What Is Hydroelectric Energy?
If you’ve ever wondered what the most widely used form of renewable energy is, you’ve landed in the right spot: it’s hydroelectric power. According to the Energy Information Administration, hydropower accounts for 6% of the electricity generated in the United States.
Hydropower is electricity that’s generated from moving water.
How Does Hydroelectric Power Work?
Hydro electricity is produced much the same way that wind power is produced.
Basically, the force of the falling or moving water pushes the blades of a turbine, which spins a shaft leading into a generator. That movement causes the generator to produce electricity.
This handy little animation, put out courtesy of the U.S. Geological Survey (USGS), helps illustrate this:
Image courtesy of USGS
Benefits and Drawbacks of Hydropower
There are a lot of great things about hydropower. And, some not so great things.
The biggest benefit to hydroelectricity is that once the dam is built, no pollution or greenhouse gasses are put into the environment. Hydroelectricity is incredibly green, and whatever pollution occurs during construction is quickly offset by the clean power it produces once it’s in operation.
Another benefit is that the dam reservoir is essentially a lake. This man-made “lake” can be used by people for recreation activities like boating and fishing. And, it also becomes a tourist attraction, which brings money into the local community.
Hydroelectric energy plants also have incredibly long lifespans when compared with wind turbines and solar panels. Those generally last 20-25 years. Hydroelectric plants, however, will last decades longer. We’re still using dams that were built 50-100 years ago.
There are some pretty big drawbacks to hydroelectric plants, however. The biggest is the risk of dam failure. When a dam breaks, millions of tons of water flood the area downstream. This is a major risk for people living below the dam.
One of the biggest dam failures in history occurred at the Banqiao Dam, in China, in 1975. That area was inundated with rain, and received more than a year’s worth in just 24 hours. The dam burst from the pressure, killing over 117,000 people, and displacing millions.
Fish ladder: Image courtesy of Wikipedia
Another major drawback is that hydroelectric plants drastically change the local environment. A lake is created where there wasn’t one, and a rushing river shrinks in size downstream.
This change disrupts the local ecosystem, especially aquatic life. In some areas where salmon migrate upstream to span, fish ladders have been built to help their movements and reduce the negative impact. But, not all hydroelectric plants implement measures like this.
Micro Hydro Power
The great news is that if you live on a steadily moving river, or near a waterfall, you can easily use the energy from that moving water to supplement, or fully substitute, your energy needs.
Think about this for a moment: the wind eventually stops blowing. The sun disappears overnight. But rivers never stop running. The power that could be utilized from moving water is endless. Which is why more and more people who are lucky enough to live on a river are starting to install small hydropower turbines.
The great thing about small hydropower systems is that they have almost no impact on the environment. Unlike large dams, small systems don’t need a reservoir. They’re set up to harness a small portion of the moving water. Once that water has pushed the blades of the turbine, it’s released back into the river downstream.
It’s extremely low impact, and incredibly clean.
The drawback to a hydropower system is that they can be somewhat unreliable. Many streams have a low flow during summertime, or during a drought. Having a backup power supply, either using normal utility power, or wind and solar, is needed for when the river flow fluctuates seasonally.
Another drawback is that there is some maintenance with these systems. Dirt and debris regularly flow down any river. Screens must be used to filter this out, but particles invariably get inside. Regularly cleaning is needed to ensure the system stays efficient and doesn’t wear out.
According to Home Power Magazine, hydroelectricity can be one of the most cost-effective forms of renewable energy.
Unlike wind and solar, you don’t need an expensive device to send power to your home. Home Power Magazine reports that any hydropower system needs the following components:
- An Intake- The intake is the highest point of your hydro system. The intake is what diverts the water from the stream into a pipe, which will power the turbine below.
- A Pipeline- The pipeline is what holds the water that’s being sluiced to your turbine. The size of your pipe depends on how much energy you need, and the size of the stream.
- A Powerhouse- The powerhouse is what holds your turbine.
- A Turbine- Your turbine is what turns the moving water into rotational force. This energy is then transferred through a drive shaft to…
- A Generator- The generator is what actually converts the energy from the moving turbine blades into usable electricity for your home.
How much will all this cost? Well, as usual, it’s going to vary depending on several factors. If your home uses a lot of energy, you’re going to need a bigger system, which will cost more. Planet Green estimates that most home hydropower systems will cost anywhere between $1,000 to $20,000.
The great news about hydropower is they’re fairly easy to build, which means with some studying you could build your own for a fraction of the price. There are several books out that will teach you how, and you can even buy home hydropower kits that have everything you need to do it yourself.