Due to global warming, governments and corporations are becoming increasingly wary of their carbon footprints from their respective industries. This concern is because global warming is caused by the emission of greenhouse gases, such as carbon dioxide, into the atmosphere. It absorbs excess sunlight and solar radiation, resulting in higher surface temperatures, more frequent droughts, more powerful hurricanes, and heavier rainfall in some regions of the world. As a result, nonrenewable energy sources such as fossil fuels and natural gasoline that release carbon dioxide are being slowly replaced in sectors such as manufacturing and transportation by renewable energy sources like wind and hydropower. Renewable energy sources diversify energy supplies, produce little to no greenhouse gases, and naturally replenish themselves. However, renewable energy sources require higher capital costs, and electricity production can be unreliable. Nonetheless, renewable energy sources are the future to covering humanity’s future energy demands and preserving the Earth.
Solar energy is the most abundant of all renewable energy sources. There are two main types of solar energy technologies: photovoltaic cells and concentrated solar-thermal power. In photovoltaic cells, made from purified silicon and semiconductor metals and commonly found in solar panels, electrical cells convert the sun's light energy into electricity. Some advantages of photovoltaic cells include their low maintenance, operating costs, and versatility; energy can be produced anywhere. However, some disadvantages include that photovoltaic cells can be damaged by wind or debris, and they cannot produce electricity during night-time or during cloudy/rainy weather. Next, concentrated solar-thermal power technologies use mirrors to focus and reflect sunlight onto a receiver, which heats a high-temperature fluid within the receiver. The heat generated then spins a turbine to produce electricity. The advantages of this type of renewable energy source include its industrial heat applications and efficient thermal energy storage. Still, it requires more capital investment than photovoltaic cells and large amounts of water for cooling, which can deplete water supplies.
Wind energy harnessed through windmills is another popular renewable energy source. How it works is that windmills capture the kinetic energy of winds/breezes to spin a turbine, which produces electricity. Specifically, the rotation of the turbine turns a generator inside the wind turbine, generating a flow of electrons and eventually an electric current sent through power lines to cities. The excess energy is stored in electrical batteries, compressed air storage, hydrogen fuel cells, or pumped storage. The advantages of wind energy include that it creates a significant number of jobs and is predicted to become cheaper than fossil fuels in the near future. But as its name suggests, wind turbines only generate electricity when there is wind, and the construction of wind turbines can destroy habitats and disrupt native ecosystems.
Furthermore, hydropower utilizes turbines and generators to convert the kinetic energy of the flowing water into electricity. The process includes water flowing through a pipe, channeling the water to a turbine. The kinetic energy is then converted into mechanical energy because the water turns the turbine. It is the cheapest source of energy overall. Once the dams and stations are built and turbines are installed, they require minimal experience in maintenance compared to the initial investment. Hydropower stations are also flexible; they need a minimal amount of energy to start working and can go from offline to maximum power in a few minutes. However, hydropower plants can impede fish breeding, and the performance of plants is immensely affected by droughts because the less water there is, the less energy is produced. Nonetheless, hydropower is a highly beneficial energy source like solar and wind.
Lastly, geothermal energy is a type of energy that harnesses the endless heat generated from the Earth’s core. Geothermal power plants produce electricity by drawing on subterranean pools of hot water or steam. These reservoirs are usually reached by drilling a well, and they are located several miles beneath the surface of the Earth. Like steam utilized in a coal-fired power plant, the hot water or steam is raised to the surface and used to produce energy. Its benefits include not harming habitable land or creating any type of pollutant during operation. Still, it is expensive and can release hydrogen sulfide and methane, two greenhouse gases, during construction. All in all, renewable energy sources have enormous potential to produce abundant amounts of electricity while generating minimal to no greenhouse gasses.