I have already covered the turbines submerged in rivers as well as in the oceans and seas. I also covered the steps, we need to take before the construction of a hydropower plant. We found out that in order to do this, we need a ton of brain power (imagination, creative thinking, research, etc.) and a lot of time. The end product of our sweat and tears is a prototype (that will most probably be a disaster), that we will love no matter what. We will do a lot of research, that will help us improve the basic idea. When the prototype is exactly how we want it to be and we gathered all the needed allowances, papers etc., the construction will finally start.
After the construction is done, we live in peace and just harvest what we sow.
From the point of view of construction workers, this usually is the case (at least until something goes wrong) but from many other points of view – not really. There are always some research that needs to be done in order to improve the construction and to keep up with the developing market. We also need to do the monitoring of the environment, to see the influence of the construction on the ecosystem. It doesn’t really mean, that there is going to be a demolition project when we (most probably) see a decrease in diversity, but still, we need to do it.
Related article: Why does it matter what lives around us?
When building the construction on the rivers, the water that is being accumulated behind it, plays the biggest role. The changes, that we see the easiest, are the change of the water level and the sedimentation rate (also known as change of habitat). We can also observe, an increase of the temperature (since the flowing water becomes a standing water body, and the sun can easier heat it up). The change of temperature also affects the oxygen levels (it’s levels decrease), and induces some other changes in the ecosystem. Result of all these changes is usually shown as an overall decrease of diversity, since the species are not adapted to new living conditions and need to migrate or die. The problem with this change of diversity is, that there are some species, that play enormous roles (keystone species) that will most probably leave as well. Of course, new species, that are adapted to these new conditions will come, but the ecosystem health won’t increase, if the conditions stay the same.
Related article: What are keystone species?
If we are talking about the construction of an enormous dam, we could be affecting even more than ”just” the diversity. I am talking about enormous accumulations (like Lake Kariba that lies on the border between Zimbabwe and Zambia) where a lot (like, 17 000 cubic meters a lot) of water is accumulated. At this kind of places, the rate of water evaporation is incomparably higher than it was before the construction was made. Another thing that changes after such an alteration is the water flow. By this I would like to point out, that the amount of water, that reaches the next body of water is a lot lower than it used to be. The hydraulics of the river also change, which lead to changes of local (or even global) water cycles. Effects of these changes can be seen as changed seasonal floods, more intense natural phenomena (typhoons, monsoons etc.).
If we build the dam and don’t maintain it or a natural disaster occurs, the dam can break. If this happens, all of the accumulated water is being released at once along with all of the accumulated sediment. I would like to add, that sediment is not an innocent thing. Sure, there are a lot of nutrients (that will help plants grow) in there, but there is also a lot of bad things (heavy metals, polluters, etc.). The same thing (but on a smaller scale) can also occur after heavy rain period or when the thawing of the ice occurs in the mountains. The only way we can really prevent this from happening would be, if we would prevent the dams from being built in the first place. In this way, we would also prevent people from building houses (or having things of any value) on potentially flood-endangered areas. With this kind of management, we would give the river the space it had before we started alternating land to serve our needs. We shouldn’t forget that the rivers were here before us and that we have brought all of this on ourselves.
Seas and oceans
Many ideas on how to obtain the energy from seas and oceans are fairly new, which means that there hasn’t been a lot of research done about their impact on the environment. Scientists have just recently found out, that the speed of the Gulf stream is slowing down due to the rise of the water temperature. Some speculations have occurred, saying, that the turbines built on the way of the Gulf stream, could slow it down even more. Why does it matter, you ask? Because these ”small” changes, bring big changes on many different levels. We are talking about the change of the local climate, rainy season periods, intensity of natural disasters, or make them more common etc.
Another disadvantage could be additional noise pollution made by spinning blades. We know that some animal species communicate with sounds (many of them use frequencies we can’t hear) and the noise pollution can seriously affect their communication. The electricity is transported to land by cables, and since the electromagnetic field affects human health, we believe, it might also affect the health of the organisms and the ecosystem.
Of course, all consequences will show in time (and with research) but we should be ready to keep an eye out for them. However, we also don’t really know a lot of the impact of the turbines on marine organisms. When talking about most kinds of turbines – the rotation of the blades is slow and they could potentially be designed in a way not to harm the organism. However, if there would come to a collision it would most probably end with death (I mean the organisms death) because of the injuries. We could partially prevent this from happening if we would install movement sensors and make them shut down the turbine when marine animals are detected. Of course this would cost much more money, but would probably greatly help the local diversity. This brings us to a point, where we need to carefully consider all the possibilities and keep in mind that the turbines should be located at a deserted place, with very little life (so that they would still be able to rotate the blades and produce electricity).
We should also not forget about the sessile organisms, which would try to find a place to call home wherever they find something solid (and its our job to try and prevent them to!). These organisms are usually filtration and can be very sensitive to the underwater currents (their source of food is in there). This made me come up with an interesting bio-artificial symbiosis, where turbines could be used to deliver the nutrients to where they are needed. This idea could potentially work but it would be expensive to build and it would only influence a small area. Another thing is, that with this method we would be changing the environment even more, which would most probably bring out some more problems, we don’t even think of at this point.
Have you ever thought about the effects that a new construction brings to the environment? What do you think would happen, if the speed and course of the Gulf stream would change? Let me know about your thoughts down in the comments, I would be very happy to read them.