Complex sentence: The energy required to generate the oxyhydrogen always exceeds the energy released by combusting it, even at maximum efficiency, the input energy of a closed system will always equal the output energy, as the first law of thermodynamics states.
Split into simpler sentences: The energy required to generate the oxyhydrogen always exceeds the energy released by combusting it, even at maximum efficiency. The input energy of a closed system will always equal the output energy, as the first law of thermodynamics states.