A gas holder is a large storage container used to hold gas, typically natural gas or biogas, at a constant pressure. These structures can be found in various shapes, often resembling large balloons or cylindrical tanks. They help manage the supply and demand of gas by storing excess gas when production is high and releasing it when needed. Gas holders operate by using a flexible membrane or a rigid structure that expands and contracts as gas is added or removed. This ensures a steady supply of gas to consumers, such as homes and businesses, while maintaining safety and efficiency in the gas distribution system.