Well, somewhat. The amount of precision that the physical worlds demand in the construction of the fuel pellets, and the amount of energy involved in using them

Well, somewhat. The amount of precision that the physical worlds demand in the construction of the fuel pellets, and the amount of energy involved in using them, guarantee that you need an extremely expensive mechanical process for the fuel. So, while physically you probably can extract energy from the pellets, it'd be like a steam train powered by gold bars instead of coal.