Open letter to Vinod Khosla

Dear Mr. Khosla,

I hope this letter finds you well.  I have no doubt it finds you wealthy.

You appear to have taken a position in re:  ethanol, claiming that it will provide "the solution" to our petroleum woes.  This has been challenged.  Robert Rapier has already done a nice job of debunking the claims you've made.  I'm just a pseudonymous analyst (and an amateur at that), but I hope that you'd explain the details behind what you've chosen to acknowledge versus what you've chosen to disregard.

The implications of what you've chosen to disregard are considerable.  Your position (please correct me if I'm wrong, I cannot view your video presentation) appears to be this:

• Ethanol production will shortly displace petroleum, so
• There is no need to take immediate corrective measures.  E.g, we needn't abandon our use of three-ton SUV's burning liquid fuels at 15% tank-to-wheels efficiency.
• Global warming isn't a problem.  We can take all the carbon we grab and put it back in the atmosphere instead of crafting a system around carbon sequestration.

I've done the math, and I can't see how you justify this position.

The facts about ethanol vs. oil

For background, the USA uses approximately 20 million barrels of crude oil per day, 7.3 billion barrels per year.  At ~6.1 gigajoules of energy per barrel, that's roughly 44 exajoules (42 quadrillion BTU, or quads) per year.

That's a whale of a lot of energy.  Even the fraction used for motor fuel is enormous.  Gasoline consumption amounts to roughly 140 billion gallons (17.6 quads @ 126,000 BTU/gallon) per year.  Diesel fuel (about 2.7 mmbbl/day out of 4 mmbbl/day of total "distillate" consumption) comes to roughly another 5.8 quads at the pump.  If we want to replace just our imported petroleum, we have to replace all of that and more.

I'm wondering how you expect ethanol to do this.  You appear to acknowledge that grain ethanol (from corn, wheat, etc.) is a dead end.  That's good.  What isn't good is your claim that ethanol from cellulose is going to be The Solution.  That's only good if it's true, and as far as I can tell it's a long way from that.

Let's forget a few inconvenient details for the moment:

• Enzymes for hydrolysis of cellulose to sugar are still quite expensive.
• There are no commercial-scale cellulosic ethanol plants anywhere in the world.
• Even if they were built, the transport of the (bulky, heavy) cellulose feedstock to those plants presents considerable difficulties and energy costs.

For the moment, let's just look at what we could make from what we've got here in the USA.

The estimated biomass available from sources not currently used is 1.3 billion tons per year.  Biomass does not have as much energy per ton as hydrocarbons (around 16 GJ/ton), so the total energy available from this is on the order of 21 EJ or 20 quads.  This is only about 45% of the energy the USA obtains from oil each year.  But it gets worse.

Conversion from biomass to liquid fuel is lossy.  Iogen claims a yield of 330 liters (87 gallons) of ethanol per ton from their enzymatic process.  This is slightly under 50% energy efficiency; the 1.3 billion tons would produce 113 billion gallons (~10 quads) of ethanol, with the energy of about 70 billion gallons of gasoline.  Conclusion:  enzymatic ethanol from unused or waste biomass not only cannot replace petroleum, it can only replace about half of gasoline.

Other processes promise somewhat higher efficiency.  Syntec's gasification process is claimed to yield 114 gallons of ethanol per ton (presumably of biomass; the highest theoretical yield would require more energetic inputs, like scrap rubber and plastic... or coal).  This is about 60% efficiency, roughly 30% better than Iogen.  But another 30% only gets up to replacing 65% of gasoline (and no diesel, no jet fuel, no heating oil, no LPG, and nothing for petrochemicals, coal or natural gas).

The end of the line

And once you've used all your 1.3 billion tons, that's it.  You're out of feedstock; you can't get any more out of the inputs without:

1. Building a new system which is able to use the inputs with higher efficiency, and
2. Scrapping part or all of the previous system (which may be brand-new), losing the investment in it.

It may be even worse than that.  If the feedstocks are locked up by long-term contracts, it may be legally impossible to convert even if the consequences of failure are disastrous.  A set of entities which have cornered the feedstock market may even scare off the venture capital necessary to create the more-efficient alternatives.  I'm sure you understand this very well.

But while that's the end of the line, it's far from the end of the issues.

Carbon dioxide and the climate

Climate change is the elephant in the room of all these discussions.  As atmospheric CO₂ increases, the climate warms.  This has knock-on effects all down the line, including a reduction of plant productivity due to heat and water stress.

Recall that 1.3 billion ton number?  That's only a historical projection based on what the climate used to be.  The steep rise in forest fires in the Western USA may very well indicate that we're not going to be able to harvest that much in the future; a lot of that biomass is going to burn, and hotter, drier conditions mean that it will grow back more slowly if at all.

This applies across the board.  Tallgrass crops can burn too (burning is how prairie prevents the incursion of trees).  Hay fields burn all too well (see Texas and Oklahoma this year alone).  Ripe grain fields can burn, and the productivity of all of these is reduced by hotter weather.  We may not have 1.3 billion tons to work with; if we can't control warming, it may be half that.

What's the relevance to your ethanol schemes?  It's the fact that we'd still need to get the following from fossil fuels:

1. At least 35% of current gasoline consumption.
2. 100% of current diesel and jet fuel consumption.
3. 100% of current heating oil and LPG consumption.
4. 100% of current petrochemical consumption.
5. 100% of demand currently served by coal and natural gas.

All of those would still be pumping CO₂ into the atmosphere.  Your proposal does involve capturing some carbon from the atmosphere, but it all goes right back; you have nothing to sequester it.  If this problem is not to get worse, all atmospheric greenhouse gas (GHG) inputs have to be at least offset by removals.

Suspicion of motives

It's very hard to believe that you don't know all of this already.  You've got net worth of over a billion dollars; you have access to the best expert advice in the world, and you have certainly used it before to make your current fortune.  Yet the reasons you've stated for supporting ethanol don't match up with the most cursory stab at due dilligence.

It's easy to come up with darker reasons for your position, each worse than the last:

• You're so enamored of the concept you didn't bother to get advice which went below business and politics down to the fundamentals.
• You liked the idea so much you didn't bother to get expert advice.
• You know better now, but you're so deeply invested in the concept you can't stand to give up until bigger fools or the public buy you out.
• You intend to be the one who corners the market on biomass feedstocks, and make a killing when scarcity drives the prices through the roof.

All of these are reasons not to listen to you.  The last two are excellent reasons to actively fight you.  Maybe you aren't familiar with being on the wrong side of a grassroots battle, but enough people writing letters, volunteering to work for candidates who oppose you, outing your support as astroturf campaigns and voting to stop your plants can throw a monkey wrench into the smoothest business plan.

My advice, offered for nothing:  don't go there.  Either there is something very important that you don't know, or something equally important that you aren't telling.  Straighten this out, and the rest will follow.

Where this all goes

I'm sure all of my numbers are good to within 10% or so (corrections accepted).  Unless I have screwed something up by at least a factor of three, ethanol can't get us off imported oil (let alone all oil) as long as it depends upon biomass.  (Making it from coal is another matter... but mind the environment and don't go there either.)  If this problem has a solution, it's not present inside the current model; to see it, you have to step outside the box.

This is my forté.

All variants of your scheme fail because of their common element:  they propose, and even demand, reliance on the internal combustion engine.  This is essential if we aren't going to replace the vehicle fleet.  But why worry about this?  The fleet wears out and is replaced regularly as a matter of course; we didn't ban cars without catalytic converters, but they're almost completely gone nonetheless.

Where we are now

The typical light vehicle has a gasoline engine coupled to an automatic transmission using a hydraulic torque converter.  The average thermal efficiency of these is abysmal; out of the energy pumped into the tank, perhaps 15% gets to the wheels.  The vast majority of these losses are in the engine itself.  Heavy-duty diesels are better, getting up to about 45% for medium-speed truck engines.

What this means is that our 17.6 quads/year of gasoline only put about 2.6 quads of energy out to wheels.  Our ~40 billion gallons/year of diesel comes to about 5.6 quads, of which perhaps 2.5 gets to wheels.  The total actually going to useful work is about 5.1 quads.  That's only about 25% of our prospective supply of energy from biomass.  This means that the problem IS solvable, in principle.  It just can't be solved with ethanol in combustion engines.

Let me make this clear:  ethanol is not a solution; it is a niche player at best.  It cannot be a mainstay, and any program relying on it to perpetuate the status quo ante is doomed.

Where we should go

Right now you're probably asking, "If ethanol won't work, then what?"  While it's logically possible for there to be no solution (e.g. the Halting Problem), you can see that I'm not going to tell you that.  Nope, there are better solutions out there.  People are putting some of these solutions into practice themselves, because they are tired of waiting for business and government to do it.  So I'll list a few for you.

Plug-in hybrid electric vehicles (PHEV's)

This is the #1 best option for petroleum independence, and eventual fossil independence.  The PHEV is a hybrid with a bigger battery pack, a charger and a wall cord.  As little as 20 miles of all-electric range would handle the average daily commute and cover 30-40% of all driving; a PHEV60 with 60 miles of all-electric range would cover as much as 74% of all driving.  Combined with roughly 1/3 less inherent fuel consumption from hybrid economy, these cars could cut fuel demand by 50-60% with a PHEV20 to a whopping 80+% with a PHEV60.

Note that it's possible to convert a PHEV20 to a PHEV60 just by adding more or updated batteries.  Note further that the daily electric demand of these cars, perhaps 15 kWh per day for a PHEV60 driven its full range, is still small enough to carry over standard house wiring at 110 volts for an overnight charge (10 hours).  A 220 volt outlet would speed this drastically.

This would convert light-vehicle energy consumption from 17.6 quads of fuel to about 3.5 quads of fuel and perhaps another 2.3 quads of electricity (about 76 GW average).  The US consumes about 13.7 quads of electricity (around 4000 billion kWH, ~450 GW average) per year; we'd notice a 17% increase, but if it was scheduled at night, during windy periods, and when generation is otherwise in surplus the grid managers would love it.

Supertrucks

The other half of the ground transport problem (that you don't touch) is heavy trucks.  These are almost exclusively diesel-powered, accounting for that 5.6 quads of fuel.  They're also a tougher nut to crack, because they run longer distances than light vehicles and could not get as much benefit out of conventional batteries.

There are ways to address this, too:

• Conventional solutions, like moving more freight from trucks to rail.
• Less conventional solutions, like making the truck itself rail-capable as a dual-mode vehicle.  (Overhead wires for power make this a fuel-free possibility.)
• Unconventional batteries, such as zinc-air fuel cells (roughly 50% throughput efficiency).
• Even less conventional possibilities, like direct-carbon fuel cells (up to 80% efficient).

The last three could pretty much eliminate petroleum requirements for long-haul trucking.  The DCFC by itself could potentially replace 5.6 quads of diesel with 3.6 quads of carbon.  If we harvested 20 quads of biomass and converted it to charcoal at 50% energy efficiency (easily done with low-tech equipment), we'd be able to run the trucks and still have 6.4 quads left over.  Even zinc-air fuel cells could manage the job, either chemically (carbon reduction) or with about 6.5 quads of electricity to regenerate the zinc metal from zinc oxide.

This also ignores potential for more-efficient trucks.  Wal-Mart is aiming to double the economy of its fleet from 6.5 MPG to 13 MPG.  Cutting the problem in half makes it even easier.

Dealing with the remainder

Getting the USA completely off fossil fuels, or just imported petroleum, is a huge task.  Slashing some of the sub-tasks, like ground transport, down to size is an essential part but not the whole job.  For instance, even a full conversion to PHEV60's would leave perhaps 20% of demand for liquid fuel.  That's about 28 billion gallons of gasoline equivalent (GGE) per year, or about 135 million metric tons of ethanol.  As luck would have it, the process of producing charcoal for DCFC's also produces an off-gas which can be burned, fermented or otherwise processed into product.  Roughly 10% of the total biomass (130 million out of 1.3 billion tons) would be carbon in the off-gas.  Two companies are pushing processes for production of ethanol from syngas:

• BRI Energy, which ferments syngas to ethanol using Clostridium.
• Syntec Biofuels, which uses a catalytic process to make ethanol.

Ethanol is 24/46^ths carbon by weight, or a hair more than half.  If half of the carbon in the off-gas could be converted to ethanol, that would be 130 million tons.  That might be a little short of the mark (especially given the difference between short and metric tons), but it's within striking distance of 100%.  A plant which uses algae to capture and recycle the unused carbon could boost this figure considerably, creating a surplus for many other uses.

These possibilities are far less developed than ethanol from grain and cellulose, but they actually have the potential to eliminate petroleum dependence.  They also have great possibilities for cutting atmospheric GHG's (for instance, the carbon from stationary DCFC's could be sequestered relatively easily... or recycled via algae).  Taken together, these possibilities make the three-sided problem of fossil-fuel dependence, oil imports and climate change look manageable.

What you could be doing

You're both wealthy and influential.  The first thing you should do is dump your positions in ethanol ventures and then state loudly why you did so.  Maybe you can help get the "flex-fuel" gas-guzzler loophole closed, just by making it obvious that you changed your mind and why.

You might also do one or several of the following:

• Help get some electric vehicles to market.  The Tango just needs money for testing and certification; you might parlay that into an exclusive dealer territory.  That position might be worth a ton of cash.
• Put the push on for PHEV's.  A little influence could get the rules written for emissions certification and the other tedious but essential details needed to get them to market.
• Rules are cheap (because pols are cheap), and you need product to capitalize on them.  Maybe you could help get Firefly Energy's carbon-foam batteries to market (classic lead-acid chemistry, radically improved weight and lifespan) while persuading Suzuki or Kia to build a hybrid car with space in the floor pan for 60 miles' worth of juice.  It would be a big bet but success would pay off like mad and be greener than anything you're doing today.
• Maybe buy a regional trucking company and some abandoned rail rights-of-way, and go the BladeRunner route?  If your lobbyists could get rail electrification hardware exempted from local property taxes you could promote a rapid shift from diesel to all-electric locomotives.
• Try to get direct-carbon fuel cells to market.
• Or, for something even more different, something in solar-thermal electricity to help feed those PHEV's and/or make air conditioning without having to use fuel, split atoms or erect wind turbines.  This group at MIT looks to have something that might be commercialized quickly.

In my less than humble opinion, the powers-that-be are promoting ethanol because it serves up subsidies to various interests while not threatening the status quo (oil companies).  If you can make an end-run around those interests, you could improve the environment, the economy and the prospects of the average American while making a huge pile of money.  Isn't that better than just being a shill for GM, the corn farmers and ADM?

Here's to your change of heart.

Update:  "Petajoules" corrected to "exajoules".

Labels: ethanol, ethanol lobby, ethanol mirage, open letter

  ¶ 7/30/2006 11:37:00 PM 21 comments

 

Ethanol Mirage II

Continuing previous thoughts, I decided that it would be a good thing if someone analyzed the merits of converting corn to ethanol vs. burning it directly for heat.

The heating value of shelled corn has several different values published on-line; my first two results were 314,000 BTU/bushel and 381,000 BTU/bushel.  (Unfortunately, the graph presented in the latter is not easily examined to determine if the two calculations are actually using very similar figures and the latter is merely a character-swapped typo.)  Assuming the lower figure is relatively safe (favors the status quo), so here goes.

Converting corn to ethanol at a rate of 2.66 gallons per bushel and using 33,000 BTU/gal of gas for distillation yields 2.66 gallons (224,000 BTU) of ethanol, at a cost of 87780 BTU of natural gas.

Burning shelled corn (314,000 BTU/bu) at an efficiency of 75% yields 235500 BTU of heat at zero cost in natural gas.  The natural gas freed up (87,780 BTU not used in distillation + 235500 BTU not used for heat) totals 323,280 BTU/bushel, or 32% more than the heating value of the ethanol the corn would otherwise produce.  The first 235500 BTU of natural gas could be used to power NGV's, and the rest would be surplus over the ethanol scenario.  (This comparison would be far more lopsided in favor of burning corn if the 381,000 BTU/bushel figure was used.)

Conclusion:  Not considering other value-added products, it is energetically more efficient to burn shelled corn for heating fuel and use natural gas for motor fuel than it is to use the corn and gas to make ethanol for motor fuel.

UPDATE 2005-Sep-08:  temposter offers the figure of 392,000 BTU/bushel (citing an Ontario source) in the comments.  Given that maize is a natural product and the fuel value is likely to vary based on oil content (which in turn depends on the exact strain and growing conditions), the value of 381,000 BTU/bu seems realistic.  At the 381,000 BTU value, each bushel burned for heat would produce 285,750 BTU of useful heat and displace 373,530 BTU of natural gas or LPG.  The ethanol which could have been produced from the maize would have produced 220,400 BTU at most, the net benefit from burning the corn as heating fuel is at least 153,000 BTU/bushel.

Labels: ethanol, ethanol mirage

  ¶ 9/05/2005 02:18:00 AM 10 comments

 

The ethanol mirage

Over on Winds of Change (and probably many other places besides), some people are promoting increased ethanol production as a response to refinery outages on the Gulf coast.

This is not merely a false solution; it would be one of the worst things we could do.  We can conserve gasoline and import more, but we cannot replace the fuels which would go to the distilleries.  Following the mirage of ethanol will just lead us further into the desert, where we shall die of thirst.

Ethanol is no solution

If corn equal to 20% of the 2004 harvest cannot be shipped because the Mississippi ports are closed, the surplus would be 2.36 billion bushels.  At a conversion rate of 2.66 gal/bu, the total ethanol production would be 6.28 billion gallons, with energy equivalent to about 3.77 billion gallons of gasoline.  The US burns about 134 billion gallons of gasoline per year; that extra ethanol would amount to a mere 2.8%, when our shortage is 10%.  That is assuming the ethanol could be produced, which it probably cannot.

We could save 10% or more by slowing down to 60 MPH on the freeways and removing gas-guzzling vehicles from the roads.  (The people who own Hummers and Navigators can afford to rent something for the duration.)  We can import gasoline from Europe, and we are doing so.

Ethanol is a problem

What we cannot do is replace the fuel needed to distill more ethanol.  (We may not even be able to afford the fuel to distill what we're using.)

It takes around 33,000 BTU of fuel to distill a gallon of ethanol (which yields a mere 84,200 BTU/gallon [1]).  Each gallon of ethanol requires about 33 cubic feet of natural gas (or the equivalent in LPG) to distill it.  This is fuel which becomes unavailable to heat homes.  The hypothetical 6.28 billion gallons of ethanol would require 207 trillion BTU of natural gas.  The average home which heats with natural gas uses ~50 million BTU per season; the extra gas usage would otherwise be able to heat 4.14 million homes.

At last count, Katrina damaged wells and production platforms in the Gulf and "shut in" gas production of 7.2 billion cubic feet per day.  Running 20% of the US corn crop through distilleries would consume gas equivalent to another 30 days of this missing production.  Using ethanol just makes a bad situation worse.

Natural gas prices have shot up to $15 per million BTU; home-heating costs are going to run to record highs this winter.  The tax subsidy of ethanol distilleries uses the taxpayer's own money to increase the cost of keeping themselves warm.  The public interest would be best served by cutting off natural gas and LPG supplies to all distilleries immediately.  Let them burn straw or stalks.

It's time to see the ethanol lobby for what it is:  leeches sucking the life's blood from the nation's taxpayers, waving flags while selling the public down the river.  If we need to dispose of 2 billion bushels of corn, let's take a hint from the corn stove sellers and use it for heat straight out of the sacks.  The people who demand we use precious heating fuel to help line their pockets should be seen for what they are:  traitors.

Thaw a family, shoot a distiller.

Footnotes:
[1]  The heat of combustion of ethanol is 12,780 BTU/lbm, and 6.588 pounds of ethanol per gallon; the heat value is thus 84,200 BTU/gallon. (back)

Labels: ethanol, ethanol mirage, false firemen

  ¶ 9/04/2005 02:27:00 PM 2 comments

 

THERE's a surprise

Researchers (including neither of the usual suspects, Pimentel and Patzek) have concluded that fuel ethanol is not worth the impacts of producing more of it, in either the United States or Brazil (!).  Article:  Physorg.

They produce an estimate of the energy payback from ethanol in the USA in the expected range:  about a 10% gain over the inputs.  This isn't anything like the return required to be worthwhile.

If we are really, really lucky, sanity just might prevail in the House-Senate conference committee handling the energy bill, and they'll get rid of all the ethanol subsidies and mandates.  And maybe monkeys will fly out of my butt.

Labels: ethanol, ethanol mirage

  ¶ 7/01/2005 06:00:00 PM 1 comments