There has recently been an interesting debate whether engineers should change the shape of tidal turbines because of the negative effects these would have on the environment, and, more specifically, the fish. Current tidal turbines’ blades are made using the pattern used in wind turbines.
University of Washington engineers have simulated how the changing water pressure around the tidal turbines could affect the way sediments accumulate and how it could risk the life of nearby fish.
In fast-moving tidal channels, the blade works just like that of a wind turbine, by creating a low-pressure and a high-pressure zone. The simulation’s conclusions were that fish traveling nearby the blade would get sucked in by the current, it would more or less avoid the blade, but would get sent to the bottom or to the surface of the water. Pressure could damage its internal organs or it could send it to in the mouths of its predators.
The worst fact is that the little harmless animal wouldn’t have time to avoid the situation, since this happens in less than 0.2 seconds, as Teymour Javaherchi, a UW mechanical engineering doctoral student says.
The phenomenon has been somewhat linked to the deaths of bats hitting the blades of wind turbines. The researchers now want to re-shape the blades so to minimize the effect by changing the pressure. For that, they will have to study the maximum pressure that a fish can bear without any problem.
It’s kind of a stupid idea studying how that little Nemo enters the current, hits the blades or not, or gets into the mouths of predators, at a first glance. Looking at the issue more thoroughly, though, you’ll soon realize that it’s not a single fish, but millions, and it’s not just one place, but thousands and thousands of them. A tidal turbine works night and day, and if its movement affects the surrounding population, we’ll again imbalance the ecosystem with our contraptions.
Just like Alberto Aliseda, a UW assistant professor, said: “Maybe the best turbine is not the one that extracts the most energy, but the one that extracts a reasonable amount of energy and at the same time minimizes the environmental effects.”
We have to be cautious with our technologies – at least that we owe to the dark past and present of using fossil fuels, imho.