People used to hunt whales, boil their blubber to create kerosene.

Kerosene acted as an energy battery, allowing you to transport it and use the energy wherever.

Similarly, Oil then came and changed the game - it was a much better battery.

Non-intuitively, the cereal companies that introduced things like cornflakes were also in their own right energy battery companies. They figured how to stabilize food energy into a container that didn't bleed energy. They sold stabilized energy.