This is excellent. So much of agricultural policy in the US is set around subsidies to farmers, most of which goes to a handful of huge corporations. This is not the only corruption of climate policy by big ag. See subsidies for Tyson's "low carbon beef", for example.

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Excellent post. Biofuels, like switching to diesel, is just another example of what happens when you ignore evidence. Unlike the diesel disaster, however, the biofuels disaster continues to harm the environment and humanity, heavily subsidised by governments everywhere.

Sadly too many scientists and commentators give a free pass to schemes that supposedly reduce emissions.

By the way the same process is underway with those advocating that we can eliminate fossil fuels with solar, wind and batteries. This is clearly absurd if you look at the numbers, but too many people ignore the real world data on these technologies until they are well entrenched and have done great harm. In the case of the solar/wind/battery brigade the harm comes from driving up electricity prices so much that electrification is delayed and public support for trying to reach net zero weakens.

Meanwhile nuclear power remains largely unexploited because it had been regulated so heavily it is commercially unviable.

Our current regulations value a life lost to radioactivity AT LEAST 100 times more than a life lost to air pollution from burning fossil fuels or biofuels.

This regulatory mismatch has accelerated climate change and kills millions of people every year.

This is inexcusable but I have yet to see this challenged by anyone who cares about the environment.

Why the silence? Why no advocacy for regulatory parity?

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I grew up in NE Iowa on a family farm. It was a good but hard life in the 60’s and 70’s and seemed virtuous and noble. Given the present thinking that is evolving around climate change it is definitely hard to think of this valuable farmland being used inefficiently for feeding animals or producing ethanol. It will be hard to change the thinking, inertia and politics around the way farming has evolved but there are signs of hope. It is not uncommon to see wind turbines and corn fields using the same land. Iowa produces the most renewable energy per unit of area of any state, https://insideclimatenews.org/news/16032023/inside-clean-energy-renewable-wind-iowa/ . Imagine what would be possible if it was dual use with solar! Educating people and showing them the reality and economics is a start but the information will have to come from a trusted source and right now because of politics, the “trusted sources” are spewing misinformation about climate change and renewables. I’m afraid significant change may require generational shifts that only happens with time.

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Insights from Paul Martin, energy expert/farmer:

Anybody who can use an EV instead, WILL DO SO, because biofuels made properly will be so expensive that they will be the tool of last resort, not something anybody would choose voluntarily.

The best review study he’s seen puts corn ethanol at about a 50% reduction in GHG emissions relative to the fossil gasoline it displaces. Proper regulatory tools- carbon taxes and emission bans- could decarbonize agriculture and corn ethanol production itself. Big job, including

- Replace fossil diesel for farm equipment.

- Minimize fossil derived ammonia as fertilizer, or replace via something like what Pivot Bio is doing with microbes produced by their fermentation production process to deliver nitrogen

- Replace fossil gas for corn plant stills and dehydrators.

- Use corn stover instead of corn to make biofuel.

- Generate char and return that to the soils, and make fuel of the energy left over.


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Good article.

My complaint is the mixing up of units of power (eg MW) and energy (MWh). In particular, in many contexts you're clearly referring to power output but give numbers as MWh (eg solar output X MWh per hectare). The most logical assumption would be that you've intended X MW per hectare, however at one point you refer to the (power) unit of MWh/year and so perhaps that's what it's intended to mean?

Perhaps it's sufficiently common usage in power generation to say MWh when you mean MWh/year (or MW) but to a layperson like me it's pretty confusing.

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But have you not overlooked the fact that if no fossil fuels were available today then it would not be possible to extract and make the solar panels, the batteries, and wires for the electricity distribution in the first place. However, the biofuel industry always has the option of switching to biofuels for their production.

You have also overlooked the use of biomass being converted to hydrogen - which potentially could be used either as a drop in substitute for fossil fuels or for further sythesis to other hydrocarbon fuels. Using the existing vehicle fleet with fossil fuel substitutes would avoid the need for China to make a whole lot more electric cars and use up resources. Biofuels (ie carbon (or for that matter hydrogen) from biomass processing) is always going to be much more sustainable than resources mined from the earth in the long run! There could be a hint of bias in your analysis!

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What about biodiesel? I raise this because although electric cars can replace gas, or ethanol fuelled cars, I think farm and heavy machinery used in mines will be much harder to run on batteries. That is because the charging time will be a major hurdle. Farmers have to harvest their crops when they are ripe, and before weather destroys them so they run their harvesters all day, and sometimes all night until the harvest is in. Of course, they could employ more machines to make up for lost time, or extra batteries for quick changes, but that would mean extra capital and increased costs. Similarly, all heavy-duty machinery is high capital cost and is run 24/7 whenever possible to be economic.

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Great article. The biofuel industry has always seemed a wasteful way to get fuel, climate change concerns aside even. If they would just shift some of those crops to cattle feed they could lessen another harmful use of land and resources---using vast amounts of CA and AZ desert lands and CO River water for cattle crops. Honestly I'm not crazy about going big on solar farms unless there is a non-storage requiring use for the electricity locally.

It's going to take some time to switch to an EV centric system. There is not nearly enough lithium on the planet to do that currently nor can most folks afford them so we will have to wait for solid state batteries with cheaper, more plentiful components.

Nuclear seems to me the best solution, especially if modular designs are used and can be built in shuttered coal plant areas that have existing grid infrastructure. And as and you mention the grid will have to be built out to a higher capacity. But all these solutions have a long time line to get in place so we need to start now.

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You should check your analysis again: "Solar PV needs about 20 m2 to generate one MWh of electricity per year". (1 MW-hr/yr) x (1 yr/365 dy) x (1dy/24 hr) = 0.11 kW

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Soy to diesel ("bio", "renewable," etc.,) is even lower/worse in gallons/acre. But the "bio-refineries" do co-produce meal and hulls and maybe tri-glycerides.

Now I read that fuel wood pellet production is expanding again. The proponents of all of these bio-fuels talk about "waste" to whatever, but when you dig in you see that 90% of the feedstock is a crop of some kind.

A couple things could help to make solar farm development more acceptable to nearby residents. They should get a big break on electricity rates when the sun is shining, vs. all the juice being spoken for through a PPA and RECs for some company from Seattle. Work with the locals to "electrify everything." The tech of choice for tractors is swappable batteries. For heat in the midwest, ground source heat pumps have been the bomb, but maybe if rates are low enough you just toast up a pile of bricks or a tank of HW when the sun is shining.

Much of the ugly fencing can be eliminated if the building code officials and insurance companies allow it, over-ruling yet another overly safteyist American regulation. Then there are wonderful bifacial vertical solar mounting systems which allow tractor use and can't reflect glare up to any sensitive types. https://next2sun.com/en/testimonials/agripv-systems/

Another thing the USA is falling behind on while we try to protect incumbent industries who co-opt their workers into claiming they can't do a single thing besides what they've been doing.

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Great article Hannah! Also note that ethanol-petrol blends have lower fuel efficiency and higher maintenance costs in some engines. This is another instance of consumer green-washing. 'Bio-fuel' really should be called 'farmed-fuel' but possibly that's not pejorative enough. Any other suggestions?

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As always, some interesting calculations, Hannah. You had me at hello when it comes to critiquing subsidized biofuel, but this is still a good quantitative exercise.

When discussing alternatives for rural land use, please keep in mind there is a profound human dimension that rational mathematical calculations cannot capture. A world designed purely by engineers would be a very dismal place indeed. This falls outside the focus of your Substack, so it is not really meant as a criticism. Before we all get intoxicated by the calculations, though, it is worth considering less analytical, more human points of view. Literature and film is a great place for that, and directly relevant to this post is Carla Simón's beautiful film from last year, Alcarràs. In questions of land use, concerns of family and sense of place are no less important than extracting energy to fuel our bodies and our machines.


And speaking of intoxication, it is such a shame that we pay farmers to sell their corn to distilleries connected to the liquid fuel industry while taxing heavily an alternative use of that corn, with the mashed, fermented, and distilled product directed instead to charred oak barrels. I'd prefer a world of no subsidies and no excise taxes, but if we have to do both, tax the biofuels and subsidize the bourbon.

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Great analysis! That being said, it seems to me like plants are the best direct air capture technology we are likely to get for a while. What prospects do you see for things like biochar and biomass burial as ways to go carbon negative once the rest of the economy gets closer to carbon neutral?

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It would not power airplanes 3X over.

Biofuels may be our only way to keep flying, and much of the "make it worse" argument goes away if we decarbonize farming...which we must do, anyway, and I think, can.

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Two words: Iowa Caucuses.


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Great post. I imagine that burning wood pellets for electricity generation is analogous.

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