Direct Injection is the process of mixing the electrolysis-produced hydrogen into the natural gas pipeline without first further converting it to methane. A small concentration of hydrogen in the natural gas grid is currently allowed today and this amount varies by geographic region. Depending on where within the natural gas grid you are injecting the hydrogen it needs to pressurized to match the pipeline pressure. Natural gas pipeline pressures can vary from 80 bar or more at the well-head to less than one bar at the end customer.