I've seen quite a few designs for harnessing the ocean's power and just about all of them don't really focus on the real challenges of making ocean power practical. The ocean is brimming with energy so it's not hard at all to find a million ways to capture some of it. The real hurtles to making it a practical source of power are listed below. This is not a comprehensive list, but just the most important points that few people seem to even address in their ideas.
1)Durability and maintenance.
- How will it hold up to the abuse of the ocean. Impact forces (day to day and storms), vibration, corrosion (salt water!), sea life, temperature changes, UV, etc...
-Metal, concrete, seals, valves, cables, bearings, etc...
-How much maintenance is needed in it's life time to keep it operational?
-Replacing parts, paint/coatings, cleaning sea life off, labor, inspection, etc...
2)Cost of implementation and return on investment (ROI)
-Will it produce enough revenue from it's power to pay the monthly loan payments (interest and principle) for constitution, ongoing maintenance, etc. including infrastructure to the grid.
-And still produce enough revenue to make it equal or more profitable than conventional power?
-And, can it pay it's loan off before it has to be completely replaced?
-Don't forget to take into account fees, permits, government regulations etc...
-Also, down time, seasonal changes, reasonable operational buffer (it's not going to produce 100% all the time)
3)Efficiency.
-How efficient is it as harvesting all potential available energy? Up/down, left/right, forward/back, etc...
-It doesn't have to get it all as long as it meets all the points of #2.
4)Environmental impact.
-Will seaweed, logs/branches/trash get caught on the devise, will whales hurt themselves on the wire or cables, how will the sea floor be impacted by any base, will it block sun light from reaching sea life that needs it, noise impact etc...
5)Transporting to the Grid.
-How will the power get from your device(s) to the grid.
- How much loss will there be to transport it? Wire distance loss, connection losses, etc...
- Can you place your system close enough to major power hubs (cities etc...), or do you need specific locations that have annually consistent conditions (wave heights or currents year round) etc..
These are the real hurtles that need to be overcome.