Saturday, June 24, 2006

Wave power for Cook Strait?

The front page of this morning's Dominion reports that Meridian Energy is looking at installing wave power generators under Cook Strait, and that this is reportedly capable of supplying all the country's electricity needs. I'm not sure about the latter - it would depend on how much energy you can get out of a turbine and how much shallow water we have which is subject to strong undersea currents - but the core idea is sound enough. Water is just like wind, only thicker; it moves, and that movement can be captured and turned into electricity with a turbine.

I'm not sure about the ecological effects. The turbines spin quite slowly, so they're not going to be directly killing fish. The real problem is likely to be noise, and possibly some minor pollution from lubricants leaking. On the plus side, you can't fish where there are turbines, so there may be some ecological benefits. The best way to investigate this is probably to build a test facility and see.

The biggest problem is the price; Meridian estimates that undersea wave energy will cost around 12 cents a kilwatthour, compared to around half that for wind or gas. But that's really Meridian's problem, and if they think they can make a profit generating electricity at that cost, then all power to them.


The RNZ news said that there would be 7000 turbines at 40 metres depth. Kind of boggles the mind and brings up yet another job I won't want. Cook Strait turbine maintenance.

Posted by Anonymous : 6/25/2006 03:15:00 AM

I've wondered about the economics of building a tidal power station in Auckland between the Tamaki River and Manakau Harbour. The two inlets are 1-2km apart at their closest, but being on separate coasts have a tidal difference of several hours (you can see this as you drive down the motorway - if it's high tide on the Tamaki River it'll be low tide on the Manukau).
Plus, there is a lot of existing power infrastructure in the area to hook into.

Does anyone know if this has ever been considered?

Posted by Rich : 6/26/2006 10:15:00 AM

Apparently there are also plans for a wave power planr in the Kaipara Harbour, ideally placed for Aucklanders...

Posted by Anonymous : 6/26/2006 02:00:00 PM