Renewable energy is clean electricity derived from natural sources. It cannot be depleted and releases no greenhouse gas emissions. It is imperative to the fight against climate change.
Renewable energy is clean electricity derived from natural sources. It cannot be depleted. The most important part about renewable energy is that it is clean; it releases no greenhouse gas emissions and does not contribute to the greenhouse effect. That's why renewable energy is incredibly important in the fight against climate change.
Renewable energy is also getting cheaper than fossil fuels. In the past 19 years, coal prices have risen by 59%, while solar PV cells have dropped by 99% in the last 40 years. While coal prices are dropping again because of lower demand (signaling the demise of coal), they are not competitive with renewable energy. Furthermore, coal is still getting more and more scarce as it is harder to find deposits.
Types of Renewable Energy
Concentrated Solar Power
Concentrated solar power (CSP) is similar to solar PV energy except it uses the sun's heat rather than its light energy. CSP systems are made up of two parts: a reflector, a mirror, directs the sunlight to the receiver, which takes in the energy directed from the reflector and converts it into usable electricity.
CSP is a relatively new technology and therefore is not widely developed. However, there are four main types of CSP, the two most prominent being the parabolic trough system and the central receiver system. The parabolic trough system has u-shaped reflectors that move with the sun, allowing for maximum concentration all day. The central receiver system can concentrate the sun's energy up to 1,500 times more than its normal intensity. In this system, there is a field of reflectors that all concentrate energy onto a single tower receiver.
Geothermal energy uses the earth's natural heat for electricity and home heating/cooling. Due to these two different uses, there are two types of geothermal energy: geothermal power plants and geothermal heat pumps.
Geothermal power plants use drilling to fracture rock and extract hot water and steam. These fluids then turn turbines to generate electricity. Geothermal heat pumps are more small-scale and simple. Fluid travels through a system of pumps extending a few hundred feet underground, where the temperature is constant year-round. During the summer, it cools the fluid, which is then used to cool the house, and during the winter, it warms the fluid to warm the house.
While geothermal energy is an enormous and untapped energy resource, it is a controversial energy source because it relies on fracturing rock, which can release greenhouse gas emissions, make the ground unstable, and contaminate water supplies.
Hydroelectricity uses the flowing movement of a river to generate electricity by building a dam on the river. This dam has gates called "sluice gates" which can open and close on demand. When they are closed, the water builds up behind the dam. When they are open, the water falls through the dam at very high speeds, turning turbines at the bottom.
Hydroelectricity is one of the most prevalent forms of renewable energy today. Because there are so many rivers across the world, it has enormous potential. However, there are some negative effects of hydroelectricity that should be mentioned, including flooding caused by the dams and disruptions to fish and other river life.
Nuclear energy is a type of energy created by splitting apart uranium atoms. It does not produce greenhouse emissions; however, it is not technically renewable since we could use up all of the element uranium one day. Uranium must be mined and milled before being used to create nuclear energy. After that, it must be disposed of safely.
Nuclear energy is helpful because it can constantly produce energy, unlike other sources which rely on wind or solar conditions. Although it is not renewable, it doesn’t pollute, so it does not contribute to climate change. It currently makes up 19.7% of America’s energy, about the same as the total energy we get from renewable sources. However, we have to be conscious of safety when using nuclear energy, as the dangerous waste it produces can be harmful or even catastrophic if it leaks.
Solar PV Energy
This type of renewable energy uses solar panels to take the sun's light and transfer it to electricity. In solar energy, there is a solar panel made up a solar cells. Each of these solar cells is specially designed with silicon to let go of an electron (a very small particle which is the basis of electricity) when hit by the sun's energy. Then wires recieve the electron, converting it to renewable energy.
One of the biggest advantages of solar PV energy is that the prices are rapidly dropping at the same time that investment in them is dramatically increasing! This combination holds promising futures for the solar industry. However, solar panels require a lot of space, which can be troubling to find, and potentially damaging to local environments.
Tidal energy is a type of renewable energy where we harness the power of the tides to power turbines. There are three types of tidal energy: a tidal barrage, tidal turbines, and a tidal lagoon. Each of these methods are slightly different.
In the tidal barrage system, gates open and close to fill a tidal basin on high tide and empty the basin through a system of turbines when the tide goes back out. A tidal turbine system operates more simply, where the general movement of water simply turns the blades of turbines placed in the water. Finally, the tidal lagoon system is very similar to the tidal barrage system, except it uses a natural lagoon rather than a human-made basin.
Tidal energy is very promising because it has enormous potential for electrical generation while taking up much less room than other forms of renewable energy. The problem with tidal energy, however, is that it can be damaging to the surrounding environment, including emitting poisonous electronic waves in the water and altering water levels.
Wind energy is one of the most promising forms of renewable energy. Although large and complex, they are prevalent across the world. In its most basic form, a wind turbine consists of three blades which, when propelled by the wind, rotate, powering a motor that generates electricity.
There is also another type of wind turbine, called a vertical axis wind turbine. These can turn when the wind is going in any direction and are position so that the blades are vertical rather than horizontal. It is still a scientific debate as to if these vertical turbines are more efficient than the traditional horizontal models.
Despite wind energy's many benefits, it also can have some negative environmental impacts that scientists are working on fixing, such as damage to habitats and bird migrations. In addition, because wind turbines take up so much land, it is difficult to find large swaths of land to put wind farms on.