Uav Methane MRV as a Tool for Circular Economy Management

Reliable and scalable methane (CH₄) monitoring is essential both for near-term climate mitigation and for supporting circular-economy strategies focused on energy recovery and the reduction of losses along value chains. Unmanned aerial vehicles (UAVs) enable facility-scale measurements with high spatio-temporal resolution. However, most studies rely on point sensors that require repeated flights at different altitudes and interpolation from low-density datasets, leading to potentially high uncertainty under turbulent and variable wind conditions. Open-path optical sensors can increase the effective sampling volume and improve plume representativeness, but practical, field-ready frameworks remain relatively under-developed. This study presents an operationally oriented UAV mass-balance framework for facility-scale CH₄ quantification using a drone-mounted open-path TDLAS sensor. The method is demonstrated across three representative emission contexts in Italy. At an intensive dairy cattle farm, UAV-derived net enteric emissions ranged from 0.182 to 0.242 kg CH4 AU⁻¹ day⁻¹ and showed strong agreement with IPCC references, with a maximum deviation of 0.54% relative to Tier 1 and a mean deviation of 4.32% relative to Tier 2. At a natural gas compression facility, site-level emissions of 14.3 ± 4.1 and 11.9 ± 2.6 kg CH₄ h⁻¹ under two operating configurations agreed with an independent Method 21 bottom-up estimate within 9.4–11.6%. At a municipal solid-waste landfill, site-scale fluxes ranged from 3.7 to 11.5 g s⁻¹, with uncertainty dominated by meteorology. Overall, the results show that the proposed open-path framework is transferable across sectors and delivers operationally deployable facility-scale estimates. This supports more frequent, management-oriented monitoring in line with circular-economy objectives.