Johnny, In the early stages of development, C1 to C5, the...

Johnny,

In the early stages of development, C1 to C5, the principle of piping the high pressure water to shore was the way to go. It meant there was no electrical gear under water and power generation was on dry land where maintenance of turbines would be easy. However as always, necessity is the mother of invention. As R&D WECs of all kinds appeared all over the world, and all in need of reliable underwater electrical connectors, so large engineering companies (Siemens, Bosch, etc) set about devising the products that would operate under high water pressure. That took about 5 years. It is an example of, if there is a sufficient demand, a supply will come.

For the last two centuries, where WECs were constructed, they were all inshore. When they worked the inventors jumped up and down with glee, “Wow, see ... It works!” but they were incredibly inefficient and often lasted one summer before being smashed on the nearby rocks.

If serious power from ocean waves is desired you sit down and do your sums more carefully: Where are the best waves; how can we achieve greatest efficiency? Best waves are high amplitude ones that are further out to sea – 10 to 20 km out. That would mean pushing fluid along 20 km of sea bed pipe plus another 10 kms of collection from the string of WECs that constitutes the wave farm. Hence the power that is lost due to the viscous flow is enormous. If the power in the WEC was converted to electric current immediately the losses in a cable of the same length would be very much reduced. This realisation in 2013 caused the major change to the CETO 6 design. Not a U turn but a skew turn.

There was a contingent requirement that a Power Take Off unit had to be in each WEC and to justify that it had to be of adequate size, i.e. ~1 MW. Since this now had moving parts regular maintenance is necessary and the ‘hot swap’ system at sea had to be devised. You can see that many changes in tandem were essential.

The C5 contract with the DoD for supply at Garden Island was always for just one year. The small print also stated that CWE was allowed to interrupt supply at any time for any testing purpose necessary. It was never intended to be a permanent supply nor a source of revenue. Posters here just assumed that it would become a source of revenue. If you receive an R&D grant it has to be used as that and not for business income. Ultimately the DoD will benefit in that it will get an independent permanent power supply from a C6 farm.

We always want things to go faster, don’t we? Recognise that ocean energy is still a new source of power and in a very hostile environment. CWE is striving to do it right the first time and capture the new market.

Juke