Standardized Reporting Needed to Improve Accuracy of Flaring Data

Abstract

Gas flaring represents a large waste of a natural resource for energy production and is a significant source of greenhouses gases to the atmosphere. The World Bank estimates annual flared gas volumes of 150 billion cubic meters, based upon a conversion of remotely sensed radiant heat data from the NOAA’s VIIRS (Visible Infrared Imaging Radiometer Suite) instrument onboard the polar-orbiting Suomi NPP satellite. However, the conversion of the remotely sensed radiant heat measurements into flared gas volumes currently depends on flare operator reported volumes, which can be biased in various ways due to inconsistent reporting requirements. Here, I discuss both known and unknown biases in the datasets, using them to illustrate the current lack of accuracy in the widely discussed flaring numbers. While volume trends over time could be derived directly from the radiant heat data, absolute amounts remain questionable. Standardizing how flared gas volumes are measured and reported could dramatically improve accuracy. In addition, I suggest expanding satellite measurements of individual flares burning under controlled conditions as a major improvement to daily monitoring, alongside the potential usage of remotely sensed flare temperature to estimate combustion efficiency.

In Situ Sampling of NOx Emissions from United States Natural Gas Flares Reveals Heavy-Tail Emission Characteristic

“…Extrapolation to the basin-scale using this resampling approach aims to incorporate uncertainty in the flare measurements, emission factor assumptions, and flare volume estimates in addition to temporal variability in flare performance. Volume estimates from VIIRS carry their own uncertainties, 42 however, in aggregate have been shown to be robust for offshore infrastructure. 43 Onshore, VIIRS likely misses smaller flares that are more challenging to quantify from space.…”

Air Quality and Health Impacts of Onshore Oil and Gas Flaring and Venting Activities Estimated Using Refined Satellite‐Based Emissions

“…Uncertainties of the regression algorithms are estimated to be ±9.5% (Elvidge et al., 2015 ). Another source of uncertainty is from the country‐ and state‐level reported FGVs, which are subject to known and unknown biases as discussed by Schade ( 2021 ). Large gaps exist when VIIRS‐estimated FGV in 2019 is compared to FGV reported by Rystad Energy ( 2022 ) for the same year (Table S4 in Supporting Information S1 ).…”

Quantification of Gas Flaring from Satellite Imagery: A Comparison of Two Methods for SLSTR and BIROS Imagery

“…Reference data used for fitting the model consisted of 47 reported upstream flares (plus venting, assumed as negligible) at a country-level and state-level reporting for two US states (Texas and North Dakota). The limitations of the approach have recently been reviewed by Schade [ 77 ].…”

“…Flaring activity based on remote sensing estimates is uncertain [ 76 , 77 , 78 ], as are emissions estimates, due to uncertain emission factors [ 79 , 80 , 81 , 82 , 83 ], on the one hand, and to limitations from both the ground-based data used for the fitting (e.g., [ 32 , 77 , 84 ]), in the case of the calibration-based approach, and the sensors (e.g., [ 85 ]), in the cases of the calibration-based and the physico-chemical-based approaches, on the other hand. The former include geographic and temporal biases: the reporting processes, the gas characteristics and the combustion conditions, for example, may have a strong local dimension and limited applicability, become outdated, be inconsistent or highly uncertain.…”