Real-Time Space Observations Can Now Monitor ‘Super-Emitting’ Power Plants

Countries that signed the 2015 Paris Agreement pledged to keep the rise in global average temperature “well below” 2°C. Every five years, they must publish “Nationally Determined Contributions” (NDCs), outlining their actions to reduce greenhouse gas (GHG) emissions and adapt to the impacts of climate change.

Countries will therefore need to track their carbon emissions not only at the national level, but also at the scale of individual “super-emitters” such as power plants, megacities, refineries and giant factories, together responsible for nearly the half of the total production of humanity. of GHG.

At the end of 2025 or 2026, the EU plans to launch its “CO2M” (Copernicus Anthropogenic CO₂ Monitoring mission) pair of satellites, the work of which will be to help with this.

Important proof of principle for CO2M

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

This success is a significant 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, an atmospheric scientist at Environment and Climate Change Canada, Toronto, and first author of the study, published in Borders in remote sensing.

The largest power station in Europe

The lignite (lignite) power plant in Bełchatów is the largest thermal power plant in Europe and the fifth largest in the world. Here, units are sometimes decommissioned and new ones commissioned, while more often units are temporarily shut down for maintenance. To be useful, satellites and instruments like OCO-2 and OCO-3 must immediately detect changes in CO₂ emissions due to these operating changes – and here Nassar and his colleagues show for the first time that they can.

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

Not all flyovers or overpasses are suitable

Satellites can assess CO₂ “improvement” – additional CO₂ emitted from a source – only in the absence of clouds and when the plume does not pass over large bodies of water or mountains. They measure “XCO2”, the average CO₂ concentration through a column directly below, subtracting the current background value (locally, averaging 415 ppm) around the plume.

Together, OCO-2 and OCO-3 produced 10 suitable CO datasets₂ plume over Bełchatów between 2017 and 2022.

Excellent agreement between observed and predicted data

The researchers compared the measurements from space to emissions estimates from Bełchatów, based on its known daily electricity production. The measurements were found to follow the daily forecast closely. This proves that even today, existing satellites can track emissions in near real time for facilities like Bełchatów. For example, OCO-2 detected a pronounced but transient drop in emissions from Bełchatów between June and September 2021, due to maintenance shutdowns.

Everything is clear for CO2M

The results are promising: they indicate that CO2M, with a joint spatial coverage approximately one hundred times greater than OCO-2 and OCO-3, will be able to meet future needs.

“The ability to obtain the most accurate information about CO₂ emissions from ‘super-emitters’, such as the Bełchatów Power Plant, around the world will increase transparency in carbon accounting and hopefully ultimately help reduce these emissions,” Nassar said.

“This future capability will lead to improved CO₂ information on emissions at the country, city or individual facility level, improving transparency under the Paris Agreement and supporting efforts to reduce the emissions that cause climate change.”