Gasum distributes biogas to its customers via the existing natural gas pipeline network or by transporting it in separate containers to destinations such as gas filling stations located in areas that are not covered by the pipeline network. Upgraded biogas and natural gas are energy gases with same chemical composition consisting mainly of methane, so: they can be mixed with each other and stored in the same gas pipeline network or container without changes in fuel properties.
Even though most of the methane gas in the grid is natural gas, customers pay the biogas producer, when they buy biogas e.g. at a filling station. This is based on a balancing principle in the same way as in the electricity market: When wind electricity is purchased, electrical energy consumed from the electrical grid does not always physically originate from a wind turbine, but the total amount of wind electricity fed into the balance always equals the total amount of wind electricity consumed. In the same way, the amount of biogas sold at, for example, the various filling stations, is always fed into the biogas balance system, and the payment for the sold biogas is forwarded to the biogas network injector.
Gasum’s biogas mass balance is managed with the Biogas Certificate System. In practice, when biogas is injected into the gas pipeline network, one Biogas Certificate is created for the system for each megawatt hour. When biogas is sold, a corresponding number of certificates i.e. megawatt hours is cancelled in the system. This ensures that the amount of biogas sold equals the amount of biogas produced and that biogas cannot be sold multiple times for different uses. Each individual Biogas Certificate has a unique identifying number, which means the original production site and time and the raw materials used for its production are trackable.
Gasum gas filling stations located outside the gas network are also included in Gasum’s mass balance.
Maintaining the separate biogas mass balance enables the distribution of biogas energy- and cost-efficiently using existing infrastructure – the gas pipeline network. There is always an amount of biogas produced concretely in Finland (Suomenoja, Espoo; Mäkikylä, Kouvola; Kujala, Lahti; Riihimäki) and injected into the Gasum network corresponding to an amount of biogas sold to a customer.
Filling stations connected to the Gasum gas pipeline network and biogas injected into the network are covered by the Gasum sustainability scheme. The sustainability scheme is a procedure in accordance with the Act on the Sustainability of Biofuels and Bioliquids (393/2013) ensuring that biofuels released for consumption meet the sustainability criteria laid down by the Act. In Finland, compliance with the criteria is supervised by the Energy Authority, to which a sustainability criteria report is submitted annually. The sustainability scheme data used for the report and the compliance of the scheme are verified annually by an external and independent verifier. The verifier of the Gasum sustainability scheme is DNV GL Business Assurance Finland Oy, a verifier authorized by the Energy Authority.