In relation to financial support the key question is - "where does the biomethane producer earn revenue from?" This can be a Feed-in tariff (as in UK), via a Certificate Scheme (as in Germany) or via a Market Demand that values the biomethane and customers are incentivised to pay more for it (as in Switzerland with use as vehicle fuel). In all these 3 examples, there is sufficient revenue to drive market development. If none of these exist, for example in Ireland, then there is no market.
Once these ‘fundamental barriers’ are overcome, the country can join the “EU Biomethane Injection Club”. In other words, the country has a potential biomethane market.