Continuous monitoring of methane emissions using Sensirion’s Nubo Sphere solution:
a performance evaluation at METEC

Executive Summary

Nubo Sphere is a continuous monitoring solution for methane emissions. In this test campaign at Colorado State University’s Methane Emissions Technology Evaluation Center (METEC), a university test site simulating conditions of upstream gas wells, we evaluated its ability to detect, localize and quantify methane emissions from different equipment types under changing environmental conditions.

  • During a 9-day test campaign featuring 27 controlled releases with methane emission rates between 0.6 and 7.7 kg per hour, Nubo Sphere successfully detected 100 % of the emissions under realistic wind conditions.
  • There were no false positive detections of emission events, or in other words, no cases where a detection was signaled that did not correspond to an actual controlled release event.
  • The quantified emission error was as low as 2 %, i.e. the total reported amount of emitted methane was very close to the actual emitted amount under favorable wind conditions. Such favorable wind conditions occur on sites regularly throughout the day.
  • Time to detection was approximately 30 minutes, with confirmed detection alerts being sent after 2.5 hours on average.
  • Emission sources were localized within a radius of 4 m around the true source.