Energy Conversion

Energy conversion is energy changing from one form to another. Like when the electrical energy in the wires to your house changes to light and heat in your light bulb when you flip the switch.

All of the energy that we have on Earth comes ultimately either from the sun or from chemical reactions. Photo by NASA, public domain.

Sunlight changes to energy for growth in a plant. The energy of flowing water can be changed into stored electricity. The energy stored in molecular bonds can be converted to kinetic, heat, sound, and light energy in a firework.

Energy moves in chains too. For example the sun gives energy to heat air and water, which create the water cycle and flowing water in rivers, and the flowing water can turn a turbine in a dam, which can generate electricity to light up a light bulb in your house.

Every time you change energy to a new form you lose some to heat or friction or sound or something else, your energy use is inefficient. There is only a finite amount of energy in the universe. The universe has exactly the amount it started with. Energy cannot be created or destroyed. This is called the principle of energy conservation.

Ultimately all these things: the chicken, the zucchini, the raspberries, the light bulb, and the car get their energy from the energy stored within and between atoms.
Ultimately all these things: the chicken, the sunflowers, the raspberries, the light bulb, and the car get their energy from the energy stored within and between atoms.

All the energy in the universe was originally stored in chemical bonds. The sun gives off heat and light as it creates and destroys chemical bonds. But energy does change form and whenever it does, it moves from high energy efficient chemical bonds to more and more inefficient forms. From order to disorder. This is the principle of entropy, moving from order to chaos, the natural state of the universe. The more energy we waste in doing jobs we did not intend, the less we have to work with at a given moment. There’s plenty of energy in the universe, there’s no fear of running out, but humans are limited in our capacity for gathering efficient, useful forms of energy. That’s why we try to conserve energy and use more energy efficient forms.

Activities To Help You Learn About Energy Conversion

  • Look for other chains of energy around your home or neighborhood. Where does the energy for your body come from? What is the chain of energy that moves your car or heats or cools your home?
  • The fewer times energy has to be converted form one form to another, the less it is lost to inefficiency. Examine some different types of ways to gather energy, follow the energy chains, and decide which is the most efficient: solar panels, hydro power, geothermal, nuclear power, coal or oil burning, wood burning, etc.
  • Stretch a rubber band repeatedly and quickly, then touch the rubber band to your face. The rubber band will feel warm. Where did the heat come from? Heat is a form of energy. Follow the energy trail back as far as you can.
  • Convert chemical energy to light and heat energy by striking a match. Then light paper or wood on fire with the match. The chemical energy to light the match to begin with is on the tip of the match, but where does the energy to keep burning the paper or the wood come from?
  • Have the kids design their own energy conversion experiment. Together brain storm sources of energy available in your home. Have them use this energy to convert it into another type of energy. Identify the energy trail and the ways energy is used usefully and how energy is wasted in the transfer.
  • Plant a seed and watch it grow using sunlight energy. See what happens if the plant is deprived of sunlight energy.
  • The efficient use of energy is what really conquered the tribal peoples of the world, including Africa, North and South America, and Australia. Without knowing about converting chemical energy into kinetic energy, there would have been no guns. Without converting chemical and kinetic energy into kinetic and electrical energy there would have been no railroads, factories or steam ships. Discuss how technology impacts history and nations.
  • See if you can convince your kids to join in the fight against entropy and clean their rooms. Humans are the only forces in the known universe that take disorganized matter and change it into organized forms. It never happens in nature.
  • How does energy move from one place to another? In your previous experiments or demonstrations identify how the energy moves from place to place. Waves, like in sound and light? Electric current? Or by a moving object?

Additional Layers

  • This unit is a great jump off place to talk about using resources wisely, like turning off lights when you don’t need them, running the dishwasher when it’s full, using what we need and not wasting food, paper, clothes, and so on. Talk about all the reasons why your family conserves.
  • One of the greatest achievements of human kind is harnessing and using energy for our benefit. Learn more about the pioneers in this field: Benjamin Franklin, Michael Faraday, Lord Kelvin, Lise Meitner, and James Joule.

One Comment

Leave a Reply

Your email address will not be published. Required fields are marked *