Hello friends! Today is the last day I will be talking about renewable energy sources before going back to discussing other green topics. We’re ending with a banger: hydroelectricity!

Hydroelectricity is similar to tidal and wave power in that they both involve water, but hydroelectricity typically comes from damming up rivers. Hydroelectricity is also much more developed than wave and tidal, and is implemented in many areas around the world, including the United States.

I’m sure we’ve all heard of the Hoover Dam, but did you know that it actually generates 4 billion kilowatt hours annually?

The way it works is water first gets redirected into a tube or channel to strengthen its current. From there, it spins a turbine, generating energy. The faster the flow of water and the greater its volume, the more energy that is produced. 

Currently, hydroelectricity is one of the biggest contributors to the United States’ renewable energy supply, at 24% in 2024. Some states, like Washington, use it much more than others but it is available just about everywhere. 

Hydropower is also fairly cheap. While it does cost a large amount of bucks to build a dam, they last for around 50-100 years with little maintenance. It costs around 2-4 cents per kilowatt hour, while coal power costs between 4-16 cents.

Hydropower isn’t only beneficial due to its creation of cheap renewable energy though; it also creates a community. Many dammed rivers result in the formation of lakes, which can be used for swimming and fishing, a great option for consumers. 

Dams can also be used to maintain water supply, support irrigation and to help control flooding. 

However, hydropower can also do the opposite, causing flooding, especially downstream. Anytime you alter nature, consequences follow, and the harvesting of hydroelectricity is no exception. Creating large reservoirs can displace animals and disrupt entire ecosystems, which isn’t good for biodiversity. 

They can also block the migration of animals such as salmon that use rivers to reach nesting grounds annually. Some dams have implemented strategies to resolve this, including fish ladders and, my favorite, fish cannons. 

I think it’s essential to realize that all forms of renewable energy will have some environmental impact. We’ve altered our world so completely that the only way to fix it is to interfere once more. For this reason, it is crucial to weigh the pros and cons of different renewable energy strategies. Yes, hydropower may disrupt ecosystems, but is that any worse than the disruption from mining fossil fuels?

My biggest takeaway from my research over the past few days is that there is no one right decision. Depending on where you live, what your local government is like and what your needs are, your energy solution will look different. We need to figure out a way to combine different strategies if we truly wish to reach a more sustainable future.

Elena