I spend a lot of time thinking about the trade-offs involved with different energy options. Take petroleum, for instance. It offers great convenience, and has been relatively inexpensive for decades. Cheap petroleum has enabled numerous people a level of mobility that had never before been possible. Some of the downsides, though, are that we get air pollution, oil spills, and resource wars. And because of U.S. dependence on petroleum, we find ourselves increasingly at the mercy of regimes hostile to U.S. interests. And when prices go up, money flows out of our economy into theirs. However, we have been willing to live with those trade-offs.
The same trade-offs hold true for renewable energy, and I actually spend a lot more time thinking about those. My near future is going to take me back into the energy sector, trying to work out sustainable, long-term solutions. Sustainable is the key word here. If the renewable option requires fossil fuels, for instance, it isn’t sustainable. It might be sustainable for a long period of time if the fossil fuel inputs are low – or if they consist of fossil fuels that we still possess in abundance – but that brings up other trade-offs.
There is no perfect solution, but there are those in which the trade-offs are more favorable. For a tropical country like Brazil, I think ethanol from sugarcane is a good solution. However, try to scale that up to fuel the world, and you start dealing with more difficult trade-offs. One of the options I think looks good longer-term is green diesel made from either hydrotreating/cracking various plant oils, or from gasifying biomass and then converting it via Fischer-Tropsch to diesel (as Choren is doing).
For the hydrocracking option, the specific plant oil (or animal fat) you use is going to involve more trade-offs. Take palm oil, for instance. It is a prolific producer of oil, to be sure. It has provided a new source of income for many tropical countries. But demand from developed countries has led to massive deforestation as some tropical countries rush to plant palm oil plantations.
Jatropha curcas, which I have written about previously, is an interesting option. The primary attraction is that it can reportedly grow in marginal soil, and it is drought tolerant. Presumably, this would imply that it doesn’t use much water. Not so, according to a recently published paper in PNAS:
The water footprint of bioenergy
In case you can’t read that, the graph shows jatropha as the highest user of water per GJ of fuel produced. Many believe the world faces some very serious issues with availability of fresh water. In that case, an important trade-off will be the amount of water a energy crop uses.
The study doesn’t describe their methodology in detail, so it is difficult for me to critique their result. I can say that other studies have shown that jatropha still produces oil under minimal water requirements:
It may be that the best yields are produced when lots of water is supplied. But then there are locations that would be willing to trade lower oil yields for low water requirements. The point is that these sorts of trade-offs are going to be involved with every energy choice. As the title says, “It’s always something.” But that doesn’t mean we don’t have options.
As we turn increasingly to bioenergy in the future, it is critical that we make choices that minimize the negative side of the trade-offs. Unfortunately, history shows that the group benefiting from the positive side of the trade-off is not always the same group getting hit with the negative side. But for me, this is going to be an important consideration as I search for optimal bioenergy options.
Note: Incidentally, when I was writing this essay, I ran across a very informative source of jatropha information that I hadn’t seen before. There are a lot of nice pictures there: Jatropha Cultivation
I'm not familiar with this particular water study; but a lot of these "studies" need to be taken with a whole lot of salt.
A lot of times they just take the average rainfall of the area where the crop is grown, and, voila, they have a "number." Obviously, this method is fraught with potential for inaccuracies.
Most crops have an "optimum" amount of water. Also, timing can be of more importance than amount.
Also, these studies, many times, don't differentiate between rainfall, and irrigation. An example being that 96% of Ethanol is from Non-irrigated corn.
Even the Type of irrigation is very important. A lot of the corn that is irrigated (from Nebraska, mainly) is irrigated from Shallow wells, river bottom wells, Not aquifer-fed wells.
There are Huge "Bucks" at play in the Global Energy Game. One needs to take Everything one reads with a healthy dose of skepticism. Everything.
I actually did the Internet research thing on jatropha a couple of years back, to the point of e-mailing people who were actually planting the stuff. I was planning to plant in Thailand.
It just did not pencil out.
Palm trees actually work, and of course there are thriving palm plantations all through SE Asia. Yields are rising handsomely, as better stock is introduced. There is talk of genomics and much higher yields even yet. Palm is a commercially proven crop, and acreage and yields will only rise for decades to come. Brazil in mind-boggling, if they ever get into palm trees. I assume an ethanol lobby is preventing it.
Still, RR is right, you need a lot of water. Palm trees equal water consumption.
Some people swear by Pongamia Pinetta, another oil-bearing tree.
I am fond of trees as you plant only once, stabilize the soil, and can grow other food-crop between the trees, such as beans or yams etc. On paper, Pongamia Pinetta looks promising, but that is what I thought about jatropha a few years back.
There is also the possibility (probability?) one could plant pongamia pinetta, only to have higher-yielding breeds come to market in a few years. This is happening in palm trees. People who planted 10 years ago are tempted to plant the higher-yielding hybrids coming to market now. But the life of a palm trees is 25 years or more.
Truth to tell, I do not see a big future in biofuels. Conservation (PHEVs, BEVs) and NG are cheap.
Given how easily a gasoline station can also become a gas station (as I witnessed at the corner of Olympic and La Cienega in Los Angeles) I see no need for heroics in developing biofuels.
A simple gasoline tax of $4 a gallon, and the US car fleet will use less and less oil for decades to come.
Problem solved. Next problem.
We don't need biofuels. I like the idea, but it seems a no-go, business-wise.
BTW: Environmental Capitalism, the WSJ blog, has a nice feature on mini-nukes. And BP World Energy review reports that global oil demand fell in 2008, from 2007. Probably 2009 is down, for a mix of reasons. That will be two years of contraction. Any bets on 2010?
You know what happenes to annually compounded growth projections, when you toss in a few down years?
"Take petroleum, for instance. It offers great convenience, and has been relatively inexpensive for decades."
Yes, too few realize what a bounty petroleum and coal provided. They allowed us to use the solar energy stored in bio-organisms over 300 million years and burn it only a century.
Compressing 300 million years of solar energy into only 100 years allowed us to make a quantum leap in our quality of life.
The problem is, no kind of bio-energy now on the horizon can compress time in the same manner.
I assume that the low requirement associated with e.g. corn is because they are counting only irrigation, not total crop water demand. That makes sense, given that what they are concerned with is footprint (i.e. additional water required) but it does make their analysis geographically dependent.
To refine a bit further on what Wendell said:
Yes, too few realize what a bounty petroleum and coal provided. They allowed us to use the solar energy stored in bio-organisms over 300 million years and burn it only a century.
Compressing 300 million years of solar energy into only 100 years allowed us to make a quantum leap in our quality of life.
Specifically, fossil fuels have allowed humanity to (temporarily) step outside of the planetary metabolic cycle.
Quoting William Ralph Inge, “The whole of nature is a conjugation of the verb to eat, in the active and passive.” Every organism on the planet lives within a whole bunch of metabolic loops of birth and death, consumption and excretion. All "waste" becomes food for something else. There is no waste in nature because any organism that lives for very long outside of this cycle dies off.
Industrial-age humans have stepped outside of these loops, but this is not a state that can persist. The challenge before us is to re-make industrial civilization so that integrates us once again with these cycles.
Takchess
Thanks for Potter Drilling info. I was thinking about posting this also but not many people on this blog seem to be interested in geo-thermal.
Hang in there with you pellet stove. I was even thinking of going into the business at one time when I lived in Oregon.
The pellet extruder is pretty simple (more or less like a regular meat grinder) but needs about 450 degrees to melt the resins in the sawdust into pellets, if I remember correctly.
John
GreenEngineer:
So what is wrong with building lots of nuke plants?
I don't particularly want to go back to the imagined bucolic but actually very, very hard agrarian lifestyle.
"I assume that the low requirement associated with e.g. corn is because they are counting only irrigation, not total crop water demand"
This particular study, they included irrigated water (from ground and surface sources) shown in blue on the chart, and also rainwater, shown in green on the chart.
for the sake of brevity and old age, i offer the same comment entered this day on "ENERGY OUTLOOK"–GEOFF STYLES SITE.
fran
"other studies have shown that jatropha still produces oil under minimal water requirements"
That other study mentioned seems to indicate there is a certain amount of water is needed to maximize Jatropha oil production. If you apply more water, your oil production drops. You apply half that water, you get less than half the oil. You apply 75% of the water, you get less than 75% of the oil. Though it's hard to be sure just from the abstract.
So it seems to me, even though you can get jatropha oil with little or no irrigation on marginal soil, it still wouldn't improve the amount of water needed per GJ of fuel produced. Though it could improve the "Blue WF" to "Green WF" ratio. At the current scale of production, maybe that's enough of a benefit.
"As we turn increasingly to bioenergy in the future …"
I have to see some of the other commenters & raise — that prediction was Dead On Arrival.
The least sustainable item in the world right now is government deficit spending — totally unsustainable, and soon.
The next least sustainable item is running massive trade surpluses with the US. (Yes, that means you, China & Germany. You guys need to find a more sustainable economic model).
One of the many consequences of this unsustainability is that the US Federal government will not long be able to continue to subsidize biofuels. Once someone comes up with a highly profitable biofuel that can pay lots of taxes & still be competitive, we will have biofuels. Until then, …
The future is severe problems (remember, the unsustainable is, well, unsustainable), maybe followed by vastly expanded nuclear power.
This reminds me of why New England has no Old Growth forests:
England was fast using up its forests for creating these
products, and potash became a valued export for the American
colonists.
Pearlash (Pure Ash) was another matter, made by manufacturers
using kilns that burned off all impurities, they were left with
pure sodium hydroxide. There was a global demand for the New
World product.
By the 1770’s England was so deforested due to industrialization, they couldn’t make soda for soap making without imports. Pearlash, or pure potash, was a product England needed so badly it restricted the colony’s export of all New World Pearlash to English buyers.
Potash-making became a major industry in British North America.
Great Britain was always the most important market. The American potash industry followed the woodsman’s ax across the country. After about 1820, New York replaced New England as the most important source; by 1840 the center was in Ohio. Potash
production was always a by-product industry, following from the
need to clear land for agriculture.
By 1850, potash had gained popularity as a fertilizer, but forests available for indiscriminate burning were becoming ever scarcer
Sugar cane can be grown in the US as well. We have vast areas along the Gulf Coast that are suitable for this crop. (and water supply is not an issue). This has the potential to give the US additional oil independence to the tune of 25 billion gallons per year. Cost of production is between $1.50 and $1.80 per gallon.
Sugarcane and sweet sorghum can also effectively be grown in vast portions of Africa and Asia.
You need solid agricultural insights to be successful in biofuel crops. The best way (in terms of investment) is to go with crops that are already being grown in certain areas. To dream of large scale crops where they are not now, is a long and tedious way with plenty of risk. Palm and Jatropha involve long growing (scale up) time. They will be therefore be highly speculative investments.
Benjamin,
Why do you assume I am suggesting a return to an agrarian lifestyle? What I'm suggesting is that we figure out how to have an industrial civilization that doesn't require abuse of the biosphere to function. If we can't (or more likely, can't be bothered to) do that, then we go back to an agrarian lifestyle, whether we like it or not. Probably with a period of really gross industrial feudalism first.
Benjamin wrote "I don't particularly want to go back to the imagined bucolic but actually very, very hard agrarian lifestyle".
This is actually a widespread misunderstanding, based on reading as the norm the distortions that were present in our more recent past and are still there in many current developing countries. Actually, when that lifestyle happens without additional requirements like involuntary rents and taxes or voluntarily applying further effort to improving land (as in pioneering circumstances), average workloads are around 20 hours per person per week – although with sustainable seasonal bursts like harvests, when everybody has to pitch in. It only turns that hard when a peasant population has to carry a lot of others or does additional work like capital improvements. To be sure, if there is a land shortage people can be poor – but that's from not having the land to work, and if anything hours go down (unless outside work is on offer – but that's not agrarian). We have distant historical records of this in our own past, e.g. intervals of peace in the Middle Ages, and more recent ones under colonial regimes, when colonialists found great difficulty getting work out of the natives while they still had earlier lifestyles available (so they undercut those, and imposed forced labour and/or taxes).
as you say the source of the numbers is not verified.
However, I wonder does anyone have a number on the water requirements of algal oil production? I believe there are two important production methods:
1. standard ponds
2. any continuous processes that can recycle water, thus decreasing water use.
If either of these options shows less water use, especially if some of the algae can use brackish water (and likely can) then that will be the solution. In the meantime, the world is just spinning its wheels looking at plants, cultivation, oil extraction, transportation, refining, and their application in existing engines.
Otherwise, i agree minimal water and food impact is the answer.