Gas flows have to be recorded at various points in CHP plants and boiler systems for the purposes of efficiency rating, quantification and control as well as to track subscription to additional sources of supply in the context of compensation for energy fed into the grid.
Biogas is generated continuously in primary and secondary fermenters. Quality and quantity varies. The composition of the gas varies based on the raw mass (substrate) used.
The levels of concentration of sulfur, moisture and dirt in biogas vary. Although the pressure in the plant is virtually constant, only a few mbar of operating pressure are available. The temperature varies dependent upon the weather. The vibrations caused by the biogas motors also have to be reckoned with.