Preface
This is my first major project in the SteemSTEM category and I'm going to write some articles on it, because the topic itself is much too big for a single article. I will also try to explain the topics in an understandable and easy way, while at the same time not softening the informed and scientifically inspired readers and also touching on complex topics.
In the future, we will have to cover all of our energy needs in the world with renewable energies. That alone is reason enough to deal with renewable energies and ask yourself why this is the case.
If you have any questions, just write in the comments and I will help you as best I can.
What are renewable energies?
Renewable energies are energy sources that are practically inexhaustible within the human time horizon or renew themselves relatively quickly. In this way, they distinguish themselves from fossil energy sources that are finite or regenerate only over a period of millions of years. Renewable energy sources are considered to be the most important pillar of a sustainable energy policy and energy turnaround, in addition to higher energy efficiency. These include bioenergy (biomass), geothermal energy, hydroelectric power, ocean energy, solar energy and wind energy. By far the most important source of energy is the sun.
The term "renewable energies" is not to be understood in a strictly physical sense, because energy cannot be destroyed or created according to the principle of energy conservation, but can only be transformed into different forms.
Renewable energy sources
The basis for renewable energies is formed by the three energy sources nuclear fusion of the sun, tidal power due to the planetary movement and geothermal energy of the Earth's interior. The most productive form by far is solar energy, whose annual energy supply on earth amounts to 3,900,000x10^18 J (3,900,000,000,000 petajoules). Geothermal energy provides 996x10^18 J, while gravity supplies 94x10^18 J.
Global energy demand in 2010 was 505x10^18 joules. This means that renewable energy sources exceed the world's energy requirements by a factor of approximately 10,000!!!
We have an increasing energy demand on earth every year, and future projects such as e-mobility do not exactly suggest that it will decrease in the near future.
Our supply of coal, crude oil, natural gas and radioactive materials such as uranium or thorium for nuclear fission is limited on Earth and is estimated to be depleted within the next 200 years. For this reason alone, we must change our energy supply.
The sun, on the other hand, emits more than 10,000 times as much energy as we human beings need per year. This "renews" itself annually; hence the term renewable energy.
Part of this energy is converted by natural processes into biomass, solar, wind and hydroelectric power.
These are the basics of renewable energies. In summary, it is relatively simple: We use the sun's existing energy to conserve our own resources. Since we have to switch to it inevitably because of the scarcity of resources on earth for our energy consumption. The sun will shine in about another 6 billion years and when the sun comes to an end, people will either die out or colonize another planet.
So it's only the best thing that we are currently focusing so much on renewable energies?
In my next posts I will come to this point, because there are a few other topics to consider: Energy storage, energy loss due to transport, efficiency, economic and ecological influences due to renewable energies, politics, lobbying, greed of mankind and finally irrationality.
Sources
https://de.wikipedia.org/wiki/Weltenergiebedarf
https://de.wikipedia.org/wiki/Erneuerbare_Energien
Jochem Unger, Antonio Hurtado: Energie, Ökologie und Unvernunft. Springer Spektrum
© Springer FachmedienWiesbaden 2013