Inspired by Tretchikoff I rang Carnegie to ask some CETO...

Inspired by Tretchikoff I rang Carnegie to ask some CETO questions and was referred to Greg (COO). He was not around so I emailed my questions to him. His responses are in italics below:

"1. I have been watching your online videos but I am a little confused as to whether the power is transferred to the water pump on the up and down stroke or just the up stroke. It looks like the buoy is tethered to the pump by a flexible connection but I could be wrong. Also, does lateral movement of the buoy provide any power to the pump? The pump is single acting and works on the up stroke. The tether is flexible and lateral movement does not actuate the pump.

2. What is the average power output of a CETO III unit in a 1m+ wave environment? I have heard that you are planning a 5 MW pilot site at Garden Island with 25 CETO III devices, so does that mean approx. 200kW per pump? Also, I'd be interested to know the optimal depth for CETO III? Can I also confirm that is CETO III in the main online video? The maximum output of single CETO 3 unit is 200kWm and the maximum output is achieved in a wave energy environment equivalent to around a 4m, 5sec period wave. The target water depth is 20- 25m. The main video is a CETO 2 unit.

3. What is the fresh water output (assuming 100% water desalination and 0% power generation) per CETO III and also, say, for a 5 MW wave farm? And what is the water quality like? I assume it is immediately drinkable but I just wanted to check. The immediate focus is a closed loop system for power generation only however, desalinated seawater was produced from the CETO 2 pilot plant at Fremantle. The water produced was readily drinkable at the output of the RO membrane however, due to the inherent flow and pressure profile of the system recovery ratios were low. Direct desalination will be the subjet of further technology development in the future.

4. What are the plans to combat barnacle/algae build-up on the devices? Is this likely to be a problem that requires significant maintenance? Are there any materials that can reduce such build-up? We are trialing various environmentally acceptable coating technologies to determine there appropriateness for our application. In short, the system has been designed to cope with the level of marine growth accumulated between maintenance intervals ( approximately 2.5 years) however, reducing growth has obvious benefits in relation to mechanical cleaning on removal. In terms of the BA, additional mass improves the output of the system (F=ma)."

The comment about desalination very much indicates to me that CETO is not ready for straight desalination yet and this may be an impact for Binningup? I never thought Binningup was much of a viable option for CNM at this early stage anyway.

2.5 years between maintenance seems like a long maintenance free period to aim for and achieving this would be an excellent result IMHO.