Lesedi “Sun Day” By Regardt van Wyk

 

As the African sun rose on Monday the 18th of October 2010 the Gr.8 and Gr.9 students of Lesedi Secondary School near Mamelodi were in for some fun with the sun. These bright eyed students represent the early spring and coming summer of our community. Creating awareness among these youngsters about the possibilities and benefits of renewable energy sources and the positive impact it will have on the future of our people, economy and planet, was the mission of team Young SESSA headed by Mr. Harald Schulz, aka. Mr. Sunshine and Mrs. Karin Petzer. A special thanks goes out to Ben Booysen from the Solar Surgeon whose sponsorship made the day’s activities a possibility. As far as renewable energy sources go, there is none more powerful than the sun, and harnessing its potential is Mr. Sunshine’s specialty. On our arrival we were greeted and made welcome by Mrs. Ancy Indiculla of Lesedi Secondary School. Soon our team consisting of Harald, Karin, Mavis, Laura and I, Regardt, sprang into action setting up some fun and educational activities for the students.

Mr. Sunshine took the lead in the school hall with 210 pairs of eyes and ears taking in his presentation of slides and experiments. Among other things he demonstrated the burning of fossil fuels and the combusting of renewable maize meal, much to the amazement of the wide eyed students. Later they were taken through practical calculations using their schools electricity bill to come up with a solar solution.

Meanwhile the tennis court was being transformed into a solar playfield. Activities included solar cars, solar fans, solar hot water and our PV (Photo Voltaic) van that demonstrates the go anywhere, remote advantages of solar power.

After the theory in the hall they headed to the tennis court for some practical exposure to the uses of solar energy. They raced the solar cars across the court, eager to speed them up by directing more sunlight onto the cars PV panels by using mirrors. The excitement was evident.

The students were given the opportunity to use multimeters alongside the solar fans, measuring the changes in voltage and current produced by the solar panels under variable conditions such as the angle of the PV panels relative to the sun, the intensity of the light and the size of the solar array, giving them an appreciation of how these various factors influence the electric output of PV panels.

The solar hot water area demonstrated just how effective the energy of the sun is to heat up water without the need of electricity. A flat panel with black pipes connected to a water tank, called a Chighubu, works by heating the water in the pipes through sunlight. The hot water then rises up and flows into the holding tank. A tap on the tank then supplies water warm enough for washing needs and the like. The big daddy of solar cooking, the papillion or butterfly, a dish shaped mirror that focuses the sunlight onto a central point where a pot can be placed to boil water or to cook a variety of dishes. Placing their hands in the focal point gave the students incredulous expressions of surprise. Be aware the power of the light side!

Finally the students headed to our PV solar installation. In this case a roving, mobile van of electric potential. They were introduced to the most important components of a professional PV solar system. These include:

• The PV panel that converts the sunlight into electricity.
• A solar controller that regulates and matches the PV panels power output to the battery and ensures that the battery charge and discharge limits are maintained.
• A battery. Its function it is to store electricity that can be used when no sunlight is available.
• An inverter that converts the 12 volt DC from the battery into 220 volts AC, opening the door to power a large selection of electric appliances.

 

Our PV solar installation brought out the more inquisitive and mature side of the young minds. They fired away with questions concerning the practicality, cost, accessibility and maintenance of such an installation. They learned how the size of the solar array and battery setup can be matched to their energy requirements.

Cost was a concern among the learners and this presents one of the challenges of future scientists and engineers which we encouraged them to become.

By the end of the “sun day” some light had been shed on the students concerning the diverse possibilities that solar energy present and that it is a reality in terms of practicality and cost and not just a novelty. Their thoughts were piqued and team Young SESSA left them with the hope of a better, cleaner future.