Energy

Upload Knowledge Introduction - Basics of Energy

Did you know that most of the energy we use here on earth actually comes from the sun? And not just through solar power, but even through fossil fuels, biomass and even wind power. Fossil fuels are made of ancient organic matter such as plants that were once alive and grew by photosynthesis, capturing energy from the sun. When they died, decayed, and eventually became fossil fuels buried in the earth, they kept that energy with them, and when we burn fossil fuels we are re-releasing that energy. Biomass also uses energy stored in plant material, only we are using plants that only recently died. Wind power also comes from the sun because the sun indirectly creates wind by sending energy to the earth that heats the earth. The imbalance of temperature from warmer places compared to colder ones combined with some influence from the rotating of the earth creates the forces for air to move as wind.

Many of the fundamental concepts you have to understand in order to understand energy are found in the Laws of Thermodynamics. For example, do you wonder why our energy has to come from the sun, and why we can’t just make energy here on earth? We can’t just make energy from nothing because the First Law of Thermodynamics states that energy and matter can neither be created nor destroyed. And do you wonder why we can’t just recapture all the energy we use to create electricity, heat, or to power our vehicles? We can’t recapture all the energy because of the Second Law of Thermodynamics, which states that transfers of energy from one source to another are never 100%. Even though no energy is destroyed in the process of moving or working, there is a loss of usable energy because some of it always spreads out in uselessly low concentration. For example, this is true for our production and use of electricity, though we may not think about it. In the United States, only 16% of commercially produced energy actually does work according to BPA and Oregon State University Extension Services. This is why investing in energy efficient products and infrastructure is so important.

For more on how energy works in general, check out this easy-to-understand website by FT Exploring Science & Technology. It explains a definition of energy, the difference between the terms energy and power, and the laws of thermodynamics. Also check out these sites if you have a specific learning style…

Straightforward Learners-- check out this site hosted by the University of Arizona.
Technical Learners-- check out this site by NASA.
Visual Learners-- check out this site by Georgia State University.


Do you know how a power plants works? If you don’t, it’s another important concept to learn because it will help you understand the basis for many of the renewable energy technologies we’ll discuss in the next section. Check out the Foundation for Environmental Education’s tutorial on how a power plant works. Go to their main site, then go to the scroll-down bar by Energy Education and select “How does a power plant work?”

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