Solar
Circuit Models
Human-sized circuit modelling.
RESOURCES REQUIRED
- 1 cardboard box/empty bin
- 1 beanbag/soft ball per pupil
- Chalk or tape (whichever works best with your floor)
TIME REQUIRED
Class time
Approximately one period
OVERVIEW
This person-sized simulation game is a good way for students to understand
about electric circuits, energy transfer and the generation and storage
roles of solar (photo-voltaic) cells and batteries.
TEACHING ACTIVITIES
Model 1 - Charging the battery with a solar cell
Here, solar light energy is radiated from the sun to a solar cell where
it energises electrons, is converted to electrical energy, then moves
around a circuit to a battery, where it is stored as chemical energy for
later use.
One pupil plays the role of the sun.
At least 6 pupils play electrons
Beanbags/soft balls represent packets of energy.
A cardboard box or bin represents a battery
1. Mark out (e.g. With chalk or tape) a circle to represent the circuit,
a rectangle on the circuit to represent the solar cell and enough evenly
spaced “bases” around the circuit to accommodate any electrons
not positioned at the solar cell or battery.
2. Position the players and props. The pupil playing the Sun is the only
one who will not move from her/his position
3. The “sun” has a stash of beanbags or soft balls which represent
packets of energy.
4. The sun tosses one of the energy packets to the solar cell, where it
is caught by one of the four electrons there.
5. The energised electron shouts “GO” and caries the energy
to first base. “GO” is the signal for the other electrons
to all move one position around the circuit (except the electrons left
in the solar cell, who can only leave when they catch some energy).
6. The sun throws in another packet of energy. The next electron to be
energised shouts “GO” and, again, all the electrons, as well
as the first packet of energy, can move around to the next base.
7. This continues around the circuit until the energy packets get to the
battery, where they are dropped (stored).
8. The electrons continue round the circuit empty handed until they return
to the solar cell where they can catch some more energy.
Bear in mind…
- The “GO” signal shouted by each energised electron as
it leaves the solar cell is important for avoiding gaps and collisions
around the circuit.
- The electrons can only move around the circuit as fast as the packets
of solar energy can be caught.
- During the exercise underline the distinction between current (material)
and energy (non-material). Explain that the electrons moving around
the circuit represent the current flowing without leaving the circuit
(i.e. the electrons which flow from a cell circulate back to the cell),
whereas the energy packets are transferred in from outside the circuit,
around the circuit and then back out into the universe.
Model 2 - Powering an appliance
Once you have charged the battery with solar energy, you can
model a circuit with the battery powering a device.
At least 4 students play electrons
One student plays an electrical appliance.
Beanbags/soft balls represent packets of energy.
A cardboard box or bin represents a battery
1. Mark out (e.g. with chalk or tape) a circle to represent the circuit
and enough evenly spaced “bases” around the circuit to accommodate
any electrons not positioned at the battery or appliance.
.
2. Position the players and props. The pupil playing the appliance is
the only one who will not move from her/his position.
3. The electron at the battery takes a packet of energy from the box
and shouts “GO” as it heads off to first base.
4. The electrons and energy packets all move around the circuit as in
the previous model until an energised electron passes the appliance, dropping
of the energy and continuing the circuit.
5. When the appliance receives the energy, it performs its function (which
could be to produce sound or movement) and rolls the energy away into
the environment (dissipation as heat).
6. The game ends when all the packets of energy are dissipated, and the
battery is “flat”.
Variations
• For a simpler exercise, eliminate the battery altogether and
have the solar cell powering an appliance directly.
• The human sized circuit can be used to model many more complex
circuits. For instance, consider introducing more appliance and creating
parallel circuits.
• Introduce a switch to the circuit. Use string (taped down at
intervals) to mark the circle and have one pupil positioned where the
ends meet, ready to “flick the switch” by breaking the circuit
and stopping the flow of electrons, possibly at a given signal.
• Ask pupils to predict what will happen if different elements
of the circuit are altered, then simulate these scenarios.
• Use this exercise to reinforce previous learning about circuits
by asking groups of pupils to make up human sized circuit simulations
from scratch, given the props described above.
• Ask the group to draw big, bold symbols for cells, switches,
buzzers and light bulbs and use masking
tape to attach the symbols to the people/objects in the circuit.
SUGGESTED HOMEWORK
Using the memory of their human-scale model, pupils design a “stand
alone” solar-electric system. Remember that as the system doesn’t
need to plug in to the mains, it can work on the move or in remote locations
not serviced by the National Grid.
- Think of a gadget, tool or piece of equipment which could be usefully
powered by solar cells, either directly or using a battery to store
energy when it is sunny and supply energy when it is needed.
- Draw a picture or write a detailed description of your design, providing
information on what it looks like, how it is used and why solar cells
are a good way of providing electricity for it to work.
- Draw a circuit diagram for your design.
- Explain the difference between “energy” and “current”
by writing a short description of each of their journeys’ around
your circuit diagram.
|
