1. Electrical
Systems
Appliances

2. Time
OApproximately 90 min

3. Prepare

4. 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.

5. Objectives
O Students will be able to correctly measure
the energy consumption of various
appliances by using a Kill-A-Watt meter
O Students will be able to calculate an
estimated annual energy cost for common
appliances
O Students will be able to correctly
differentiate between energy and power

6. 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

7. 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.

8. Crosscutting Concepts
O 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)

9. Materials
O Kill-A-Watt meters ( one per group of 3-4
students
O Activity worksheets
O Calculators
O At least 5 various classroom and home
appliances for the students to measure
O Arrange the appliances in stations around the
classroom

10. 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 ÷ 1000
O Phantom load – the electrical power consumed an appliance
when it is switched off or in standby mode; sometimes called
vampire load.

11. 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?

12. Appliance Watts Hours
/ day
Days /
week
Weeks
/ year
Annu
al
watt-
hours
Annua
l
kilowa
tt-
hours
(kWh)
1. On
Off
2. On
Off
3. On
Off
4. On
off
5. On
Off