What is houille?

Houille is a French word that translates to "coal" in English. It is a type of sedimentary rock that is formed through the compression of organic materials like dead plant matter over millions of years. The organic material is first transformed into peat, which is then buried and compacted, forming lignite, bituminous coal, and eventually, anthracite - the most carbon-rich and hardest form of coal.

Coal has been used for various purposes for centuries, including heating, cooking, powering machines, and producing electricity. It is also used in the steel-making process, as a raw material for the manufacture of synthetic fuels and chemicals, and as a source of carbon fibers and carbon black, which are used in various technological and industrial applications.

However, mining and burning coal also have negative environmental impacts, such as air and water pollution, greenhouse gas emissions, and habitat destruction. This has led to efforts to shift towards cleaner and more sustainable energy sources, such as renewable energy and natural gas.