High school students show more motivation to learn new concepts when these are taken from activities that mimic real life. We report an easy methodology based on the fabrication of handmade solar cells to produce clean energy from chlorophyll a (chl-a) extracted from the leaves of Diacol Capiro potato. Our findings show that there is no proportionality between the chl-a concentration and the output voltage. The results also indicated that nickel-silver electrodes were the most efficient among other tested electrode pairs, yielding a maximum voltage value of 1.006 V from an individual cell. Therefore, a low-cost natural dye as chlorophyll can be used as light-harvesting material. As a result, 90% of the students learned basic techniques and applications of visible light for characterisations and 85% understood the electric potential in an electrochemical cell.