Most of the cases are about 1 and 2 , but 3 and 4 are still for future use. The main component of biogas is methane gas, but it is not pure methane gas, but carbon dioxide and other trace components are mixed, so a refining device is required to mix it with vehicle fuel and city gas. ..
In addition to having to prepare a refinery, a vehicle that can use gas is required when using it as fuel for the vehicle, and in the case of city gas, there must be a city gas pipe nearby. However, the available situations are limited.
Some gas companies have a biogas purchase procedure, and if you do not refine the gas according to this procedure, you cannot sell it to the gas company as city gas.
In Japan, which is still unfamiliar with biogas, it is currently difficult to find business feasibility such as buying and selling as gas like overseas, and the difference in policy between Japan and overseas has an influence.
Furthermore, in Japan today, there are many places where it is difficult to purchase surplus electricity due to the lack of power transmission system, and it is often forced to use it in a different way. However, other methods are not profitable, and there are many issues such as future infrastructure development.