Describe the history of energy usage.

Since the earliest records of human history, most cultures paid close attention to the sun that plays the role in sustaining life on the Earth.

People in history made use of the light energy to tell time and made use of the heat energy from the sun to keep themselves warm.

Mankind burned wood and other forms of biomass to keep warm, cook food and to forge knives and other types of weapon.

As the knowledge that people in the past have is limited, there were no such thing as electrical energy. The people in the past lived with simple tools for eating and keeping warm. They will only need to use heat energy and light energy.