Geothermal: Geothermal energy is derived from the heat of the earth. This heat can be sourced close to the surface or even from reservoirs of hot water miles beneath the surface. This energy is harvested on a large scale by geothermal power plants, which are becoming far more popular with each passing year. However, for smaller buildings, a geothermal heat pump may be used to heat the building and even help keep it cool using the earth's natural energy.
Geothermal energy is also being used to heat water at fish farms, aid with a variety of industrial processes, help to run greenhouses and grow plants, or simply heat commercial buildings and reduce energy use.
Ocean Power: The ocean is able to produce two types of sustainable energy, mechanical energy from the motion of the waves and thermal energy from the sun's heat. Systems that rely on warm water temperatures can easily convert ocean thermal energy into electricity. And ocean mechanical energy utilizes the tides caused by the rotation of the earth and gravity.
Unfortunately, use of ocean energy is limited by geography and regulatory guidelines. However, cold water from the ocean can be used to keep buildings cool and areas near the ocean can utilize the ocean energy for energy needs and power generation.
Hydrogen: Hydrogen is the most abundant element in the universe but does not actually occur naturally as a gas on earth. However, this element can be found in organic compounds and water. Additionally, hydrogen may also be produced under certain circumstances by some bacteria or algae. Fortunately, this element is high in energy but produces little pollution when burned. But until costs come down and the durability of using hydrogen improves, there will be little commercialization.
Hydrogen is commonly used to refine petroleum, produce fertilizer, treat metals, and process foods. It can also reduce energy costs when it powers marine vessels and remote buildings. Car companies are also experimenting with hydrogen fuel cells, which emit water vapor instead of harmful greenhouse gases, and the first U.S. hydrogen fueling stations are currently being tested in California.
Over half of renewable energy in the U.S. is used for producing electricity, and around 13% of all electricity generation in the U.S. came from renewable energy options in 2015. While this is certainly a great start, more and more people are trying to figure out ways to utilize more renewable energy options. Using renewable energy options can not only save people money on energy costs, but it's better for the planet too.