Most tidal systems are "trap and release" style (barrages) - you wait until high tide, trap the water, then run the differential through a turbine. This kills

Most tidal systems are "trap and release" style (barrages) - you wait until high tide, trap the water, then run the differential through a turbine. This kills a ton of sea life. Tidal Kinetic systems suffer from bursty power output. Other systems are too expensive, too early, or both.