US sea-bottom sensor net powered by 'stroking buoys'

The US Navy, often at odds with environmentalists, made a move which might please the green community yesterday. The service has awarded a $3m contract to a company producing wave-power buoys, intending to use them in an oceanic sensor array.

The cash goes to Ocean Power Technologies of New Jersey, which has been working on its PowerBuoy® kit since 1997 and is listed on both the London AIM and Nasdaq exchanges. The Nasdaq flotation last year raised some $90m. The firm is also involved in more conventional wave-power projects based in the US, UK and Spain.

The USN intends to use the buoys to power the second phase of its Deep Water Active Detection Systems (DWADS) programme, which is expected to see a fixed, unattended sensor network deployed in the oceans off America's coasts carrying out such tasks as "vessel tracking for homeland security".

The contract follows a trial of a single PowerBuoy off the New Jersey coast last month, serving to confirm the company's performance predictions.

"We are very pleased to have received this new contract from the US Navy, following the deployment of our first DWADS PowerBuoy last month," said the CEO of Ocean Power, George Taylor.

"It builds on our experience in deep-water power source applications, and we believe the PowerBuoy will make a unique contribution to the success of the Navy's highly advanced data gathering and communications program."

According to the Ocean Power Tech website, a PowerBuoy "moves freely up and down. The resultant mechanical stroking" is used to generate energy.

This is in contrast to other, more radical "bulge wave" designs lately proposed, which would operate by "squeezing the tube more and more and causing the bulge... to get bigger and bigger". ®