Cookstoves with SIM cards are reviving a contested carbon credit

The 2020s have been a turbulent decade for carbon markets. For one popular project type — schemes that provide lower-emission cookstoves to households in developing countries — it has been a particularly bumpy ride. 

C-Quest, a project developer, admitted to a $250 million fraud in 2024 following U.S. Securities and Exchange Commission charges. The case is considered an outlier, but a study released that year by researchers at the University of California, Berkeley, identified a host of flaws in key cookstove methodologies that were allowing project developers to issue many more credits than the emissions savings justified. After years of growth, the issuance of such credits dropped sharply, according to a report by the nonprofit RMI.

Now, a series of developments promises to put the sector back on track.

Among the problems flagged by the Berkeley team were overly optimistic assumptions about how often the stoves were used. But last week, Gold Standard, a carbon credit registry, approved the release of an initial 1,600 credits from one Bangladesh-based project, because each stove distributed by the developer is equipped with a SIM card that transmits usage data to a third-party verifier.

Watch the meter

The SIM cards are one way for developers to comply with the registry’s “metered” methodology, which was approved around a year ago by the Integrity Council for the Voluntary Carbon Market, a key standard-setter. Buyers interested in cookstove credits should focus on projects that follow this methodology, advised Annelise Gill-Wiehl, an author of the Berkeley paper who is now at Columbia University.

Buyers should also pay attention to a metric known as the fraction of non-renewable biomass (fNRB), which measures the extent to which households source fuel for conventional stoves from unsustainable sources. Projects that overestimate fNRB issue more credits than the emission savings warrant. Both RMI and Gill-Wiehl recommend using fNRB values generated by the MoFuSS tool from by the National Autonomous University of Mexico and the Stockholm Environment Institute.

In a paper published earlier this year, Gill-Wiehl and colleagues provided a further boost to cookstove projects by confirming an assumption that underlies cookstove credits. Project developers generally assume that households won’t acquire cookstoves by other means, thus ensuring that the intervention is “additional.” After reviewing data from controlled trials of cookstove distribution the team agreed.

Demand from aviation

These developments are likely to reassure buyers that had been made wary of cookstove projects by all the negative headlines. One source of demand will be airlines seeking to comply with the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), which requires participating airlines to cap emissions at 85 percent of 2019 levels; any subsequent growth must be offset by purchasing CORSIA-approved credits. Last week, Gold Standard announced that Japan Airlines used 180,000 cookstove credits to help meet its CORSIA obligations.

For advocates of cookstove credits, the advances are welcome votes of confidence for a project type that has benefits beyond emissions savings, including improved indoor air quality. “It’s one of those project types that once you understand it, it’s very difficult to just walk away,” said Owen Hewlett, Gold Standard’s chief technical officer.