The Market Is Converging on MoFuSS: What It Means for Clean Cooking Carbon Projects in Africa
Lilian Njuguna
Environment and Climate change Director
LinkedIn-ready angle: For years, one number has quietly decided how much a cookstove project is worth on the carbon market: the fraction of non-renewable biomass, or fNRB. It sounds like a technical footnote. It isn't. Overstate it, and a project mints credits for "savings" that were never real forest loss to begin with — a big part of why cookstove credits have taken such a public beating on integrity grounds over the past few years. That's finally changing, and not because of one registry's initiative. Gold Standard retired the old CDM Tool 30 in mid-2025 and let every existing fNRB value expire by the end of that year. The ICVCM has gone further, mandating the more rigorous MoFuSS model across cookstove methodologies market-wide. Verra is now the last major registry catching up, with a public consultation on VM0050 v2.0 open through August 10. The market has converged — the only question left is how ready individual projects are for it.
For years, one number has quietly decided how much a cookstove project is worth on the carbon market: the fraction of non-renewable biomass, or fNRB. It sounds like a technical footnote. It isn't. Overstate it, and a project mints credits for "savings" that were never real forest loss to begin with — a big part of why cookstove credits have taken such a public beating on integrity grounds over the past few years. That's finally changing, and not because of one registry's initiative. Gold Standard retired the old CDM Tool 30 in mid-2025 and let every existing fNRB value expire by the end of that year. The ICVCM has gone further, mandating the more rigorous MoFuSS model across cookstove methodologies market-wide. Verra is now the last major registry catching up, with a public consultation on VM0050 v2.0 open through August 10. The market has converged — the only question left is how ready individual projects are for it.
- For years, one number has quietly decided how much a cookstove project is worth on the carbon market: the fraction of non-renewable biomass, or fNRB. It sounds like a technical footnote. It isn't. fNRB determines how much of the wood a household stops burning actually counts as an emission reduction — and it has been one of the most contested, most gamed, and most consequential assumptions in the entire voluntary carbon market's cookstove sector. Overstate it, and a project mints credits for "savings" that were never real forest loss to begin with. That overstatement is a big part of why cookstove credits have taken such a public beating on integrity grounds over the past few years.
- This is why the shift toward MoFuSS across the standards landscape matters more than any single announcement might suggest — this isn't one registry's initiative, it's becoming the market norm.
- This has been building for a while, and it's bigger than one registry
- Gold Standard actually moved first. Back in 2025 it announced that CDM Tool 30 would stop being eligible for new GS4GG cookstove activities from 30 June 2025, and that all fNRB values already locked into design-certified projects would expire entirely on 31 December 2025. In their place, Gold Standard named a short list of eligible replacements — MoFuSS, Tool 33 default values, or a revised Tool 30 under the Paris Agreement Crediting Mechanism. The ICVCM went further still, setting conditions across cookstove Core Carbon Principle assessments that require projects to use either the MoFuSS model or the CDM's conservative 0.3 default — a marked tightening from the roughly 0.86 average fNRB that had been common in existing projects.
- Verra is now catching up to that standard. On July 9, 2026, it opened a public consultation on a major revision of VM0050 — the methodology governing energy-efficiency and fuel-switch cookstove projects — moving it from version 1.0 to version 2.0. The comment window runs through August 10, and Verra is separately soliciting an independent expert review of the draft.
- The centerpiece of the Verra revision is the same shift Gold Standard has already made: integrating the MoFuSS-DS tool to determine fNRB, and dropping the older CDM Tool 30 option entirely. A few other changes are bundled in alongside it:
- Explicit accounting for the Hawthorne effect — the tendency of monitored households to change their behaviour simply because they know they're being observed, which has historically inflated measured fuel savings.
- Expanded scope to cover heat retention devices, not just stoves themselves.
- Standardised use of Stove Usage Monitors (SUMs) alongside Kitchen Performance Tests, under the CLEAR monitoring framework.
- ## Why MoFuSS specifically
- MoFuSS — Modeling Fuelwood Savings Scenarios — is a GIS-based model built by UNAM and the Stockholm Environment Institute that simulates woodfuel harvesting impacts across real landscapes over time, rather than relying on the static regional defaults that Tool 30 used. It factors in where wood is actually sourced, how far it travels to reach demand centres, and how vegetation cover responds dynamically to changes in harvest pressure. The variant now being written into methodology text, MoFuSS-DS, has also been recalibrated using observed aboveground biomass data and Monte Carlo methods to tighten the uncertainty range around its estimates.
- The practical effect, across all three standards bodies converging on it: fNRB stops being a single defensible-sounding number pulled from a lookup table and becomes something closer to a spatially explicit, locally grounded calculation. For projects in landscapes where deforestation dynamics are genuinely site-specific — which is most of them — that's a meaningfully higher evidentiary bar, and a harder one to game. It also explains the scale of the correction: the ICVCM has noted the average fNRB across existing projects sits around 0.86, while the new, more conservative approaches are expected to push most projects below 0.5. That's not a rounding adjustment — it's a substantial cut to how many credits a given amount of avoided woodfuel use can generate.
- It's worth noting this isn't uniform across every layer of the market yet. The Article 6.4 Mechanism's own expert panel has been reviewing MoFuSS developments in parallel, but has so far concluded the model isn't yet ready to displace the existing CDM-approved fNRB defaults at the compliance-market level. The voluntary market standards — Gold Standard, the ICVCM's CCP framework, and soon Verra — are moving faster than the compliance architecture on this point, which is itself a useful signal for where things are likely heading next.
- ## The timing isn't a coincidence
- Verra's consultation is landing in the same week the IEA announced $900 million in fresh commitments for clean cooking access across Africa, taking total pledges since the 2024 Paris summit past $3.1 billion. Roughly $740 million of the original Paris pledge has already been deployed across 22 countries, and governments across more than 30 African countries have introduced upwards of 120 new clean cooking policies in that window. Kenya, notably, has set a 2028 target for universal clean cooking access — the first African country to adopt a fully costed, multi-fuel national transition strategy.
- Put those two threads together and the implication is fairly direct: there's a wall of capital moving toward clean cooking in Africa, and across every major voluntary market standard, the rules for how that capital converts into verifiable carbon credits are tightening at the same moment. Projects that can already produce landscape-level, spatially grounded fuelwood data will be well positioned regardless of which registry they use. Projects still leaning on generic regional fNRB defaults — wherever they're certified — have a shrinking runway to prepare before that option disappears everywhere.
- ## What this means for project developers on the ground
- A few practical takeaways for anyone running or advising a cookstove or biomass-related carbon project in this region:
- 1. Start engaging with MoFuSS data requirements now, not after v2.0 is finalised.
- MoFuSS-DS needs landscape-level inputs — woodfuel supply and demand data, harvest zones, transport distances — that take real time to assemble properly. Waiting until the methodology is locked in leaves no room to fix data gaps.
- 2. Monitoring design needs to anticipate SUMs, not just KPTs.
- If your project's MRV plan currently rests on periodic Kitchen Performance Tests alone, the shift toward continuous stove-usage monitoring is a design change, not a paperwork change.
- 3. The Hawthorne effect provision is a signal, not a formality.
- Projects that have relied on short observed-use windows to establish baselines should expect more scrutiny on how representative those windows actually are.
- 4. This is a genuine opening for credibility-conscious developers.
- Given how much reputational damage the cookstove sector has taken over inflated fNRB assumptions, being an early, transparent adopter of the more rigorous approach is a real differentiator with buyers and raters — not just a compliance cost.
What it does mean is that the developers who get ahead of this — building the landscape-level woodfuel data, the continuous usage monitoring, the documentation that MoFuSS actually needs — won't just avoid a compliance scramble. They'll be the ones buyers and raters trust first, in a sector that badly needs that trust rebuilt. Given how much capital is now moving into African clean cooking, that head start is worth more than the credits themselves. The moment to get MoFuSS-ready is now, not once every registry has formally caught up.
Share with your network
LinkedIn-ready angle: For years, one number has quietly decided how much a cookstove project is worth on the carbon market: the fraction of non-renewable biomass, or fNRB. It sounds like a technical footnote. It isn't. Overstate it, and a project mints credits for "savings" that were never real forest loss to begin with — a big part of why cookstove credits have taken such a public beating on integrity grounds over the past few years. That's finally changing, and not because of one registry's initiative. Gold Standard retired the old CDM Tool 30 in mid-2025 and let every existing fNRB value expire by the end of that year. The ICVCM has gone further, mandating the more rigorous MoFuSS model across cookstove methodologies market-wide. Verra is now the last major registry catching up, with a public consultation on VM0050 v2.0 open through August 10. The market has converged — the only question left is how ready individual projects are for it.
Sources & further reading
- 01Gold Standard for the Global Goals rule updates and PA-alignment documentation; ICVCM cookstove CCP decisions; Verra Project Hub public consultation notice; Carbon Herald reporting, July 2026; IEA clean cooking summit briefing, July 2026; UNAM MoFuSS project documentation.
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