This is a short guide outlining what renewable energy is, what non renewable energy is, and why exactly different energy sources are considered renewable.
What Is A Renewable Energy Source?
Essentially, renewable energy sources generally come from natural sources and/or natural processes, replenish quickly (immediately or within the course of a human lifetime), and won’t deplete when used.
What Is A Non Renewable Energy Source?
Essentially, renewable energy sources generally require processing, take hundreds of thousands or millions of years to replenish, and may deplete in the future as we continue to use them.
Non renewable energy includes energy sources like coal, oil, natural gas, and uranium (for nuclear energy).
Why Is Solar Considered A Renewable Energy Source?
Solar energy comes from the sun, and as long as the sun is out, we can continuously use solar energy for things like the generation of electricity and for heating (of water for example).
According to most estimates, the Sun is going to last for roughly another 5 billion years (theconversation.com).
Why Is Wind Considered A Renewable Energy Source?
Wind energy is available as long as winds are blowing (onshore of offshore), and we can continuously use wind energy for electricity generation.
Wind energy actually comes from the sun (originating from the sun’s radiation warming the Earth and bodies of water that result in an air exchange and wind) (wisepowersystems.com)
As mentioned above, the Sun is expected to last billions more years.
Why Is Hydro Considered A Renewable Energy Source?
There’s probably two types of hydropower to consider when classifying hydro as a renewable or non renewable energy source:
Hydro Power On Rivers
Includes hydro electric dams (usually built on large rivers – like the Three Gorges Dam built on the Yangtze River), and run-of-river hydro.
Hydropower is called a renewable energy source because it is replenished by snow and rainfall. As long as the rain falls, we won’t run out of this energy source (lsa.colorado.edu)
Hydro Power From Pumped Storage Hydro
These hydro energy sources may or may not have access to replenishable water (from rainfall/snow, or from other sources).
Why Is Geothermal Considered A Renewable Energy Source?
Because its source is the almost unlimited amount of heat generated by the Earth’s core.
Even in geothermal areas dependent on a reservoir of hot water, the volume taken out can be reinjected, making it a sustainable energy source (energy.gov)
Why Are Bioenergy & Biomass Considered A Renewable Energy Source?
There are many different types of bioenergy and biomass (that are used for bio energy like electricity and heat energy, and for biofuels for transport).
Biomass is considered renewable because it comes from organic matter, and organic matter gets it’s chemical energy from photosynthesis from the sun.
Organic matter can be re-grown fairly quickly.
Some types of bioenergy have somewhat of an asterisk against them though because if they involve biocrops, there can be a question to how resource intensive they might be (using land, water, fertilizers, pesticides, and so on), and how sustainable this might be long term.
Why Are Tidal & Wave Energy Considered Renewable Energy Sources?
Waves comes from the wind blowing across the surface of ocean water with enough consistency and force (boem.gov) … and, as mentioned above, wind comes from the Sun’s radiation
High and low tides are caused by the moon (scijinks.gov)
The future of the moon seems to be closely tied to the future of the Sun (futurism.com)