Biogas projects of large & medium-scale husbandry farms are significant in reducing environmental pollution and getting access to renewable energy. However

they are all generally dependent on government subsidy in China

and their profitability is poor. In this work

we made contrastive analysis on the economy of pig farm biogas projects in China and Germany based on biogas fermentation steady-state model. Biogas fermentation process

generator efficiency and tariff are the key factors that affect economic efficiency. Currently

low electricity tariff [0.42 CNY·(kW·h)-1] is the root cause for the loss of biogas projects. On the basis of improving the technology of biogas and power generation and reaching the level in Germany

changing the policy of giving construction subsidies without paying attention to operational efficiency to attaching importance to actual emission reduction and increasing tariff to 1.5 CNY·(kW·h)-1 can shorten the payback period of the project within 3 years

which is of great importance to accelerating the development of biogas industry in China.