Hydroelectric Methane Emissions

GHGSat is working with several hydro customers to demonstrate the use of satellite-based remote sensing technology for monitoring GHG emissions from hydro reservoirs. For more detailed information, please contact GHGSat at [email protected].


Greenhouse gas emissions from hydroelectric dams and reservoirs vary significantly from site-to-site, and over time. For example, emissions from facilities in tropical regions are more significant than those from facilities in boreal regions. Also, emissions are more significant during early operations of a facility and are believed to decrease quickly over time.

Obtaining accurate data for greenhouse gas emissions from hydroelectric facilities is difficult. Measurement of greenhouse gas emissions resulting from hydroelectric reservoir creation and operation requires multiple measurements upstream of, within and downstream of the reservoir, for multiple years prior to, during and after reservoir creation.

Existing instruments and methods are logistically challenging, labour intensive and expensive to purchase and to maintain. Operators typically use eddy covariance towers, flux chamber measurements, and/or direct measurement of water samples. Challenges include (but are not limited to) sparse sampling, persistent year-round measurement, consistent multi-year measurement, site access, and health & safety for personnel collecting data.

There is therefore significant interest from operators for evaluating alternative methods for collecting GHG data from hydroelectric reservoirs.

Demonstration Overview

GHGSat demonstrations generally include:

  • Definition of demonstration requirements
  • Initial estimates of site emissions, including test measurements and analytics
  • Measurement campaign
  • Validation of results

Experience with multiple operators has proven the value of an early understanding of customer information/data needs, agreement on the extent of the measurement campaign, coordination of coincident ground measurements (as available), and an agreement on an approach to validation.

Demonstrations with hydro operators included measurements of dams, reservoirs and reference sites – generally for a full year. Analytics included both point-source and area emissions estimates, and variations over time/seasons. Coincident measurements were generally limited water sampling, over approximate periods.


GHGSat has publicly released a satellite measurement of methane emissions from the Lom Pangar Dam in Cameroon. The full dataset is available, free of charge, upon request at [email protected].

satellite observation - Lom Pangar Methane Plume

Benefits to Operators

The projects offer the opportunity to assess GHGSat’s potential to:

  • Augment existing reservoir GHG monitoring programs;
  • Augment baseline and post-flood monitoring of new reservoirs;
  • Reduce the extent of field measurements;
  • Provide spatial monitoring coverage of large areas such as flooded areas, which are costly to monitor by ground methods;
  • Provide monitoring information throughout the year;
  • Provide ready access to monitoring data.

Hydro operators generally require reservoir GHG information to:

  • Support environmental licensing;
  • Confirm that hydro operations are low carbon emitters;
  • Verify that any remaining GHG emissions from mature reservoirs and flooded areas are negligible;
  • Help hydro operators to secure export sales by confirming hydropower is a low carbon emitter;
  • Support the inclusion of hydropower in future energy and climate policy in large energy markets; and
  • Advocate the merits of hydropower as a renewable energy source and climate change solution.