Uploaded April 2026 | Updated September 2026, 2 weeks ago
Jet fuel is not just dirty. It is brutally hard to replace.
That is the physics problem behind aviation decarbonisation.
My guest is Dan Sutton, co-founder and CEO of Syntholene Energy, a climate tech company working on clean, drop-in synthetic aviation fuel, or eSAF. Dan’s argument is direct: aviation is one of the hardest sectors to decarbonise because hydrocarbons are astonishingly energy dense, and because most alternatives still struggle with cost, scale, and infrastructure reality.
That matters now because aviation demand keeps growing, policy pressure is rising, and fossil fuel supply chains are looking more fragile by the day. Jet fuel price shocks, geopolitical risk, SAF mandates, and net zero targets are all colliding with a stubborn question: can clean aviation fuel become commercially credible without depending forever on subsidies?
What changed my thinking in this conversation was the production pathway. Syntholene is not starting with waste oils or bio-feedstocks. Dan explains how synthetic fuel can be built from water, carbon, and energy, using geothermal heat, solid oxide electrolysis, and captured CO2. The critical point is hydrogen cost. If that falls, the economics of clean fuels change. If it does not, the PowerPoint decks can go back in the drawer where they belong.
We also get into why Iceland’s geothermal resources matter, why baseload clean energy is so important for industrial decarbonisation, and why mandates only work if they help projects reach real cost competition. Dan claims Syntholene’s first commercial footprint could target around $1.25 per litre factory-gate production cost, compared with many eSAF peers starting closer to $6-$8 per litre. That is a major claim, and exactly the kind of claim that deserves scrutiny.
This is not a silver-bullet conversation. It is about physics, infrastructure, project finance, policy, fossil fuel phaseout, emissions reduction, and the hard economics of the energy transition.
For climate professionals, energy leaders, policymakers, investors, aviation strategists, and anyone serious about cutting emissions in difficult sectors.
If you’re working on aviation decarbonisation, synthetic fuels, SAF policy, geothermal energy, or climate tech deployment, I’d be interested in your perspective in the comments.
🎧 Climate Confident podcast: climateconfidentpodcast.com
🔔 Subscribe for more conversations on real-world decarbonisation, climate tech, clean energy, and the energy transition.
Chapters / Timestamps
00:00 - Jet fuel’s energy-density problem
00:32 - Why Syntholene is betting on eSAF
04:03 - Why synthetic fuel is different from biofuel
07:34 - Water, carbon, energy: the eSAF feedstocks
08:21 - Why baseload clean energy matters
09:31 - Geothermal heat as the secret ingredient
11:44 - Fossil fuel supply chains and political risk
14:25 - Why aviation fuel is a canary in the coal mine
18:08 - The cost problem synthetic fuels must solve
21:03 - Targeting $1.25 per litre eSAF production
22:38 - SAF demand, mandates, and final investment decisions
25:19 - Why Iceland matters for geothermal fuel production
30:54 - What the Iceland demo plant must prove
32:21 - Why unit economics matter more than hype
35:20 - What success could look like in 5-10 years
37:30 - Lightning round: mandates, economics, and oil shocks
40:54 - The case for clean hydrocarbon abundance
Jet fuel is not just dirty. It is brutally hard to replace.
That is the physics problem behind aviation decarbonisation.
My guest is Dan Sutton, co-founder and CEO of Syntholene Energy, a climate tech company working on clean, drop-in synthetic aviation fuel, or eSAF. Dan’s argument is direct: aviation is one of the hardest sectors to decarbonise because hydrocarbons are astonishingly energy dense, and because most alternatives still struggle with cost, scale, and infrastructure reality.
That matters now because aviation demand keeps growing, policy pressure is rising, and fossil fuel supply chains are looking more fragile by the day. Jet fuel price shocks, geopolitical risk, SAF mandates, and net zero targets are all colliding with a stubborn question: can clean aviation fuel become commercially credible without depending forever on subsidies?
What changed my thinking in this conversation was the production pathway. Syntholene is not starting with waste oils or bio-feedstocks. Dan explains how synthetic fuel can be built from water, carbon, and energy, using geothermal heat, solid oxide electrolysis, and captured CO2. The critical point is hydrogen cost. If that falls, the economics of clean fuels change. If it does not, the PowerPoint decks can go back in the drawer where they belong.
We also get into why Iceland’s geothermal resources matter, why baseload clean energy is so important for industrial decarbonisation, and why mandates only work if they help projects reach real cost competition. Dan claims Syntholene’s first commercial footprint could target around $1.25 per litre factory-gate production cost, compared with many eSAF peers starting closer to $6-$8 per litre. That is a major claim, and exactly the kind of claim that deserves scrutiny.
This is not a silver-bullet conversation. It is about physics, infrastructure, project finance, policy, fossil fuel phaseout, emissions reduction, and the hard economics of the energy transition.
For climate professionals, energy leaders, policymakers, investors, aviation strategists, and anyone serious about cutting emissions in difficult sectors.
If you’re working on aviation decarbonisation, synthetic fuels, SAF policy, geothermal energy, or climate tech deployment, I’d be interested in your perspective in the comments.
🎧 Climate Confident podcast: climateconfidentpodcast.com
🔔 Subscribe for more conversations on real-world decarbonisation, climate tech, clean energy, and the energy transition.
Chapters / Timestamps
00:00 - Jet fuel’s energy-density problem
00:32 - Why Syntholene is betting on eSAF
04:03 - Why synthetic fuel is different from biofuel
07:34 - Water, carbon, energy: the eSAF feedstocks
08:21 - Why baseload clean energy matters
09:31 - Geothermal heat as the secret ingredient
11:44 - Fossil fuel supply chains and political risk
14:25 - Why aviation fuel is a canary in the coal mine
18:08 - The cost problem synthetic fuels must solve
21:03 - Targeting $1.25 per litre eSAF production
22:38 - SAF demand, mandates, and final investment decisions
25:19 - Why Iceland matters for geothermal fuel production
30:54 - What the Iceland demo plant must prove
32:21 - Why unit economics matter more than hype
35:20 - What success could look like in 5-10 years
37:30 - Lightning round: mandates, economics, and oil shocks
40:54 - The case for clean hydrocarbon abundance
