Energy Is Everywhere
We are an energized society. Everywhere you look people are talking on cell phones, driving cars, using computers, cooking food, turning on lights, and so much more. Can you imagine trying to go an entire day without electricity? Even if you could put your phone away and read a book instead of watching TV, you'd have to shut down all of the traffic lights, use candles in your house, and either walk or bike to work.
And that's just YOU! Think of all the hospitals, power plants, and other facilities that require a constant supply of energy in order to keep people safe and healthy.
Energy sources that can be regenerated are great to take advantage of for our massive energy needs. In fact, we already utilize some of these resources, like wind, water, and the sun. Let's look more closely at each of these to see how we can benefit from them and in turn power our lives.
Windmills are becoming a common sight across the United States because they are incredible power-producing machines. The wind turbines you see in fields, along coasts, and even in people's backyards convert wind energy into electrical energy. The blades of the turbine spin as the wind blows, which then turns a mechanism inside the structure. This mechanism is attached to a generator, which is what produces usable electricity.
The wind is going to blow whether we use it for generating electricity or not. But there are ways to make windmills more efficient. For example, most modern windmills are about 130-325 feet tall. This is because higher up, wind speeds are faster and there's less turbulence.
Sometimes a household will have a single windmill on their property for their own power generation. But more often, you'll see a bunch of windmills hanging out together in a wind farm. Just like a large agricultural farm produces a lot of food, a wind farm produces a lot of energy from wind, so the more turbines, the better.
Wind power is one of the most efficient ways to generate electricity. This means that we get much more from it than what we put in: twenty to twenty-five times as much, in fact! This is more than nuclear energy and natural gas combined.
Wind power isn't perfect, though. First, you can only generate electricity from wind if you have wind in the first place. Some places are windier than others, so if you live in a fairly stagnant area, you may not have much luck. Those big rotating turbine blades also pose a hazard to flying animals, like bats and birds. However, they are not nearly as dangerous as moving vehicles, power lines, and window-covered buildings.
If you've ever stood in the middle of a strong current, you know just how powerful moving water can be. Hydroelectric power, which is electricity generated from flowing water ('hydro' means 'water'), provides about 7% of the power in the U.S. and about 19% of the world's total electricity production.
With this natural resource, electricity is most often generated through hydroelectric dams. A dam is constructed along a flowing waterway where there is a large elevation drop because as the water travels downhill, it picks up speed. This is why we often find dams in mountainous regions, like the Rockies, but not in flat places like the Southeast coast of the U.S.
As the water flows downhill and through the dam, turbines inside the dam are spun around by the moving water. This is very much like how a pinwheel is spun around in a good gust of wind. The turbine shafts are connected to a generator and the spinning of those turbines is what creates electricity. The electricity travels through power lines that are connected to the generator, sending it to homes, buildings, and other places.
The water itself is not affected by the turbines, but there are some issues with hydroelectric power production. For example, dams disrupt the natural flow of the waterway, which in turn disrupts the natural plant and animal communities both above and below the dam. However, hydroelectric power is quite reliable (as long as the water is flowing!) and does not generate pollution like coal plants do, so it remains a popular source of natural power.
Last, but definitely not least, is solar power. Sunlight might just be the most important form of natural energy on Earth. It keeps the planet warm, which makes it possible for life to exist, it provides food for plants when they photosynthesize, and it can also be used as an energy source for our own needs.
There are two main ways that we can harness the power of the sun. Passive solar power is when solar energy is collected passively through absorption. In contrast, active solar power is when solar energy is actively focused, moved, or stored with technological devices.
To passively collect solar power, buildings may be redesigned with solar panels or other structures to maximize their absorption of sunlight. I mean, they're already sitting there in the sun; why not put them to work? It's like standing outside on a sunny day wearing a dark jacket instead of a light one - you'll definitely feel the difference in your own passive solar power collection!
When solar power is collected actively, devices are put in place to collect the sunlight, but then they go one step further and convert that sunlight into electrical energy. This energy is either stored for later use or it's sent off to be used right away. The power of the sun can be greatly magnified if it's collected over a wide area and then concentrated into a much smaller area. A satellite dish on your house works much the same way - the dish itself is wide to collect the signal, but that signal is then concentrated and sent to your TV. Solar power can be collected the same way, powering thousands of homes and other buildings nearby.
The best part about solar energy? It's ALWAYS there! We don't have to worry about running out of sunlight for a very, very, VERY long time. Although one downside is that solar power equipment tends to have very high upfront costs, once installed, it's relatively inexpensive to maintain. And while the sun doesn't always shine through the clouds, it can sometimes be stored for later use.
We have become pretty dependent on electricity - it powers our homes, cars, electronic devices, and so much more. Luckily, there are many resources that we can utilize for electricity production. Some of them, like wind, water, and sunlight, are both renewable and relatively inexpensive.
Both windmills and dams have turbines that spin and generate electricity. Windmills have rotor blades on the outside that turn when the wind blows them, and dams have turbine blades on the inside that spin when water rushes past them. In either case, the structure simply sits back, relaxes, and passively transforms these natural sources of power into usable electricity.
Solar power can be passively collected as well, but it may also be actively collected. Redesigning buildings is a primary way to maximize their solar absorption and passively collect sunlight. Or solar panels may be spread out over a large area to collect sunlight but then actively concentrate it for use either now or later.
After this video on energy creation, you should be able to:
- Recall how energy is involved in most areas of life
- Explain how wind power can be used to produce electrical energy
- Discuss hydroelectric power and how it is used to produce electrical energy
- Differentiate between passive solar power and active solar power
- Explain how solar power can be used as an energy source