extends into a cold water bath.
This is shown in Figure 2.
After about a minute from
the time the legs are submerged
into the water baths, the TEG
generates sufficient electric
power to spin a homemade
paper propeller on a high
efficiency, low power electric
motor (see Figure 3).
Not all small electric motors
will work, however. You need a
motor that requires only a small
amount of power to function.
You can try a cassette motor if
you have one available.
Otherwise, you can pick up a
motor from the Sources List.
The aluminum legs are each
made up of two smaller 1/8”
thick aluminum plates as in
Figure 4. Two machine screws
4-40 x 3/8”and nuts hold the
plates to make up a leg.
The components for the Thermoelectric generator
are illustrated in Figure 5.
Once the legs are assembled, they can be secured to
the TEG using a large spring paper clip. The electrical
leads from the TEG are soldered to the high efficiency,
low power motor mentioned earlier. Two water canisters
are needed for the hot and cold water baths. The
rectangle shape allows the containers to be positioned
next to one another. This allows the legs — which only
have about 1/2” space between them — to slide into the
hot and cold water baths simultaneously.
Fill the cold side with cold water and ice cubes. Fill
the hot container with boiling hot water. Place the legs of
the thermoelectric generator into the
Aside from powering an electric
motor, you can also use a multimeter
to measure voltage and current output
of your TEG module.
■ FIGURE 3.
■ FIGURE 4.
top side of the aluminum plate is painted with a high
temperature black paint to improve heat absorption from
the sun. Next, Styrofoam is attached to the bottom side of
this plate. I used a spray adhesive on the aluminum plate
to secure it.
The Styrofoam performs two functions: one as a
flotation device to keep the aluminum plate and TEG
module floating in water; and the second as insulation to
keep the water from touching and cooling down the
aluminum plate. (The Styrofoam may degrade from the
heat of the aluminum plate baking in the sun, but for my
prototype, I’m checking function, not longevity.)
On the opposite side of the TEG module, a large deep
heatsink is attached. This heatsink is partially submerged in
To further demonstrate how our
TEG module works, we’ll construct a
sunflower. This sunflower is a passive
solar device that uses the warmth from
the sun to heat the hot side of the TEG
and cool ocean water or cool water in
your salt water pool to cool the
opposite side see Figure 6A.
An aluminum plate is attached to
the hot side of the TEG module. The
■ FIGURE 5.
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