There was a company called Wiferion that was bringing this exact product to market. They were bought by Tesla though and nothing has since come out.

There is another company called Witricity that claims to have a product ready in 2025.

At the extremes one is, as far as our technology allows, irreplaceable as a carbon neutral fuel. That being SAF. The other other viable alternatives even today. Why are you presenting a scenario where both would be needed to be created in equal measures?

So what if they can both come from the same feedstocks? There will be a day we likely don’t need diesel in any capacity. We’ll need SAF long before that. Why would we divert the valuable carbon neutral feedstocks to something like biodiesel if our goal is carbon neutrality for both?

There is a regional chain of grocery stores in my area that have level 2 and 50Kw level 3 chargers. They give you 1 free hour of level 2 charging per day (per location, I later discovered). At 9.6k charge rate, its not a huge savings, but I almost always use it when I grocery shop and its nice to come out to the car with 5% or 8% charged added.

This is extremely disappointing. Replacing existing purchased government vehicles early is neither fiscally sound nor environmental. The only group that benefits from this is petroleum companies that stand to gain back additional fuel consumption lost to EVs.

Years ago there were few public EV chargers, and even then it was common when I used one that I was the only one there. Today there are many more public EV chargers and and multi-stall chargers, its more rare that I’m the only one charging.

It doesn’t really matter whether you’re producing biodiesel or SAF; it’s a slightly different length of carbon chain coming out of the refinery.

The difference isn’t the slight variation in chemical structure of the molecule between the two products, its the drastic difference in the applicable use case of the resulting product, and the economic incentives to produce one vs the other. These are what make the SAF and biodiesel gigantically different product with hugely different economic, climate and geopolitical implications.

No amount of B5, B20 or B100 grades of biodiesel are going to enable carbon neutral air travel where SAF can. However, alternate fuels or methods of ground transportation can offset or replace diesel or biodiesel. With today’s technology only a number of small electric prop planes (certainly no commercial jets) can operate with anything close to carbon neutrality without SAF. Commercial aviation is a reality in our world and we can choose to find carbon neutral alternatives or embrace its carbon rich nature and try to make drastic carbon cuts elsewhere. I believe the latter is much less likely than the former. Alternatively we can simply turn a blind eye to our climate and reap the consequences. I’m not ready to throw in the towel and embrace that yet.

The same problem of competing with food is there because that’s where you’re sourcing carbon and hydrogen from.

Even if a portion of input feedstocks that go into producing SAF today are food or competing with food, how are you holding the position that municipal waste, used cooking oil, and agricultural waste are sources of food? I’ve posted sources that show the alternates available and possibly upcoming that would enable more non-virgin SAF. Are you holding the position that humanity will simply never achieve anything except fossil based fuel for aviation or something else I haven’t understood of your position yet?

Further yet, what is the connection you’re making a food supply with regard to hydrogen? Are you referring to fertilizer?

First, that is a great link. I don’t follow biodiesel efforts very closely and always appreciate the data from a real world execution perspective.

That said, while the article contains a number of criticisms you’re pointing out, the article is mostly focused on biodiesel and not necessarily SAF, and even less applicability to California where the majority of North American SAF is produced. The article even called this out with the distinction that biofuels (SAF in this case) from virgin feedstocks doesn’t qualify for the Low Carbon Fuel Standards (LCFS) laws in California that make SAF economically viable. Meaning there is far lower incentive to try to produce SAF from virgin feedstocks, which I believe is your primary criticism of SAF.

“Additionally, the Producer’s Tax Credit, coupled with the California LCFS, will heighten the demand for lower carbon-intensity feedstocks like tallow, UCO, and corn oil. Under the LCFS, west-coast market demand is stronger for feedstocks that provide greater carbon-emission reductions than virgin vegetable oils like canola and soybean oil. These policies will continue to pull available global feedstocks into the California renewable diesel market, and boost U.S. import demand for feedstocks that make lower carbon-intensity biofuels that generate additional credits in the California market.”

from your provided source

The other point your article highlighted was the bottleneck to using less virgin sources was the need to increase the non-virgin sources of feedstocks. As in, the market is demanding more biofuel from non-virgin feedstock than can supplied. This is important as it goes back to the work identifying and introducing further non-virgin feedstocks that I linked in my other post on this topic here.

Food. Food oils in particular.

While certainly possible technologically, for the main efforts in North America you are incorrect on the use of food (meaning something humans can eat) for SAF.

The largest producer of SAF in the USA is in California (and partially fuels LAX airport, BTW). This operation is using waste from other processes and not food that would otherwise be eaten.

source

That is a very important question. SAF is a name for a bunch of different fuels produced from sustainable sources. I posted a larger reply to the main article that details some of the input feedstocks which answers your question here.

I’ll preface this by saying that SAF by itself isn’t a silver bullet that solves all problems with carbon use in aviation. It can, however, be an important piece of a larger solution. Additionally, even in isolation without a larger plan it has a net benefit on carbon reduction which is a win in the battle against climate change.

The basic problem is that “sustainable” aviation fuels, if based on biofuels, would substantially compete with food production.

Certainly possibly, but not absolutely.

Virgin feedstocks (the stuff needed to feed in to make SAF) would support your position because the plants grown specifically for harvest to be turned into SAF would displace food crops, or possibly support destruction of other non-agricultrual land to grow net more crops. I agree with you that both of these situations would be a net negative to SAF.

However, virgin feedstocks aren’t the only nor even most desired feedstocks for SAF. There are many ways to produce the fuels that fall into the definition of SAF. Things that we would otherwise consider waste streams can be SAF feedstocks such as the following:

source

There are other pathyways being explored too such as the waste water runoff from dairy farms and beer breweries:

“To that end, the Argonne Lab scientists look to using carbon-rich wastewater from dairy farms (and breweries, for other reasons) as feedstock for SAF production. The study author at Argonne, Taemin Kim, said that the energy savings come in two ways. “Both [dairy farms’ and breweries’] wastewater streams are rich in organics, and it is carbon-intensive to treat them using traditional wastewater treatment methods. By using our technology, we are not only treating these waste streams, but [also] making low-carbon sustainable fuel for the aviation industry.””

Source

Unless we as a global society choose to simply eliminate air travel for people and cargo, we have to accept that a better approach to energy used for air travel is needed to meet reality. SAF is an important part of that in my mind.

Yes, I’m one.

Like most things, not one thing will fix a problem. SAF is one piece that measurable makes our situation better. The fact you can possibly fly on a plane today partially with SAF is an amazing achievement and the result of lots of hard work by lots of people trying to make a positive difference.

LFP

Thank you for that.

Its odd calling LFP “new” and “a change is coming”. The first production EV to ship in the USA with an LFP was in late 2021 I think.

I would have thought this might be talking about cheaper chemistry Sodium Ion batteries, which are already on the road in small quantities in China.

I think the “swapping” may be a different use case the author is talking about. I don’t think the author was referring to an end-user executed swap to simply put in a charged battery.

This would be a service center option where a mechanic would have to take tools and removed panels and connectors to make the swap. Something done maybe only a few times, if ever, for a car during its life.

A structural battery pack is constructed to not be serviced in parts. The author calls this out with his comments on “replacing a single bad cell”. He’s right that this is a concern for structural battery packs. Here’s a Tesla structural battery pack when it was attempted to be disassembled:

There was more of that pink foam wrapping around the cells now exposed. All of that pink foam is needed for strength and its thermal properties because the battery pack is part of the structure of the vehicle carrying load forces.

Clearly replacing a bank of cells would be difficult to do if there was a cell failure, and no wear near cost effective for a consumer to have done on their car. The author is suggesting having some of THIS type of battery, but also another part of the battery in the standard hard plastic modular cases where the whole module could be removed and replaced (“swapped”)

The author is suggesting SOME of the battery be the pink foam type that is unserviceable, and SOME of the battery be behind panels in cases that a technician can swap at a service center when the module has reached the end of its life.

I had spare batteries for my smartphone for events like all-day conferences/conventions to swap batteries in the afternoon.

Sure, but how often are you going to all-day conferences. Once a year? Twice? Is it worth having the possibly 20% less battery capacity the other 363 days a year for that swapability?

Something seems missing from the description. What would make the most sense with the articles description is if there were two packs each with different chemistries. One cheap and low density, such as NA-Ion (Sodium-Ion) that could take care of 90% of EV driving needs for trips under, say, 100 miles. The second pack being a much higher density chemistry like NMC (Nickel, Manganese, Cobalt) which could add significantly more range for the same cubic cm of volume in the vehicle, but the battery would have far fewer cycles compared to other chemistries.

The idea being, beat the heck out of the Sodium Ion battery and make it easily serviceable/replaceable at the cost of range for the same volume consumed, while the NMC battery would be gently cared for and only called on in the more extreme demands of range.

If that’s what the author was trying to say, it was not clear.

This article is a bit confusing because its talking about the theoretical use cases of structural battery packs in EVs, the possible problems, and possible mitigations.

The Tesla Model Y has been using a structural battery pack for over 2 years (since 2022 model year, I think). While Hyundai/Kia may make different choices, the pros and cons from Tesla’s choices can be used as at least one path for what Hyndai/Kia want to keep or what they would want to change from Tesla’s choices.

Here’s the articles cited problems:

However, placing cells inside load-bearing components would also make them hard to replace, offsetting this practice.

In practice almost no service of the battery is done at the shop where the car is. If there is a fault anywhere in the pack, from a cell to a BMS component, the entire pack is swapped.

Most EV drivers rarely use all of their battery range; they only need it on long trips. Therefore, batteries built into load-bearing automotive components would not be needed for daily use; they could be maintained at the ideal charge level for the battery formulation and rarely used except for long trips.

This is such a strange description. This isn’t how EV batteries are used at all today, as far as I know, because it would be very inefficient in regular use. You wouldn’t want to put extra strain/stress/charge/discharge on specific cells in the battery. That would lead to unbalanced packs. Further it would be much less efficient and slower to charge the segregated pack that the article is describing. The more full a cell gets of charge, the harder/more power you need to work it to take additional charge. Also, deep discharge of cells significantly shortens their life. The author’s design description of a segregated pack would also experience much worse cold weather range reduction.

if the carmaker were to use modular battery packs, it would reduce the related cost of repairs across all of the car batteries; if they had better batteries, the need to replace them would be substantially reduced

Several automakers have tried making modular packs the way the author is describing them here. They turn out to be a bad choice because of all the extra stuff you have to do to make it flexible to accept fewer or more modules. This same thing happened to mobile phones. You used to have a removable battery, which was nice. However to make the battery removable, you had to add spring contacts, a separate tray to hold the battery, and a battery door. All of these things took space. The only time you’d ever use these, practically, would be years into the phone’s life you’d open it up to replace the battery once, maybe twice in the phone’s entire life. Manufacturers could just put a larger battery in and make it cheaper. Many phones don’t live long enough to ever kill their first battery.

The author of the article is well credentialed and has worked in the tech and automotive industry for years, so I’m very confused as to the content of this article. Its almost like it was written 3 years ago, even though it is showing a Feb 14th 2025 dateline.

there are multiple scenarios and budgets that can support these initiatives. In fact, many of the ideas I’ve proposed have already been implemented quickly in places I’ve lived:

All of those things still require dense urban environments. There’s a whole bunch of the world that doesn’t apply to that ICE vehicles rule. EV replacement of any of those ICE vehicles is a net gain for the CO2 reduction movement.

We could even argue that the carbon footprint associated with the early replacement of functioning vehicles, driven by fear of ICE vehicle restrictions, should be considered in the total cost.

That would be a valid argument if the replaced ICE vehicles were immediately going to the scrapyard, but I think you’d agree with me that isn’t what is happening with a replaced ICE vehicle. Further, I stipulated that I wasn’t advocating for people with nearly new ICE vehicles to immediately got out and buy an EV, but instead when they are planning on replacing their ICE with another ICE, and EV would be a better choice for the environment.

Here’s some data. 6.8% of new cars in the USA are EVs. That 6.8% replaced otherwise ICE vehicle purchases. I think if you’d ask most climate scientists if nearly 7% of new cars no longer running on fossil fuels they would say thats a substantial improvement.

Okay, I think I understand your position better, thank you.

The biggest flaw that I see in your approach is that nearly all of those changes require the population to decide to make the changes together. If that agreement isn’t there, the only other way to implement most of those would be with authoritarian decrees. There are places in the world where that is possible, but I wouldn’t call that a recommended solution to apply. A number of your suggestions would require additional funding too. That has to come from somewhere and the origin of that funding is also likely a contentious debate. Without everyone agreeing on the need for these things, few, if any will be implemented and that means more CO2 being emitted.

For example, ADEME (a French organization) estimates that: “A reduction in average meat consumption of 10 grams per day per person leads to a decrease of approximately 200 square meters in land footprint, as well as a 5.2% reduction in total greenhouse gas emissions.” (Source).

This is a good one that can be done at an individual level. It requires no agreement other than the person making the choice for themselves. This definitely resonates well on the “punk” of solar punk.

The meat reduction is the closest thing EVs for your cited solutions. Its an individual choice on the part of the consumer that can have the intended positive impact. That makes it extremely realistic as far as a component on the path to a full solution.

First, I see your post before mine was downvoted. That wasn’t me. I share a different opinion than yours, but your opinion is equally valid in this discussion. I see nothing in your post which is insulting or takes away from the discussion to deserve a downvote.

It seems way more sensible to act on what we know works now rather than hoping for future discoveries to save us.

So I don’t put words in your mouth, what do we “know works now” in your opinion that could be implemented in a faster time frame than EVs that would have a positive impact on the reduction of CO2?

You should also take into account for your analysis that sustaining a world with EVs as a drop-in replacement for ICE vehicles would require extracting significantly more rare earth metals than we currently do, requiring new mines that are known to impact biodiversity through significant earth and water pollution (not all environmental impacts are CO2-based).

Does this analysis work under the assumption that technology remains static and unchanging? Does it account for the efforts to decouple from exotic materials? We’ve already seen two very large steps that are in place commercially in EV consumer products, so this isn’t simply theoretical:

• Cobalt and Nickel used to be required for any usefully sized EV battery. Many current EVs now ship with zero Cobalt or Nickel in their batteries with the wide adoption of LFP (Lithium Iron Phosphate).
• Lithium is another element that is pointed out as a downside for EVs because the environmental impacts from its extraction from nature. However, there are EVs in China on roads with zero lithium and instead use Sodium based batteries.

Considering how short a time it has taken industry to not only identify cleaner alternatives and get them into use, it suggests that an assumption in analysis that EV technology of one day projected over an infinite future may be flawed logic.

Full disclosure, I’m a EV owner/driver. Its not going to surprise you for me to say EVs are not a scam.

The most obvious and easy to understand part of problem solving is to define the desired end goal. In that picture for what many see as the solar punk vision, most people see few if any cars. So the natural conclusion would be to say that EVs are not part of the solution.

However, what far too many people ignore when problem solving is the transitional period between the start toward the goal and reaching it. For most solarpunk visions this will require decades of changes with massive impacts all around the world. This is why I believe EVs are not a scam. They are an important part of the transition.

Most “EVs are a scam” folks immediately point to public transportation as the reason why EVs are unnecessary. In developed urban centers this is true! While New Yorker may curse the MTA when waiting on a delayed train or a Dubliner waiting for the Tram, they cannot deny that they are able to perform nearly all functions of daily life with intercity trains, metro rail, and buses. However, when we look at the land where people live there are vast vast regions that are non-urban. Most of the people that live in those regions have limited access to public transportation. If cars disappeared overnight, it would be catastrophic for those populations and all of us that rely on them for portions of our food chain (as an example). The very closest bus stop to my house is 5.4 miles away, and only runs service for 8 months out of the year. The next closest one with daily service year round is 7.3 miles away, and that one has only two stops in the morning and two in the evening. Public transportation simply doesn’t serve my area at this time.

So realistically even if we had the money and the mandate right now (and we don’t) to throw our efforts behind wider access to public transportation, it would mean accepting many decades more of burning carbon based fuels in cars and trucks. Consumers will replace their vehicles during that time, and if and EV can be a choice that is less carbon (or no carbon at all!) being emitted into our atmosphere for its operation that is only a good thing.

Replacing an ICE car with an EV actually (for those that don’t have public transit options) moves the needle in the positive direction if the other choice is yet another ICE car.

Further, specifically for solar punk visions, the “punk” part for my understanding is a sense of independence or self reliance. A “do it yourself” or “don’t simple accept what is force upon you”. So an EV actually fits that well. That doesn’t mean a rejection of public transportation, but it does recognize that there’s more than one way to do something and sometimes that way is doing it yourself.

In my mind, EVs are a critical part of the transition to a solar punk future. We don’t get the luxury of skipping right to the end goal. We have to go through the long, messy, and less efficient transition. EVs are an important part of that.