Generating Electricity

What Is Energy? Energy has many different forms. When an object is able to change its environment, we say the object has energy. Energy is the ability to do a task, such as moving an object.

Common Forms of Energy Form of energyExamples Chemical- Gasoline; food; fireworks Thermal- Warmth from a fire Sound- voices; music Radiant (light)- sunlight; microwaves Mechanical- wind; running water Electrical- lighting; electricity for your home

Energy Transformations There are many ways to change or transform one form of energy into another form. – Your body and a car’s engine change chemical energy into mechanical energy. – When you bang a drum, the mechanical energy is changed into sound energy. – A wind turbine changes mechanical energy into electrical energy.

Examples of Energy Transformations ExampleEnergy Transformations Solar panelLight energy  electrical energy FireChemical energy  thermal energy and light energy Wind turbineMechanical energy  electrical energy Car engineChemical energy  thermal energy  mechanical energy Light bulbElectrical energy  thermal energy and light energy

Generating Electrical Energy The Grid: Most or the electrical energy we use comes to us through the electrical energy distribution grid. The electrical energy distribution grid is a network that carries electricity from the energy generating station to the consumer.

Generators: Most energy is distributed by the gird is produced in electrical energy generating stations. These stations use generators. A generator is a machine that converts mechanical energy into electrical energy.

The energy in the wind, flowing water, or stream can be converted into electrical energy. The movement is used to push blades of a fan- like device called a turbine. The turbine is connected to the wire coils inside a generator. When the turbine spins, the coils of a wire generate electrical energy as they spin at high speed near powerful magnets.

Measuring Electrical Energy All energy is measured in joules (J). How quickly we use electrical energy can be measured as the number of joules used per second. A joule per second is called a watt (W). A 20 W bulb uses 20 J or energy per second.

A joule is very small, so we often use a much larger unit, the kilowatt hour (kW∙h). A kilowatt is 1000 W.