The previous essay on solar energy got picked up and linked to from a number of places. Between those links and the original blog entry, some of the comments I read were largely in left field, and many of them didn’t come close to representing my actual position or arguments. Maybe that’s partially my fault for spending all of 20 minutes writing the post. Which brings up another point: It seems like the less time I spend on a post, the more comments and hits it gets. But I digress.
So, let me clarify a few things.
1. I am not against biofuels. In certain situations, biofuels may be (and probably are) an appropriate solution to the problem. In fact, I continue to work on solutions to biofuel problems, and I wouldn’t waste my time doing this if I didn’t think there were some applications. My argument is that we won’t, as many people believe, displace large amounts of petroleum with biofuels. Presuming we can is presuming that technology that does not currently exist will inevitably be invented.
2. I am not against technology. I love technology – especially biotechnology. But I am well aware of the “technology will save us mentality.” Technology doesn’t always proceed as you think it should, and it doesn’t always respond to monetary incentives. If it did, cancer and AIDS would no longer be with us, and 40 years after the moon landing, a manned Mars expedition wouldn’t still be a distant dream.
3. This is not a new revelation for me. I have long believed that our future must be electric for at least 4 reasons. First, is the photosynthetic efficiency that I discussed. Second, internal combustion engines are notoriously inefficient relative to electric motors. Third, we have a lot of rooftops available that will not compete with arable land. And finally, electricity can be produced from a tremendous diversity of sources. Start with biomass, solar, wind, hydro, nuclear, natural gas, coal – all are easily converted into electricity. Contrast that with the uncertainty of a future based on cellulosic ethanol and algal biodiesel. If we are to embark on a Manhattan Project to get off of our petroleum dependence, we should direct our efforts toward an eventual electric transportation infrastructure.
4. As one person argued, “solar collectors don’t self propagate.” True, but biofuels don’t self-harvest and convert themselves to useful end products. Once the solar panels are in place, they keep giving for a long time.
5. The rapeseed example is merely a thought experiment. Don’t spend too much time worrying about all of the implications of planting a majority of our land in rapeseed, or whether instead I should have planted palm oil or corn everywhere. It is just an example to frame the problem. But I do not believe, as some have suggested, that using land that is presently non-arable is going to provide a fraction of the yields you would get from planting all the arable land in rapeseed. So, I think it is a very conservative thought experiment.
6. Several people have suggested that I am just wrong about biofuels; that technological advances will change everything. All I can say is that hope is a wonderful thing. But you better plan for contingencies in case those visions of algal biodiesel fail to materialize.
7. Yes, I know that SI units are better in the context of a scientific paper. And I do use SI units in the chapter. But for most casual readers in the U.S., a yield of gallons per acre is going to be more meaningful than a yield of liters per hectare.
8. I am aware that biomass is stored energy. But you can’t harvest all of that stored energy and use it, or you will rapidly deplete the soil. This is why you will never convert anything close to theoretical photosynthetic efficiency into liquid fuels. And theoretical photosynthetic efficiency is still far short of solar cell efficiency.
The shorter, less-well thought out post is typically more controversial, and hence generates more comments. If you really want to generate traffic, you have to be wrong a certain portion of the time, or else you give everyone nothing to argue about.
Ouch. 8 points and not a one about efficiency.
(I think I saw about a dozen Priuses on my walk to lunch through Lake Forest, CA. Maybe the trend is spreading. That really should be the best-selling car in America. Plug-In hype is designed to prevent that ;-), but I’m not sure it will.)
Ouch. 8 points and not a one about efficiency.
I didn’t really feel like there was anything to clarify there. I am a big fan of efficiency, and recognize the need for efficiency throughout the energy supply chain. In fact, that is a big part of my job.
Ouch. 8 points and not a one about efficiency.
Ah, but a quick reread says that I did mention efficiency. Point 3: Electric motor efficiency versus ICE efficiency. Point 8: Solar cell efficiency versus photosynthetic efficiency.
If you really want to generate traffic, you have to be wrong a certain portion of the time
That price is too high to pay.
🙂
I just thought you were dissing me 😉
And I got to mention the Prius sightings.
How many annual vehicle miles does each square meter of land provide?
Corn ethanol – 1.5 miles
Wind Turbine – 120 miles
Photovoltaic – 1200 miles
Note, however, that wind turbines only actually “use” about 5% of the land area they occupy. The other 95% is still available for crops or whatever. On that basis wind gives 2400 miles per square meter. Also note that roof-mounted PV doesn’t really “use” any land whatsoever (infinite miles/sq meter).
How about cost?
Corn ethanol – 10 cents/mile
Wind turbine – 1.2 cents/mile
Photovoltaic – 7 cents/mile
Note that wind is equivalent to 30 cent per gallon gasoline. If thin-film PV innovators like Nanosolar deliver on their miraculous claims, PV will reach the same level. Of course we need a fleet of PHEVs to run on these ultra-cheap, renewable fuels. Since PHEVs can also run on equally cheap power from coal, nuclear and other non-jihadist fuels, it’s an absolute no brainer that we fund their development and widespread deployment ASAP.
I am not against technology. I love technology – especially biotechnology. But I am well aware of the “technology will save us mentality.” Technology doesn’t always proceed as you think it should, and it doesn’t always respond to monetary incentives. If it did, cancer and AIDS would no longer be with us, and 40 years after the moon landing, a manned Mars expedition wouldn’t still be a distant dream.
The counter-argument is this: Necessity is the mother of invention. There is a degree of urgency difference between having the option of making money solving a problem and having your back against the wall.
Judged by the current investments in renewable energy (and biofuels in particular) things are going to get a lot more urgent before they get better. But inevitably that urgency will help get us off the dumb ideas and onto the workable solutions.
Exhibit 1: Nazi Germany has already survived Peak Oil. At an early stage, Britain estimated that Germany only had 1 year’s supply [of oil]. Even allowing for a spectacular miscalculation on England’s part, that’s is way more urgent than our current situation.
How did the Germans do it? In part because they managed to apply Fischer-Tropsch at full scale and did so under war conditions. The chief source of supply, and the only source for aviation gasoline, was 13 synthetic plants together with a small production from three additional ones that started operations in 1944.
Some would go so far as to say: Thanks for the Cheap Gas, Mr. Hitler!
Exhibit 2: Again the Germans, this time producing synthetic rubber during WWI: The first large-scale commercial production occurred in Germany during World War I, as a result of shortages of natural rubber.
There are countless other examples of technologies that were developed and implemented during the world wars, showing how innovative we humans can be, when we have our backs against the wall.
“Nazi Germany has already survived Peak Oil.”
Heh, you must have watched different movies than I did growing up … something about Telly Savalas and a fuel dump?
The more I ponder this, the more I think we will in fact see a seamless transtion to a post-fossil oil world (I define as regualr annual delcines in fossil oil consumption, or also Peak Demand.
Odograph is right. We will make the liquid stuff somehow. A more recent example is South Africa, which ran Sasol in the old embargo days, and made liquid fuel from coal. Their economy was the best in Africa.
Okay, so only real sickos can make synthetic fuel. You have to be a Nazi or rascist.
OPEC is flexing market muscle now, but they are lucky that Iran, Iraq, Libya. Nigeria and even Russia are run by nuts, and Venezuela is worse, and Mexico is eating its seedcorn (Cantarelli).
We will see declines in fossil oil consumption going forward, and if OPEC plays tough, we will see all sorts of alternatives.
$70 a barrel is enough to slowly get the ball rolling. If oil goes up, many more alternatives come to the fore. And conservation.
We will see Peak Demand before we see Peak Oil.
I touched a nerve, see point 7 above.
I note that when I hear reports from Iraq, our military gives everything in metric. If they can do it so can we.
Any book on bio-fuels is going to attract an audience that can handle metric.
I touched a nerve, see point 7 above.
Someone else mentioned it at another link as well, so I thought I should clarify: SI units are what I used in the chapter. I just think those would have been lost on a general audience here.
Apparently the WSJ reads your blog:
link
How is it that the general audience in US does not get SI units?
Get with the program! This is 21st century and about science
🙂
Sorry, had to get that off my chest.
I hope you understand Robert, that most people comment on your blog, because it’s good, not because they necessarily disagree with you or think that you made a mistake (which you very rarely do).
It’s just that when you write in terse or quick mode, the big picture may be lost on the “average reader”.
Like my example about comparing conversion efficiencies in the previous post.
I’d still like somebody to do thermal ceiling calcs and approximations for improvement for various transport energy cycles:
Solar -> electricity -> hydrogen -> fuel cell -> electric motor
Solar -> photosynthesis -> biomass feedstock -> biofuels -> combustion engine
Solar -> hydrogen (using a catalyst, look up Nakamura’s research on this, if you’re interested)
Yes, there are density, weight, volume, refueling and other issues.
However, the basics are in the cycle efficiencies, imho.
If that fails badly, it doesn’t really help if the technology can scale or if the density is optimal compared to petroleum oil.
Just my 2 cents worth.
This is all great stuff–posts and comments. I particularly like your precautionary principle about technology. I would take it a bit further and argue that even if all the renewable energy technologies that we love do develop as we want, the practical realities of deploying them and the urgency of acting to stop and reverse global warming means that no one technology can be a silver bullet–we’ve got silver buckshot at best.
On the other hand, if we limit ourselves to extrapolating BUA out for all technologies and policies, I would argue that it’s impossible to get to a sustainable future. So a non-intuitive corollary to being cautious about assuming any one technology will save the day is that we have to assume an ability and societal willingness to innovate and change.
Especially given the need to start achieving GHG reductions within the next 10 years and the infrastructure and consumer acceptance challenges around electric power in transportation, I would argue that we actually need to make biofuels work environmentally at least through 2050 and probably 2100.
Putting biofuels in the context of a global commitment to cut our GHG emissions and thus in context of commitment to innovation and change, it actually not that hard to construct scenarios where biofuels play an important role in meeting our transportation energy service needs. They have to be pursued as part of a package of all the technologies that you discuss here: energy efficiency first and foremost, reduced VMT through smart growth, plug-in hybrids powered by as green a grid as we can get, and international agreements to protect our forests and other critical land-based carbon stocks and sinks. Nevertheless biofuels could be an important chunk of reductions–probably on the order of our current light-duty vehicle GHG emissions.
Finding these plausible scenarios that get us to a sustainable energy future strike me as much more telling than thought experiments such as planting the world with corn or rapeseed, which only show that we can think up bad ideas.
On the question of land sufficiency for biofuels, I’m part way through a series of posts summarizing a really interesting discussion and analysis of the topic. Please drop by and check it out if you’re interested. My blog is http://switchboard.nrdc.org/blogs/ngreene/
I’d still like somebody to do thermal ceiling calcs and approximations for improvement for various transport energy cycles:
1. Solar -> electricity -> hydrogen -> fuel cell -> electric motor
2. Solar -> photosynthesis -> biomass feedstock -> biofuels -> combustion engine
3. Solar -> hydrogen (using a catalyst, look up Nakamura’s research on this, if you’re interested)
Well, as part of answering #2:
The German company, Choren – claims to produce one liter of diesel from 4 kg of wood, or 1.43 bbl/ton of wood. One liter of diesel contains about 36 MJ of energy. Wood has an energy content of about 18.5 GJ/t or 18.5 MJ/kg. Apparently that would be “bone dry” wood, as confirmed on page 29 out of 156 of this presentation or page 9 of the Enerkem presentation. The “capture” efficiency of the Choren process is then 36/(4×18.5) = 49%. According to Choren’s Download page (see “Biomass to Liquid – BtL Implementation Report, Summary) BtL is assumed to have a conversion efficiency of 42% (read the fine print below Figure 1).
The fact that the capture efficiency is so close to the conversion efficiency would imply that the bulk of the processing energy is supplied by the feedstock.
King, if I’m not mistaken you had an opinion about this?
For some reason the links above all got screwed up. Delete the “www.blogger.com/” in front of each link, and hope it works…
Optimist – yes, that is very good conversion, within the realm of possibility for an F-T process. It appears that CHOREN has their own gasifier technology but is using Shell’s F-T hydrocracking technology. Shell has very good F-T technology.
Wait a minute. I was looking over the Freiberg Beta plant. I saw some liquid oxygen storage. That is cheating!
The mass balance isn’t very good. You start off with 4 kg of biomass but only end up with 0.7 kg of diesel. The other 3.3 kg of feedstock goes out the stack as air emissions or out the back end as ash.
The German company, Choren – claims to produce one liter of diesel from 4 kg of wood, or 1.43 bbl/ton of wood.
Those guys read this blog. I have exchanged lots of e-mails with them, and I mentioned them in my book chapter.
I think long-term, the technology is viable. My fear is that we will exhaust GTL and CTL before we get around to BTL. A carbon tax would solve that problem, I think.
Wait a minute. I was looking over the Freiberg Beta plant. I saw some liquid oxygen storage. That is cheating!
That’s right. There is some energy involved with producing and storing liquid oxygen that needs to be taken into account.
Those guys read this blog.
Who knows, maybe they’d grace us with a comment?