A pragmatic view of cellulosic biofuels or why VC Khosla is very wrong

So VC Vinod Khosla is not happy with with my recent attack on his (willful) ignorance, “VC Khosla blows his credibility dissing plug-ins.” Grist has given the billionaire a platform to defend himself, but he just spouts even more nonsense in the bizarrely titled post, “Pragmatists v. environmentalists, part I”:

I have been accused of dissing hybrids. I was mostly discussing Prius-type parallel hybrids and all the support they get, when one can get the same carbon reduction by buying a cheaper, similar-sized and -featured car and buying $10 worth of carbon credits. I was objecting to greenwashing (powered by a large marketing machine) that suggests hybrids can solve our problems….

Corn ethanol, which has been heavily maligned in the mainstream media, reduces carbon emissions (on a per-mile-driven basis) by almost the same amount as today’s typical hybrid….

The Prius is the corn ethanol of hybrid cars….

Seriously! This is like one of those newspaper puzzles: Can you spot all the errors?

1. Anyone who thinks buying offsets and a Prius-sized non-hybrid is equal from a carbon perspective to buying a Prius has no clue about climate, offsets or carbon. Offsets are so transparently dubious, I made them a separate category on Climate Progress. Burning petroleum and releasing carbon dioxide into the atmosphere where much of it will last for centuries cannot be undone by, say, planting some trees or buying some cheap RECs, which are probably the most popular U.S. offsets.

2. The Prius is in fact a parallel-series hybrid, with lots of other intelligent design features absent from most other hybrids (see this Scientific American article), which makes it easily the most fuel-efficient no-compromise affordable hybrid ever built. Easily. And it will pay for itself in fuel savings at current gas prices (with the carbon savings for free), something you won’t be able to say about cellulosic ethanol for a long time.

3. Nobody “suggests hybrids can solve our problem” — Vinod, please provide even two links to support this absurd straw man. But they are a key part of the solution — as I will discuss in a subsequent post. Indeed, nobody I have ever met (other than maybe Vinod) suggests cellulosic ethanol can solve our problems without either hybrids or more likely plug ins (and I was a major advocate and funder of cellulosic ethanol long before Vinod jumped on the bandwagon, pushed the driver off, and tried to take over the reins — Vinod has the fanaticism typical of the newly converted).

4. “Corn ethanol, which has been heavily maligned in the mainstream media” — actually corn ethanol has been heavily maligned in the scientific and policy literature. Why? Its benefits are small if not nonexistent, whereas its drawbacks are large, as I explain at length in this article. Indeed, it now appears that corn ethanol is actually driving up tropical deforestation (!) and it may even increase total greenhouse gas emissions, as one recent scientific analysis argues. I think the most defensible statement one can make today is that, most corn ethanol probably provides no net climate benefit compared to gasoline. And if corn ethanol once had a role accelerating the transition to cellulosic ethanol, thanks to recent energy legislation it has simply become Frankenstein’s monster.

5. “Corn ethanol … reduces carbon emissions (on a per-mile-driven basis) by almost the same amount as today’s typical hybrid.” No. As I’ve said, most corn ethanol probably has no net carbon emissions reductions, if all of its impacts were fully accounted for. And don’t let Khosla’s clever wording — “today’s typical hybrid” — confuse the issue:. The Prius is not a typical hybrid. It is the best hybrid by far, and it cuts carbon emissions 50% compared to a comparably-sized non-hybrid (which corn ethanol does not come close to even under incomplete life-cycle analyses). Yes “today’s typical hybrid” probably only cuts emissions 25%, but that’s because a) it isn’t as well-designed as the Prius and b) a number of manufacturers used some or all of the efficiency gains to increase acceleration (you know who you are, Honda). That is hardly justification for dissing the Prius, as Khosla does (“it is no different than Gucci bags”). Quite the reverse. The Prius should be praised and the Accord V6 “muscle hybrid” condemned. But of course there’s no need to do that since the marketplace has spoken: The Prius is the best- and fastest-selling hybrid (by far) whereas Honda discontinued the Accord V6 because of poor sales. Hmm, I never realized that Gucci made the best- and fastest-selling bags in the world….

5. Corn ethanol is the Hummer of alternative fuels. ‘Nuff said.

6. “Pragmatists v. environmentalists.” As if. Khosla is no pragmatist. And I am not now nor have I ever been an environmentalist. Energy pragmatists like me are happy Khosla is dropping big bucks on cellulosic ethanol, but are far more sober about its potential. I don’t believe even 10% of the energy technology community shares Khosla’s view, whereas at least that many think cellulosic ethanol is a going to be a small part of the solution. The vast majority hope it can be a big part of the solution, but know the jury is out. An interesting story will illustrate my point:

I was recently at a conference listening to a cellulosic ethanol panel. During one typically upbeat presentation, I said to the person next to me, “That company gave pretty much the same exact presentation when I was at DOE in the mid-1990s.” Indeed, they had promised to build dozens of commercial cellulosic ethanol plants over the next decade. Never built one. I had forgotten that the person next to me once worked for the Solar Energy Research Institute. He said he had funded one of the panelists three decades ago. Still no commercial product.

This story does not mean that cellulosic ethanol is a dead end. But it should make any true pragmatist skeptical that “this time it will be different.” Certainly $90+ barrel oil is a big help, and we have much better genetic and chemical engineering technologies, and we are much more worried about climate, and cellulosic ethanol done right could probably stick a fair amount of carbon into the soil. But cellulosic ethanol has a fundamental problem.

Biomass is a very inefficient means of turning sunlight into energy, and transporting biomass very far has a high monetary and energy cost, and internal combustion engines are a very inefficient means of energy conversion. All that inefficiency and energy loss means you need a huge amount of land to deliver a lot of zero-carbon energy to the wheels of a car, especially compared to say solar (PV or thermal-electric) and wind (especially since the actual land area a wind turbine renders unusable is quite small) charging a plug in or electric vehicle.

In the next day or so I will have a long post on plug-in hybrids, which Khosla sometimes disses as a “toy” and sometimes says has some “longer term” promise (or at least he’s “open and hopeful”). In fact, it is a seminal climate solution, more so than cellulosic biofuels.

To avert catastrophe, the rich countries need to cut greenhouse gas emissions in the transportation sector by 80% to 90% in four decades or less. So even once we have a lot of plug ins, we are still going to need a zero-carbon fuel for much travel — airplanes, big trucks, ships, and cars/SUVs on longer trips. I very much hope that cellulosic biofuels can provide that huge amount of fuel, which would certainly be a stunning achievement given that this country doesn’t yet have a single commercial cellulosic planet.

But I seriously doubt biofuels could do more. The very few people I’ve ever met who think otherwise are non-pragmatic partisans like Khosla who make heroic assumptions about both technology improvements and the prospects for completely redesigning our agricultural system.

Remember, most countries don’t have the excess arable land that we do. Plus we’ll have some 3 billion more people in 2050 to provide food and water for. And we’ll have probably three times the number of cars. Plus global warming is already causing droughts, desertification, and water shortages, so water shortages will be much worse in 2050 on our current emissions path. Plus our very, very limited use of crops and cropland for energy is already jacking up the price of food to record levels and promoting deforestation around the globe. Speaking pragmatically, just how much excess arable land and water will be available for growing biomass for biofuels in 2050?

So you can see why an energy pragmatist might believe that most cars/SUVs in 2050 had better be doing most of their travel on carbon-free electricity — or else the dream of avoiding catastrophic climate change by staying below 450 ppm will remain just a dream.

We could use cellulosic biofuels for sure. I hope we get a lot, and I’m glad Khosla is placing some big bets on promising technologies — as the country has for three decades. Just don’t listen to anything he says.

11 Responses to A pragmatic view of cellulosic biofuels or why VC Khosla is very wrong

  1. Daniel Bell says:

    Khosa is using first costs instead of lifetime costs to make his argument look better. Total amortized cost of ownership is certainly lower for a plug-in or prius, but as our economy is stuck in the here and now, it can be an issue. The upfront cost of renewables and efficiency is something we’ll have to contend with as a society if we want to see a long term decrease in energy costs.

    I contend that, as a good businessman, Khosla understands this and is trying to benefit from it. The car companies don’t want electric cars because they require less maintenance and don’t make the owner beholden to big oil, which is bad for profits. Khosla sees this and realizes that if he can get you to buy a car that makes you beholden to him for twenty years, it will be very good for business.

    Big Oil, biofuels, and hydrogen – all these fuels keep you beholden to a top-down corporate hegemony which concentrates profits upward and out of local communities. When people own their own power (solar panels) and can plug their car into them, the money stays with them in a bottom-up economy with greater income parity and a better chance for long-term economic growth.

    But as this distributed wealth can’t be captured as easily, its much harder to fund with venture capital. Hence, Khosla.

  2. David B. Benson says:

    Biopact does not agree with you regarding the (eventual) availability of bioenergy solutions:

  3. Joe says:

    Biopact is biofuels advocates, so no big surprise.
    BTW, re their top story (Thursday Night)” If you could gasify biomass with coal — you’d use it to make negative-carbon electricity, not low-carbon biofuels.

  4. Paul K says:

    When you say “Nobody suggests hybrids can solve our problem” that doesn’t mean that they and plug ins are not key parts of the solution. The solution has many requirements and the automotive one is a 90% hybrid/plug in fleet by 2040. Not only is it required, it is probable. How far away can affordable 100 mile per charge driving be? Therefore, attention must be given to altering the electrical generation and delivery system to accommodate the new source of motive power.

    You wrote that the Prius is not a typical hybrid. It is the best hybrid by far. Have you driven any of the G.M. or Ford hybrids. They come in many sizes from compact to SUV and I’d bet with your growing reputation as a guy who can assess a car, you’d be welcomed for test drives. Here’s something the politicians could do right now, use the money now being spent on automobiles by all branches of government at all levels to buy American made hybrid vehicles. Start right now. The next vehicle bought by any state, local or federal agency must be an American Hybrid. Keep buying them until they run out.

  5. John Mashey says:

    1) Amazon is good: I ordered a handful of H&HW paperbacks to give to friends, and they came within a couple days.

    2) We really, really, really need to address two issues well, ignoring all the too-and-fro over current (dumb) ethanol subsidies, which after all, started with a whole lot of other (dumb) subsidies for corn, for such things as high-fructose corn syrup and feedlot beef.
    This is what Iowa says they & US do with corn [ignoring the sales pitch]:

    3) Issue 1: cars are *relatively* easy to fix. I have no doubt I’ll be able to get decent PHEV and EV vehicles I like in just a few years, and as fuel prices go up (one way or another), they’ll be encouraged more, and if CA and co ever get past the EPA, that will help.

    But, I just don;’t know what to do with Class 8 trucks, or bigger tractors, or combines, or ships, in the long-term, i.e., after oil gets very expensive. I don’t know how to electrify a John Deere combine with 400HP & a 300-gallon diesel tank. Maybe these things disappear?

    From EERE, we have:
    but maybe you’ve got a better one.

    When I look at that one, I see good news and bad news:
    Good: cars & (some of) light trucks is low-hanging fruit that we can go after with PHEVs and EVs.
    bad: I don’t know what to do with the heavy trucks, off-road, and shipping. I’m not sure how much of the light truck space is light trucks actually used to haul things.

    Anyway, for better or worse, US agriculture is pretty energy-intensive, although direct energy use is lower than I’d have expected offhand:

    4) Issue 2: farms again. Regardless of all the calculations, as an old farmboy, I observe that farmers have long dedicated acreage for fuel, if that made any sense. Farmers are notorious for wanting independence. I grew up on farm that had been in the family since ~1840. We reserved some land for trees for firewood. Of course, for a while in the late 1800s, our farm had an oil well and that was the best cash crop :-) Farmers really, really hate fast jiggles in their costs.

    Even assuming that the dumb subsidies go away, if gas and diesel get expensive enough, and especially if fuel prices gyrate, it will get overpoweringly attractive to be growing first corn for ethanol, to have a cash crop that tracks fuel prices, and if any kind of cellulosic becomes plausible, especially if it works with less fertilizer (which we know will get more expensive), they’ll certainly do that.

    As long as it isn’t worse for the climate, and even if it’s just more predictable, I find it hard to believe that the Mid-West won’t be growing some biofuels. To be honest, if the subsidies go away, I’d rather they grow biofuels than use more oil, or worse CTL, and in any case, some of the uses of the existing corn seem pretty negative to me. Farm subsidies have long encouraged awful effects.

    Old Amish allocate some land & crops to support horses, because otherwise, their overall revenue would go down, so that hay = biofuel :-)

    This isn’t to be in the middle of arguments with Vinod, and I haven’t worked on a farm for a long time, but I think there are some relevant farm-psychology issues here. Farmers already have to figure out how to deal with more expensive fertilizer.

  6. Earl Killian says:

    David B. Benson says biopact does not agree, but when I look at their material, I don’t see what he seems to see.

    Biopact is advocating using biofuels for the North, produced in the South, as a way of bringing development to the South. That’s a very different agenda than solving global warming.

    It is important to recognize that even when (1) biofuels are possible, and (2) small use of some biofuels may have small greenhouse gas benefits (i.e. they are good, locally), that does not imply that biofuels can replace fossil fuels. The question is one of public policy. Shouldn’t public policy be focused upon things that are steps in the right direction? Some biofuels may be good in small amounts, but they are still a dead-end detour because they cannot scale up to replace our fossil addiction. With very optimistic assumptions, it would take 318,309 sq.mi. to grow enough switchgrass to produce cellulosic ethanol (not corn!) to power U.S. passenger vehicle travel in 2050. In comparison, using conservative assumption, it would take only 4,973 sq.mi. of Concentrated Solar Power to do the same thing for a fleet of battery electric vehicles. The latter is feasible; the former is not. Cellulosic ethanol is 64 times the land area. There is no synergy between cellulosic ethanol and electric transportation. Cellulosic ethanol is a dead-end; go that way and all you do is waste time.

  7. David B. Benson says:

    Studies have been done, Biopact reorts, suggessting that after taking the food, fiber and animal feed needs for a population of 11 billion people, there is still the potential to produce up to 1400 exajoules of bioenergy per year from biomass. To do so would require massive investments.

    To put this in perspective, the world currently uses about 400–420 exajoules per year from all sources. In the yead 2050 CE, with a population of about 9 billion assumed, a reasonable guess is a consumption of about 800 exajoules per year. Providing about half this via bioenergy appears feasible. Obviously the most economic methods should be used first.

    Regarding global warming issues, bioenergy is essentially carbon-neutral, that is, does not add more fossil carbon to the active carbon cycle. Using carbon capture and sequestration (CCS) techniques and firing with biomass, the result is carbon-negative.

  8. Earl Killian says:

    David Benson, you suggest 1.4 ZJ of biomass. Accept that for the moment, but compare it to the sunlight reaching the Earth. Wikipedia says, “The total solar energy available to the earth is approximately 3850 zettajoules (ZJ) per year.” That is a factor of 2750 times larger. It makes sense to exploit sunlight directly, rather than using plants as an intermediary. Even wind, at 6 ZJ/year is a much better place to look than 1.4 ZJ from plants. Either will leave far more habitat for wildlife, compared to raking over every acre of soil with tractors. Moreover, one has to avoid depleting the soils by removing so much from them.

    Also, when I looked up the report, Table 1 gave a range of 40-1100 EJ with 1100 EJ being “most optimal”. I am not sure where the 1.4 ZJ you cited came from, but note the 40 EJ lower bound is enormously lower. Should we bet on being able to be closer to the 1100 than the 40?

    One must also consider the conversion efficiency from different forms of energy to others. Biomass energy is not directly usable; it needs to be converted to a fuel like ethanol or to electricity. This is typically 30-60% efficient. Fuels like ethanol need to be burned, and this is only 30% efficient again.

    To generate the projected 0.9 ZJ in 2050 from sunlight, it takes only 3 ZJ of of 3850 ZJ (0.08%) and 30% efficient CSP or PV. To generate 0.9 ZJ of electricity from 1.4 ZJ of biomass requires essentially 100% of earth’s crop land and 64% efficient power plants. Coal power plants are 30-40% efficient today.

    0.08% of the Earth seems like a better starting place to me.

    Finally, let me quote from for the rest of this comment:

    Critical issues include:
    * Competition for water resources: Although the estimates presented in Table 1 generally exclude irrigation for biomass production, it may be necessary in some countries where water is already scarce.

    * Use of fertilisers and pest control techniques: Improved farm management and higher productivity depend on the availability of fertilisers and pest control. The environmental effects of heavy use of fertiliser and pesticides could be serious.

    * Land-use: More intensive farming to produce energy crops on a large-scale may result in losses of biodiversity. Perennial crops are expected to be less harmful than conventional crops such as cereals and seeds, or even able to achieve positive effects. More intensive cattle-raising would also be necessary to free up grassland currently used for grazing.

    * Competition with food and feed production: Increased biomass production for biofuels out of balance with required productivity increases in agriculture could drive up land and food prices.

  9. says:

    We found an interesting article about the problems with Ethanol on

    “But there are some problems with increasing ethanol blends. Ethanol contains less energy than gasoline, so increasing the amount of ethanol in gasoline will likely result in lower fuel economy. Increasing standard fuel blends from zero to 10 percent ethanol, as is happening today, has little or no impact on fuel economy. In tests, the differences occur within the margin of error, about 0.5 percent. Further increasing ethanol levels to 20 percent reduces fuel economy between 1 and 3 percent, according to testing by the DOE and General Motors. Evaluations are underway to determine if E20 will burn effectively in today’s engines without impacting reliability and longevity, and also assessing potential impact on fuel economy.” would like to invite readers to post their own views and ideas in’s Investor Forum:

  10. With respect to the two most often mentioned biofuels, corn-based ethanol and cellulosic ethanol, there is considerable misinformation and dubious assumptions. Although well intentioned, those groups and individuals that believe these two particular biofuels will be the answer to our dependence on fossil fuels are just unrealistic in the relative short-term. For the next dozen years, fossil fuels will still be an intregal part of our transportation and power generation needs. Certainly, we can and should decrease fossil fuel usage with hybrid vehicle use but carbon-based fuels will not go away any time soon.

    Right now, the current corn ethanol subsidy distorts the market and gives it an insurmountable advantage over cellulosic ethanol. As a practical matter, the most cost effective use of cullulosic ethanol is as a “systemic” biofuel. It can be used for small-scale, local-use or peak-shaving electricity generation by means of gasification and it can be used as a gasoline additive in transportation vehicles.

    Currently, there is still a lot of debris standing on the road to clear thinking about biofuels and the impact they will have on the U.S. in the next several years.

  11. John Taylor says:

    Could you recommend any specific resources, books, or other blogs on this specific marketing topic?