4. Tidal Streams

13. Tidal Current Turbines: The Next Stage

14. Tidal Current Assessment
The uncertainties about tidal streams are lower, I think they can take a lot of technology from wind, and I think they are a more predictable environment ；so I would expect that would reach commercial viability sooner than wave energy. The problem is that it is not such a large resource, and we can use all of it and still want more, whereas wave energy is such a big resource that it is worth going for, even if it looks hard to start with. (stephen salter said)