Why I'm Learning About Airplane Fuel at 68 (And You Should Care Too)

Never thought I'd spend my retirement years researching jet fuel, but here I am at nearly seventy, reading technical papers about hydroprocessed esters while my coffee goes cold. My daughter thinks I've lost it – she called last week and I spent twenty minutes explaining sustainable aviation fuel before she could tell me about my grandson's soccer game. Poor thing probably regrets asking how I'm keeping busy these days.

It started because of guilt, honestly. Pure and simple guilt about flying to see my sister in Florida twice a year since my husband died. Those visits are precious to me – she's eighty-one and we both know our time is limited – but every flight makes me feel like a hypocrite. Here I am, hanging laundry to save electricity, composting kitchen scraps, walking to the pharmacy instead of driving, then I turn around and burn massive amounts of fossil fuel flying across the country.

My granddaughter Emma mentioned once that a single round-trip flight can undo an entire year's worth of other environmental efforts. She wasn't being mean about it, just stating facts the way kids do, but it hit me hard. I'd been so focused on reducing my household emissions that I hadn't really thought about the bigger picture of my carbon footprint.

So I did what I always do when something bothers me – I started researching. Spent hours at the library, printed out articles until the librarian probably thought I was writing a dissertation. What I learned was both fascinating and deeply frustrating.

Aviation accounts for about 2.5% of global carbon emissions. Doesn't sound like much until you realize that's still enormous, and it's growing fast as more people around the world can afford to fly. Unlike my car, which I could theoretically replace with an electric version, you can't just stick a battery in a Boeing 737 and call it sustainable. The weight and energy density requirements make that impossible for anything beyond short hops.

That's where sustainable aviation fuel comes in, or SAF as the industry calls it. The basic idea is creating fuel that burns like regular jet fuel but produces far fewer carbon emissions over its lifecycle. Sounds simple enough, right? Well, as usual with environmental solutions, the devil's in the details.

The most developed option uses something called HEFA technology – don't ask me to pronounce the full name, but it basically turns oils and fats into jet fuel. Used cooking oil, animal fats, vegetable oils, that sort of thing. When I first read about planes running on old french fry oil, I thought it was brilliant. All that waste oil from restaurants and food processing, turned into something useful instead of clogging up landfills.

Then I did the math. The entire world's supply of used cooking oil could power aviation for maybe a few days. Even throwing in all available animal fats wouldn't make a dent in global fuel demand. It's like trying to fill a swimming pool with a teacup – technically possible but completely impractical.

That realization sent me down a rabbit hole of research that left me pretty discouraged. If we tried to grow crops specifically for aviation fuel – palm oil, soybeans, whatever – we'd need agricultural land the size of small countries. Land that could be growing food or left as natural habitat. Not exactly the environmental win I was hoping for.

I remember sitting in my kitchen last summer, surrounded by printed articles, feeling like I was back at the insurance office drowning in paperwork. Every solution seemed to create new problems. Use food crops for fuel and you're competing with food security. Use waste streams and there's not nearly enough. The whole thing felt impossible.

But then I learned about newer technologies that gave me a bit of hope. There's something called alcohol-to-jet that converts ethanol into aviation fuel, and the ethanol can come from agricultural waste or crops grown on marginal land that's not suitable for food. Another process – with a name I can't pronounce involving gasification and synthesis – can turn municipal waste, forest residues, even purpose-grown energy crops into jet fuel.

The most interesting option to me is what they call power-to-liquid fuels or e-fuels. These combine hydrogen made from renewable electricity with carbon dioxide captured from the air to create synthetic jet fuel. If powered by wind or solar energy, this could theoretically be carbon-neutral. The plane would still emit CO2 when burning the fuel, but that CO2 was pulled from the atmosphere to make the fuel in the first place.

I got so excited about this concept that I tried explaining it to my neighbor Mrs. Peterson over the fence. She listened politely while I gestured wildly about carbon cycles and renewable hydrogen, then asked the obvious question: "Well Donna, why aren't we using this stuff already?"

Good question. Turns out sustainable aviation fuel currently makes up less than 0.1% of all jet fuel used worldwide. The stuff costs two to eight times more than regular jet fuel. The most promising technologies are still being scaled up from small demonstration plants. And while airlines love making announcements about sustainability commitments, actual usage remains tiny.

I discovered this firsthand when I tried booking my last flight to Florida. Spent an entire afternoon searching airline websites for sustainable fuel options. Found exactly one carrier offering to let me pay extra to "offset" my emissions, but they weren't actually putting sustainable fuel in my specific plane. Just taking my money and promising to buy some SAF somewhere else at some point. Felt like buying indulgences in medieval times.

The biggest problem is simple economics. As long as regular jet fuel is much cheaper, airlines will keep using it. They're businesses, not environmental charities, and their shareholders expect profits. Making sustainable fuel cost-competitive would require some combination of carbon taxes, government subsidies, and technological improvements that drive down production costs.

Progress is happening, but slowly. The European Union is requiring airlines to use increasing percentages of sustainable fuel starting next year. Similar policies are emerging elsewhere. But the timeline feels agonizingly slow when you consider how urgent the climate crisis is.

My nephew Tom works in renewable energy, and he's more optimistic than I am. He points out that solar panels and wind turbines were expensive and niche twenty years ago, but costs plummeted as production scaled up. "The learning curve is real," he insists. "Once SAF production reaches commercial scale, prices will drop fast."

Maybe he's right. I hope so. But I'm old enough to remember a lot of promises about technological solutions that took longer than expected or didn't pan out at all. And we don't have decades to figure this out if we're serious about avoiding catastrophic climate change.

There's also the problem that almost every sustainable fuel pathway faces limitations on available inputs. Whether it's waste cooking oil, agricultural residues, or renewable electricity, there's only so much to go around. The renewable electricity that might make synthetic jet fuel could also be replacing coal power plants or helping electrify home heating systems.

It's enough to give you a headache, honestly. Every solution creates new complications and trade-offs. But I'm still cautiously hopeful because the technical pieces exist. Multiple approaches are moving from laboratory experiments to pilot projects to commercial demonstrations. Policy support is gradually increasing, even if too slowly. And consumer pressure is starting to make airlines take this seriously.

British Airways partnered with Phillips 66 to use sustainable fuel from waste oils. United Airlines invested in companies developing new fuel sources. These aren't just publicity stunts – they represent real financial commitments that suggest the industry sees sustainable fuel as inevitable.

I've started asking airlines about their sustainable fuel plans when I book flights. Not because I expect my individual question to change corporate strategy, but because enough people asking forces companies to respond. Maybe it's naive, but I believe consumer pressure matters when it's persistent and widespread.

In the meantime, I'm trying to be practical about my own flying. Replaced a couple domestic flights with train trips – took Amtrak to visit my cousin in Chicago last year instead of flying, and actually enjoyed the scenery and extra space. When I do fly, I look for direct routes and more fuel-efficient aircraft. And I've had honest conversations with myself about which trips are truly necessary versus just convenient.

The irony isn't lost on me that researching sustainable aviation has made me want to fly less. But that's probably the reality for now – we need both better technology and changes in behavior while the technology catches up.

My sister teases me about it when I visit her. "You spend the whole flight reading about airplane fuel instead of relaxing," she says, pouring iced tea on her porch. "Just enjoy the journey for once." She's right, of course. But I can't stop learning about this stuff because the stakes feel so high.

So I continue my odd retirement hobby of tracking sustainable aviation fuel developments. I cheer each new production facility announcement, each policy incentive, each airline commitment. I share what I learn with anyone patient enough to listen. And I hold onto hope that my grandchildren will someday fly on planes powered by truly clean fuels.

The technology exists. Multiple pathways show promise. The question is whether we have the collective will to overcome economic and practical barriers fast enough. Some days I'm optimistic, other days discouraged, but I refuse to give up hope. The alternative – accepting that sustainable long-distance travel might remain impossible for generations – is too depressing to contemplate.

And honestly? At my age, what else am I going to do with my time? I've already organized forty years worth of photo albums, my garden is as perfect as it's going to get, and I can only read so many mystery novels. If boring people at community center meetings with sustainable fuel facts is my contribution to solving climate change, so be it.

My generation created a lot of these environmental problems through decades of thoughtless consumption. The least I can do is spend my retirement years learning about solutions, even if they're complicated and imperfect. Progress happens through both breakthrough innovations and millions of people making small, persistent pushes in the right direction.

I plan to keep pushing, one conversation at a time. Even if it means explaining hydroprocessed esters over Sunday dinner while my family rolls their eyes. Especially then, actually. Because if a retired insurance administrator from suburban Boston can understand this stuff well enough to care about it, anyone can. And we're going to need everyone caring if we want sustainable aviation to become reality instead of just a nice idea.

The future my grandchildren inherit depends on it. That's motivation enough for me to keep learning, keep asking questions, keep pushing for better solutions. Even if it means becoming the neighborhood expert on jet fuel chemistry. Stranger things have happened in retirement, I suppose.

Donna

Donna’s retired but not slowing down. She spends her days gardening, reusing, and finding peace in simpler living. Her writing blends reflection with realism—gentle reminders that sustainability starts at home, in daily habits and quiet choices.