data cables that are essential to completing construction of the PacWave South wave energy testing facility off the coast of the U.S. state of Oregon.

The cables will support PacWave South, which Oregon State University said is the first pre-permitted, utility-scale, grid-connected wave energy test site in the U.S. When the facility is completed, wave energy developers will be able to test technologies for harnessing the power of ocean waves and transmitting that energy to the local electrical grid.

The work includes installing four power and data cables ranging in length from about 10 to 13 continuous miles from a vault under the parking lot of Driftwood Beach State Park south of Newport out to the test site offshore. Louisiana-based subsea cable services contractor R.T. Casey is overseeing the installation.

“Transmitting power from wave-energy generators to shore in a form compatible with the regional power grid is a huge challenge, and cabled connection from PacWave South provides the capability to test power-delivery technologies,” said Burke Hales, PacWave’s chief scientist and a professor in the OSU College of Earth, Ocean, and Atmospheric Sciences. “These cables are highly specialized and their installation and burial is a keystone of wave energy development in the U.S.”

The installation process is expected to take six to seven weeks, depending on ocean conditions, said Dan Hellin, deputy director of PacWave.

The cables will be anchored in an underground vault at Driftwood and will run through conduits from the shore under the beach, then come up out of the seafloor about 1 mile out. From there to the test site, the cable will be buried about 3 feet under the seafloor.

The subsea cables, which were manufactured in Norway by Paris-based firm Nexans, were transported via freighter to Louisiana and transferred to Offshore Support Vessel (OSV) HOS Innovator, which will be used to lay the cables, to make their way to Oregon. Once the work begins, the OSV Nautilus will follow behind to bury the cable using a remotely-operated vehicle. Those two vessels are expected to work around the clock for the duration of the installation, Hellin said.

A third vessel, the M/V Liberty, will support diving operations during the cable installation and provide other assistance as needed. That vessel will make trips back and forth from Newport while the work is under way, Hellin said.

On land, another group will be installing cables that run from the vault to a shoreside utility connection and monitoring facility on the east side of Highway 101 just south of Driftwood. Two of the three buildings at the site are nearly completed and the third is a couple of months behind them, Hellin said.

Once the cables are installed, the open ocean test site will be marked with a series of buoys to alert mariners traveling in the area, Hellin said. The first wave energy developer is expected at PacWave South in 2025, and the first cable-connected test is expected in 2026 under current timelines.

The ocean test site is on a sandy-bottomed stretch of the Pacific Ocean away from popular commercial and recreational fishing reefs, about 7 miles off the coast south of Newport. The site will have four test berths, which combined can accommodate up to 20 wave energy devices at any one time.

PacWave South is supported by grants from the U.S. Department of Energy, state of Oregon and other public and private entities. Oregon State’s College of Earth, Ocean, and Atmospheric Sciences is managing the construction and operation of the more than $100 million facility.