Advantages - Coal is one of the most abundant fossil fuels on Earth, with significant reserves in many countries. Its widespread availability contributes to energy security and a stable energy supply. Coal has a high energy density, meaning it contains a large amount of energy per unit mass. This characteristic allows for efficient transportation and storage of coal. The infrastructure for coal extraction, transportation, and power generation is well-established in many regions, making it a readily available and familiar energy source.Yao, Z.T., Ji, X.S., Sarker, P.K., Tang, J.H., Ge, L.Q., Xia, M.S. and Xi, Y.Q., 2015. A comprehensive review on the applications of coal fly ash. Earth-science reviews, 141, pp.105-121.