Ali: I'm working on my science project about energy sources. I need to find information about solar panels.
Zeynep: That sounds interesting! I read that solar panels convert sunlight into electricity.
Ali: Exactly! But I'm not sure how efficient they are in cloudy weather.
Zeynep: Well, according to a recent study, they still work but produce less energy.
According to the conversation above, what is the main topic of Ali's project?
A)The history of electricity
B)Energy sources and solar panels
C)Weather conditions in Turkey
D)How to build a solar panel