Melondy Phillips
Staff Writer
The first law of thermodynamics states that energy cannot be created or destroyed; but it can be transformed from one form into another.
The different types of energy are mechanical, thermal, sonic, nuclear, chem- ical, gravitational, kinetic, potential, electromagnetic and ionization. This article will only cover a few of these since it will be geared toward homemade devices. This first part will lay the definitional foundation for parts 2 and 3.
Definitions
Kinetic energy is the positive value of energy produced from a body in motion while potential energy is the energy of an object’s position.
Mechanical energy is the energy produced from moving an object and is the result of potential energy plus kinetic energy. Some examples of mechanical energy are turbine generators, alternators, hydroelectric plants, windmills, pelton wheels and pendulums (which are subject to gravitational force). An induction generator, which works on the principle of electromagnetic induction, is needed in order to produce electricity using mechanical energy.
Thermal energy is produced when temperature rises. Heat is the flow of thermal energy which means anything that is warm emits thermal energy, some examples are: baking a cake, heating a room, the sun drying clothes, using an iron, composts and compressed air from heat (steam).
Chemical energy results from chemical reactions between atoms or molecules. There are different types of chemical energy. One type of chemical energy is electrochemical energy. This is a type of energy that involves the transfer of electrons between chemical species. It is used to generate electricity or to store energy in batteries. Another type is chemiluminescence, this may have a limited release of heat but is mainly light emission (luminescence) as the result of a chemical reaction. An example of this type of chemical reaction is a glow stick.
Electromagnetic energy is energy from light or electromagnetic waves, examples are: x-rays and microwaves.
Sonic energy is the energy of sound waves and is used for wireless charging of batteries underwater; as well as to charge implanted electronic devices such as pacemakers and defibrillators.
Gravitational energy involves the attraction between two objects based on their mass.
Ionization energy is the form of energy that binds electrons to the nucleus of its atom, ion, or molecule; some examples are fluorescent lamps, Geiger Müller counter, saltwater solutions, potatoes, citrus fruits.
Solar energy is the radiant energy emitted by the sun.
Geothermal energy – heat: heat from the earth
A generator converts mechanical energy into both AC and DC energy but is considered less efficient and has a lower output than alternators. In a generator, the magnetic field is stationary and the armature winding spins.
An alternator is a device that converts mechanical energy into alternating current (AC) by using a magnetized niche (rotor) which spins inside the armature (stator).
Diode rectifier converts the alternating current (AC) electricity from an alternator into direct current (DC) electricity, allowing a battery to be charged.
A voltage regulator controls and maintains a steady amount of voltage to the battery.
A turbine is a device that harnesses the kinetic energy from things such as water, steam, air, or combustion gases – and turns it into the rotational motion of the device itself.
• Impulse turbines: most common types of impulse turbines include the Pelton wheel and the Turgo wheel.
• The pelton wheel, an inward flow impulse turbine, was invented in the 1870s by the American inventor Lester Allan Pelton. Unlike a traditional overshot water wheel, which uses the kinetic energy of falling water, the pelton wheel harnesses energy from the impulse of moving water by funneling water into a pressurized pipeline with a narrow nozzle at one end.
• A Turgo impulse wheel is a smaller more efficient version of the Pelton wheel. Due to the improved design, the Turgo wheel can also operate under low-flow conditions which requires a medium to high head.
• Jack Rabbit turbine, also known as an Aquair UW Submersible Hydro Generator, can produce power by placing it in a stream with at least 13 inches of water, no head is needed. Although this unit does not require a head, it only has a maximum output of about 100 Watts.
• Conventional pumps are less expensive and easier to find than specialty turbines. By reversing the action of the pump, it can be made to work like a turbine, although it is less efficient.
• A vortex turbine for water is a dam-less hydroelectric generator that has minimal environmental impacts since it does not obstruct water flow. Due to its low RPM impeller, fish are able to past through unharmed. A vortex turbine for wind is a slender, cone-shaped generator featuring the motor at its base.
Part two will cover ways to harness energy so it can be used for electricity.
