Streamlining of CETO 6 wave unit well underway

The CETO 6 wave energy unit (Image: Carnegie Clean Energy)

 
Australian clean energy developer Carnegie Clean Energy has made further progress with the design of its CETO 6 wave energy technology which is now ready for wave tank testing activities at the University of Plymouth in South West England.

The CETO design team has been progressing the CETO unit architecture design – including modelling – to establish the optimum physical implementation of the power take-off (PTO) inside the Buoyant Actuator (BA) to maximize power and facilitate construction for the Albany Wave Energy Project (AWEP), Carnegie informed.

Testing campaigns to validate preferred PTO designs are currently under development, according to Carnegie, while further design and analysis of the CETO Unit performance has been undertaken across the range of expected sea states at the Albany site to achieve the best BA geometry for power production, load optimization and manufacturing, local logistics and operating costs.

The optimized BA geometry will now proceed to wave tank testing at the University of Plymouth in South West England.

A tank testing campaign at 1:20 scale will begin in the coming weeks to test the preferred geometry and power take off design for CETO 6 and the validation of the computational work undertaken for the Albany as well as at Wave Hub, in Cornwall, UK.

As announced earlier, Carnegie signed a memorandum of understanding with the University of Plymouth to collaborate on the development of CETO wave energy projects at Wave Hub in Cornwall.

Carnegie has in November 2017 informed that its new CETO 6 unit will have a nominal capacity of 1.5MW – up from 1MW for the previous design.

CETO 6 builds on Carnegie’s decade long development of CETO technology, and over the past two years, incorporates internal and external collaboration efforts as well as significant time and resource investment to deliver a step change in performance.

The CETO 6 design builds on intellectual property first lodged by Carnegie in 2013 incorporating on-board power generation and multiple moorings and power take off (PTO) modules.
 

Collaboration drives further Carnegie wave energy innovation

 

When it comes to other research and development activities, Carnegie said it completed further Computational Fluid Dynamics (CFD) numerical simulations for estimation of the power, loads and motions of CETO 6 at Albany.

This work supports the load and motions case that will feed into final design specifications for components such as the foundations, according to Carnegie.

Also, a wave to wire model of the CETO 6 technology at Albany is also being developed using Mathworks products. Virtual prototyping such as this reduces risk and fosters innovation because it allows the rapid testing of novel ideas and cost-effective understanding the dynamic behavior of specific components, Carnegie said.

Earlier version of CETO technology – the CETO 5 unit (Photo: Carnegie Clean Energy)

In addition, a design load calibration methodology is also under development.

“There is currently no wave energy converter (WEC) design standard the industry can directly rely on to define a relevant safety factor. The method developed is a statistical approach based on extreme value analysis to define the relevant design load. This aims at ensuring the design load considered delivers the appropriate level of safety without being overly conservative and therefore adding unnecessary cost,” Carnegie stated.

This work is being developed in collaboration with University of Western Australia via the Wave Energy Research Centre (WERC).

Further work has been performed to develop a system level Failure Mode and Effect Analysis (FMEA) building on best system engineering practice for Albany wave project to ensure early identification of potential failures and triggers the implementation of relevant mitigation actions.


Furthermore, Carnegie has become a partner on the Au$4 million Australia Research Council (ARC) Linkage project awarded to BioPower Systems.

The project aims to develop a common input PTO system, capable of accepting inputs from multiple different sources, including differing wave energy conversion technologies. Carnegie will apply knowledge and experience gained from developing PTO technologies for wave energy converters over the last decade, the company said.


In addition, Carnegie and the UWA continue to build on their ongoing collaborative relationship through the development of the new Wave Energy Research Centre and work on existing and new funded R&D projects.

Carnegie and UWA were successful in applying for funding under the European MARINET program, being awarded funding for 15 days of tank testing at the COAST facility at Plymouth University in March 2018.

UWA and Carnegie will be investigating the response of wave energy converters in extreme conditions as well as methods for determining the design wave of the CETO device.

Work also continues under the ARC Linkage grant between the University of Western Australia and Carnegie on foundation design for extreme events and the ARENA funded R2 project, developing cost optimization techniques for wave energy converter design, according to Carnegie.

Carnegie said UWA has been developing numerical modelling tools around the interaction between wave energy converters in arrays, while the work is now underway for the development of secondary mooring connection solutions.