Wizz Air’s Sewage-to-Fuel Deal Helps Blow Up Five Energy Myths

Wizz Air made headlines recently by signing a major deal to purchase sustainable aviation fuel derived from treated human poop. The optics are amusing, but the implications are profound. This isn’t a fringe experiment or a corporate PR stunt. It’s a signal that the aviation industry is moving toward a serious decarbonization strategy grounded in real chemistry, real feedstocks, and real-world constraints. The decision to bet on SAF from municipal waste not only speaks volumes about what airlines think is possible, it also helps dismantle five of the most persistent misconceptions still infecting energy and climate discourse.

The first incorrect assumption is the idea that we are going to need vastly more liquid fuels than we do today. This belief underpins a surprising number of energy transition scenarios, especially those that downplay electrification or assume a strongly increasing demand curve for jet fuel, diesel, and bunker fuel decades into the future. But the numbers don’t support it. Global oil demand for transport is peaking or has already peaked, and all signs point to a rapid contraction over the next 25 years.

In my own modeling, published over the past several years, I’ve projected a scenario where 100% of ground transportation is electrified—cars, buses, trucks, rail, two- and three-wheelers. In that world, the demand for liquid fuels drops by over 80%, and what’s left is concentrated in the hard-to-electrify sectors: long-haul aviation and deep-sea shipping. Aviation fuel demand does grow modestly through 2050 under my model, which is more pessimistic and I think realistic about growth, but hybrid electric regional turboprops take over shorter hops of up to 1,000 km as battery energy densities climb. My projection is for only 110 million tons of liquid fuels required for aviation.

Maritime shipping fuel demand, meanwhile, shrinks dramatically as bulk fossil fuel and iron ore shipments decline. Oil, coal, and LNG shipping collectively represent about 40% of tonnage today, raw iron ore is another 15% and all four are in structural decline. By the end of the century, I project annual liquid fuel demand for marine shipping is likely to be in the 70 million tons of diesel equivalent range globally. That’s less than a third of today’s shipping fuel volume, and with reductions in aviation fuel demand due to electrification, high-speed rail and other factors, we’re looking at a future where the total global need for liquid fuels might be one-tenth of what it is today.

The second misconception that refuses to die is the notion that biofuels can only come from prime agricultural land. This fear traces back to first-generation biofuels—corn ethanol, soy biodiesel, palm oil—where concerns, some legitimate if overstated, about land use, food prices, and deforestation emerged. But that legacy doesn’t reflect the reality of advanced biofuel production today. The Wizz Air deal is a perfect example. Biosolids—essentially the residual organic matter left over from wastewater treatment—are abundant, underutilized, and pose a methane emissions risk if unmanaged. Converting them to SAF doesn’t displace food crops or use new land. Instead, it turns a municipal waste liability into a high-value, low-carbon product.

And biosolids are just one category. In my comprehensive assessment of viable biofuel pathways, I catalogued at least ten scalable options that rely entirely on waste and non-food biomass: municipal solid waste, forestry residues, agricultural byproducts like corn stover and wheat straw, animal manure, and even landfill gas. The global supply of these materials is vast. The world wastes approximately 2.5 billion tons of food annually. Europe alone generates over 1.5 billion tons of livestock manure per year. At a conservative yield of 0.4 tons of fuel per ton of dried biomass, the waste streams we’re currently mismanaging could supply well over 500 million tons of low-carbon fuel annually. That’s more than enough to meet the residual liquid fuel demand in a maximally electrified transport system. No new farmland required. No tradeoff between food and fuel. Just a redirection of waste into the energy system.

The third false belief is that renewable electricity will become effectively free, enabling a cascade of ultra-cheap electrochemical pathways to dominate. This misconception stems from the marginal cost argument: since wind and solar have no fuel cost, they must eventually drive electricity prices to zero part of the time. It’s true that the marginal cost of generation is low. But the system cost of delivering firm, reliable, high-quality electricity is not. In high-renewables grids like California or South Australia, we do see negative pricing events during solar peaks. But these are short-duration, location-specific artifacts of a misaligned supply-demand curve.

To actually power a process like hydrogen electrolysis or synthetic fuel synthesis economically, you need high-capacity-factor electricity, 60% or more. If you’re relying only on intermittent surplus, your electrolyzers or synthesis reactors are sitting idle most of the time, and your capital costs explode. I’ve run the numbers in multiple regions, and the story is consistent: surplus renewable electricity is not free when you need it at scale, and its temporal distribution makes it unsuitable as the backbone of any major fuel production system. California’s duck curve is not a business model.

This brings us to the fourth fantasy: that green hydrogen will be cheap. It won’t. Hydrogen is a valuable industrial input for very specific contexts—ammonia production, petrochemical refining and perhaps steelmaking. But as a general-purpose energy substitute, it fails the physics and the economics. Electrolyzers are expensive, and their cost per kilogram of hydrogen is highly sensitive to utilization. Hydrogen is expensive to compress, store and distribute.

In transportation, hydrogen fuel cell vehicles have a total cost of ownership roughly 2 to 3 times that of battery electric equivalents. I’ve documented multiple real-world cases where hydrogen trucks, buses and other vehicles failed on economics alone, let alone the infrastructure challenges. In energy terms, green hydrogen multiplies the upstream electricity demand by a factor of 3 compared to direct electrification. Every kilowatt-hour routed through an electrolyzer, then compressed, stored, and run through a fuel cell ends up delivering a fraction of the useful energy that a battery does.

That’s playing out now, as every organization that created fantastical projections of cheap green hydrogen adjusts their cost projections to fit the realities that were obvious when they first made them five to ten years ago. BNEF, CSIRO, LUT and more are all finally realizing that their numbers are bogus, but only BNEF has so far had the guts to triple its electrolyzer cost projections for 2050, with the rest only nudging costs up every year since 2020’s projections. Contacts tell me that the IEA gave the task of doing the first projections to an intern, and I find that credible. This wasn’t intentional disinformation, by the way, this was technoeconomic incompetence combined with cognitive biases. It remains indefensible in my eyes, however. Billions of dollars and years of time have been wasted, and more money and time that could be spent on actual climate solutions continue to be thrown at the space.

The reality is that hydrogen is an industrial feedstock that will see significant declines in demand from current levels as 40% of current use is for petroleum refining. Another 30% is used for ammonia, which is also going to see declines as its price increases and agrigenetic nitrogen fixing, precision agriculture, drone spraying and other levers displace its current overuse.

The final myth that needs to be retired is the idea that synthetic fuels—those created from green hydrogen and captured CO₂—will be cheaper than biofuels, perhaps even as cheap as fossil fuels. This one gets a lot of airtime in e-fuel hype circles, particularly in Europe where policy compromises have allowed synthetic fuels to keep internal combustion engines on life support past 2035. But the thermodynamics are unforgiving. Making a synthetic hydrocarbon fuel requires enormous amounts of electricity: to make hydrogen, to capture and purify CO₂, and to run the synthesis process itself. The round-trip efficiency is dreadful—somewhere between 10% and 15% from grid electricity to motion when burned in an engine. That means you’re spending five to seven times more electricity per kilometer than you would with a battery electric vehicle. And that electricity isn’t free, as we’ve established.

Today, synthetic jet fuel costs between $5 and $10 per gallon in pilot quantities. Bio-based SAF, by contrast, is already being produced at commercial scale for $2 to $4 per gallon from used cooking oil, tallow, and now, biosolids. Even as e-fuel technology improves, the gap will persist. Airlines aren’t ideologues, they’ll buy the cheapest low-carbon fuel that meets ASTM specs and avoids reputational risk. Right now, and likely forever, that’s biofuel. Wizz Air knows this. That’s why they’re locking in biosolid-derived SAF, not hydrogen-derived e-kerosene.

Biofuels are always going to be two to three times more expensive than fossil fuels if we let the atmosphere be used as a free sewer, but synthetic fuels will be four to six times as expensive. As a result, no synthetic fuels.

The reality is simpler and more elegant than the myths. We will electrify everything we can—cars, trucks, buses, rail, ferries, short-hop planes—and we will use sustainable biofuels made mostly from waste biomass streams for what we can’t electrify yet. That residual demand is modest, and we have the feedstocks to meet it without touching a single hectare of food-producing land. We will grow a bunch of soy beans and similar things for biofuels simply because we have lots of agricultural land. There’s no shortage or competition for food, as evidenced by us throwing away a full third of the calories we manufacture annually.

The energy transition isn’t about miracle molecules or magic catalysts. It’s about physics, economics, and pragmatic deployment. Wizz Air’s poop-to-jet-fuel deal is just one data point, but it helps illustrate why the five persistent illusions have to be removed from policy and investment decisions.