Hydro Power 101: how to produce energy from water
People have been capturing the energy in moving water for thousands of years. And today, it’s still a powerful resource that can generate clean, renewable, and affordable electricity. That’s what we call hydroelectric power or hydropower.
Water flows from a higher elevation to a lower elevation, and a hydropower facility uses turbines and generators to convert this motion into electricity.
Today, hydroelectricity generates about 15% of global electricity and provides at least 50% of the total electricity supply for more than 35 countries. It is one of the largest source of renewable power.
So what makes hydropower renewable? It’s simple: water. Water evaporates into clouds and recycles back to Earth as precipitation. The water cycle is constantly recharging and can be used to produce electricity along the way.
How does it work?
Basically, there are several ways hydropower technologies can generate electricity.
You may recognize dams like this one.
This technology is called an impoundment. The impoundment stores water in a reservoir. When the water is released, it flows through and spins a turbine, turning a generator that produces electricity.
Here’s another technology. This is a diversion (run of river). It channels a portion of a river through a canal or pipe into a turbine and generator system.
What’s cool about this method is that it uses the natural flow of the river and usually doesn’t require a large dam.
And have a look at this: this is called pumped storage hydropower. Basically it works like a huge battery. To charge the battery, water is pumped back up into a reservoir during periods of low energy use, often during the night when people are using fewer appliances. Then, when people need more power during the day, the water can be released to produce electricity.
With how long we’ve been capturing energy from water, you may think there’s nothing new in hydropower technology. But actually we can upgrade many older facilities by increasing the efficiency of the turbines and generators. And we can add generators — or retrofit — dams that were built without power, like dams used to water crops or prevent floods.
New technology is also making hydropower even more environmentally friendly. For example, researchers are reducing adverse impacts on fish and their natural habitats.
Hydropower is an essential, reliable, and renewable source of clean energy with a rich history. And it’s meeting substantial energy demands today. With new technologies, it will be even more efficient and have greater production capacity,