Solar panels can be a sustainable energy source as they capture the sun.
Since the Industrial Revolution in the mid-18th century, human society has largely been run by unsustainable forms of energy. The draining of fossil fuel reserves combined with an increase in understanding of the environmental damage caused by fossil fuels has led to an increase in the search for sustainable energy sources. There are many different forms of sustainable energy, although most remain in technological infancy and require further scientific advances and investment before being fully capable of handling modern energy consumption.
A hydroelectric dam.
Fossil fuels, most typically in the form of coal, oil and natural gas, are used in almost all types of devices that require energy to run. These fuels come from a natural degradation of organic fossils over millions of years. Although fossil fuels have been used throughout human history for various purposes, their extreme importance did not occur until the Industrial Revolution and the development of motorized transportation. Since cars, jets and motorized heating systems became prominent, human use of fossil fuels has increased enormously, leading to a devastating overuse of available resources. As a result, most experts suggest that Earth’s fossil fuels will run out in the next few centuries, making the search for sustainable fuels not only altruistic, but imperative for the survival of human technology.
Wind energy is a form of sustainable energy.
A sustainable energy source is one that does not deplete the original resource or uses resources that can be replenished easily and efficiently. The use of solar energy, for example, is considered sustainable, as absorbing and using the heat or light of the sun does not reduce the power or size of the sun. Ethanol, made from certain crops, is also sometimes considered sustainable energy, as crops can be easily replanted and replaced.
Biodiesel can represent an alternative to traditional diesel oil.
Hydropower is sustainable energy used to power generators. This widely used renewable energy source works by using the gravitational pull of water. Falling water or incoming tidal flows are channeled through machines, forcing the internal turbines to spin and generate energy. In most cases, water is pushed back and forth between reservoirs at different elevations or released back into the ocean after flowing through the turbines. Wind and geothermal energy operate in the same way, using renewable natural forces to power turbines and, consequently, generators.
Biogas fuel is produced when organic matter, such as cow manure, is broken down by anaerobic bacterial digestion.
Solar energy operates by absorbing light and heat from the sun. Solar thermal energy can absorb heat from the sun and transfer it to the water, making it an efficient sustainable energy source for water heaters and swimming pools. Photovoltaic solar energy absorbs sunlight into solar panels, where the absorbed electrons bounce off silicon solar cells, creating an electrical current that can then be used to generate power.
Solar panels for residential roofs can provide sustainable energy for a home.
Ethanol, biodiesel and biogas are slightly more controversial sources of sustainable energy. These technologies use the processed products of plants and organisms to create fuel alternatives. Unfortunately, in the case of ethanol, processing and burning results in high levels of greenhouse gas emissions. Biofuels, such as algae biodiesel, are a possibly greener alternative, but remain mostly in experimental or small-scale use. However, many experts believe that all three technologies will play an important role in expanding the sustainable energy market.