What Is Hydropower, and How Does It Work?
Hydroelectric Power (or hydropower for short) is the use of flowing water to generate electricity. It is actually one of the oldest forms of energy production. Humans haven’t been using it as long as we have been using fire, of course, but it was used by the ancient Greeks to grind flour.
First, the flow of a river must either be obstructed or at least partially diverted. Then, the kinetic energy of the flowing river is turned into rotational energy when it spins turbines, which are connected to generators. The generators then convert the rotational energy into electricity, which is then either distributed or stored for later use.
Hydropower currently accounts for about 20% of the world’s energy production, and about 40% of the world’s renewable energy. Some countries, such as Norway and the Democratic Republic of Congo, receive nearly all of their energy from hydropower.
Advantages of Hydropower
Hydropower is a renewable energy source. As long as water flows downhill, we will be able to convert its energy into electricity.
Once they are built, hydropower plants are relatively inexpensive to maintain, when compared to other means of generating electricity. Thus, the electricity they produce is also relatively cheap. Hydroelectric power plants produce no greenhouse emissions, unlike their fossil-fuel burning counterparts.
Critics of hydropower contend that, for all its environmental benefits, hydropower still isn’t the way to go. Why? Because the dams used to harness the power of the river in large-scale hydroelectric projects obstruct the natural flow of water.
This blocks migratory fish species from making their annual journey upriver to spawn. If they are not allowed to procreate, then they will be unavailable as a food source to other animals, which, in turn, affects other aspects of the ecosystem. It also wipes out the riverside habitats of some animals, and it changes the habitats of others.
Additionally, large-scale hydroelectric power plants create drier conditions downstream. This affects not only the wildlife, but also the livelihoods and lifestyles of the people in surrounding communities.
As you can see, hydropower has its pros and cons. Solutions for some of the negative effects of large-scale hydropower have been developed. Fish ladders, for example, are designed to permit migratory fish to complete their annual spawning run.
However, the future of hydroelectric may be in microhydropower: small hydroelectric plants designed to produce electricity for a limited number of consumers. They tend to be less disruptive than their large counterparts, as they don’t necessitate damming the entire river. They generate electricity by simply diverting a portion of the river’s current.