Renewable energy, which is also known as clean energy, comes from sources or processes that are made by nature. There is no time or weather that stops sunshine or wind from shining or blowing.
Renewable energy is sometimes thought of as a new technology, but it has been used for heating, transportation, lighting, and other things for a long time. Wind has pushed ships across the oceans, and windmills have crushed grains of wheat and other crops. A fire could keep going late into the night because the sun kept it warm. People have been using coal and fracking gas for energy for the last 500 years or so because they’re less expensive and dirty than other sources.
Renewables are becoming more important as a source of power in the United States. They now make up more than one-eighth of the country’s electricity. This is because we have more creative and cheaper ways to catch and store wind and solar energy. Renewables are growing in all shapes and sizes, from rooftop solar panels on homes that can sell electricity back to the grid to huge wind farms off the coast. Some rural areas use only renewable energy to heat and light their homes and businesses.
As the use of renewable energy grows, one important goal will be to make the U.S. power system smarter, more secure, and more connected across the country.
There are many Different Types of Renewable Energy
For a long time, people have used the sun’s energy to grow crops, stay warm, and dry their food. NREL says that in one hour of sunlight, “more energy is absorbed by the Earth than everyone on Earth uses in a year.” Today, we use the sun’s rays in a lot of different ways, like heating homes and businesses, warming water, and powering things.
Solar cells, also called photovoltaic (PV) cells, are made of silicon or other materials that convert sunlight into energy right away. They are also called solar cells. People and businesses near each other use distributed solar systems to get energy from the sun. These systems can be set up on rooftops or through community projects that power whole neighbourhoods. Solar farms, which use mirrors to direct sunlight over a lot of solar cells, may be able to produce enough electricity to power a lot of homes. It may be possible to use wastewater treatment plants and water that isn’t very important to the environment to build floating solar farms. These farms are called “floatovoltaics.”
Solar power makes up less than 1% of the total amount of electricity used in the United States. Solar, on the other hand, accounted for about a third of all new power capacity added in 2017, behind only natural gas.
People who use solar energy systems don’t put pollutants or greenhouse gases into the air, and as long as they are properly placed, most solar panels have no effect on the environment outside of the manufacturing process.
We’ve come a long way since the days when windmills were the only way to get power. There are now wind turbines that are taller than buildings, with turbines almost as wide. They are all over the world. Wind energy moves the blades of a turbine, which in turn moves an electric generator and makes electricity.
Wind, which makes up less than 6% of US power, has become the cheapest source of energy in many parts of the country. California, Texas, Oklahoma, Kansas, and Iowa are some of the best places to build wind turbines. Turbines can be built anywhere with strong wind speeds, from hilltops and broad plains to the open ocean.
Other Renewable Energies
Hydropower is still the most common renewable source of electricity in the United States, but wind energy is expected to overtake it soon. Hydropower is a way to turn the force of water into energy by spinning the turbine blades of a generator with the movement of the water. This is done with water that moves quickly in a river or falls quickly from a high point.
They are often thought of as sources of nonrenewable energy on a national and global level. Mega-dams, which are large hydropower projects that use a lot of water, are one example. Mega-dams change and cut off the natural flow of water, making it more difficult for river-dependent animals and humans to get to their habitats. Small hydroelectric plants with installed capacity of less than 40 megawatts that are well-managed don’t do as much damage to the environment because they only divert a small amount of the flow of water.
It is made from plants and animals, so biomass includes crops, waste wood, and trees. When biomass is burned, the chemical energy in it is released as heat. This heat can then be used to make electricity with a steam turbine.
Biomass is sometimes portrayed as a clean, renewable fuel that is better than coal and other fossil fuels for making electricity. Recent research, on the other hand, shows that many types of biomass, especially those that come from forests, emit more carbon than fossil fuels. There are also bad consequences for biodiversity. It’s still possible to use biomass energy in the right way and make it a low-carbon choice. For example, sawdust and chips from sawmills can be used to make low-carbon energy. These things would normally break down and release carbon, but they can be used instead.
People use geothermal energy when they sit in a hot spring, which is when they use it. In part, this is because radioactive particles in rocks at the earth’s core are breaking down over time. This makes the earth’s core about as hot as the sun’s surface. When you drill deep into the ground, very hot subsurface water comes to the surface as a hydrothermal resource. This water is then pushed through a turbine to make electricity. If geothermal facilities return the steam and water they use back into the reservoir, the emissions are usually very small, but this is not always the case. When there is no subsurface reservoir, there are ways to build geothermal plants where there is no risk of earthquakes.
Tidal and wave energy are still in the early stages of research. The moon’s gravity will always rule the ocean, making it a good idea to use its power. Some tidal energy techniques, like tidal barrages, which work like dams and are placed in an ocean bay or lagoon, may harm species. People who make waves use dam-like structures or devices that are anchored to the bottom of the sea. This is the same way that people make tidal power.
People who make their own renewable energy at home
On a smaller scale, we could use solar panels or passive solar home design to get the sun’s rays and use them to power the whole house. These homes are built to let in light from south-facing windows and then keep the heat in with concrete, bricks, tiles and other materials.
Some solar-powered homes make more energy than they need, so the owner can sell extra power back to the grid. Batteries are also a good way to store extra solar energy for use at night. They may also help you save money. Scientists are hard at work coming up with new ideas that are both beautiful and useful, like solar skylights and roof shingles.
Heat Pumps Geothermal
This is a modern twist on a process that has been around for a long time. The coils at the back of your refrigerator act as a small heat pump, expelling heat from the inside to keep things fresh and cold. Geothermal or geoexchange pumps in homes use the same temperature of the ground a few feet below the surface to cool and heat homes in the summer and winter, and even to heat water. They do this because the ground is always the same temperature.
Geothermal systems may cost a lot to build at first, but they often pay for themselves in ten years or less. They also make less noise, don’t need as much maintenance, and last longer than standard air conditioners.
A wind farm in your back yard? That’s not good. Small wind turbines are often used by boats, ranchers, and even businesses that make cell phones. Dealers now help homeowners find, build, and maintain wind turbines, but some people do it themselves. A wind turbine could help you cut back on your use of electricity, depending on how much power you use, how strong the wind is, and what zoning rules are in your area.
Selling Your Energy
Wind and solar-powered homes can run on their own, or they can be connected to the larger electrical grid through their power supplier. Most places let people pay for only the difference between what they use from the grid and what they produce, which is called “net metering.” It might be possible for your energy supplier to pay you the retail price for energy that you make more than you use.
Renewable Energy and You
If you speak up for renewable energy or use renewable energy in your home, you could help speed up the transition to a more sustainable energy future. Even if you can’t put solar panels on your house, you might be able to choose power that comes from a source that doesn’t harm the environment. (Check with your utility provider to see if this is an option.) If your utility doesn’t offer renewable energy, you can buy renewable energy certificates to compensate for your use.