Opinion piece by Andrew Hinkly, Managing Partner of AP Ventures
Last week, at the signing of the UK–California climate, clean energy and environmental cooperation Memorandum of Understanding, Governor Gavin Newsom made a point that deserves more attention than it usually gets. The U.S. Clean Air Act and the creation of the California Air Resources Board in 1967 did not merely clean up smog; they laid the groundwork for one of the world’s most powerful clean‑technology ecosystems. California did not become a cleantech powerhouse despite regulation, but because of it.
That history matters today, with investors and policymakers in Sustainable Aviation Fuel (SAF) gathering in London this week to discuss the current regulatory landscape and scaling up the technology. As policymakers again grapple with sectors that are hard to decarbonise, it is worth remembering what happens when regulation sets out a clear destination, and industry is forced to build the road. The evolution of catalytic converters offers a useful reminder of how quickly scepticism can give way to scale, cost reduction, and industrial leadership, and why e‑fuels will follow the same path.
When catalytic converters arrived on U.S. cars in 1975, almost nobody liked them. They were seen as expensive, unproven, and awkward to integrate. Some critics warned they would cripple the auto industry. Instead, they became one of the quiet success stories of modern environmental policy. Emissions of key tailpipe pollutants fell by more than ninety percent per vehicle the technology spread worldwide, and the cost all but disappeared into the price of a car.
The complaints aimed at e‑fuels today sound familiar: too expensive, inefficient and too early. History suggests those objections won’t age well.
Catalytic converters didn’t spread because drivers asked for them. They spread because the Clean Air Act forced a clear outcome: drastically lower tailpipe emissions. Once that destination was set, innovation followed. Europe reinforced the trend with its own tightening standards. The rules kept getting tougher, and the technology kept improving.
E‑fuels are now on a similar path. ReFuelEU Aviation sets a rising requirement for sustainable aviation fuels, including e‑fuels, starting this decade and increasing steadily toward mid‑century. That kind of long‑term clarity is what allows engineers to optimise systems and investors to invest in large-scale projects with confidence.
Early catalytic converters really were expensive. They needed unleaded fuel, relied on precious metals, and added noticeable cost to vehicles. But progress came fast. Better catalyst chemistry reduced metal loadings. Smarter engines kept converters operating efficiently. Mass manufacturing did the rest.
By the time converters were being produced in the tens of millions each year, they had become standardised, durable, and cheap. The chemistry didn’t magically change. The system around it did.
E‑fuels today look a lot like catalytic converters did in the 1970s, the technology works, it just hasn’t been built at scale yet.
Electrolysers are becoming more efficient. Fuel‑synthesis processes continue to improve. Carbon capture is moving from bespoke projects to industrial systems. Renewable electricity keeps getting cheaper. Large plants perform far better economically than small ones.
None of this is surprising. It’s exactly what happens once regulation creates a real market and forces learning to happen in the real world.
Catalytic converters were once dismissed as a costly burden. Over time they became an ordinary, indispensable part of every car. E‑fuels are at the same point in their story.
Aviation will not decarbonise through voluntary adoption or perfect early economics. It will decarbonise the same way cities cleaned their air: set the rule, scale the technology, and let engineering and manufacturing do the work.
One part of the catalytic‑converter story is often missed. It didn’t just reduce pollution; it built companies. Regulation created demand at scale, helping Johnson Matthey, Umicore, and Engelhard to grow into global leaders. Entire supply chains formed around catalysis, materials science, and recycling.
E‑fuels can do the same. Large‑scale electrolyser manufacturing, carbon‑capture systems, fuel‑synthesis technologies, and global markets for clean molecules don’t emerge by accident. They emerge when policy is clear and sustained.
E‑fuels are often criticised for being an inefficient use of electrons. That criticism misses the point. Long-haul aviation cannot electrify. The fleet turns over slowly. Emissions are rising now.
Waiting for a perfect solution locks in decades of fossil fuel use. Deploying e‑fuels creates learning, lowers cost, and builds supply chains. They decarbonise a sector that has no alternative and avoid massive infrastructure replacement.
E‑fuels are not thermodynamically perfect. Neither were early catalytic converters. What matters is that they work, they scale, and they solve a problem that cannot be ignored. That is what makes them indispensable.
