Renewable energy is rapidly gaining importance as an energy resource as fossil fuel prices
fluctuate. At the educational level, it is therefore critical for engineering and technology students
to have an understanding and appreciation of the technologies associated with renewable energy.
One of the most popular renewable energy sources is solar energy. This paper describes a
capstone design project where a student in Electrical Engineering Technology designed and built
a microcontroller-based solar panel tracking system. Solar tracking enables more energy to be
generated because the solar panel is able to maintain a perpendicular profile to the suns rays.
This system builds upon a prior senior design project where students built a solar-powered
battery charger, thus making this system ideally self-contained. The student was able to
demonstrate a working system, thus validating the design. Potential improvements to the system
are presented.
Introduction
There are three ways to increase the efficiency of a photovoltaic (PV) system1. The first is to
increase the efficiency of the solar cell. The second is to maximize the energy conversion from
the solar panel. To better explain this, please refer to Figure 1. A solar panel under an open
circuit is able to supply a maximum voltage with no current, while under a short circuit is able to
supply a maximum current with no voltage. In either case, the amount of power supplied by the
solar panel is zero. The key is to develop a method whereby maximum power can be obtained
from the voltage and current multiplied together. This maximum power point is illustrated by
looking at a voltage-current (VI) curve in Figure 1, and finding the knee of the curve. A
number of maximum power point tracking (MPPT) algorithms have been developed and
employed.2
Figure 1. Illustration of a V-I Curve for a Solar Panel
The third method to increase the efficiency of a PV system is to employ a solar panel tracking
system. Development of solar panel tracking systems has been ongoing for several years now.
As the sun moves across the sky during the day, it is advantageous to have the solar panels track
the location of the sun, such that the panels are always perpendicular to the solar energy radiated
by the sun. This will tend to maximize the amount of power radiated by the sun
