Technology Buoys Wave Energy - Aug 5, 2011 - Bill Opalka - - Technical Articles - Index - Library - GENI - Global Energy Network Institute

Technology Buoys Wave Energy

Successful trials off Scotland

Aug 5, 2011 - Bill Opalka -

Initial test results are in and an ocean wave technology is exceeding its projections in a challenging environment.

The last time we wrote about this company, Ocean Power Technologies, Inc., the trials had just started off the Scottish coast and were expected to last for three months.

OPT said the first of its new generation utility-scale PowerBuoy device, the PB150, has delivered better-than-expected initial results from tests being conducted off the northeast coast of Scotland.

“The results to date of this ocean trial, along with the Company’s experience with its grid-connected Hawaii PowerBuoy system, continue to build our confidence in the survivability, operating characteristics and energy generation capability of the PB150,” said Philip R. Hart, chief technology officer of OPT. “We are extremely pleased with the performance of the PB150. The overall system performance has exceeded our expectations, and the energy production capability of the PowerBuoy demonstrates its ability to produce utility-grade power in dynamic wave conditions around the world.”

The 150-kilowatt device was designed and developed by OPT to work in arrays of multiple PowerBuoys to generate renewable energy at commercial-scale wave power stations worldwide. It was deployed on April 15, 2011 for ocean trials at a site approximately 33 nautical miles from Invergordon, Scotland. The trials are expected to continue for an additional one to two months.

Wave conditions encountered have included storm waves, and electrical power generated by the PB150 has included peaks of over 400 kilowatts.  Average electrical power of 45 kilowatts was generated at wave heights as low as 2 meters. These levels of power exceeded OPT’s expectations of performance for this first PB150 deployment, and verifies that the system could produce up to 150 kilowatts on average, in higher wave conditions. 

The company said on-board equipment replicates grid-connection conditions to ensure its systems are subjected to full operational testing for utility applications. The power take-off system’s performance has exceeded expectations with respect to its energy conversion efficiency in the irregular ocean wave conditions encountered.

The device is transmitting data in real-time for analysis by OPT’s engineers in both the United Kingdom and the United States. A wave data buoy located near the site provides detailed information regarding incoming waves.  Using that information, OPT’s engineers calculate the power levels that should be achieved by the PB150, and analyze these against actual power generation.

During the ocean testing, periodic inspections of the system have been conducted utilizing Scottish marine operations personnel and vessels.

According to a recent report, the sector has more than 45 wave and tidal prototypes expected to be ocean tested in 2010 and 2011, after only a dozen were installed in 2009. Early success would mean the industry is ready to scale up, with some estimates that more than 1.8 gigawatts of ocean projects in 16 countries are currently in the pipeline.