http://www.economist.com/news/science-a ... magination
"Well yes, but what about also getting a leg up from tides?
A seasonal 15m tide range is the globes biggest in bay of fundy, but big tides are not uncommon, especially in the UK.
So these underwater "bladders" (in no anchoring zones
) could generate as well as store power.
~Fluid pumped in around low tide at relatively low pressure, is squeezed by extra weight at high tides (1 tonne is 1 cubic m of water). and then expelled for a net gain in power.
In Fundy btw, they have 2 tides a day.
This is a new approach, in that tidal power, mostly assumes harnessing water movement using ~turbines. This method relies on simple weight. No obstructive, surface mega structures, messing with fish migrations etc.
so a 100 sq m of seafloor bladder experiencing a conservative 10m tide twice daily, has 2000 tonnes of daily force applied/released to play with.
Its also harnessing gravity, which is pretty cool. Einstein would be pleased."