- Energy conversion, or energy transformation, is the process of changing one form of energy to another form.
- Any form of energy can be transformed into another form.
- Energy is often converted from its most available form such as chemical energy (e.g., fossil fuels) into a more useful form (e.g., electricity).
- A series of conversions may be needed in order to convert energy into the desired form.
- Example: Chemical energy from fuel is changed into thermal energy in a vehicle engine; then into mechanical energy of the rotating crankshaft that turns the wheels.
- Electricity cannot be used unless it has been converted to some other form of energy.
- Magnetic Energy is used to make machines move.
- Electricity flowing in a coiled wire will form a magnetic field.
- Example: electromagnets that cranes us to lift metal in a junk recycling yard.
- Example: electric motors have 1 or 2 electromagnets that interact with each other or a permanent metal magnet to make motion.
- Thermal Energy (heat)
- Electricity flowing through metal conductor with high electrical resistance will convert to heat (as well as some light).
- Example: stovetop burners get very hot when electricity is passed through them. There is some light as well.
- Light Energy
- Electrons flowing through an LED (Light Emitting Diode) or an incandescent bulb filament will convert to light (as well as some heat).
- Example: LED television sets have millions of tiny LEDs that create a picture when electricity is passed through each of them.
- Electrons flowing through an LED (Light Emitting Diode) or an incandescent bulb filament will convert to light (as well as some heat).
- Electricity flowing in a coiled wire will form a magnetic field.
- Magnetic Energy is used to make machines move.
- Any form of energy can be transformed into another form.
Replace Light Bulb to Fluorescent: Example: an incandescent light bulb converts electrical energy into radiant energy in the forms of visible light and infrared radiation. The light is useful; however, the infrared radiation (heat) is wasted. Modern CFL (compact fluorescent lamp) and LED (light-emitting diode) bulbs are more efficient than incandescent bulbs because they produce the same amount of light but much less infrared radiation. A lighted incandescent bulb feels hot to the touch; whereas, a CFL or LED bulb does not.
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- In any conversion process, some energy is used because some of the original energy turns into forms that are neither wanted nor needed for the desired purpose.
- Following the Law of Conservation of Energy, wasted energy is not lost, and it does not disappear.
- The total amount of energy put into a conversion process equals the total amount of energy put out in all forms.
- Most often energy is lost in the form of heat. Heat lost to the environment is difficult to use and eventually is lost from the earth into space.
- The efficiency of an energy conversion process equals the ratio of the amount of energy desired to the amount of energy put in.
- Because every energy conversion wastes some energy, the efficiency ratio is always less than one.
- Question: What is the efficiency ratio of an energy conversion that requires 400 joules of energy to produce 100 joules of useful energy? (Joules are units of energy measurement.)
- Calculation: 100 ÷ 400 = .25
- Answer: The energy efficiency ratio is 25%. (75% of the energy is wasted.)
- Question: What is the efficiency ratio of an energy conversion that requires 400 joules of energy to produce 100 joules of useful energy? (Joules are units of energy measurement.)
- Because every energy conversion wastes some energy, the efficiency ratio is always less than one.
Electric Engine Selective Focus: Can you see how fast the generator is spinning? Inside a power plant, a generator spins at top speed to create electricity.
- An electrical generator is a device that converts mechanical energy into electrical energy. Following are the basic principles of an electrical generator:
- Electric conductors such as coils of copper wire are tightly wound inside a frame.
- The conductor and its frame are called the armature.
- Magnets are mounted on a spinning rotor inside the armature.
- As the magnetic field spins through the coils of copper, the electrons in the conductor are set in motion to create a flow of electric current.
- Remember the electricity is the motion of electrons. We can’t store motion. To store electricity, it must be converted to a type of potential (stored) energy.
- Batteries have potential energy stored as (chemical energy).
- Stored water at a higher elevation (potential energy).
- Some systems pump water into a reservoir using renewable sources when there is extra power. It is then passed through generators to make electricity at a later time to convert it back into electricity.
- Remember the electricity is the motion of electrons. We can’t store motion. To store electricity, it must be converted to a type of potential (stored) energy.
- Electric conductors such as coils of copper wire are tightly wound inside a frame.
Difference between source and resource :
Source: A place where one can get a valuable item. Example: A coal mine is a source of coal.
Resource: A valuable item that one uses. Example: Coal is a resource.