Real-time space observations can now monitor “super emitter” power plants

Signatories to the 2015 Paris Agreement have pledged to keep global mean temperature increases “well below” 2°C. Every five years, they are to issue so-called “National Determined Contributions” (NDCs), in which they describe their measures to reduce greenhouse gas (GHG) emissions and adapt to the consequences of climate change.

Countries must therefore track their CO2 emissions not only at the national level, but also at the level of individual “super-emitters” such as power plants, megacities, refineries and giant factories, which together account for almost half of humanity’s total production of greenhouse gases.

At the end of 2025 or 2026, the EU wants to reduce its “CO2M” (Copernicus Anthropogenic CO₂ Monitoring Mission) pair of satellites whose task will be to help with this.

Important proof of principle for CO2M

But now scientists have shown that such tracking at the source is already possible with existing “super-emitter” satellites such as the Bełchatów power plant in Poland. For this proof-of-principle, they used five years of measurements by NASA’s Orbiting Carbon Observatory 2 (OCO-2; launched 2014) satellite and the OCO-3 instrument, which has been attached to the International Space Station (ISS) since 2019. .

This achievement is an important achievement as the OCO missions were designed to measure carbon emissions at much larger spatial scales.

“Here we show for the first time that it is already possible to measure changes in CO₂ Emissions from a large power plant, with observations of existing CO₂-tracking satellites,” said Dr. Ray Nassar, atmospheric scientist at Environment and Climate Change Canada, Toronto, and first author of the study, published in Frontiers in remote sensing.

Largest power station in Europe

The Bełchatów lignite-fired power plant is the largest thermal power plant in Europe and the fifth largest in the world. Here sometimes units are decommissioned and new ones commissioned, while more often units are temporarily shut down for maintenance. To be useful, satellites and instruments such as OCO-2 and OCO-3 should detect changes in CO immediately₂ Emissions due to these operational changes—and here, for the first time, Nassar and colleagues show they can.

CO₂ is emitted from the 300 meter high chimneys in Bełchatów and carried by the wind in the form of an invisible cloud approximately 10–50 km long and 550 meters above the ground. Orbiting the Earth at an altitude of 705 km, OCO-2 passes near or directly over Bełchatów every 16 days. OCO-3 orbits at an altitude of 420 km and more often overflies or near Bełchatów. OCO-3 has the additional ability to scan back and forth in a region, providing better local coverage or a wider view.

Not every drive-by or overpass is suitable

Satellites can evaluate the CO₂ “Boost” – additional CO₂ emitted from a source – only in the absence of clouds and when the cloud does not pass over large bodies of water or mountains. They measure “XCO2”, the average CO₂ Concentration over a column directly below, subtract the current background value (local, averaging 415ppm) around the plume.

Together, OCO-2 and OCO-3 provided 10 suitable datasets on CO₂ Cloud over Bełchatów between 2017 and 2022.

Excellent agreement between observed and predicted data

Researchers compared measurements from space with estimates for Bełchatów’s emissions based on known daily power generation output. It turned out that the measurements closely tracked the daily predictions. This proves that existing satellites can track emissions for plants like Bełchatów in near real time. For example, between June and September 2021, OCO-2 noted a pronounced but temporary decrease in emissions from Bełchatów due to maintenance shutdowns.

All set for CO2M

The results are promising: they suggest that CO2M, with a combined spatial coverage about 100 times larger than OCO-2 and OCO-3, will be able to meet future needs.

“The ability to get the most accurate information about CO₂ Emissions from “super emitters” like the Bełchatów power plant around the world will increase transparency in carbon accounting and hopefully ultimately help reduce those emissions,” Nassar said.

“This future capacity will result in improved CO₂ Emission information at the country, city or individual entity level, improving transparency under the Paris Agreement and supporting efforts to reduce emissions that cause climate change.”