How to make hydropower generation process eco friendly

Ever since 1895, when the first dam was built in the Niagara Falls waters, that the entire world has been benefiting from hydro power. Since then, millions of new dams have constructed, and some are still in use.

The reality is that from the time the first dam was built up until now, hydropower basics remain pretty much the same. However, with everyone concerned about environmental issues, both engineers and scientists are trying to make this kind of energy more eco friendly.

Hydropower is the renewable electricity that is most used around the globe – about 85%. However, scientists have been noticing that there are issues with habitat disruption, they tend to be common in these areas. Plus, there are some studies [ The Guardian ] that have been demonstrating that the reservoirs that are created by these dams are a huge source of greenhouse gas emissions.

So far, different entities, scientists, researchers, and engineers from all over the world are trying to provide answers to make hydropower better for the environment. One of this entities is the U.S. Department of Energy. But the entire hydro industry is also involved.

One of the things that most people aren’t aware of is that even though dams represent about 85% of the world’s renewable electricity, as we mentioned above, hydros are only producing about 2% of their entire capacity. And this presents a lot of opportunities in the future. This can be backed up by the Hydropower Vision report [ https://energy.gov/eere/water/new-vision-united-states-hydropower ] that was released about 1 year ago. According to it, this energy can grow about 50% by 2050.

What is important to retain from all this data is that we’re not just making future projections. The reality is that according to a study that published in the Aquatic Sciences journal, in 2015                             [ https://link.springer.com/article/10.1007/s00027-014-0377-0] estimated that almost 4,000 new hydroelectric dams were either proposed or under construction, and most of them located in developed countries.

Based on all these developments, a new protocol launched back in 2011 – the Hydropower Sustainability Assessment Protocol -, signed up for non-governmental organizations, utilities, and an international coalition of governments. Even though the standards are only voluntary, these were the first step taken into trying to make hydroelectric dams more environmentally friendly.

Although we should only see the results of such a protocol in some years from now, many NGOs didn’t waste time and immediately started criticizing it. According to more than 60 organizations, the standards and criteria aren’t rigid enough, and there are no considerations made regarding the risks of dams setting off earthquakes as well as related to human rights.

At this point, we need to take one step aside and understand that environmental groups would prefer if there were no dams at all. They believe that other renewable energy sources can be better alternatives, like wind or solar. However, there are others who despite their main goal is to protect the environment, understand that a hydropower generation can be extremely beneficial. So, the people in charge need to have an idea about the cost of each project for the environment and the impact that is causing.

One thing is for sure – we will continue to see more hydropower. So, we just need to make sure that we can reduce the impact this energy has on the environment. And this work is already begun..

The U.S. Department of Energy, for example, is already working on a modular “plug-and-play” hydropower units [ http://hydropower.ornl.gov/smh/ ]. The primary goal is to maintain healthy natural stream functions to make sure that new hydro electrics can cause less harmful impacts. But the DOE is also working on some new environmental metrics to ensure that every new hydro electric that is built can be able to show its effects concerning greenhouse gas emissions, energy efficiency, and fish migration, among others.

More than worried about the future and what new electric dams can bring or do to the environment, many local communities and environmental groups are concerned about the fixing the current problems:

One of the main problems that keeps being mentioned is that the fish passage that needs to be restored. Most of the dams that were constructed didn’t have in consideration the fish migrations. So, they don’t have any fish ladders which prevents this natural migration to occur. As if this wasn’t enough, climate changes are also a concern here. Steelhead and salmon, for example, are two species that need to reach the cold-water habitat.

Even though fish ladders could be a solution, the truth is that they exceed the costs in most larger dams. So, one of the possibilities could be to collect and transport the fish on tanker trucks around dams.

Another primary concern is related to both the intensity and timing of the water releases. Some tests have already been performed at the Glen Canyon Dam on the Colorado River, having short periods of high-velocity water releases. From what it was possible to observe, this has helped restore the riparian habitat since the high-velocity waters were able to move the accumulated sediment in the river channel. Plus, this can also be taken as an advantage for kayakers and rafters, for example.

There is also a lot of research going on regarding the greenhouse gas emissions that come from the water reservoirs. Some of the solutions that currently discussed include managing the water elevation more carefully or controlling erosion in upstream watersheds. But these reservoirs also tend to maintain the pollutants that were released by old industrial practices. These can cause a huge problem when people drink this water as well as they can affect fishes as well, that are later going to be eaten.

Although removing all these chemicals from the water reservoirs is a huge logistical challenge, the truth is that a solution already presented at the Mirror Lake in Dover, Delaware. The sediments in the river were contaminated with mercury, pesticides, dioxins, and PCBs. However, a professor of chemical engineering at the University of Maryland, Baltimore County, Upal Ghosh, was able to develop a method to deal with this waste. It involves a mixed solution that put into a pellet form and that these pellets dispersed in the water. As soon as they sink, they will create a layer on the lake bed which will cap and absorb all the contaminants.

Even though many environmental problems need to be studied to get to the best solution, the reality is that hydropower is already significant and it will become even more in the future. This is why we need to take action now and start implementing the different solutions on both the dams that already exists as well as in the ones that are about to be built.

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