Renewable Energy

Electricity consists of moving charge. When we think of the path for electricity, we think of wires most of the time. In metallic solids, electrons make up the charge that moves; however, the charge can also move through certain liquids and gases as well as space itself. In this section, …

Series and parallel circuits are two basic arrangements of the source and loads. Series and parallel circuits are often combined to form complex circuits that can be understood on the basis of simpler series and parallel arrangements.  Series Circuits A series connection is one with a single path. A series circuit has …

When there is current through a resistance, electrical energy is converted to heat or other forms of energy such as light. A common example of this is the incandescent light bulb that becomes too hot to touch when it has been on for a short time. The current through the …

With the exception of a special class of materials called superconductors, all materials have resistance, which is the opposition to current. Conductors are generally metallic materials with low resistance, whereas insulators are materials with high resistance. When there is current through a resistive material, heat is produced by the collisions …

The original idea of current was based on Benjamin Franklin’s belief that electricity was an unseen substance that moved from positive to negative. Conventional current is defined based on this original assumption of positive to negative. The original definition is widely used, although there is another definition of current called electron flow. Electrons move …

These three basic electrical quantities—energy, charge, and voltage—are closely related. It is difficult to visualize or measure energy directly because it is an abstract quantity and represents the ability to do work. The electrical charge can be positive or negative, and it can do work when it moves from a …

Sailing ships have been using the wind for thousands of years. The wind was thought to be first used for pumping water by the ancient Persians. They adopted the idea of using the sail to capture the wind in a vertical-style windmill. The Persians and later the Romans also used …

The solar energy directed at earth is considerable. The sun has far more energy associated with it than we need, but its energy is spread out over the surface of the earth. The solar constant of 1,368 W/m2 is the amount of energy received on a surface that is outside the …

Environmental Concerns The environmental concerns associated with nuclear reactors are very different than with fossil fuel–burning power plants. On the positive side, reactors do not emit greenhouse gases or other atmospheric pollutants. They also use significantly less fuel in terms of weight than coal-fired plants. Reactors for electricity production have …

Nuclear Energy Nuclear energy derives its power from the enormous amount of stored binding energy in the nucleus of the atom, which is the energy that holds the nucleus of the atom together. By tapping this energy, a substance such as water is heated and converted to steam to drive …

The environmental effects of using fossil fuels can have a serious impact on the quality of life. The process of burning fossil fuels combines carbon in the fuel with oxygen in the air to form carbon dioxide (CO2) that is released to the atmosphere. This is true for all fossil …

Fossil fuels are fuels formed from decaying plant and animal matter that was primarily formed over millions of years. Fossil fuels include coal, oil (petroleum), and natural gas. These fuels have been the primary energy source for over 200 years, but they will eventually have to be replaced by other sources …