> If not, it sounds like a reasonable idea to try something new from time to time.

Oh certainly!

But funding is always finite. Unless some radical new wave/tidal technique comes to light (and it hasn't, yet!), then the project funding would surely be better directed to other renewable energy sources.

The cynic in me says wave/tidal projects based on existing technologies (shown to perform or scale poorly) are simply to grab funding for green energy projects. The Swansea Tidal Lagoon fiasco is a classic example.