A pragmatic view of cellulosic biofuels
So Vinod Khosla is not happy with with my recent attack on his (willful) ignorance, “Khosla blows his credibility dissing plug-ins.” Gristmill 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?
- Anyone who thinks buying offsets and a Prius-sized nonhybrid is equal from a carbon perspective to buying a Prius has no clue about climate, offsets, or carbon. Offsets are transparently dubious. 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.
- 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 [PDF]), 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.
- 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).
- “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 (PDF). 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.
- “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 percent compared to a comparably-sized nonhybrid (which corn ethanol does not come close to even under incomplete life-cycle analyses). Yes “today’s typical hybrid” probably only cuts emissions 25 percent, 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 …
- Corn ethanol is the Hummer of alternative fuels. ‘Nuff said.
- “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 percent 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-plus-per-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 “toys,” and sometimes says have 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 percent to 90 percent 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 plant.
But I seriously doubt biofuels could do more. The very few people I’ve ever met who think otherwise are nonpragmatic 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.