The liquefaction of biomethane—also known as bio-LNG (Liquefied Natural Gas)—is an innovative step toward the efficient use of renewable energy sources. It opens up new possibilities for using biogas not only in stationary applications for energy generation but also as a sustainable fuel for transportation and mobility. By cooling purified biomethane to approximately –162 °C, the gas is converted into a liquid state. This reduces its volume by a factor of 600. This enormous compression saves space, facilitates transport and storage, and makes biomethane particularly versatile. Bio-LNG is thus a renewable alternative to fossil LNG and contributes significantly to reducing dependence on fossil fuels.