Next Generation Energy is managed and written entirely by Seed editors and expert guest bloggers. Read more about them In order to know whether biofuels could be a major climate solution, the scale of low-carbon energy deployment needed to avert climate catastrophe must be understood.
According to the Latest Intergovernmental Panel on Climate Change report, if carbon emissions average 11 billion tons a year (GtC/yr) this century, then carbon cycle feedbacks will probably take us to atmospheric concentrations of 1000 ppm of carbon dioxide and some 5.5°C warming from preindustrial levels. And I think we can probably all agree that is the end of life on this planet as we know it with the loss of the inland glaciers that provide water to a billion people, widespread desertification for up to one third of the planet, loss of most species on land and sea, and ultimately an ice free planet with sea levels up to 250 feet higher.
Unfortunately, unless we sharply reverse national and global energy policy, we'll be over 11 GtC/yr in 2020. So what would it take to then freeze at 11 GtC/yr for most of the rest of the century? It would require 11 of Princeton's "stabilization wedges" -- strategies and/or technologies that over a period of a few decades each reduce global carbon emissions by one billion metric tons per year from projected levels. Click to enlarge the figure.
Princeton's Socolow and Pacala describe one wedge of biofuel in their original August 2004 Science article on the wedges:
Option 13: Biofuels. Fossil-carbon fuels can also be replaced by biofuels such as ethanol. A wedge of biofuel would be achieved by the production of about 34 million barrels per day of ethanol in 2054 that could displace gasoline, provided the ethanol itself were fossil-carbon free. This ethanol production rate would be about 50 times larger than today's global production rate, almost all of which can be attributed to Brazilian sugarcane and United States corn. An ethanol wedge would require 250 million hectares committed to high-yield (15 dry tons/hectare) plantations by 2054, an area equal to about one-sixth of the world's cropland. An even larger area would be required to the extent that the biofuels require fossil-carbon inputs. Because land suitable for annually harvested biofuels crops is also often suitable for conventional agriculture, biofuels production could compromise agricultural productivity.
Biofuels thus have several problems as a large-scale medium-term climate solution:
First, virtually all crop-based biofuels are worthless from a climate perspective (see "here") and probably a bad idea from most other perspectives (see "here"). Second, there is not a single commercial cellulosic ethanol plant in United States yet. Third, I'm not sure there is an agreement in the scientific community about how to do lifecycle analysis needed to determine the net carbon benefit from cellulosic fuels. Fourth, in a post-2050 world with 3 billion more people who are losing water from melting glaciers and desertification, arable land and water will be very dear commodities. That means the only biofuels that would make sense to fight global warming would be ones that do not require arable land or much fresh water.
So I think the jury is very much out on whether a wedge-scale contribution from cellulosic biofuels is practical and affordable and a climate-constrained world. Perhaps half a wedge is more likely. For anything larger, we may need something like microalgae-to-biofuels to succeed on a very large scale.
If you want to see the entire Princeton discussion on the biofuels wedge, and see all of their assumptions, go here.
One final point. Princeton's wedges are based on a deployment time of 50 years. Sadly, we don't have 50 years anymore -- "stabilizing" at 1000 ppm means destroying the health and well-being of perhaps the next 50 generations. We need to stabilize below 450 ppm if we are to keep warming near 2°C from preindustrial levels, as the IPCC and the world's National Academies of Science urge. That requires starting the wedges sooner -- around 2015 -- and finishing them much faster -- in 25 years. And that requires deployment on a scale comparable to what we did during World War II.
As for the entire solution (including a possible biofuels wedge), here are 14 wedges, since I have no doubt that everybody (including me) will find something objectionable in a few of these wedges:
No, I don't think all of those are equally plausible. But I am listing these because I do not think there are lots of other plausible wedges out there -- especially since 11 of these wedges must be deployed from 2015 to 2040, meaning we must avail ourselves almost exclusively of technologies that are commercial today or will be within about five years.1 wedge of vehicle efficiency -- all cars 60 mpg, with no increase in miles traveled per vehicle. 1 of wind for power -- one million large (2 MW peak) wind turbines 1 of wind for vehicles --another 2000 GW wind. Most cars must be plug-in hybrids or pure electric vehicles. 3 of concentrated solar thermal -- ~5000 GW peak. 3 of efficiency -- one each for buildings, industry, and cogeneration/heat-recovery for a total of 15 to 20 million GW-hrs. 1 of coal with carbon capture and storage -- 800 GW of coal with CCS 1 of nuclear power -- 700 GW plus 10 Yucca mountains for storage 1 of solar photovoltaics -- 2000 GW peak [or less PV and some geothermal, tidal, and ocean thermal] 1 of cellulosic biofuels -- using one-sixth of the world's cropland [or less land if yields significantly increase or algae-to-biofuels proves commercial at large scale]. 1 of forestry -- End all tropical deforestation.
Comments
Nuclear @ 700GW but solar (photo & thermal) at 10 times that power output!?
Posted by: No One Of Consequence | July 17, 2008 2:53 PM
Cellulostic ethanol is a good thing, but relying on it a major critical source of fuel isn't.
There is no reason not to turn agricultural and forestry waste into energy. That is just a win-win. Instead of thinking about allocating current cropland to grow biofuels, we should be thinking of using the stalks, straw, and grasses growing on marginal lands in a sensible manner. Cellulostic ethanol means another, parallel, product from crops, not replacing them.
That said, it almost certainly won't be able to supply huge chunk of our fuel needs. And actually, ethanol production may not be the best thing to do with all that biomass.
We must weigh ethanol production against other options such as burning biomass (can be done quite cleanly and produces more power than ethanol) and/or generating biochar (which is very promising in terms of sequestration and has side benefits of minor energy production and improving soils).
As I have mentioned on pretty much every thread here, power generation is a very different problem from fuel production. We really need to distinguish between the two. We have a lot of good options for power generation, and just need to actually use them (carbon tax now please).
For fuels, we need easily transportable high energy densities... fuel should be relatively expensive and there is absolutely nothing wrong with fuel production being a net negative energy wise. For economic stability, national security, and environmental sanity we need fuels which can be produced from a variety of energy inputs. H2 is very good in this respect, but will take a bit of time to develop (using it as a mass fixed energy storage medium (big battery) would be a good first step).
In the short term, efficiency and replacing fuel with grid power where possible is by far the biggest gains. Plug in hybrids for personal transportation are a great step. More rail (and electrified rail) for freight is another great step. Lets encourage these now, and work on developing better batteries (allowing more fuel requirements to be replaced by grid power), and work on the developing fuels which can be made efficiently using common material inputs and power from whatever energy source is on hand.
Posted by: travc | July 17, 2008 3:30 PM
Here's a test case for solid biofuel. Burn switchgrass at 8500 BTU/lb and 10 T/hectare (medium yield - not intensively farmed as for the liquid case), yield = 50MWh per hectare energy as heating, or 30MWh per hectare as electricity. To generate a 5 million gigawatt-hour wedge: 100 million hectares of medium yield cropland for direct heat (2.5x more efficient than liquid biofuels), or 166 million hectares of medium yield cropland for electricity (1.5x more efficient than liquid biofuels). For the electricity route, this is the output of 600,000 25MW local power plants. Even if these could be built for $1 million each (lowball in extremis), it would cost $600 billion. The capital cost of each wedge is astronomical when you look at it on this local basis generation basis (50 mile collection radius), which points toward just using it directly as heating fuel.
It still takes a lot of cropland to get one wedge, but it's a lot more efficient than going the liquid fuel route, whether ethanol or Fischer Tropsch. It should have a null effect for carbon, since the grass sequesters an amount equal to what is burned. And it's proven technology for cellulosics that works on a large scale.
Posted by: tom quick | July 17, 2008 3:51 PM
Correction to above: a 25MW local powerplant generates
25 x 24 x 350 = 210,000 MWh/year = 210GWh/year. The number of powerplants for a 5,000,000 GWh wedge comes down to 24,000, and capitalization comes down accordingly. But $1 million isn't nearly enough to build one....
Posted by: tom quick | July 17, 2008 4:10 PM
travc:
We need more research on biochar. I saw a paper about a month or two back (I don't have a pointer to it). But the results were that for their test plot (Boreal forest) adding charcoal to the soil changed the soil microfauna such that net soil carbon was lost. I suspect that the effect is probably very dependent upon the local soil ecology. If we are lucky (we have very little population and industry in the Boreal forest), most zones will benefit from it. But we do need to do the research and monitoring.
Posted by: bigTom | July 17, 2008 6:14 PM
Random thoughts.
If, as recent reports have hinted, temperature levels for a decade or two but CO2 continues to increase, would not that count as a wedge in effect?
If the short, medium or long terms solution to the fuel production and use issue places a demand on infrastructure creation with its associated energy use and carbon emissions via concrete (for example) or fertiliser production combined with negative carbon sequestration via deforestation, would that counter any net gain from the reduction in energy input from the sun and thus the level or reducing temperature? In other words would the required construction, even to the level of proof of concept, act as a negative wedge?
Given variability is unavoidable so far as we know now and well into the future accurate estimates are difficult. But if we accept that energy input can be averaged over time and that the Sun is the only obvious source, it seems it should not be difficult to work out a nominal balance of input to usage year by year. Let's assume that such a balance of the energy books was required every year since the reserve store - the fossil fuels perhaps - have been used.
We could therefore assume that the planet's ecosystem in general for all living things can support an energy usage, for all needs, of something like pre-industrial levels.
So that leaves us with an option to reduce total consumption to that level. We may gain a little additional benefit by greater efficiencies than were known back around, say, 1800. Other than that the only gains per capita available would seem to be to reduce human population or reduce the fauna population to remove the competition for energy.
There may be some potential for secondary stored energy sources - uranium, thorium, whatever - to cushion the problem for a while. And I suppose a very long shot might seek to leverage deep thermal since the earth core energy does represent another non-renewal energy source.
So, reverting to pre-industrial levels (or close to that) and ensuring that most ambitions for self improvement (for example another industrial revolution based on stored energy sources) were avoided might be a way to go.
Painful in the short term but, with strict controls, sustainable.
What I struggle to feel comfortable with is that humanity, if it has any worth, is geared to creativity and invention on a grand scale. With that impetus suppressed, what would be the point of continued existence?
What incentive could anyone offer, other than active repression, that would offer the remainder of humanity a reason to exist in a stable population that had no obvious creative objective?
Perhaps fuel for the future simply reverts to animal feed stuffs the the industrialised world reverts to animal power. Some parts of the world are already ahead of the game on that one, though finding it difficult to feed themselves.
Posted by: Grant | July 17, 2008 9:05 PM
Thank you, Joe. The previous posts had me worried that maybe you guys really were inside Shell's corporate bubble. But here you expose the true scope of the problem. Biofuels are nothing but misdirection.
I think, as you've said elsewhere, we need to start applying known technology right now and on a massive scale. Sure, we need to continue R&D into new tech, but that will take a long time to have a significant affect.
The biggest known technology is conservation; let's do that.
The next are wind and solar. Let's do those on a big scale and reap the benefits -- both in immediate clean energy and economically by making the USA a hotbed of zero carbon energy technology just like the Silicon Valley became a hotbed of high-tech. (Or do we want to concede this to Germany?)
I hope in a future post you guys talk about Lester Brown's Plan B 3.0. Brown provides data to back up his views.
Posted by: Trinifar | July 17, 2008 10:57 PM
bigTom, thanks for the update on biochar. However, I would slightly quibble with saying it 'needs more research'.
Of course you are correct, research is good. But 'needs more research' is a common code-phrase for 'should not be used now'.
Biochar most certainly should be used now, just not haphazardly. Places with soils (and climates) where it has been tested, in some cases for over a thousand of years, should be adding it to the soil. Large scale processing facilities need to designed and built... not difficult, but re-optimizing the process to use little input energy (or better yet produce excess energy) and handle different feedstocks has yet to be done.
Biochar is almost certainly not a silver bullet, but quite possibly a critical technology. Using it as a method to offset the carbon output of difficult to substitute fuels is one decent idea IMO.
--
@Grant
I don't follow your logic. Humanity has much greater capability to harness sustainable power today than we did pre-industrialization. We also have much more efficient crops and agricultural methods (even without use of petrochem based fertilizers) along with many other technological abilities which are much more efficient than centuries ago.
Also, anyone talking about going back to animal power is exposing vast ignorance. Animal power is very inefficient energy wise, and an environmental nightmare on many many fronts. There are very few cases where it is a wise or environmentally sound option... Good for packing gear through the mountains though ;)
Posted by: travc | July 18, 2008 7:59 AM
Another potential type of "wedge" is direct carbon removal strategies that don't try to produce energy. For example, the proposals to create algal blooms by seeding areas of seawater with iron. Such methods have potentially considerably environmental effects where they are implemented, but I can't think of any wedge that doesn't.
Posted by: Anthony | July 18, 2008 12:38 PM
2003 costs for a hog fuel boiler that can burn 600 TPD of biomass are about $23 million. Energy production is in the 50-100MW range, depending on whether steam or electricity is the end product. So $1 million was a definite lowball, and assuming 10,000 of plants this size are needed to give a 5,000,000 GWh wedge, this is $230 billion capitalization for one wedge. This does not include the equipment needed to generate electricity.
http://www.epa.gov/chp/documents/biomass_chp_catalog_part5.pdf
Posted by: tom quick | July 18, 2008 12:38 PM
Biochar, the modern version of an ancient Amazonian agricultural practice called Terra Preta (black earth), is gaining widespread credibility as a way to address world hunger, climate change, rural poverty, deforestation, and energy shortages� SIMULTANEOUSLY!
This technology represents the most comprehensive, low cost, and productive approach to long term stewardship and sustainability.Terra Preta Soils a process for Carbon Negative Bio fuels, massive Carbon sequestration, 10X Lower Methane & N2O soil emissions, and 3X Fertility Too. Every 1 ton of Biomass yields 1/3 ton Charcoal for soil Sequestration,and 5.5 barrels of Bio-oil & syn-gas to burn.
Indeed, Dr. James Hansen, NASA's top Atmospheric authority, is now placing it in the center stage of pro-active solutions for the climate crisis.
http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf
I hope you will come to share my passion in getting the word out on the wonderful solutions provided by TP soils.
I'm sort of the TP list (and data base at REPP-CREST) cub reporter, most all my list postings, under shengar@aol.com, are news items, collaborative work, lobbying efforts with government, writers and journals.
http://terrapreta.bioenergylists.org/?q=node
The new Yahoo Biochar discussion group;
http://tech.groups.yahoo.com/group/b...guid=122501696
Thanks for your interest
Cheers,
Erich
Posted by: Erich J. Knight | July 19, 2008 11:37 PM
travc,
I had prepared a response some days ago but it all looked too convoluted. Let's try this.
You wrote:
"Humanity has much greater capability to harness sustainable power today than we did pre-industrialization."
Yep. And assuming that any upcoming changes are not too catastrophic, whether controlled or beyond control, we might how to see that knowledge retained.
Efficiency is good, but what does it give us?
Let's see the budgets. (I claim no intent of accuracy here, just concept and someone else can crunch the numbers if they really feel they have the necessary information.)
As at today we have some savings to work with, some not very accessible (the energy in the earth's core, and subsequent geothermal options most of which we can't get to) and some somewhat accessible (Fossil fuels, Uranium, Thorium, etc. Latent heat, some in the earth but mostly the oceans.)
Our new income is from a single source - the sun. Part of that income is variable but, overall, it can be considered to be relatively stable for our purposes here.
If we wish to live within the annual budget and not use savings and capital other than finding some form of 'interest' income that may be available, we have to balance the annual income and outgoings.
We are committed to some base load costs - similar to taxes - that keep the locale running. So some of the incoming energy must be reserved for flora and other fauna although some part of the flora (and fauna?) may also be considered returnable input for humans - the 'interest on investment'.
Once we have made those deductions we can use the rest provided we have no feeling that we need to save any form of 'benefit' for the long term future (i.e. invest resource that might become replacement fossil fuels in a couple of billions years from present.
So now we know how much energy we have available to live on we can work out what our living costs need to be (based on expected comfort level) and that will tell us how big a family we can support.
Yes, there may be some marginal efficiency to be gained form the system and possibly some double budgeting could be identified though it should not be relied upon - the mistake may be rectified a few years down the line and repayment expected.
We would most likely wish to pitch out comfort zone much closer to now than to pre-industrial times. No problem in theory. Just work out the per capita budget and see how many people can be supported. If the number is small, does that have a knock-on effect to manufacturing economies of scale and throw those numbers off?
Or would the population prefer less industrialization and more people? Those used to large families, beasts of burden and lack of internal combustion engines may push for their personal status quo and be quite happy with that. In a democratic system they would likely be in the majority.
technological advances in energy 'capture' - better windmills and water 'wheels' for example - May allow us to extend the budget although what might happen to surface wind speeds and weather patterns with a few million windmills taking energy out of air movement patterns would seem to be unknown so would justify some budgetary reserve (i.e., fewer people.)
You then get into debates about balance (or population tipping points.)
Of course if anyone knows of a sustainable source of energy that requires no input then my concepts will be torn to shreds. Likewise of an addition external input source can be discovered or the existing source persuaded to pump out more input the situation would also change.
But right now it seems to me we are wondering how to wedge the available salary and those providing energy conversion products, such as our sponsors, are wondering where their future markets will lie and how big they will be.
Anyone with the ability to feed 5000 people with a few loaves and fishes could make a dollar or two in such a regime. Turning water to wine could be useful too, assuming the pressure on water supplies would be reduced and the ability would by-pass the need far any energy consumption in the process.
Maybe we have been here before ...
Posted by: Grant | July 26, 2008 7:01 PM
travc also wrote:
"Also, anyone talking about going back to animal power is exposing vast ignorance. Animal power is very inefficient energy wise, and an environmental nightmare on many many fronts. There are very few cases where it is a wise or environmentally sound option..."
I totally agree of course. Hence the discussion of budgets
Is anyone developing an electric or fuel cell tractor? Or would they always need to be bio-diesel?
Sorry I forgot to include this in the previous post.
Posted by: Grant | July 26, 2008 7:06 PM
Grant -- Or would the population prefer less industrialization and more people? Those used to large families, beasts of burden and lack of internal combustion engines may push for their personal status quo and be quite happy with that. In a democratic system they would likely be in the majority.
You know, you should try looking at the physical world around you as a reality check on that. Looking at Sub-Saharan Africa and rural Asia, people are in no way enamored of that status quo, and appear to be committed to obtaining technology and birth control as soon as they can physically get access to them.
In traditional (non-industrialised) agrarian societies, it was common to have as many children as possible simply because fewer than 50% of them were expected to survive to adulthood. Pumping out a baby a year is incredibly hard on most women. Humans in general have been thrilled to change that pattern. And, I have worked both farm and ranch, growing up -- technology means better, easier lives.
The best way to reduce burgeoning populations in industrialising countries, is to improve women's rights and women's health and child healthcare, because the voluntary takeup of birth control under those circumstances slows the birth rate RIGHT down. But people will never voluntarily give up or renounce the industrial technology which makes life easier -- and we need to work with that realistically, by making energy-efficient technologies available cheaply and quickly enough that people will pick them up *instead* of energy-wasteful tech.
Posted by: Luna_the_cat | July 27, 2008 12:18 PM