Executive Summary
Our Nubo Sphere continuous methane monitoring solution was put to the test at the Advancing Development of Emissions Detection (ADED) campaign of 2023, a blind controlled-release testing campaign organized by the Methane Technology Evaluation Center (METEC), of Colorado State University (CSU). In the ADED 2022 campaign, Nubo Sphere used a common metal oxide (MOx) sensor to measure ppm concentration of methane in the air (you can find the results here). It showed great performance compared to other technologies and solutions. During the ADED 2023 campaign, Sensirion’s proprietary photoacoustic-based laser spectroscopy sensor technology was under test, and performance improved dramatically in all aspects of the solution. This provides our Nubo Sphere solution with a field-leading price-to-performance ratio compared to the other nine continuous monitoring solutions participating.
At Sensirion Connected Solutions, we understand oil and gas operators’ needs regarding emissions management. Our customers are looking for solutions that can reliably and quickly detect emissions in their facilities by maximizing true positives and minimizing both false negatives and false positives (false alarms). They want to be pointed towards the emitting equipment group and to know the urgency of that leak with respect to its emission rate. The ADED campaign is designed to evaluate methane monitoring technologies against those precise metrics: detection, localization and quantification of methane emissions under real-world conditions.
The ADED 2023 campaign lasted roughly three months, from February 8th to April 28th. It performed 254 experiments, including 535 individual controlled releases. Nubo Sphere detected 92% of all release experiments correctly, only missed 8% of experiments and did not send any false alarms (false positives) while achieving a 90% probability of detection of 0.8 kg/h. The lowest release rate correctly detected by our solution was 7.8 g/h—well below the 0.4 kg/h limit of detection proposed by the EPA for continuous monitoring solutions in their final NSPS oooob and EG ooooc rules. Nubo Sphere also demonstrated outstanding localization capabilities by assigning emissions to the right equipment group or even unit in 96% of all releases. Finally, it proved its superior quantification capability by quantifying cumulative emissions over all releases with 98.1% accuracy.
