Wave has obvious problems with mechanical wave action and corrosion quickly destroying any machine you leave in the waves, access and maintenance. It's unsurprising this is very difficult to scale and it does seem a dead end.
Tidal energy does seem like in principle it should work without many moving parts at all save the turbines, which don't have to be metal. Is it the turbines themselves which are very difficult to maintain in salt water?
This one is a floating design, which isn't ideal for maintenance, but I imagine at a large enough scale a dam between two bits of land with turbines in it would work - something we already do with hydro power and fresh water, and a concrete dam with access tunnels would solve a lot of problems with access and maintenance.
>Is it the turbines themselves which are very difficult to maintain in salt water?
The real key is they are far more difficult to maintain than wind turbines. Also, dams are ecological nightmares and disrupting huge swaths of coastline is not ideal. Dams also made use of very specific geological conditions where a maximum amount of water power could be achieved with the least amount of money, time, materials, etc. Coastlines don’t have steep cannon walls to build up hundreds of meters of water to push through turbines at high pressure. Coastal tides are moving water meters high, not hundreds of meters. It isn’t that it can’t be done, it is just that it can’t be done more economically than other technologies.
That's for sure. I don't know anything about this specific application but having worked in the shipping business and in commercial fishing I can attest to the problems with marine growth and corrosion, not to mention electrolytic issues for any contacting dissimilar metals that are immersed. Presumably all this is accounted for but I have to think the maintenance requirements for a long-term floating installation like this are no less than they would be for a commercial vessel, i.e. about 10% of the "hull value" per annum at a minimum.
Tidal energy does seem like in principle it should work without many moving parts at all save the turbines, which don't have to be metal. Is it the turbines themselves which are very difficult to maintain in salt water?
This one is a floating design, which isn't ideal for maintenance, but I imagine at a large enough scale a dam between two bits of land with turbines in it would work - something we already do with hydro power and fresh water, and a concrete dam with access tunnels would solve a lot of problems with access and maintenance.