Humanity has a sordid history with Airships. What was once the thing of dreams, literally went down in flames with the Hindenburg.

But the dream never fully died. The Goodyear Blimps are still going strong (and recently updated their fleet), and there are startups now building airships for surveillance, and others like Hybrid Air Vehicles, who built the below Airlander 10 prototype, in hopes of spurring the “air-cruise” industry.

And while airships’ relatively slow speeds (40–80mph) will never rival that of their airplane cousins – with the growing climate crisis hurtling into the collective consciousness, and the concept of flygskam (or flight shaming) taking hold, there’s a case to be made for blimps as a low carbon alternative to air travel. Airships could also be ideal for cargo transport as well.

You’re probably wondering what airships have to do with Climate Change – and we’ll go deep into that in a sec, but before that, we need to talk about Carbon Capture.

Now you’ve probably heard of the phrase Carbon Capture – according to the IPCC special report in October 2018, if we have a chance of staying within 1.5º C of warming (which you know, would be really, really, ideal) then they stipulate that we need to get serious about our efforts throughout the 21st century to be actively pulling carbon dioxide from the atmosphere.

And while there are many ways to capture Co2 (including just planting trees) there’s now a lot of emphasis on engineered solutions. One idea is to collect Co2 at the flue stacks of fossil fuel plants, though this would be considered carbon neutral, as you’re only really preventing new Co2 from being released into the atmosphere. What the IPCC is really referring to, are processes that are actually carbon negative. And so other startups are working on what are called Direct Air Capture (DAC) machines to grab Co2 that’s floating around in the ambient air and either bury it or re-use it in some way.

Now there are some issues around the current DAC approaches:

1. Cost — There is currently no clear way that this get’s funded on a mass scale. That does start to change if we could actually pass a Carbon Tax / put a price on Co2 (similar to 45Q.) But without that in place, startups in this space are instead trying to find ways to use Co2 as a commodity, what’s known as Carbon Capture and Utilization (CCU). And while there are some intriguing examples (like using it to help build concrete, plastics & to create fuels) it’s by no means a mature market, and depending on what they turn it into, it could still just be carbon-neutral.
2. Energy expended — In a recent model simulation conducted by Nature they calculated that for the amount of Co2 we’ll need to remove, it could require upwards of 25 % of our global energy by 2100 (seems a little overboard, but point taken.) And they go on to explain that if the capture efforts fail(which could be for a few reasons, including shifts in ocean Co2 absorption rates), all those energy resources that had been allocated to DAC, instead of being used to power our normal daily operations like the grid, transportation, and industry – would result in a global temperature overshoot, rather than the desired undershoot.

Alright, alright, so what about those airships?

Right — so my concept (shown below), is to modify airships to become an additional method for Direct Air Capture. The main rationale for what I’m calling the The Capture Ship or CapShip is that:

1. It would theoretically need less energy to operate
2. It would be able to capture higher concentrations of Co2 (probably not as much as if it were on-site at a flue stack, but more than standard ambient air Direct Air Capture.)

More on where the CapShip would be deployed below, but first, let’s talk about those giant wing-like panels — which, yes, are the filters that capture the ambient Co2. There are already proven processes for this – where ambient Co2 essentially clings (known as adsorption) to special filters. When full, the filters are taken into a closed environment and heated up, which causes the Co2 to then be released from the filters, and easily captured for use or sequestration. This video shows how one startup Climeworks goes about it:

You’ll notice in the video, the machine has these big fans that constantly pass air through the filters, which is important to get at as much Co2 as possible. The problem is that to power rows and rows of fans is an energy intensive process —which highlights the issue of increased power demand for Direct Air Capture. And keep in mind that all the power used for these plants should be from clean sources, or what’s the point, right?

But herein lies a key benefit of the CapShip — instead of spending energy bringing in all that air, the CapShip moves through the air – and so this part of the process could use very little

And on top of that, if it was powered by solar, the CapShip as a whole could be a Zero Emission Vehicle, you could even call it a Negative Emission Vehicle.

If you’re wondering how long an airship can actually stay in the air on solar power, the Chinese now have a solar-powered airship that is estimated to be able to stay in the air for as long as 6 months! Now a CapShip would be weighted down with the filters and solar, but honestly anything more than a day of flight time is a win. And as for the weight considerations, keep in mind that the Airlander 10 mentioned above has a cargo capacity of 10 metric tons, and a similar Lockheed Martin concept holds double that.

Another task for the CapShip would be to monitor Co2 levels. The think tank, Carbon180 explains in their Innovation Report that there are what they refer to as “sweet spots” for Co2. But we currently need more data on that. And so the CapShip is ideal to help build that database.

We’ll inevitably learn a lot from this, like maybe there’s an ideal elevation to capture Co2 at, or maybe an ideal time of the day (we do know there are seasonal fluctuations of Co2.) And this resulting data could help inform the airship’s ideal route, as the CapShip would fly to the areas with the highest Co2. But it could also potentially help plan for future installation locations for more robust, on-the-ground, Direct Air Capture plants.

Where Will CapShips Be Deployed?

As mentioned above, it’s really about flying to where the highest concentrations of Co2 are. And for the most part, that means going to where the emissions are being released. Here are a few specific ideas that I think would be interesting to pursue.

In Cities

Cities are a major contributor to Climate Change, according to C40, they account for 70% of emissions. But it’s becoming obvious that they’re going to play a huge role in fighting it as well. Organizations like C40 Cities, Climate Mayors, and Beyond Carbon are doing great work. And Los Angeles (where I live) recently released their own Green New Deal, which has some bold targets, showing just how committed they are to fighting Climate Change.

So the strategy of deploying CapShips specifically for cities could be a great way to help meet their emissions targets. And unlike a costly build-out of an on-the-ground facility in the middle of Downtown, CapShips could fly in for the day, then return to their processing facility outside the city (on cheaper land) at night.

I don’t know about you, but if I saw a CapShip flying overhead on my commute home, knowing that its sole job was to combat Climate Change, it would be a pretty good end to my day.

If there’s one thing LA has to tackle, it’s transportation emissions. And while EV adoption rates are increasing, we’ll still have gas guzzlers on freeways for years to come. So one potential route for the CapShip would be to fly above major freeways during or just after rush hour (depending on wind currents-heat-Co2 elevation rise.)

Above Flue Stacks

Imagine that in the next few years, we do get a Carbon Tax in place and there are small fossil fuel plants who may not be able to pay to overhaul their current systems with on-site capture — they could potentially “rent” a CapShip to fly over their stacks and capture a good portion of the Co2. This would hopefully be a short-lived enterprise as the clean energy transition should ideally be swift — but it could also add a cushion to give legacy workers time to transition into new jobs.

Or potentially the market for Co2 as a commodity just scales and CapShip operators become Co2 Harvesters and head to where it’s most abundant.

At Wildfire Sites

I’ll be honest, this use-case was the impetus for the idea originally. Because wildfires are going to become a bigger part of our lives as we move further into this century, and unfortunately, we can’t yet fully manage them.

Note – people might be scratching their head and wondering why you would fly something flammable into an actual wildfire, and it’s important to point out that while some airships do use hydrogen still (flammable) others use helium (non-flammable). So while helium wouldn’t be necessary for all flights, it would be ideal specifically for wildfire applications. And typically embers do not fly up as they move laterally, so a ship 1000ft in the air, should be safe.

Now let’s talk about some of the specific benefits of a wildfire CapShip:

1. It creates a local eye-in-the-sky control center to monitor the fire’s progress, movement, and trouble spots. Now sure, monitoring and communications with ground crews are obviously achievable through satellite, but the CapShip becomes a dedicated command center; you could even put the people managing the efforts up there.
2. With a clear picture of how much is burning & smoke volume, we could create algorithms to then estimate just how much Co2 was released from a specific wildfire. Now this is obviously important firstly for the overall Carbon budget, which if we’re going to be honest, we really have to start doing a better job at quantifying. But it’s also important because then if we know who’s responsible for a wildfire — like PG&E was during the recent California Camp Fire – we can more easily hold them accountable. And if we do get a price on carbon into place, we can actually tally up the monetary damages, without getting bogged down in the courts.
3. Generally speaking, the air above wildfires are unfortunately a “sweet-spot” for Co2, so one’s return on investment in capturing it here, is theoretically pretty high.

I’d remiss not to bring up the Rainforest here. As this gets into tricky territory, because one of these CapShips (potentially in partnership with a conservation non-profit) could fly into Brazilian air space in attempts to mitigate some of the Co2 and be met with fighter jets sent out by an anti-climate Brazilian government. Maybe they would just be ushered away, but one could envision how this could lead to issues.

But on the other hand, in some crazy awesome imagined future scenario, all UN countries could help to buy into a sanctioned UN CapShip Fleet that travels the world hunting wildfires. That would be pretty badass, right?

So how much Co2 can a CapShip capture?

I should caveat that this is all just a theoretical exercise, and not being an engineer, I’m in no way qualified to say whether in its current shape it would fly, or what the actual carbon capture capacity would be. But I’ve provided an estimate below, based on similar current technologies and studies.

To put the potential of Direct Air Capture into context, the Nature study mentioned above concluded that to eventually capture a desired 30gtCo2/yr (~ 80% of our current global emissions) would mean building 30,000 large scale DAC facilities.

This means that each of these DAC facilities (the size of football fields) would capture roughly 1 megaton of Co2 per year. The image to the left shows a model of what the startup, Carbon Engineering’s large scale facility will look like. As you can see, the stacked structure on the left is all fans. This starts to give a sense of just how much power they’ll need to operate it (side note — it’s a bummer the model doesn’t have a solar roof installation.)

While the CapShip could be a similar size (the Airlander 10 mentioned above is 100m nose to tail) let’s assume that CapShips, are going to be less efficient. And at say half the efficiency, they’d be capturing 0.5Mt/year.

If we again take Los Angeles as an example, the city’s emissions are now at ~ 23 million tons of Co2e (with plans on halving that number by 2040). That means, that if each ship could indeed capture .5Mt/year, in order to remove all of L.A.’s current annual emissions, we’d theoretically need 46 of these CapShips (23 million tons x .5Mt = 46, with 1 Megaton = 1 million tons).

Now it seems doubtful that we’d ever see that many Airships over a city, but to me, it feels realistic that maybe 6 could be put into commission, criss-crossing the city on any given day (potentially with a poster of the newest Mission Impossible movie on it, because let’s be honest, ad revenue would probably be helpful revenue.) In this scenario, those 6 CapShips could capture nearly 15% of LA’s current emissions.

The build costs are hard to estimate. For reference, a new Goodyear blimp costs $20 million – but this will take R&D, capture panels, plus a robust solar system (which would need to be thin film). With all that baked in, it would be safe to assume that each CapShip could be anywhere from $50-$100 million to build.

But the real, sustained costs come from the capture process itself, which is currently quite high. Though a 2018 study published by Joule, made news when they concluded that specifically for Carbon Engineering’s facilities, levelized costs were ~ $100/ton. And keep in mind, this estimate is inclusive of the capitol cost + Operations and Maintenance (O&M) + energy costs.

Theoretically, the CapShips sees some savings here as it includes the capture element, which is passive because it will fly through the Co2 rather than needing to bring the Co2 in with those large, power-hungry fans. And the energy it does use, is generated by solar.

But you would still need a facility on the ground to actually process the saturated panels. And the current technology requires a good amount of power as well, as it demands the filters be heated to high temperatures (212º F) to allow for the chemical reaction of releasing the Co2. So while the actual levelized cost of the CapShips could theoretically be lower, let’s still just assume that it’s $100/ton.

So that means that the cost to process nearly 15% of current Co2 emissions in Los Angeles, or 3 million tons (6/46 x 23 million tons) x $100 = $300 million/year.

Given that LA is already spending $26.2 billion on vital public transit projects over the next 10 years — it doesn’t seem that crazy to build out a project like this, that could theoretically cost ~ $345 million per year over ten years of operation (inclusive of build costs). There could also be opportunities to offset costs with a Carbon Tax or to sell back a product from the Co2 … and let’s not forget about the good ‘ole advertising opportunities.

Also keep in mind that this is a new technology, and there will surely be more efficient methods discovered in the years to come (Mosaic Materials already looks like promising new tech in this space.) Not to mention the fact that, if the 2040 LA emissions projections hold true, then the percentage that those same 6 CapShips capture will essentially double in 20 years. And that by mid-century, all our capture efforts would start to put us into negative territory.

So CapShips alone won’t get us to carbon neutral, let alone carbon negative. But it could be thought of as a piece of our overall Carbon Negative Toolkit, which is looking like something we’ll need to have at our disposal in order to to hit the IPCC 1.5º Scenario.

Next Steps

This was merely an exercise for an imagined idea, who knows if anything like this will even work. Maybe at the end of the day, a hot air balloon version makes more sense, though let’s be honest, airships are just way cooler!

But in general, I feel like climate solutions as a whole are just something more people should be playing with — there are so many smart & creative people out there, and it’s obvious we have the ability to solve this, we just need to get more people out there and doing it!

Also, just saying … but seeing as how Google’s The Team at X have already built zero emission delivery drones, high altitude internet balloons, energy kites … oh and Google’s founder Sergey Brin already has plans to build the world’s largest aircraft — it seems like they could at least tinker with this idea over an afternoon cup of coffee, right?