The fluctuating energy supply at different places of the Earth is a natural phenomenon since the most important energy source on planet Earth is the Sun, that is, solar energy. Humans have been the beneficiary of this natural phenomenon. Making a fire with wood uses stored solar energy. Utilization of biomass, however, is limited by the finite area of arable lands. The housing structures do that job and protect us against external hot or cold temperatures. In the industry, e.g., steel industry, so-called recuperators are applied. The latent heat method is more powerful than the use of sensible heat. Molten material can store heat more efficiently: A large amount of heat can be stored in a small volume. The hydrogen pressure also has an important effect on methane yield. Low pressure of hydrogen is preferred by oxidizing organisms, but high pressure of H2 is needed for methanogens.