Electricity and Conserving Resources State Objectives 2.d. and 4.d.

What is Electricity? Electricity is a form of energy produced by the flow of electrons from one point to another. Current electricity is a continuous flow of electricity or the amount of a charge that moves past a certain point each second SI unit for current is the ampere or amp

DC versus AC Current DC current is when the electrical charge moves in one direction Ex. Batteries Always flow from the negative terminal to the positive terminal. AC current is when the electrical charge flows in one direction, then in the reverse direction over and over again Ex. Electrical current from the power plant to your home

Controlling a Current Voltage: the measure of how much electrical potential energy each electron can gain (push) Standard Unit: Volts Resistance: the measure of how difficult it is for electrons to flow through a material (friction) – Standard unit: Ohms Insulators have a higher resistance than conductors.

Currents Flow In Circuits An electric circuit is a complete path for the flow of electricity Open circuits have a break in the path Closed circuits have no breaks in the path

Generating Electricity Generators are devices that spin a coiled wire within a magnetic field to produce electricity The mechanical energy of a spinning turbine is transformed into electrical energy for human use. Primary method for producing the electricity in homes, schools, & the community.

What Spins the Turbine? Energy is produced by burning fossil fuels to boil water produces steam that turns a turbine to generate electricity. Burning fossil fuels causes a large amount of pollution

Coal Power Plant

Power Grids A power grid is a transmission network that connects power plants to multiple substations near a populated area. Allows distant energy sources (such as hydroelectric power plants) to be connected to consumers in population centers

The U.S. Power Grid

Substations A substation is a part of an electrical distribution system that switches, changes, or regulates electric voltage. transform voltage from high to low, or the reverse. A substation that has a step-up transformer increases the voltage while decreasing the current. A substation that has a step-down transformer decreases the voltage while increasing the current for domestic and commercial distribution.

Substation

Transmission Lines Transmission lines carry electricity from power plants to distribution systems that power commercial and domestic consumers.

Transmission Lines

Transformers Device that transfers electrical energy from one circuit to another & changes the voltage by increasing or decreasing it. Helps monitor the operation of the power grid and measures current.

Transformers

Path of Electricity through a Power Grid Power Plant Substation ( there are several along the way) Transmission Lines ( high & low voltage) Transformer (lowers voltage before entering the home) Junction Box on the home (brings it into the home) Outlet (sends it to electrical devices) Electric circuit for a blow dryer

Power Grid