Hydroelectric Power

Summary

In this video, Mr. Andersen discusses hydroelectric power, a renewable energy source harnessed from water movement. He highlights the evolution of hydroelectricity with China's Three Gorges Dam leading current production. The video explains different types of systems like run-of-the-river, tidal, and dams, emphasizing their benefits such as reduced carbon emissions and flood control. However, it also addresses challenges like siltation, habitat disruption, and limitations in suitable locations for construction.

Takeaways

• 💧 Hydroelectric power is generated by the movement of water.
• 🏭 In 1980, the United States was the leader in hydroelectric power, followed by Canada.
• 🌏 China has emerged as a leader in hydroelectric power due to the Three Gorges Dam.
• 🔄 Hydroelectric power is renewable because it relies on the sun's evaporation of water.
• 🌊 There are different types of hydroelectric systems: run-of-the-river, tidal, wave, and impoundment (dam) systems.
• 💨 Hydroelectric systems can reduce carbon dioxide emissions by providing a clean energy source.
• 🌊 Dams can be used for flood control by regulating water flow.
• 🏞️ Impoundment systems create lakes that can be used for recreational activities.
• 🚫 Disadvantages include siltation, disruption of natural river flow, and limited locations for construction.
• 🐟 Dams can disrupt the natural life cycles of fish, such as salmon spawning.
• 🌳 Hydroelectric dams can displace human populations and cover native tribal areas.

Q & A

What is hydroelectric power?

Hydroelectric power is power created by the movement of water, often through the use of dams or turbines to generate electricity.

Which country led in hydroelectric power in 1980?

In 1980, the United States led in hydroelectric power, followed closely by Canada.

What is the significance of the Three Gorges Dam in China?

The Three Gorges Dam is the largest dam on the planet and is expected to produce up to 10 percent of China's electricity needs.

How does hydroelectric power relate to the water cycle?

Hydroelectric power is related to the water cycle as it uses the sun's energy to evaporate water, which then condenses and falls as precipitation, and the runoff from this process is used to generate electricity.

What are the different types of hydroelectric systems mentioned in the script?

The script mentions run-of-the-river systems, tidal systems, wave systems, and impoundment systems (dams).

What are some advantages of hydroelectric systems?

Advantages include reducing carbon dioxide emissions, flood control, and the creation of recreational areas through the formation of lakes.

What are the disadvantages associated with hydroelectric power?

Disadvantages include siltation, which can fill in dams over time, disruption of the natural flow of rivers, and the limitation of viable locations for dams.

How does a run-of-the-river system differ from an impoundment system?

A run-of-the-river system does not have a dam and uses a turbine in the river itself to generate electricity as water flows, whereas an impoundment system uses a dam to trap water and regulate its release through turbines.

What is the role of the Grand Coulee Dam mentioned in the script?

The Grand Coulee Dam is the largest concrete structure on Earth, located in Washington state, and serves multiple purposes including flood control, irrigation, and recreation.

How does hydroelectric power affect fish populations?

Hydroelectric power can disrupt the natural flow of rivers, affecting fish migration, particularly for spawning fish like salmon. Measures such as fish ladders are sometimes implemented but are not always effective.

What is the environmental impact of building hydroelectric dams?

Building hydroelectric dams can be environmentally impactful as it can lead to the displacement of human populations, covering of native tribal areas, and the eventual siltation of the dam.

Outlines

00:00

💧 Hydroelectric Power Explained

This paragraph introduces hydroelectric power, which is generated by the movement of water. It discusses the historical leaders in hydroelectric power production, such as the United States and Canada, and the emergence of China due to the Three Gorges Dam. The paragraph explains that hydroelectric power is considered renewable because it relies on the sun's energy to evaporate water, which then falls and can be used to turn turbines for electricity. Various types of hydroelectric systems are mentioned, including run-of-the-river, tidal, and impoundment systems (dams). Advantages include reduced carbon dioxide emissions, flood control, and recreational opportunities. Disadvantages include siltation, disruption of natural river flow, and limitations on suitable locations for dam construction.

05:01

🌊 Advantages and Disadvantages of Hydroelectric Power

The second paragraph focuses on the advantages and disadvantages of hydroelectric power. It highlights the environmental benefits of reducing carbon dioxide emissions and the potential for increased recreational activities around the created lakes. It also mentions the flood control capabilities of dams. Disadvantages include siltation, which can eventually render dams useless, and the disruption of natural river flow, affecting fish migration. The paragraph emphasizes the limited locations suitable for hydroelectric power generation and the negative impact on ecosystems and human displacement caused by dam construction.

Keywords

💡Hydroelectric Power

Hydroelectric power is a form of renewable energy generated by the movement of water. In the video, it is discussed as a significant source of electricity, with historical leaders in this technology being the United States and Canada. The concept is central to the video's theme, as it explains how water's kinetic energy is harnessed to produce electricity, which is vital for understanding the video's exploration of renewable energy sources.

💡Three Gorges Dam

The Three Gorges Dam is identified in the script as the largest dam on Earth and a key reason for China's emergence as a leader in hydroelectric power. It exemplifies the scale and potential of hydroelectric projects, aiming to supply up to 10 percent of China's electricity needs. This keyword is crucial as it provides a real-world example of the video's discussion on hydroelectric power.

💡Renewable

Renewable refers to energy sources that can be replenished naturally and sustainably. In the context of the video, hydroelectric power is classified as renewable because it relies on the water cycle, which is driven by the sun. The script explains that the sun's energy evaporates water, and as it falls, it can be used to generate electricity, emphasizing the sustainability aspect of hydroelectric power.

💡Run-of-the-River Systems

Run-of-the-river systems are a type of hydroelectric system where a turbine is placed in a river to generate electricity from the flowing water without the need for a dam. The video contrasts these with impoundment systems, highlighting their advantage of avoiding siltation issues. This keyword is important for understanding the different methods of harnessing hydroelectric power.

💡Tidal Systems

Tidal systems are a subset of hydroelectric power that harnesses the energy from the rise and fall of ocean tides. The script mentions these as an emerging technology, indicating the innovation and expansion in the field of hydroelectric power. Tidal systems are relevant to the video's theme as they represent an alternative approach to traditional dam-based systems.

💡Water Impoundment System

A water impoundment system, or dam, is a structure built across a river to store water, which can then be released to flow through turbines and generate electricity. The video uses the Grand Coulee Dam as an example, illustrating the advantages such as flood control and recreation, as well as the disadvantages like high costs and environmental impacts.

💡Carbon Dioxide Emissions

Carbon dioxide emissions are greenhouse gases produced by burning fossil fuels. The video discusses how hydroelectric power can reduce these emissions by providing a clean energy alternative. This keyword is integral to the video's narrative on environmental benefits and the fight against climate change.

💡Flood Control

Flood control is the management of water levels to prevent flooding. In the context of the video, dams are mentioned as tools for flood control, as they can regulate the release of water, thus preventing downstream flooding. This keyword is significant as it ties into the broader benefits of hydroelectric systems beyond just energy production.

💡Siltation

Siltation refers to the process where sediment or silt accumulates in a body of water, such as a reservoir behind a dam. The video explains that this can eventually fill up the reservoir, reducing its capacity to generate electricity. This keyword is crucial for understanding one of the main challenges associated with hydroelectric power.

💡Fish Ladders

Fish ladders are a series of pools or steps built into dams to allow fish to swim upstream around the dam. The video mentions these as a solution to the problem of fish, like salmon, being unable to navigate dams. This keyword is relevant as it highlights efforts to mitigate the environmental impact of hydroelectric projects.

💡Natural Flow Disruption

Natural flow disruption refers to the changes in a river's natural course caused by dams or other human-made structures. The video discusses how dams can disrupt the natural flow of rivers, affecting ecosystems and the life cycles of aquatic species. This keyword is important for understanding the environmental concerns associated with hydroelectric power.

Highlights

Hydroelectric power is created by the movement of water.

In 1980, the United States and Canada were leaders in hydroelectric power production.

China has emerged as a leader in hydroelectric power due to the Three Gorges Dam.

The Three Gorges Dam aims to produce up to 10 percent of China's electricity needs.

Hydroelectric power is considered renewable because it relies on the sun's energy to evaporate water.

Run-of-the-river systems generate electricity without dams by using turbines in the river.

Tidal and wave systems are emerging types of hydroelectric power generation.

Water impoundment systems, or dams, regulate water flow to generate electricity.

Hydroelectric systems can reduce carbon dioxide emissions.

Dams can be used for flood control by regulating water flow.

Dams create lakes that can be used for recreational activities.

Dams can fill in over time due to siltation, requiring maintenance or removal.

Hydroelectric power is limited by the availability of suitable locations for dams.

Dams disrupt the natural flow of rivers, affecting fish migration.

The water cycle is central to hydroelectric power generation.

Run-of-the-river systems do not have siltation problems but generate electricity only when water is flowing.

The Grand Coulee Dam is the largest concrete structure on Earth and serves multiple purposes.

Hydroelectric power is a renewable energy source that can be used for irrigation.

Dams can be used for flood control, though sometimes they need to work in conjunction with other dams.

Dams create reservoirs that can be used for recreation.

Hydroelectric power does not produce carbon dioxide, helping to reduce emissions.

Building and maintaining dams is expensive and can disrupt ecosystems and human settlements.

Siltation is a significant problem for dams, eventually rendering them useless.

Fish ladders are an attempt to mitigate the impact of dams on fish migration, but their effectiveness is limited.

Transcripts

Hi. It’s Mr. Andersen and this is AP environmental sciences video 26. It is on hydroelectric

power, which is power created by the movement of water. If we look back in 1980 at the world

lead in the hydroelectric power, it was the United States followed quickly by Canada.

Nearly 300 billion kilowatt hours being produced mostly by dams. If we look at what has happened

over the last 35 years however we see a new country emerge. China. And the reason why

is the Three Gorges Dam. It is the largest dam on our planet. And they hope to produce

up to 10 percent of their electricity needs from this one dam alone. And what is hydroelectric

power? It is power through the movement of water. And we call it renewable. And the reason

why is it is really the sun. The sun is evaporating the water. It is moving up and as it falls

down again we can move that water through a turbine in most of the systems and we can

generate some electricity. The major types we will talk about are the run of the river

systems. Instead of having a dam they simply have a turbine on the river itself. So as

the water flows they can generate electricity. We have tidal systems. And we are starting

to bring on wave systems. And so as the water moves back and forth we can generate energy.

And then finally we have the most famous type, the water impoundment system or the dam. So

we essentially take a river, we build a wall on it and we can trap the water behind it.

Now we can regulate when we let the water out and when we let the water flow through

the turbines to generate electricity. And so what are some of the advantages of these

hydroelectric systems? We can reduce the amount of carbon dioxide into the atmosphere. Now

a lot of it is going to be produced as we are producing the dam, but once it is going

it is really cheap to maintain. If we look at flood control we can also regulate how

much water is moving down, especially in an impoundment system. And then you are creating

a lake so you can create a recreation system that can be used. What are some of the disadvantages?

Well these things fill in over time. So as the water flows into the impoundment system

it drops the silt and that is going to fill it up with solid material. So we either have

to remove that material or remove the dam. They are also limited. So if we look in the

US we pretty much used all of the viable places to have dams in our country. And since it

is disrupting flow it is disrupting natural flow of the river and anything that moves

in the river. For example spawning fish. And so how does this work? Well if you are familiar

with the water cycle you really know what is going on. We have evaporation, condensation,

precipitation and runoff. And as the water is running off we are capturing that energy

of the flowing water. We could also have tidal systems. So as the moon pulls on the water

on our planet and moves the water back and forth we can generate a little bit of energy

there as well. First type I want to talk about is the run-of-the-river system. Now this is

not a dam. It looks like a dam, it is just a very wide river. And so as the water runs

through it, it is generating electricity. What are some of the nice things about this?

We are not going to have that siltation problem. But the problem is that is only going to be

generating electricity when the water is actually flowing. In an impoundment system what we

have is a dam. We have a huge wall and then we just have a reservoir behind it. So we

have a bunch of water behind it. As the water is let through we can generate electricity

as it moves down to the river. And so you can see we have a huge amount of potential

energy on that side. And if you look at the size of that Three Gorges Dam you can just

start to imagine how much electricity can actually be generated. We also have tidal

systems. So in a tidal system the water is moving back and forth as the tides come in

and out. And so if we lower this down we can generate electricity. We also have a turbine

in there as well. What are the advantages? Well if we look at the Grand Coulee Dam, which

is the largest concrete structure that has ever been made on our planet. It is in Washington

state. Some of the advantages? It is a renewable form of energy. So the sun is actually generating

the lifting of that water and as it flows down we can tap some of that energy. We can

then use the water to irrigate crops in the nearby areas. This is an area that was actually

plagued by floods in the past. And so one of the reasons they put the Grand Coulee dam

there was for flood control. Did not really work so they had to work with other dams in

Canada to actually do that. We have created a giant reservoir behind here, a recreation

area that can be used. And then finally these are not carbon dioxide producers. We can reduce

our carbon dioxide emissions by running more hydroelectric power. What are some disadvantages?

Like everything, incredibly expensive to build and maintain. They destroy everything that

was there before. So this used to be a river that flowed up here. And so you are displacing

humans. You are covering up a lot of the Native American tribal areas as well. Siltation is

a problem. Silt is going to fill it in. Eventually it becomes useless. Fish can not move up.

So they can put fish ladders but they are not super effective. And then it is limited.

So there are limited places on our planet where we can actually use hydroelectric power.

And so did you learn the following? Could you pause the video at this point and fill-in

all of the blanks? Let me do that for you. It is a renewable form where water flows through

a turbine in these systems. That could be run-of-the-river, impoundment or tidal systems.

Some of the advantages, lowers carbon dioxide emissions, increases recreation and also decreases

floods. Disadvantages, siltation disrupts the flow, it is limited. And the big thing

is it is breaking down the natural flow of the river. And so spawning fish, for example,

like salmon can not make their way up. That is hydroelectric power. And I hope that was helpful.