Hydroplants: Simplest Explanation of How They Work
Hydroelectric dams are structures that use the power of water to produce electricity. When water flows through a turbine, it turns a generator which creates electricity. Hydroelectric dams can be found all over the world, and they’re usually built in places where there’s plenty of flowing water.
What are dams?
Surely, everyone knows what a dam is. Even if you don’t know what it does, you would have definitely seen one or driven past one.
A dam is, quite simply, an artificial reservoir made out of concrete, steel, rock, or earth. They are found all over the U.S., in places they have access to a steady stream of water.
Most dams get their water from natural sources, such as rivers, lakes, springs, or even rain. They are built on high ground and act as a “blockade” in the path of water flows. This is why dams are built in mountainous areas most of the time.
Pumped Storage Hydropower Plants
Pumped storage hydropower plants, however, operate quite differently. These hydroelectric dams have two reservoirs; one upper reservoir and one lower reservoir. A pump in used to transport water uphill to be stored in the upper reservoir.
The water stored inside could be used for a variety of purposes, such as irrigation, producing drinking water, etc.
In this article, however, we will only be focusing on one type of dam: hydroelectric dams. These retrofitted dams use flowing water to generate electricity. Power generated this way is dubbed “hydropower” and makes up a significant percentage of the grid.
Hydroelectric dams are artificial reservoirs that use the water stored in them to generate electricity. The water stored in the artificial reservoir is released downstream and is used to turn a turbine linked to a generator. This process generates electric energy.
Electricity generated using hydroplants account for 6.5% of U.S.A.’s utility-scale electricity generation. Hydroplants add a whopping 260 billion kilowatthours to the U.S. grid.
Hydroplants are environmentally friendly because they do not require coal, oil, or natural gas; they only use water. Hydroelectric dams also have a long lifespan, typically lasting over the centuries. In fact, the world’s oldest operational dam is well over 3300 years old!
How do hydroplants work?
Hydroplants rely on water stored in the artificial reservoir to generate power. Without going too deep into technical details, here is a rough overview of how dams work:
1. Water is collected in the reservoir. The reservoir is always built above the turbines and generator since the gravitational potential energy stored in water is what’s used to generate electricity. Water stored on higher grounds has more gravitational potential energy.
2. Water is released in controlled amounts downstream, through a “flood gate”. The floodgate can be opened partially or completely, depending on the demand for power.
3. Water flowing downstream has high kinetic energy. The gravitational potential energy in water is converted to kinetic energy as it flows downstream.
4. Kinetic energy of flowing water is used to turn a turbine. This is a simple concept: the kinetic energy in the water is transferred to the turbine, which spins in the flowing water.
5. The spinning turbine turns the generator. The turbine is mechanically connected to the generator. The turbine is technically a part of the generator itself.
6. The generator converts kinetic energy to electrical energy. The generator converts the kinetic energy from the turbine into electricity which is transported through the grid.
What are the benefits of hydropower plants?
Hydroelectric dams are one of the oldest and most common forms of renewable energy. They have been around for such a long time purely due to the benefits they offer.
Hydroplants produce electricity using water, which is a renewable, clean source of power.
While using renewable energy is always accompanied by countless benefits, we formed a list of hydropower benefits that will interest you:
- Water is a sustainable resource, making hydroelectric dams a sustainable method of generating power.
- They are environmentally friendly since they do not rely on fossil fuels and release greenhouse gases. This makes hydropower a clean source of power.
- They can produce power as long as the reservoir still has water left. This is important for areas with unreliable grid systems.
- Some models of hydroelectric dams such as pumped storage dams can produce electricity all year round.
- They produce cheap electricity. The costs of operating a hydroelectric dam are minimal. This is because its main resource (water) comes completely free of charge.
- They can provide baseload power, meaning that they can keep a region running even if other sources of energy are unavailable.
What are the drawbacks of hydropower plants?
There are some major drawbacks to hydroelectric dams.
- The most significant drawback is that the dams can cause major environmental damage by blocking the migration of aquatic life, disrupting the flow of water through rivers, and destroying habitats.
- Downstream communities are greatly affected by dams if released water isn’t redirected properly.
- Dams contain large quantities of water, which makes the risk of tsunamis and floods ever-present.
- Dams can only be constructed in locations with a natural flow of water, limiting their existence to rivers and lakes.
- Hydroplants can be costly to construct, requiring a significant investment of money to build and retrofit.
- Additionally, the construction of a hydroelectric dam can also result in the displacement of people.
Since ancient times, humans have constructed artificial reservoirs of water for a variety of purposes, such as irrigation and drinking.
Modern hydroplants provide a significant boost to the grid by generating clean, renewable power. They create electricity by using the kinetic energy of flowing water to turn turbines, which are mechanically linked to a generator.
Even though they are expensive to build and require a significant investment, they are capable of producing cheap electricity for extended periods of time. This is mostly because the main resource (water) is obtained through naturally flowing rivers and lakes.