4. Discussion

4. Discussion

4.1 Key Findings, Comparison, and explanations

From the data collected, it was clearly found that the most efficient way to angle your solar panel if your light source is fixed is directly above the solar panel, as this gives out the most amount of voltage output, as observed in figure 3. From figure 3, we can conclude that the higher the angle relative to the top of the solar panel, the more the voltage output from the solar panel will be. Another observation we made is that the voltage output increases dramatically from 15^o to 30^o, and it just slowly increases from there. This means that the bare minimum angle your light source should be angled at is at least 30^o, as the voltage output difference between 30^o and 90^o is just 0.45 volts while the difference between 15^o and 30^o is a whopping 1.22 volts. In our experimental findings, it differed from what we had originally expected. Our original hypothesis stated that the voltage output would go down as the angle of the light source relative to the top went up, but the exact opposite happened in our case and the voltage output increased when the angle of the light source relative to the top increased.

From our research of past experiments that are similar to what we have done, we found that in other instances of people doing similar experiments, the results were the same as the ones we obtained, that the voltage output from the solar panel was the greatest around midday/noon (12 pm) which is about 90^o relative to the light source being above the solar panel. The rest of their graphing is also in line with the results we had, with the amount of electricity generated by the solar panel increasing as the day (or angle in our case) goes on/increases. Our data can also be used to extrapolate to see the decrease in the voltage output after its peak point during noon. This can be done because 75^o relative to it being directly above the solar panel is the same on both sides, meaning that if we were to plot a full graph from morning to night (15^o to 90^o and back down to 15^o on the other side), it will form the shape of a mountain. This “mountain” graph result is also what we see in their experiment, with the amount of electricity generated by the solar panel dropping after 1 pm and decreasing downwards from there. (Sahab & Mosli, 2011)

The reason why the output is higher when the light source is directly above it compared to at the side is because when the light source is angled, the same amount of light will be spread out over a larger plane of area as the light rays will have to travel further before hitting the solar panel, meaning some light rays may not have even hit the solar panel, which results in a drop in the amount of voltage outputted by the solar panel. This is in stark contrast to when the light source is directly above the solar panel, this is when most of the light rays are concentrated into a certain spot on the solar panel, with the extra rays that angles off the light source hitting the far ends of the solar panel, which increases the total voltage output of the solar panel. (Wald, 2018)

4.2 Limitations and Recommendations

Throughout the planning of the proposal for our experiment, we did our best to make it as simplified and as easy to do and understand as possible. But all good things come with at least some hardships/limitations. The first limitation we faced was that we were not able to get a dark room to do our experiment, since everyone was doing their own experiments in the lab. As such, we had to improvise and come up with a better solution on the spot, to which we chose to use a box that we got from the ADMT Studio to simulate a dark room, which turned out to work relatively well. Secondly, another limitation we faced was that the 3D printed model’s dimensions shrunk due to the heat from the 3D printer. As such, we were forced to use scissors to slowly but surely saw off bits of the model to ensure that the solar panel will be able to snuggly fit in there, along with the voltage probes to ensure that it is connected to the voltage meter. Our last limitation was that the torchlight was too big to fit in the box when held up by the retort stand. We resolved this limitation by getting a smaller but still effective torchlight so that it will be able to fit in the box.

Through these improvements, we were able to express that we could think on our feet when given a tough situation, allowing us to easily adapt and change into different atmospheres and environments. This also enabled us to quickly continue on with our experiment and not waste any precious lab experimental time on other things.

4.3 Evaluation of Hypothesis

From the results obtained above, we can generally conclude that the hypothesis H1 that “The lower the degree of the light source relative to it being directly above the solar panel, the more voltage output there will be” has been proven wrong. Specifically, the experimental results that were obtained after we concluded the experiment showed the complete opposite of what our hypothesis predicted. The correlation of the experimental results showed that as the higher the degree of the light source relative to it being directly above the solar panel increases, the more the voltage output will be. This new hypothesis is also in line with the real-world observations of how the sun’s rays are the strongest and how the most UV rays are shone down on Earth around noon, which is when the sun is directly above us. We expected the trend to be in a decreasing direction where the higher the angle relative to it being at the top the lower the voltage output. However, the trend turned out to be in an increasing direction where the higher the angle the higher relative to it being at the top the voltage output.

To summarise, our expected trend was a decreasing trend, where as the angle relative to it being at the top increases, the voltage output decreases. Instead, after our experiment, our obtained results showed an increasing trend, where as the angle relative to it being at the top increases, the voltage output increases as well.