These trees are so cool! I wonder where they get energy when the sun isn't out
That actually happens through a process called Cellular Respiration... Let me explain:
The first step is Glycolysis where glucose, NAD+, and ADP+P is inputted and broken down into pyruvic acid, NADH, and ATP.
Glucose
ADP+P
NAD+
Pyruvic Acid
ATP
NADH
The second step is the Krebs cycle which has a bunch of chemical reactions that produces CO2 (the stuff you exhale) and ATP energy.
Krebs Cycle
ATP
CO2
The final step is the Electron Transport Chain which is a chain of structures that carry electrons. These electrons are passed down until they are accepted by oxygen molecules and converted into energy.