Tidal power is very challenging. Tidal stream devices like this have a very high LCOE (levelized cost of energy) because the stresses on them are massive so th

Tidal power is very challenging. Tidal stream devices like this have a very high LCOE (levelized cost of energy) because the stresses on them are massive so they are built like tanks but capture little of the energy flowing past them. Tidal range designs like La Rance (https://en.wikipedia.org/wiki/Rance_Tidal_Power_Station https://en.wikipedia.org/wiki/Rance_Tidal_Power_Station) are significantly more economic, but actually developing them and building them due to the size they need to be to be economic presents a major headwind for developers. There is huge potential globally for this but the will from investors and governments to really focus on it hasn't been there. These are mega-engineering projects with big risks, so capital flows to simple solar and wind instead.