Explore how we get electricity and how renewable and non-renewable power is generated.
Even though electricity is a major component of our environmental footprint, we tend to ignore it in favor of recycling and consumer choice.
It may seem like you can’t do anything about the energy you use, but it’s important to understand where your energy comes from and how it affects your environmental footprint. Knowing your own energy sources and their ecological costs will help you decide where to focus your actions to make the biggest difference.
power mix
Few people in the United States rely on a single source of energy. The overall power mix in the United States can vary widely by state and region. In Arizona, natural gas and coal produce the majority of the state’s electricity. In Washington State, where the Grand Coulee Dam is located, 66% of energy Hydroelectric power is used.
Hydropower is a type of renewable energy. This means that the water source is naturally renewed and is not used up in the process of power generation. Other renewable energy sources include solar power, wind power, biomass, and even geothermal energy. Hydroelectric power is the single largest source of renewable energy in the United States. Together, renewable energy produces about 12% of the United States’ energy, of which about 6.3% comes from hydroelectric power. However, since it is playable, Dams are not good for the environment.
How hydroelectric power works
to generate hydroelectric powerdams are built across moving bodies of water. The water flows back behind the dam to form a reservoir, from which water rushes through the dam at a controlled rate. When water flows through a dam, it turns a turbine, which turns a generator and produces electricity.
Compared to other energy sources, hydropower is cost effective. Although dams are expensive to build, they are cheap to operate and often result in lower energy bills in the long run.
Environmental benefits of hydropower
Clearly, being renewable is a major environmental advantage of hydropower. However, in addition to being renewable, hydropower is also considered a clean energy source.
Operating dams do not produce toxic air pollutants, like coal-fired power plants, or hazardous solid waste, like waste-to-energy. Also, it does not generate radioactive waste Like nuclear power. Dams control the flow of rivers, thus minimizing or even eliminating the risk of impacts from extreme weather events. Dams prevent downstream flooding after heavy rain or when snow melts. In times of drought, reservoirs provide water for irrigation. In the United States, reservoirs are naturalistic park-like areas that provide outdoor recreational opportunities and wildlife habitat.
Hydropower has negative environmental impacts
Unfortunately, recreational areas created by damming rivers are not completely natural.
Lakes created by hydroelectric dams can become ecosystems in their own right, but they permanently destroy the natural river ecosystems that existed before the dam’s construction. Native species — like salmon — Those that depend on rivers are threatened; extinct. Major dam projects around the world are also displacement and the destruction of human communities, especially ethnic minorities and poor communities.
Upstream flooding that creates reservoirs is the most obvious environmental impact of hydropower. But the latest science suggests that may not be the most important thing.
Recent research has revealed that hydropower is not as clean as previously thought. More and more studies are identifying reservoirs. important producer Effects of greenhouse gases. Because this is a fairly new field of research, efforts to quantify impact are inconclusive. However, the methane produced by the reservoir could be equivalent to 1 billion CO2 equivalents.
Environmental balance of hydropower generation
Hydropower is far more problematic than other renewable energies such as solar and wind. In some cases, older, inefficient dams are used. deleted and their habitat has been restored. However, despite their environmental and social drawbacks, new hydropower plants are typically orders of magnitude cleaner than comparable coal-fired power plants. This makes the decision to build new hydropower plants a difficult choice for the population. the lesser of evils Not a truly sustainable option.
However, truly sustainable energy sources are still much more expensive. It also cannot always be scaled up to meet energy demands. Hydropower remains the clear winner for large-scale energy production, especially in developing countries.
run-of-river hydropower
When most people think of hydropower, they think of traditional giant dams like the Hoover Dam. these confinement Hydroelectric systems are the most common type. However, very small scale, damless hydroelectric systems are also possible.
run-of-river systemAlso known as diversion facilities or small hydropower, they direct some of the water from the river to turbines with little or no reservoir. This eliminates most of the environmental damage caused by traditional dam structures. Since there is no reservoir, the area of ​​influence is much smaller and no methane is produced.
Run-of-river systems can generate distributed power in small facilities up to 100 kilowatts or less. It can also be scaled up to 50 megawatts (MW). Unfortunately, they do not produce energy on the scale they replace. existing dam infrastructure. For example, the Three Gorges Dam, the world’s largest dam, The problemproducing 22,500 MW. Grand Coulee, America’s largest, generates 6,800 MW.
Still, small-scale hydropower is renewable, sustainable, and cheap: a rare triple threat in energy production. Countries with abundant rivers, such as Canada, are beginning to consider developing river systems. diesel alternative Generators in remote locations. In these situations, small-scale hydropower is viable, but there are few other energy sources that can compete.
what you can do
Few people build their homes near running water, with conditions suitable for individual or community-scale diversion hydropower plants. Fortunately, many of us have access to community renewable programs such as: Pacific Gas and Electric Company or puget acoustic energyand many more. These programs enable utility customers to purchase a more sustainable energy mix. To find out if such a program is available where you live, contact your local utility company.
No matter what energy source you use, the most sustainable choice is to use less of it. If you’re not sure where you can improve, start with a home energy audit and prioritize changes based on the results. Many local power companies also have efficiency programs to help customers reduce their energy usage.
Read Part 4 of this series: What you need to know about nuclear power.
Editor’s note: This article was originally published on January 13, 2020 and updated in December 2024.
