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On this pageThe great carbon crossoverWhat Substrate is buildingWhy this investor, and why this structureChoosing a registryBringing together an estranged carbon family
The great carbon crossoverFor most of the last decade, the carbon market has sorted itself into two camps that don't talk to each other much. There's the established avoidance side, which has been around for longer: REDD+, cookstoves, improved forest management, and conservation, with its own investors, registries, and political baggage. Then there's the carbon dioxide removal side, which is largely newer entrants to the market: direct air capture, enhanced rock weathering, biochar, and a habit of defining itself against everything the first camp built. Whatever the messy terms, the two sides have spent a lot of energy being unkind to each other. But some players are waking up to relinking this estranged family.Substrate Biochar is one of the companies healing this rupture. Rainbow was a natural registry partner for them in part because Rainbow also straddles both worlds (they cut their teeth on non-removal credits before expanding into removals). This overlap is becoming less of an exception and more of a pattern, and is worth paying attention to: it may say more about where carbon markets are heading in 2026 and beyond than we realize.)
Biochar GTM Step #1: Find a ridiculous quantity of waste biomass.
Biochar GTM Step #1: Find a ridiculous quantity of waste biomass.What Substrate is buildingSubstrate Biochar is a UK-registered, South Africa-based biochar project developer founded by Oliver Glanville and Charlie Cornish. Their first production facility, near Port Shepstone on the KwaZulu-Natal coast, is commissioning a roughly 5,000-tonne-per-year carbon removal operation. They plan to double capacity on the same site. They have a pipeline of additional locations targeting around 50,000 tonnes per year. And they’re unabashed about their mission to scale biochar carbon removal in Africa.The feedstock is what drew them to the region. South Africa has a large forestry industry, and the small and midsize sawmills that serve it have a genuine waste problem. Wet sawdust accumulates in massive piles, and until recently, many mills simply burned it in the open. That's no longer permitted, and some mills have had to stop operating because they have nowhere to put the material.Substrate collects the sawdust, runs it through continuous pyrolysis using rotary drum kilns, and produces biochar with physical offtake into three markets: low-carbon asphalt, large-scale organic fertilizer companies, and mine rehabilitation. They're also seeing early interest from the macadamia and citrus farmers that surround their site, drawn to biochar's benefits for soil health.It's a lean operation by design. The model, which relies on large, point-source forestry biomass, is built for scale. It's what drew Substrate to South Africa in the first place: the existing biochar and forestry market meant they could produce a high-quality biochar product without taking on extra value-add in-house, like mixing their own fertilisers to sell into an early market. Glanville had seen other biochar companies, particularly across Africa and the Global South, try exactly that and run into complexity that didn’t work at scale. Substrate’s approach freed the founders to apply what they knew best - carbon markets, engineering, infrastructure project development at scale - to the market in as lean a way as possible.The same logic extends to how the business is financed. Glanville is direct about the reasoning: if your ambition is to scale carbon removal, the business model can’t rely on a single revenue stream. Substrate deliberately positioned itself where there is existing demand for physical biochar, not just carbon credits. The company is also structured to be capital-efficient enough to reach cash-flow-positive operations without the kind of fundraising that most CDR companies treat as a prerequisite. The carbon credit is one revenue line in a diversified model, not the entire business.
Why this investor, and why this structureOkavango Capital Partners is a small impact investment firm with a portfolio concentrated in Africa. Their track record on carbon is mostly focused in nature-based avoidance projects like conservation and REDD+, though their investments include exposure to removals around forest regeneration, improved grazing, and savanna fire management. Their thesis has long been that protecting and restoring ecosystems in emerging markets is both good impact and good business: it creates diversified revenue while reducing exposure to risks like flood, drought, fire, and soil degradation.Okavango recently invested in Substrate through TerraLabs, its carbon-focused holding. At first glance, it might seem strange for an investor who’s been in carbon markets for so long to branch into something new like biochar. Normally the communities between novel and legacy credits remain divided with not a ton of crossover.But Okavango Managing Partner Josep Oriol frames the move as evolution, not contradiction. Biochar, in his telling, sits at a natural intersection: you take refuse biomass that would otherwise rot, burn, or become a hazard, and you transform it into a stable carbon store that also happens to be a high-quality soil amendment. "It's an incredibly nice story," Oriol told me. "Not everybody does it that way, but one of the things that we really liked about the guys at Substrate is they got very right the value chain they wanted to affect." The forestry waste, the agricultural demand, the mining rehabilitation market, the carbon credit… they all reinforce each other in a way that makes the business more resilient than a company that depends on any single one.The investment was made through Terra Labs - a holding company, not a fund - and the distinction matters. Oriol is blunt about why: carbon doesn't lend itself well to limited-life fund structures. When you raise a typical ten-year venture fund, you're eventually dragged by your investors toward liquidity events, which means you end up incentivizing quick exits rather than patient company-building. Terra Labs’ preferred investment period, borrowing from Berkshire Hathaway, is "forever." If Substrate gets the model right, it will be a cash-flow-positive business that can fund its own growth. And the right structure for that is a long-term hold, not a countdown clock to a sale.Oriol was also candid about what he saw in the broader biochar landscape and why Substrate stood out. His team looked at multiple companies. Some were well run, but many struck him as overvalued; biochar companies were pricing themselves at venture-capital multiples as though they were Silicon Valley software businesses. "Biochar is an industrial endeavor," he said. "You're moving atoms, not bytes." Substrate's founders came with a reasonable valuation, a lean setup, and a plan that didn't require magical thinking about the market. For an investor who has watched carbon project scandals erode trust across the sector, that sobriety was part of the appeal.
Choosing a registrySubstrate evaluated multiple registries before landing on Rainbow. Oliver described the decision as partly about methodology fit: their project produces biochar that goes into applications like asphalt, which not every methodology accommodates cleanly, and partly about operational reality. For an early-stage company, the speed of the certification process and the responsiveness of the registry team are not minor considerations; they're existential. Cash flow matters, and the time between starting a project and issuing a credit is time you're burning runway.Rainbow, by Glanville's account, moved fast and stayed engaged. The co-founders were personally accessible. They answered technical questions quickly and walked through the process in a way that felt built for a company at Substrate's stage. "They've been incredibly helpful," Glanville said. "Rainbow really bent over backwards to try and demonstrate it had what we needed."
Bringing together an estranged carbon familySubstrate’s story hints at a much-needed maturation and bringing together of an estranged carbon family.Rainbow and Okavango both straddle the line in dealing with removals and non-removals alike, and they both see a future with more companies like Substrate. Carbon dioxide removal project developers have focused to date on seeking new investors and new buyers from outside of the “legacy” carbon space. Bringing new interest in is, of course, a great value for growing the industry. But we need the expertise from those who have been doing this work for decades.If more investors make that same move, it changes the capital landscape for biochar in particular and CDR more broadly. The money that has historically backed nature-based projects at scale is orders of magnitude larger than what's available in the CDR-specific investor pool. When that new synthesis occurs, old rivalries and positioning narratives can fall away, and we can focus on delivering high-quality carbon projects, whether they are removals, avoidances, or whatever categories we create next. When that happens, it’s going to be a big day for carbon markets, and those carbon dioxide removal project developers savvy enough to build this future.