Windstalks are a proposed alternative to wind turbines for electric generation. Vertical wind columns are pressed against by air. This tension puts pressure on piezoelectric materials that generate electricity. This column is static, and it is meant to be relatively safe for birds and bats, unlike wind turbines. 
There is a proposal to install 180 ft tall windstalks at Masdar city. The stalks are to be made of a carbon fiber exterior connected to a concrete base, and LEDs display when the windstalk is producing power. Two electricity carrying cables are connected to alternating piezo discs that are inside each hollow windstalk.
Could this technology be adapted to generate electricity from tidal currents?
- Nunez-Ameni, Dario. "Windstalk". ADNA.
- Richard, Michael. "Windstalk Concept Removes Blades from Wind Power!". Discovery.