What is the earth's primary source of energy?

The main source of energy on Earth is electricity. This source of energy is used in houses. Transport also becomes electric. Electricity is a renewable source of energy. The most famous scientist, which explored electricity was Tesla. Oil, coal and gasoline are also sometimes used to heat buildings, for example, gasoline is used for cars. But these energy sources are exhaustible. Therefore, the whole world turns to electricity. I believe that electricity will become the main source of energy in this millennium.