Why, from the point of view of energy conservation, is it not advisable to use hydrogen produced by electrolytic water as a conventional energy source? Is it because you need a lot of power?

Why, from the point of view of energy conservation, is it not advisable to use hydrogen produced by electrolytic water as a conventional energy source? Is it because you need a lot of power?

Because the energy we usually use is electric energy, you use electric energy to produce hydrogen, and then you have to convert chemical energy back into electric energy.

Will the hydrogen produced by the electrolysis of 1 J of water release more energy after complete combustion than 1 J?

No; according to the second law of thermodynamics, it is impossible to transfer heat from a low-temperature object to a high-temperature object without producing other effects; it is impossible to take heat from a single heat source to completely convert it into useful work without producing other effects; the microincrease of entropy in an irreversible thermal process is always greater than zero. Energy is always converted to a direction that is more difficult to obtain, and there is also energy loss in the process, so there is a problem of high and low energy conversion rate. Therefore, the heat release of hydrogen combustion obtained after electrolysis of water must be less than 1J