Series of experiments to measure the efficiency of solar cells in
dependence
of the geographical position
Material:
solar ventilator, stop-watch
Preparation: We put the solar ventilator with the solar cell in the direction
South- South East, so that the solar cell points towards the sun
between 9.45 and 10 o’clock even when the sun is covered by clouds.
Realization: The series of experiments will be carried out on all schooldays in
February and May 2006 between 9.45 and 10 o’clock.
The stopwatch will be switched on at 9.45, as soon as the ventilator
starts moving. The speed is not important.
When the ventilator stops we stop the watch as well.
When the ventilator starts moving again we let the stopwatch run
on (maximum 10 o’clock).
The measured time in minutes and seconds will be written down in
the minute sheet every day.
At the end of February and May the number of schooldays will be
multiplied with 15 minutes.
This is the total time of the series of experiments for each month
(e.g. 20 days x 15 minutes = 300 minutes).
Expressed in mathematical terms this is the basic value.
The daily measured minutes and seconds will be added.
The result in minutes is the percent value.
With these results we calculate the percentage and with it the
efficiency of the solar ventilator for the geographical position of
each city in February and May 2006.