Sunlight is heating the air and also heating the copper tubes in order to function the solar energy system. It's using the heat of the sun to power the panels.
This is because hydroelectrical energy is produced from hydropower – the force created by running water. Hydroelectric energy is usually generated by constructing a dam on a river, such that the water which flows through the dam is used to power turbines that generate electricity.
Solar energy is more Natural since it comes from the sun and easier to harness, while chemical energy is Dangerous because it may fail and cause damage.
I think that you meant autotroph, but the answer is producer
Explanation: the definition of autotroph is "an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide."