Solid-fuel is a term used to describe a substance that is used as a source of energy. There are many synonyms for this term, including wood, coal, charcoal, peat, and even biomass. All of these substances are solid and can be burned to create heat and energy. They are commonly used in stoves, furnaces, and other appliances to generate heat and electricity. These fuels are often preferred over liquid fuel for certain applications because they are less expensive, easier to store, and more readily available in some regions. Whether you are looking for an efficient heating source or a renewable energy option, solid-fuels offer a variety of solutions.