There is a big difference between generating power and generating electricity.
Power is the ability to do work while electricity is the process of Ions attempting to return to a state of balance. This definition of electricity isn’t very useful if you don’t know what an Ion is so, an Ion is an atom that has an imbalance of protons and electrons. Positive Ions are missing an electron and Negative ions have an extra electron. As you may or may not be aware particles with the same charge (positive or negative)will repel each other and particles with a different charge will attract each other. Electrical current is a large number of electrons going from one place to another such as from a negative ion source to a positive ion source. In other words the attraction of the different polarities will pull the extra ions in the negative ion material through the wire towards the positive ion material in order to reach the state of balance.
Many people see no distinction between Power and electricity and will consider the generation of power to be the same thing as the generation of electricity. Electricity is a form of power but it requires power to generate electricity.
Hydro power can be used to generate power but Hydro power is not a method of generating electricity. This is one of the earliest forms of generating power we have all seen water wheels that grind wheat and do not generate electricity because in and of itself hydro power does not generate electricity but generates power
Burning coal is an effective means of generating power but is not a method of generating electricity. We have all seen charcoal briquettes burned to generate the power to cook our meals when we barbecue, Burning coal releases power in the form of heat and does not in and of itself generate electricity.
Burning oil is an effective means of generating power but is not a method of generating electricity. As with coal we have all seen oil lamps and know that the burning of oil does not in and of itself generate electricity but instead releases power in the form of heat.
Burning natural gas is an effective means of generating power but is not a method of generating electricity. I think you can see where I am going.
Nuclear reactions is one of the most efficient means of generating power but is not a method of generating electricity. If you look up at the sun we can all feel its power and we also know that the nuclear reactions in and of themselves do not generate electricity. Hiroshima and Nagasaki were not destroyed by electricity released from a nuclear detonation.
There is a common denominator when using any of these forms of generating power to produce electricity that is the principle of inducing a current in a wire which we will get to momentarily. Each of these methods of generating power uses induction to produce electricity.
So how is electricity generated? There are six methods of generating electricity that we are currently aware of today.
1. The first method is Friction and it produces static electricity. This is only included here in order to give as complete a survey of the methods of generating electricity as possible. For the most part this method of generating electricity is not very useful. Of course there may come a time when someone discovers a really neat and useful way to take advantage of friction for the purpose of generating electricity.
2. The second method is by Induction. This is one of the most useful methods of generating electricity that we currently use today. When a wire passes through an electromagnetic field the electromagnetic field induces a current in a wire. By using a fuel or natural source of energy to do work such as burning coal to make steam turn a wheel, passing water through a turbine, or making wind turn a wheel we can make the wire pass through the electromagnetic field many times per second. This is the principle behind most modern power plants. When used in this manner Induction creates Alternating current.
3. The third method is Photoelectric. This method of generating electricity occurs by releasing electrons when a negative ion rich photosensitive material is struck by light. A common use for this method is your common solar powered calculator. This method produces Direct Current.
4. The fourth method of generating electricity is Thermo electricity. By heating a negative ion rich thermally sensitive material electrons are released. While I know of no examples of this method my instructors at Tech Core (the navy’s basic electronics school) assure me that it does work for producing direct current.
5. the fifth method of generating electricity is the Piezoelectric effect. This method works by applying pressure to crystals to release electrons. The Modern Liquid Crystal Display is an example of this effect even though it isn’t used to generate electricity in that instance.
6. The sixth and final method that I am aware of for generating electricity is the Voltaic Cell or more commonly known as the battery. What is happening in the voltaic cell is that there is a shortage of electrons on the positive pole (carbon) and an abundance of electrons on the negative pole (zinc) and the electrolytic solution (H2SO4) makes sure that the imbalance remains in such a way as to pull electrons through the wire from negative to positive. This is the probably the most common and one of the most useful methods for generating electricity as well as the oldest known form. Recent discoveries have found ancient Egypt using clay pots that were thought to contain voltaic cells. Even the more recent Hydrogen fuel cell is based on this method of generating electricity. This method generates Direct Current.
Now you know how one can generate electricity and what is required to actually do it.