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EHL Group: Latest update on their US wave energy technological research project

By Neil Ritchie

Taranaki’s EHL Group, formerly Energy Hydraulics, is hoping its first major involvement in an international research project – the design, fabrication and testing of a wave machine destined for use by the American Navy – proves a success.

For the past few years EHL has been assisting the Northwest Energy Innovations (NWEI) company based in Portland, Oregon, to develop its Azura wave power technology for converting the endless supply of ocean waves into electricity to help meet the rapidly growing global demand for renewable energy.

And EHL design engineer Derek Shotbolt believes if the current and future trials are successful -- and the US Navy adopts the Azura prototypes and starts using full-scale wave machines -- then the EHL-NWEI research project could prove very worthwhile.

“This was our first real research project and we got involved after the initial involvement by the government’s Callaghan Innovation organisation.

“I could say this is ground breaking work, though ocean breaking would be more appropriate, with possibly huge potential.”

Photo below: EHL design engineer Derek Shotbolt (left) and American electrical and test engineering consultant Terry Lettenmaier with the half-scale prototype wave machine being tested at EHL’s New Plymouth workshop for the United States Navy.

EHL and electrical and test engineering consultant Terry Lettenmaier, who is contracted through the University of Hawaii to undertake work on behalf of NWEI, are presently testing a scaled down version of the planned full size Azura wave machine in EHL’s Bell Block premises, particularly the electrics and electronics, as well as conducting simulation programmes.

Then at the end of July the half-scale machine, which still weighs about 4.5 tonnes and is about eight metres tall, will be shipped to Hawaii for a year-long test off a US naval base and likely further refinements. This half-scale machine will be capable of producing about 20kW of power, though the full-sized version will be capable of producing about 1MW or so.

This latest demonstration project will also involve connection to the local electricity grid at the US Navy’s Wave Energy Test Site at the Marine Corps Base.

Extensive performance data will be collected over a wide range of wave and electrical loading conditions. And data collected will be analysed to help optimise the wave machine’s performance and inform the partners of possible future developments of commercially viable devices.

Unlike other wave energy technologies, Azura extracts energy from both the heave (vertical) and surge (horizontal) motion of the wave, producing power from the relative motion between the hull and float.  

Since commencing operations in 2010, NWEI and its partners have successfully completed several pilot scale projects in New Zealand and Oregon, with the US Department of Energy and Callaghan Innovation (formerly Industrial Research Ltd) providing initial funding for this prototype research work.

The Hawaii project represents the fourth ocean deployment of the Azura technology. Experience gained from each round of testing is being used to increase power output, reduce costs, and improve the durability and survivability of this innovative wave energy converter.

EHL is a Taranaki based specialist company that provides precision-engineered solutions for a wide variety of mobile, oil and gas, industrial and marine markets. It is also a leading provider of motion and control technologies and systems.

“EHL has grown substantially since founder and current chief executive Peter Jannings started the company years ago with only a few staff. Now we have about 60 staff in our New Plymouth and Auckland workshops.

“And the future will look even brighter if we prove the commercial viability of this wave machine and we go into production,” Derek concludes.

View EHL Company Capability profile here