Renewable energy is energy that comes from Earth’s resources, such as the sun, wind, water, and geothermal heat. This kind of energy can be replenished naturally by the Earth in a relatively short period of time, which is why it is called renewable energy. Renewable energy is growing quickly because our need for energy is also growing. The fossil fuels and other nonrenewable resources are diminishing, so we need to rely on other methods of acquiring energy. Although renewable energy does have its disadvantages, many people think it is the best way to go in the future.
Solar energy is one kind of renewable energy. It converts solar radiation from the sun into electricity. There are many different kinds of solar energy, including photovoltaics and concentrating solar power. Photovoltaic cells (PV) are devices that convert the sun’s light, or any kind of light, into electricity. PV cells are usually put into modules, which are then wired to form arrays, then wired to an inverter. Inverters produce power at a desired voltage. Next, concentrated solar power is when dozens of lenses or mirrors focus the sun’s light into a small beam. This beam then heats a regular power plant, and makes electricity. A disadvantage of solar energy is the sun doesn't shine all the time. To solve this, grids usually have a stored energy supply to use on cloudy or rainy days.
Wind energy uses turbines to make energy. Winds turn the turbines, which spin a generator that makes electricity. Turbines are usually put in groups, in places where winds are constant and strong. These groups of turbines are called wind farms. Wind farms have the most potential for being a major energy source because it can produce a lot of electricity if installed around the world. Some disadvantages of wind energy is that the wind doesn’t blow all the time. If the wind doesn’t blow, the turbines are not turned, and there is no electricity.
Hydroelectricity, or water energy, is electricity generated by water. When rivers or lakes are dammed, the water can be let through intakes and through the penstock, and the water runs through. The water spins a turbine, which generates electricity. The amount of electricity generated depends on the difference between the starting height and the end height, and the amount of water flowing through. Some disadvantages of hydroelectricity is that the water source might run out over time, such as a lake. Also, dams can be built improperly and can cause floods if it is leaking or falling apart. But, overall, hydroelectricity is more reliable than wind and solar energy because there is an almost constant flow of water.
Geothermal electricity is electricity that is formed from the heat inside earth. Since the inside of Earth is hot and heats bodies of water in the crust, the result is steam. This steam turns a turbine, which spins a generator and makes electricity. Geothermal energy is harnessed and used in geothermal plants. This kind of energy is very reliable because the Earth will constantly be hot, so there will be a constant flow of electricity.
As you can see, renewable energy is not yet ready enough to become the world’s major electricity resource, but it is still usable. Not only is this kind of electricity better for the environment, it will never run out unless something happens to the Earth. People around the world are converting to renewable energy; around 10% of electricity the world uses is produced by renewable means. Renewable electricity might not be a very major thing now, but it might be in the future.