Due to circumstances that the gas might not be consumed while it is produced the gas needs to be stored. There are different storage techniques available
There are two basic reasons for storing biogas storage for later on-site usage and storage before and/or after transportation to off-site ussage or storage.
Inner-tubes from tractors are great for gas storage. They can easily be sealed if cracked. One downside is that they are limited in volume and therefore more of them are needed or they are mainly used for transporting gas from one location to another.
Biogas could be stored in a PVC bag. The bags are available in different sizes from different companies. There is also a gas storage backpack available.
See main article about Floating Dome / Floating Drum
A floating drum digester consists of a fixed base and flexible top. It was established in India after early British sanitation efforts.
See main article about ARTIBC.
ARTIBC is a combination of 2 IBCs so that it actls like a floating drum.
Due to the circumstance that Biogas other than Biomethane comes with a high proporition of CO2 Biogas itself usually is not bottled. In order to bottle it Biogas gets scrubbed off CO2 and H2S before it is compressed and bottled.
A Mini-Grid is more a buffer than a gas storage. It consists of a pipe system burried in the earth besides the digester. If the a corresponding pipe diameter is considered the possible "storage" capcity could be increased.