Gorgon shows CCS boasts are built on technical uncertainty

The latest data release from Chevron on its Gorgon carbon capture and storage (CCS) project, the world’s largest, showed the lowest amount of carbon dioxide (CO₂) captured and stored for a year since it started in August 2019.

This matters as CCS has been promoted as a climate solution by the fossil fuel sector, which last year pumped a collective 37.8 billion tonnes of CO₂ into the atmosphere. This puts the world on a trajectory to reach a global average temperature rise of 2.6°C above pre-industrial levels, according to Climate Action Tracker.

According to the oil and gas sector, one way to avoid this is to adopt CCS, and government should be putting taxpayer funds into this “solution”. However, CCS has a chequered history and is beset by technical issues that its proponents, often engineers, say can be overcome. Yet Gorgon CCS shows no signs of improving; its performance has declined significantly since the first year of operation, as the chart below shows.

_{Source: Chevron. Gorgon Gas Development and Jansz Feed Gas Pipeline Five-year Environmental Performance Report 2020-2025. Page 112.}

To put Gorgon CCS’s underperformance into context, the 1.33 million tonnes (Mt) of CO₂ it captured in FY2024-25 represents 25% of the CO₂ removed (5.22MtCO₂) in that period from the Gorgon and associated gas fields that feed the Gorgon LNG plant on Barrow Island off Western Australia. This is a fraction of the total greenhouse gas (GHG) emissions by the gas produced at Gorgon. 

Chevron is not obliged to disclose the amount of CO₂ released into the atmosphere from its largest source of emissions: when the gas is combusted by its customers (or Scope 3 emissions). This makes up about 90% of the total emissions released by Gorgon CCS and its associated gas and LNG projects. However, in one of its Gorgon CCS planning documents, Chevron estimated that if all the gas from the project were consumed at gas-powered generation stations in the Asia-Pacific, emissions would amount to 50MtCO₂ a year. Based on the assumptions in that scenario, Gorgon CCS captured just 2.66% of the total emissions from extracting, processing and burning gas from the Gorgon fields.

So even if Gorgon were working at its design rate of capturing and storing 4MtCO₂ a year, it would still just amount to 8% of the total emissions from the associated projects. This is the case for any gas field promoting a CCS project, such as Woodside’s Browse gas project and Inpex’s Bonaparte CCS project. The latter is slated to host some of the CO₂ from Inpex’s Ichthys gas project in the Browse Basin in the Timor Sea.

Nonetheless, Gorgon CCS remains a bellwether for the CCS sector. Despite the relatively small amounts of CO₂ it captures, it still represents a significant proportion of the world’s dedicated CCS projects. The Global CCS Institute’s (GCCSI) annual report on the status of CCS around the world does not provide data on how much CO₂ is captured each year, only projects’ nameplate capacity. As is evident at Gorgon CCS, it stored only about one-third of its annual target capacity in FY2024-25. Trawling through the dedicated CCS projects in the GCCSI annual report, the total CO₂ stored by the world’s CCS projects is little more than 10MtCO₂ a year or 0.00026% of global fossil fuel emissions. (Note: CCS is distinct from CCUS projects; the U stands for the utilisation of captured CO₂ to squeeze more oil out of the ground, also known as enhanced oil recovery.)

However, you’re unlikely to find any mention of these facts in the oil and gas sector narrative, which promotes CCS as a solution to reduce the industry’s emissions and justify opening new gas reserves. 

Yet there are more economical ways to reduce global emissions. The costs of solar PV and storing electricity through grid-scale batteries have come down sharply in the nine years since Chevron started building Gorgon CCS. This year, renewables overtook coal for the first time in generating electricity whereas the costs of CCS and its technical challenges remain.
 

This commentary was originally published in RenewEconomy.