TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The borohydride and hydroxide salts are homogeneously distributed within the solid fuel composition. Preferred Composition: The hydroxide salt is present in 0.3-80 wt.%. It is present in 1-50 wt.% of the borohydride salt. Water is present in the solid fuel in 1-96 wt.% of the borohydride salt. The sodium borohydride is present in 87 wt.%; and the sodium hydroxide is present in 13 wt.%. Preferred Material: The borohydride salt is sodium borohydride, lithium borohydride, potassium borohydride, calcium borohydride, or their mixtures. It is hydrated. It is sodium borohydride dihydrate, potassium borohydride trihydrate, potassium borohydride monohydrate, or their mixtures. The hydroxide salt is calcium hydroxide, sodium hydroxide, lithium hydroxide, potassium hydroxide, or their mixtures.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The solid fuel composition comprises a compacted solid fuel, which is in the shape of a tablet, a caplet, or a granule. The compacted solid fuel has a shape consisting rectangular parallelepipeds or spheres. A surface(s) of the compacted solid fuel is textured or scored. The solid fuel composition comprises a solid acid component and a solid carbonate component for producing carbon dioxide. It comprises a disintegrant, which is diammonium decahydrodecaborate. At least one of the solid acid component and the solid carbonate component are homogenously distributed within the solid fuel. They are present in a compressed pellet inside the solid fuel. Preferred Composition: The solid acid component is present in 1-10 wt.% of the borohydride salt. The disintegrant is present in 0.1-0.5 wt.% of the borohydride salt. Preferred Compound: The solid acid component is citric acid, tartaric acid, fumaric acid, adipic acid, maleic acid, or oxalic acid. The solid carbonate component is sodium carbonate, sodium bicarbonate, potassium carbonate, or magnesium carbonate. Preferred Method: The method comprises compacting the mixture in a mold to produce solid unit form(s) consisting of a caplet, a tablet, a granule, a sphere, a parallelepiped, or a cube. Preferred Parameter: The compacted solid fuel composition has a density of 0.7-1.2 g/ml. EXAMPLE - A fuel tablet containing sodium borohydride (NaBH4) (87 wt.%) and sodium hydroxide (13 wt.%) was prepared by mixing NaBH4 (15.2 g) and sodium hydroxide (NaOH) (2.28 g). The powder mixture was compressed using 10000 pounds of force to produce a puck of 2 inches in diameter. The degree of compaction and the height of the puck were controlled by the amount of force used in compression. When dissolved in water, the tablet produced fuel solutions with sodium borohydride and sodium hydroxide in a 6.7 to 1 ratio by weight.