This was an innovation made by James Watt in the late 18th century that greatly increased the demand for coal.

The innovation made by James Watt was the improvement of the steam engine in the late 18th century. Watt's steam engine was more efficient and powerful than previous versions, leading to increased demand for coal as a source of fuel to power these new engines. This innovation spurred the Industrial Revolution and transformed society by enabling machinery to be powered by steam, ultimately leading to advancements in various industries such as mining, transportation, and manufacturing.