Electrical Systems Appliances

Time

OApproximately 90 min

Prepare

Overview O In this lesson, students determine

the financial and environmental cost of some common appliances by measuring their energy consumption with a watt meter. Then, the cost effectiveness of a new refrigerator purchased is evaluated through payback calculations.

Objectives OStudents will be able to correctly

measure the energy consumption of various appliances by using a Kill-A-Watt meter

OStudents will be able to calculate an estimated annual energy cost for common appliances

OStudents will be able to correctly differentiate between energy and power

Standards Addressed

O P.12.C.2- students know energy forms can be converted

O P.12.C.6 – students know electricity is transferred from generating sources for consumption and practical uses

O N.12.B.2 – students will know consumption patterns , conservation efforts and cultural or social practices in countries have varying environmental impacts

Next Generation Standards

O HS-PS3-1: Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

O HS-PS3-3: Design, build, and refine a device that works within given constraints to convert one form of energy into another form of energy.

O HS-PS3-5. Develop and use a model of two objects interacting through electric or magnetic fields to illustrate the forces between objects and the changes in energy of the objects due to the interaction.

Crosscutting ConceptsO Energy and Matter: Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system. (HS-PS3-3)

Materials OKill-A-Watt meters ( one per group of 3-4

students OActivity worksheets OCalculators OAt least 5 various classroom and home

appliances for the students to measure OArrange the appliances in stations

around the classroom

Vocabulary O Energy - a measureable quantity of work; energy= power × time O Power – the rate at which energy is used ; power= energy ÷ time O Watt – energy unit equivalent to the power you need to

lift 100g. (a small apple) a distance of 1 meter in 1 second

O Watt-hours- a measure of energy usage; watts × hours of use

O Kilowatts –hours - watt ÷ 1000O Phantom load – the electrical power consumed an

appliance when it is switched off or in standby mode; sometimes called vampire load.

Questions 1. What is the difference between

energy and power ?

2. List three appliances that you think may have a phantom load and give your reasoning?

3. Explain how appliances usage impacts the environment?

Appliance Watts Hours / day

Days / week

Weeks / year

Annual watt-hours

Annual kilowatt-hours (kWh)

1. On

Off

2. On

Off

3. On

Off

4. On

off

5. On

Off