Elenco Green Projects - Manual (Page 53)

Project #79 Storing Energy in Water
Big Thrust
This circuit combines several power
sources to run several devices in
series. Build the circuit as shown, and
place the solar cell (B7) in sunlight or
near an incandescent lamp. Set the
switch (S5) to position B. If your light is
bright enough, the LEDs may be dimly
lit and the fan may spin if you give it a
push to get started.
Now turn the hand crank clockwise to
make more power. The LEDs should
be brighter and the fan should spin
faster.
Place ½ teaspoon of salt into a small amount
of water and stir until it dissolves. You can use
a compartment on the liquid power source for
this, but don’t use a metal container. If
available, use a thermometer from your home
to measure the water temperature. If no
thermometer is available, test the water
temperature by touching it with your finger.
Connect the red & black jumper wires to the
hand crank (HC) and place the loose ends in
the water so they aren’t touching.
Turn the crank to heat the water. You should
see the temperature rise on the thermometer
or feel the difference with your finger. You may
have to crank for a minute or two before the
water gets warmer.
Solar or wind power
may be used to heat
water during the day,
then use the hot
water to keep homes
warm at night.
Project #80
It takes a lot of voltage to run
both LEDs and the motor
when they are connected in
series, but combining the
battery, solar cell, and hand
crank gives you enough.
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See projects 1 & 3 if you need to recharge the battery (B4).