Preferred embodiments provide a system and method of generating steam comprising providing a continuous supply of coal, combusting the coal in a primary processing chamber in the presence of oxygen and water to provide a first product gas stream, recovering heat from the first product gas stream in a first heat recovery steam generator (HRSG) to produce a first steam output, processing the first product gas stream in a secondary processing chamber in the presence of oxygen and water to provide a second product gas stream substantially free of inorganic, organic and particulate contaminants, recovering heat from the second product gas stream in a second heat recovery steam generator (HRSG) to produce a second steam output, and combining the first steam output and the second steam output. In preferred embodiments, the combined steam output is used to drive a steam turbine. In certain preferred embodiments, the steam turbine is operatively coupled to an electric generator to produce electricity. In preferred emb