The Implications of Biofuel Production for United States Water Supplies

In addressing the supply side of oil and gas depletion, much hope has been put into the scaling of 'biofuels', by applying new (and old) technologies to annual crops to create ethanol or biodiesel, thus providing chemically viable alternatives to the transportation liquids derived from crude oil. Much of the biofuels debate thus far has focused on their lower energy balance, vis-a-vis crude oil. While this is important, analysis of the impacts on non-energy inputs and impacts should a massive scaling of biofuels occur, urgently needs to be discussed. The National Academy of Sciences recently published a report titled "Water Implications of Biofuel Production in the United States". The paper outlines impacts and limitations on both water availability and water quality that would follow the pursuit of a national strategy to replace liquid fossil fuels with those made from biomass.

Existing and planned ethanol facilities (2007) and their estimated total water use mapped
with the principal bedrock aquifers of the United States and total water use in year 2000.(Source USGS) Click to enlarge.

Some long time readers of think we have beaten the corn ethanol horse to death. While this may appear true to certain camps (especially ethanol stock investors!), the fact remains that corn ethanol technology is still at the forefront of our nations mitigation responses to 'energy security' and Peak Oil. Production is slated to increase from 5 billion gallons last year to 35 billion gallons in a decade. The DOE projects that biofuels can provide us with 30% of our liquid fuel needs by 2030. However, given that we have limited amounts of high quality resources: crude oil, gasoline, fresh water, breathable air, healthy soil, productive ecosystems, etc., one of the highest policy priorities (in conjunction with attempts to change our conspicuous consumption paradigm) should be to establish the best use of these scarce resources to secure future energy flows. Two of the most precious of these are energy and water, and are the subject of todays post.

This post is a summary of an excellent recent report commissioned by the Natural Resource Council via the National Academy of Sciences, titled "The Implications of Biofuel Production for United States Water Supplies" It can be purchased in book form or downloaded as a pdf here. (Editors note: As I've discussed here recently, two University of Vermont colleagues and I have written a related paper highlighting the critical and limiting role that water will play in future energy production, particularly from bioenergy. "Burning Water - EROWI - The Energy Return on Water Invested", is currently (still) in the review/rejection/resubmittal process so I've been unable to post it here, even though it was written over a year ago). Since corn ethanol looks to still be a key policy issue in the upcoming Presidential primaries in Iowa, I thought a brief overview of this important NAS paper would be informative to our readers. The grey boxes and graphs are from the paper, "Water Implications of Biofuel Production in the United States", interweaved throughout the authors summary. The 'bottom line' and graphic at the end, are my own.

The Implications of Biofuel Production for United States Water Supplies

These were the scientists that oversaw/wrote the report:


JERALD L. SCHNOOR, Chair, University of Iowa, Iowa City
OTTO C. DOERING III, Purdue University, West Lafayette, Indiana
DARA ENTEKHABI, Massachusetts Institute of Technology, Cambridge
EDWARD A. HILER, Texas A&M University, College Station
THEODORE L. HULLAR, Cornell University, Ithaca, New York
G. DAVID TILMAN, University of Minnesota, St. Paul


Because of a strong U.S. national interest in greater energy independence, biofuels have become important liquid transportation fuels and are likely to remain so for the foreseeable future. Currently, the main biofuel in the United States is ethanol derived from corn kernels, with a very small fraction made from sorghum. Biodiesel from soybeans also comprises a small fraction of U.S. biofuels. Ethanol from “cellulosic” plant sources (such as corn stalks and wheat straw, native grasses, and forest trimmings) is expected to begin commercially within the next decade.

US Production of Biofuels from Various Feedstocks 2006 Click to enlarge.

Recent increases in oil prices in conjunction with subsidy policies have led to a dramatic expansion in corn ethanol production and high interest in further expansion over the next decade. President Bush has called for production of 35 billion gallons of ethanol annually by 2017, which, if achieved, would comprise about 15 percent of U.S. liquid transportation fuels. This goal is almost certain to result in a major increase in corn production, at least until marketable future alternatives are developed.

Among the possible challenges to biofuel development that may not have received appropriate attention are its effects on water and related land resources. The central questions are how water use and water quality are expected to change as the U.S. agricultural portfolio shifts to include more energy crops and as overall agricultural production potentially increases. Such questions need to be considered within the context of U.S. policy and also the expected advances in technology and agricultural practices that could help reduce water impacts.

To help illuminate these issues, the Water Science and Technology Board (WSTB) of the National Research Council held a colloquium on “Water Implications of Biofuels Production in the United States” in Washington, D.C., on July 12, 2007, which was attended by more than 130 people from federal and state government, non-governmental organizations, academia, and industry. WSTB established a committee to organize and host the colloquium and to develop this report (see Box 1-1). This report draws some conclusions about the water implications of biofuels productions based on discussions at the colloquium, written submissions of participants, the peer-reviewed literature, and the best professional judgments of the committee.

Water is an increasingly precious resource used for many purposes including drinking and other municipal uses, hydropower, cooling thermoelectric plants, manufacturing, recreation, habitat for fish and wildlife, and agriculture. The ways in which a shift to growing more energy crops will affect the availability and quality of water is a complex issue that is difficult to monitor and will vary greatly by region.

In some areas of the country, water resources already are significantly stressed. For example, large portions of the Ogallala (or High Plains) aquifer, which extends from west Texas up into South Dakota and Wyoming, show water table declines of over 100 feet. Deterioration in water quality may further reduce available supplies. Increased biofuels production adds pressure to the water management challenges the nation already faces.

Some of the water needed to grow biofuel crops will come from rainfall, but the rest will come from irrigation from groundwater or surface water sources. The primary concern with regard to water availability is how much irrigation will be required—either new or reallocated— that might compete with water used for other purposes. Irrigation accounts for the majority of the nation’s “consumptive use” of water—that is the water lost through evaporation and through plant leaves that does not become available for reuse.

FIGURE 1-1 The agricultural water cycle. Inputs to a crop include rainfall and irrigation from surface
water and groundwater. Some water is “consumed” (that is, incorporated in the crop or evapotranspired),
some returns to surface waterbodies for human or ecological use downstream, and some infiltrates into
the ground. Click to enlarge.

Figure 1-1 makes it clear that crop water may originate from one source, such as rain or groundwater, and be discharged to another, such as surface water. Precipitation, groundwater, and surface water sources—and groundwater and surface water discharges—are not only viewed differently in water law and policy, but also have different consequences for long-term sustainable use of the resource base. Since groundwater accounts for almost all of the long-term storage of water on the continents, extracting groundwater for irrigation that is subsequently discharged to streams may decrease the water available for future users of the aquifer.

The question of whether more or less water will be applied to biofuel crops depends on what crop is being substituted and where it is being grown. For example, in much of the country, the crop substitution to produce biofuel will be from soybeans to corn. Corn generally uses less water than soybeans and cotton in the Pacific and Mountain regions, but the reverse is true in the Northern and Southern Plains, and the crops use about the same amount of water in the North Central and Eastern regions.

FIGURE 1-2 Irrigated land in the United States. Note that most of this is located in the more arid regions
of the country. SOURCE: N. Gollehon, USDA ERS, written commun., July 12, 2007. Based on data
from U.S. Department of Agriculture (USDA) Economic Research Service (ERS) Census of Agriculture.. Click to enlarge.

Understanding water quantity impacts is dependent on understanding the agricultural water cycle depicted in Figure 1-1. Crops can be either rainfed or irrigated (see Figure 1-2). Irrigation water can come from groundwater or surface water, and groundwater can be withdrawn from either a surficial aquifer (connected directly to the surface) or a confined aquifer (overlain by a low permeability layer, or aquitard, such as clay). Some of the applied water is incorporated into the crop, but most of it leaves the fields as (1) evaporation from the soil and transpiration from plants (called evapotranspiration or ET), (2) runoff to rivers and streams (sometimes called “return flow”), and (3) infiltration to the surficial aquifer. The water that is incorporated into the crops or lost to evapotranspiration is referred to as “consumptive use,” because it cannot be reused for another purpose in the immediate vicinity. Rates of ET vary greatly by the type of crop. During a growing season, a leaf will transpire many times more water than its own weight. An acre of corn gives off about 3,000- 4,000 gallons of water each day while a large oak tree can transpire 40,000 gallons per year (USGS, 2007). Grasses that might be in cellulosic production have a slightly higher ET rate than corn, but considerably a lower ET rate than trees.

Projection of ethanol production by feedstock assuming cellulose-to-ethanol production
begins in 2015. Dedicated energy crops refer to those grown solely for energy production.
SOURCE: D. Ugarte, University of Tennessee Click to enlarge.

Distribution of the production of cellulosic materials in dry tons by the year 2030.
SOURCE: D. Ugarte, University of Tennessee Click to enlarge.

There are many uncertainties in estimating consumptive water use of the biofuel feedstocks of the future. Water data are less available for some of the proposed cellulosic feedstocks—for example, native grasses on marginal lands—than for widespread and common crops such as corn, soybeans, sorghum, and others. Neither the current consumptive water use of the marginal lands nor the potential water demand of the native grasses is well known. Further, while irrigation of native grass today would be unusual, this could easily change as production of cellulosic ethanol gets underway.


FIGURE 2-1 Regional irrigation water application for various crops for six regions of the United States.
Irrigation application is normalized by area, and is in feet. SOURCE: N. Gollehon, U.S. Department of
Agriculture (USDA) Economic Research Service (ERS), written commun., July 12, 2007. Based on data
from USDA Census of Agriculture.Click to enlarge.

Shifting land from an existing crop (or noncrop plant species) to a crop used in biofuel production has the potential to change irrigation water use, and thus the local water availability. Conversion to the different type of biomass will result in increased water use in some cases, in other cases a decrease. As an example, in much of the country, the crop substitution is from soy to corn. The regional effects of this can be seen in Figure 2-1. Corn generally uses less water than soybeansand cotton in the Pacific and Mountain regions. The reverse is true in the Northern and Southern Plains, and the crops use about the same amount of water in the North Central and Eastern regions. Changes in agricultural water use would generally parallel these trends. Another example is in Northern Texas, where annual evapotranspiration (ET) rates per year for alfalfa, corn, cotton, and sorghum are estimated to be about 1,600, 760, 640, and 580 mm (63, 30, 25, and 23 inches), respectively. Therefore, regional water loss to ET will likely decrease if alfalfa acreage is converted to corn, but increase if cotton or sorghum is converted.

FIGURE 2-2 State-by-state water requirements in 2003 of irrigated corn (gallons of irrigation water per
bushel). SOURCE: N. Gollehon, USDA ERS, Based on data from
2003 Farm and Ranch Irrigation Survey (USDA, 2003).
Click to enlarge.

Given the regional differences in rainfall and groundwater storage, the feasibility and sustainability of biofuel crop production as a function of water availability may vary significantly by region. Figure 2-2 shows the state-by-state water requirement of irrigated corn in the continental United States. It demonstrates that the amount of rainfall and other hydroclimate conditions in a given area causes significant (10-fold) variations in the water requirement for the same crop. Clearly there will be geographic limits on certain kinds of biofuels feedstock simply based on their water requirements.

In the next 5 to 10 years, increased agricultural production for biofuels will probably not alter the national-aggregate view of water use. However, there are likely to be significant regional and local impacts where water resources are already stressed.

Water Quality Impacts

FIGURE 3-1. Comparison of fertilizer (top) and pesticide (bottom) application rates for corn, soybean,
and low-input high-diversity (LIHD; “biomass” in the figure) mixtures of native grassland perennials.
Fertilizer and pesticide application rates are U.S. averages. SOURCE: Tilman et al. (2006).
Click to enlarge.

Biomass feedstocks such as corn grain, soybeans, and mixed-species grassland biomass differ in current or proposed application rates of fertilizers and of pesticides. Of these three potential feedstocks, the greatest application rates of both fertilizer and pesticides per hectare are for corn (Figure 3-1). Phosphorus application rates are somewhat lower for soybeans than for corn. Nitrogen application rates are much lower for soybeans than for corn because soybeans, which are legumes, fix their own nitrogen from the atmosphere. Pesticide application rates for soybean are about half those for corn. The native grasses compare highly favorably to corn and soy for both fertilizers and pesticides, with order-of-magnitude lower application rates.

FIGURE 3-2 (left) N fertilization rates and stream concentrations of nitrate. (right) Atrazine
application rates and stream concentrations of atrazine. FIGURE SOURCE: J. Ward, U.S.
Geological Survey.
Click to enlarge.

The impacts of these differences in inputs can be visualized nationally by comparing N inputs (such as fertilizer and manure) and the concentrations of nitrate in stream water (Figure 3-2, left). There are similar patterns for stream concentrations of atrazine, a major herbicide used in corn cultivation (Figure 3-2, right), although the environmental effects of pesticides in current use are difficult to decipher. Both of these maps show that regionally the highest stream concentrations occur where the rates of application are highest, and that these rates are highest in the U.S. “Corn Belt.”

FIGURE 3-3 Dissolved oxygen contours (in milligrams per liter) in the Gulf of Mexico, July 21-28,
2007. SOURCE: Slightly modified from

Click to enlarge.

The effects of biomass production on the nation’s coastal and offshore waters may be considerable. Nitrogen in the Mississippi River system is known to be the major cause of an oxygen-starved “dead zone” in the Gulf of Mexico (Figure 3-3), which in 2007 was the third largest ever mapped ( The condition known as hypoxia (low dissolved oxygen) occurs because elevated N (and, to a lesser extent, P) loading into the Gulf leads to algal blooms over a large area. Upon the death of these algae, they fall to the bottom and their decomposition consumes nearly all of the oxygen in the bottom water. This is lethal for most fish and other species that live there.

FIGURE 3-5 Environmental effects from the complete production and combustion lifecycles of corn
grain ethanol and soybean biodiesel. The figure shows the application of both (a) fertilizers and (b) and
pesticides, per unit of net energy gained from biofuel production. SOURCE: Hill et al., 2006
Click to enlarge.

There are many possible metrics, but an index that builds on the work shown in Figure 3-1 is inputs of fertilizers and pesticides per unit of the net energy gain captured in a biofuel. To estimate this first requires calculation of a biofuel’s net energy balance (NEB), that is, the energy content of the biofuel divided by the total fossil energy used throughout the full lifecycle of the production of the feedstock, its conversion to biofuel, and transport. U.S. corn ethanol is most commonly estimated to have a NEB of 1.25 to 1.3, that is, to return about 25-30 percent more energy, as ethanol, than the total fossil energy used throughout its production lifecycle. The NEB estimated for U.S. soybean biodiesel is about 1.8 to 2.0, or about a 100 percent net energy gain. Switchgrass ethanol via fermentation is projected to be much higher—between 4 and 15. Similarly high are the estimates for (a) cellulosic ethanol and (b) synthetic gasoline and diesel from certain mixtures of perennial prairie grasses, forbs, and legumes (NEB=5.5 and 8.1, respectively). Per unit of energy gained, corn ethanol and soybean biodiesel have dramatically different impacts on water quality. When fertilizer and pesticide application rates (Figure 3-1) are scaled relative to the NEB values of these two biofuels, they are seen to differ dramatically (Figure 3-5). Per unit of energy gained, biodiesel requires just 2 percent of the N and 8 percent of the P needed for corn ethanol. Pesticide use per NEB differs similarly. Low input high-diversity prairie biomass and other native species would also compare favorably relative to corn using this metric. This is just one possible metric of biofuels’ impact on water quality. Other measures might incorporate land requirements per unit of biofuel, soil erosion, or impacts of the associated biorefinery

Fertilizers applied to increase agriculture yields can result in excess nutrients (nitrogen [N] and to a lesser extent, phosphorous [P]) flowing into waterways via surface runoff and infiltration to groundwater. Nutrient pollution can have significant impacts on water quality. Excess nitrogen in the Mississippi River system is known to be a major cause of the oxygen starved “dead zone” in the Gulf of Mexico, in which many forms of marine life cannot survive. The Chesapeake Bay and other coastal waterbodies also suffer from hypoxia (low dissolved oxygen levels) caused by nutrient pollution. Over the past 40 years, the volume of the Chesapeake Bay’s hypoxic zone has more than tripled. Many inland lakes also are oxygen starved, more typically due to excess levels of phosphorous.

Corn, soybeans, and other biomass feedstocks differ in current or proposed rates of application of fertilizers and pesticides. One metric that can be used to compare water quality impacts of various crops are the inputs of fertilizers and pesticides per unit of the net energy gain captured in a biofuel. Of the potential feedstocks, the greatest application rates of both fertilizer and pesticides per hectare are for corn. Per unit of energy gained, biodiesel requires just 2 percent of the N and 8 percent of the P needed for corn ethanol. Pesticide use differs similarly. Low-input, high-diversity prairie biomass and other native species would also compare favorably relative to corn using this metric.

Another concern with regard to water quality is soil erosion from the tillage of crops. Soil erosion moves both sediments and agricultural pollutants into waterways. There are various farming methods that can help reduce soil erosion. However, if biofuel production increases overall agricultural production, especially on marginal lands that are more prone to soil erosion, erosion problems could increase. An exception would be native grasses such as switchgrass, which can reduce erosion on marginal lands.

All else being equal, the conversion of other crops or non-crop plants to corn will likely lead to much higher application rates of N, which could increase the severity of the nutrient pollution in the Gulf of Mexico and other waterways. However, it should be noted that recent advances in biotechnology have increased grain yields of corn per unit of applied N and P.


There are many agricultural practices and technologies that, if employed, can increase yield while reducing the impact of crops on water resources. Many of these technologies have already been developed and applied to various crops, especially corn, and they could be applied to cellulosic feedstocks. Technologies include a variety of water-conserving irrigation techniques, soil erosion prevention techniques, fertilizer efficiency techniques, and precision agriculture tools that take into account site-specific soil pH (acidity, alkalinity), soil moisture, soil depth, and other measures. Best Management Practices (BMPs) are a set of established methods that can be employed to reduce the negative environmental impacts of farming. Such practices can make a large, positive environmental impact. For example, in 1985, incentives were put in place to encourage adoption of conservation tillage practices. According to data from the National Resources Inventory (NRI), maintained by the Natural Resources Conservation Service, overall annual cropland erosion fell from 3.06 billion tons in 1982 to about 1.75 billion tons in 2003, a reduction of over 40 percent (

In addition, biotechnologies are being pursued that optimize grain production when the grain is used for biofuel. These technologies could help reduce water impacts by significantly increasing the plants’ efficiency in using nitrogen, drought and water-logging tolerance, and other desirable characteristics.


FIGURE 5-2 The overall water balance of a typical 50 million gallon per year corn-based Dry Mill
ethanol production facility. All figures are in gallons per hour. SOURCE: Courtesy of Delta-T Corp.
Click to enlarge.

Assuming the common figure of about 2.7 gallons of ethanol from one bushel of corn, 2,100 gallons of water/bushel * 1 bushel/2.7 gallon of ethanol = about 780 gallons of water per gallon of ethanol. (Additionally), current estimates of the consumptive water use from biorefinery facilities are in the range of 4 gallons of water per gallon of ethanol produced (gal/gal) (Pate et al., 2007). For perspective, consumptive water use in petroleum refining is about 1.5 gal/gal. Overall water use in biorefineries may be as high as 7 gal/gal, but this number has been consistently decreasing over time and as of 2005 was only slightly over 4 gal/gal in 2005. Thus for a 100 million gallon per year plant, a little over 400 million gallons of water per year would be withdrawn from aquifers or surface water sources (1.1 million gallons per day). The total water requirements for ethanol from cellulose are thought to be large—about 9.5 gal/gal, but this likely will decline as efficiency increases with experience at cellulosic-ethanol plants.

Existing and planned ethanol facilities (2007) and their estimated total water use mapped
with the principal bedrock aquifers of the United States and total water use in year 2000. Click to enlarge.

Siting of some ethanol plants is occurring where the water resource is already under duress. Figure 5-3 shows, for example, that many bioethanol plants that each require 0.1-1.0 million gallons per day are located on the High Plains aquifer. This aquifer is currently being pumped at a rate of more than 1.5 billion gallons per day for agriculture, municipalities, industry, and private citizens. Thus, 15 million gallons per day for bioethanol would represent only 1% of total withdrawals. But it is an incremental withdrawal from an already unsustainable resource. Current water withdrawals are much greater than the aquifer’s recharge rate 0.02 to 0.05 foot per year in south-central Nebraska, resulting in up to 190-foot decline in the water table over the past 50 years. It is equivalent to “mining” the water resource, and the loss of the resource is essentially irreversible.

All biofuel facilities require process water to convert biomass to fuel. Water used in the biorefining process is modest in absolute terms compared to the water applied and consumed in growing the plants used to produce ethanol. However, because this water use is concentrated into a smaller area, its effects can be substantial locally. A biorefinery that produces 100 million gallons of ethanol per year would use the equivalent of the water supply for a town of about 5,000 people. Consumptive use of water in biorefineries is largely due to evaporation losses from cooling towers and evaporators during the distillation of ethanol following fermentation. However, consumptive use of water is declining as ethanol producers increasingly incorporate water recycling and develop new methods of converting feedstocks to fuels that increase energy yields while reducing water use.

Water Quality of Waste Streams from Two Existing Ethanol Facilities in Iowa
Click to enlarge.

Ethanol plants have various waste streams. First, salts build up in cooling towers and boilers due to evaporation and scaling, and must be periodically discharged (“blowdown”). Second, the technologies used to make the pure water needed for various parts of the process (e.g., reverse osmosis [RO], ion exchange, iron removal; not shown in Figure 5-1) result in a brine effluent. Under the National Pollutant Discharge Elimination System (NPDES) permits are required from the states to discharge this effluent. These permits often cover total dissolve solids (TDS), acidity, iron, residual chlorine, and total suspended solids. Table 5-1 gives chemical characteristics of waste water from the RO operation and from the cooling tower blowdown for two plants in Iowa. Some violations of NPDES permits have been reported in Iowa and Minnesota from ethanol facilities, primarily for TDS.


Subsidy policies for corn ethanol production coupled with low corn prices and high oil prices have driven the dramatic expansion of corn ethanol production over the past several years. These policies have been largely motivated to improve energy security and provide a cleanburning additive for gasoline. As biofuel production expands, and particularly as new cellulosic alternatives are developed, there is a real opportunity to shape policies to also meet objectives related to water use and quality impacts.

As total biofuels production expands to meet national goals, the long-term sustainability of the groundwater and surface water resources used for biofuel feedstocks and production facilities will be key issues to consider. From a water quality perspective, it is vitally important to pursue policies that prevent an increase in total loadings of nutrients, pesticides, and sediments to waterways. It may even be possible to design policies in such a way to reduce loadings across the agricultural sector, for example, those that support the production of feedstocks with lower inputs of nutrients.

Cellulosic feedstocks, which have a lower expected impact on water quality in most cases (with the exception of the excessive removal of corn stover from fields without conservation tillage), could be an important alternative to pursue, keeping in mind that there are many uncertainties regarding the large-scale production of these crops. There may be creative alternatives to a simple subsidy per gallon produced that could help protect water quality. Performance subsidies could be designed to be paid when specific objectives such as energy conversion efficiency and reducing the environmental impacts of feedstock production— especially water quality—are met.

Biofuels production is developing within the context of shifting options and goals related to U.S. energy production. There are several factors to be considered with regard to biofuels production that are outside the scope of this report but warrant consideration. Those factors include: energy return on energy invested including consideration of production of pesticides and fertilizer, running farm machinery and irrigating, harvesting and transporting the crop; the overall “carbon footprint” of biofuels from when the seed is planted to when the fuel is produced; and the “food vs. fuel” concern with the possibility that increased economic incentives could prompt farmers worldwide to grow crops for biofuel production instead of food production.


Currently, biofuels are a marginal additional stress on water supplies at the regional to local scale. However, significant acceleration of biofuels production could cause much greater water quantity problems depending on where the crops are grown. Growing biofuel crops in areas requiring additional irrigation water from already depleted aquifers is a major concern.

The growth of biofuels in the United States has probably already affected water quality because of the large amount of N and P required to produce corn. The extent of Gulf hypoxia in 2007 is among the three largest mapped to date, and the amount of N applied to the land is also at or near its highest level. If not addressed through policy and technology development, this effect could accelerate as biofuels expand to 15 percent of domestic usage to meet President Bush’s 2017 goal, or to 30 percent of domestic fuel usage as proposed by President Bush as the ultimate goal.

If projected future increases in the use of corn for ethanol production do occur, the increase in harm to water quality could be considerable. Expansion of corn on marginal lands or soils that do not hold nutrients can increase loads of both nutrients and sediments. To avoid deleterious effects, future expansions of biofuels may need to look to perennial crops, like switchgrass, poplars/willows, or prairie polyculture, which will hold the soil and nutrients in place.

To move toward a goal of reducing water impacts of biofuels, a policy bridge will likely be needed to encourage development of new technologies that support cellulosic fuel production and develop both traditional and cellulosic feedstocks that require less water and fertilizer and are optimized for fuel production. Policies that better support agricultural best practices could help maintain or even reduce water quality impacts. Policies which conserve water and prevent the unsustainable withdrawal of water from depleted aquifers could also be formulated.

end National Academy of Sciences
begin Nate...


As discussed often here in the past, biofuels not only have a much lower energy return vis-a-vis conventional crude, but have between one and two orders of magnitude lower in power density, (or how much energy we get per unit of land). Furthermore, in our 'Burning Water' paper, (and alluded to here in this NAS report), biofuels also require significantly more water than even the least efficient fossil fuel systems. There are also concerns about pesticides, nitrate and other environmental impacts. So when replacing energy with a 'substitute', all other things do not usually remain equal. I commend the National Academy scientists for highlighting what will be a central issue in upcoming natural resource science - that of systems, and tradeoffs.

It is highly likely we will have liquid fuel shortages in the not too distant future, either via higher prices, or through actual unavailability or rationing. The chart below (thanks Khebab) shows the progression of year over year declines, in different colored lines, of United States oil production. The trend is reasonably clear. We have found the cheap and easy oil.

Energy and water are but 2 of the central inputs that power our modern society. Many of the key resources are either not currently valued by the market system, or may give too late a market signal of scarcity for effective mitigation. The figure above (not from the NAS report..;) gives a conceptual example of potential tradeoffs that a concerted efforts to increase liquid fuel production (or any limiting variable that has linkages to other limiting inputs) might engender. The columns on the left in blue (and red) are when we are in a perceived liquid fuels shortfall. The columns in purple are hypothetical amounts of resources remaining after a portion has been devoted to an 'increase liquid fuel policy'. Focusing on the limiting input du-jour risks pulling in more resources from the periphery which are currently non-limiters. As can be visualized, successful addition of the variable in shortage may come at a cost, which might not be immediately visible or financially recognized, but a cost nonetheless.

We CAN increase our internal production of transportation liquids. In addition to ethanol and biodiesel, we can use coal-to-liquids via Fischer Tropsch; we can drill the Arctic or Alaska Wildlife Refuge; we can expand land to dedicated energy crops, etc. A joint study of the U.S. Department of Energy and the U.S. Department of Agriculture concludes that the United States could produce 60 billion gallons of ethanol by 2030 through a combination of grain and cellulosic feedstocks, enough to replace 30% of projected U.S. gasoline demand. Scientists and policymakers should be asking them 'at what cost'? When they reply XX billions, the comeback should be 'we didn't mean in $ terms-what are the costs in other scarce inputs needed by society?'. In robbing Peter to pay Paul, we have to realize that Paul is pretty insatiable. Who will we rob after Peter?

The subject of the origins of exponential growth, habituation and "Pauls" addiction to oil will be the subject of next weeks post.

Superb post!

Your conclusion:


A joint study of the U.S. Department of Energy and the U.S. Department of Agriculture concludes that the United States could produce 60 billion gallons of ethanol by 2030 through a combination of grain and cellulosic feedstocks, enough to replace 30% of projected U.S. gasoline demand. Scientists and policymakers should be asking them 'at what cost'? When they reply XX billions, the comeback should be 'we didn't mean in $ terms-what are the costs in other scarce inputs needed by society?'. In robbing Peter to pay Paul, we have to realize that Paul is pretty insatiable. Who will we rob after Peter?

The subject of the origins of exponential growth, habituation and "Pauls" addiction to oil will be the subject of next weeks post.

(End of quote)

Deserves to be broadcast far and wide.

The presidential debates ought to include summaries like this, and also questions like:

"What kind of integrated national policy to address the various environmental issues we face will you implement? Please include issues such as global warming, peak oil, peak water, peak natural gas, and peak soil in your answer."

We need an intentional, informed, and integrated national path to sustainability.

"The presidential debates ought to include summaries like this, and also questions like:

"What kind of integrated national policy to address the various environmental issues we face will you implement? Please include issues such as global warming, peak oil, peak water, peak natural gas, and peak soil in your answer."

Me thinks we need a completely different crop (no pun intended) of presidential candidates, the current one doesn't seem to have a clue or they haven't got the guts say what needs to be said.

Good Luck to all of us.

There is a whole lotta things that should be discussed at a national level - energy is just one of 'em.

So far no one has made a 'Hey, discuss these things' web site as a social web offering.

Has anybody thought of growing sugar beets for ethanol in the high plains/Canada?

I again sugest growing plants in the sea to be used to make biofuel
A study of arctic climatology reported that azolla may have had a
significant role in reversing a greenhouse effect that occurred 55
million years ago that caused the region around the north pole to turn
into a hot tropical environment. This research conducted by the
Institute of Environmental Biology at Utrecht University claims that
large dense patches of azolla growing around freshwater lakes formed by
the climate change eventually consumed enough carbon dioxide for the
greenhouse effect to reverse.
"Leaf protein isolate from water hyacinth (Eichornia crassipes) was
prepared and the chemical composition was studied. It contained 49.6%
protein, 16.0% total lipids, 26.9% total carbohydrates, 1.7% fibre
and 5.8% ash."

T. M. Abo Bakr, N. M. El-Shemi and A. S. Mesallam (1983,
January).Isolation and chemical evaluation of protein from water
hyacinth. Retrieved May 30, 2007, from the SpringerLink website:

I guess the question would be: what are the chain lengths of the
resultant oils, and whether sufficient bulk of material could be
produced cheaply enough to make up for lower lipid concentration.

Warning, this is the water plant from hell. I grew up in Florida and
it choked the waterways down there. Yeah it grows fast, and God help
you if it gets out into native waterways in a tropical/subtropical
region. I did see a controlled usage at Walt Disney World in
Kissimmee where it was used as a part of the wastewater treatment
facility there.

I am confused a bit. You discuss azolla, then reference water hyacinth.

Azolla still exists, are you just suggesting the water hyacinth would work even better?

basic idea grow a water plant in costal area with agricultural municipal runoff and convert this plant to fuel and soil.

I don't know about north america, but the sugar beet is used elsewhere. An ethanol producer here in Sweden is suggesting sugar beets. Looks better than say wheat, not to mention corn. Best efficiency is achived when the ethanol plant is operationg in tandem with a biogas (methane) plant, generation methane for the by-product. Or the by-product can be used as a high value animal feed.

France has substantial production from sugar beets, according to them one hectar of beets produces in excess of 8000 liters of ethanol. Or more than ~855 gallons per acre.’ethanol-a-partir-de-betteraves/

The link i sin french, but google does a servicable translation.

855 gallons/acre from beets vs. 400 gallons/acre from corn.

US Cropland: 442 million acres (20 percent of the land area)

1 bushel of corn yields 2.5 gallons of ethanol.

1 acre yields 160 bushels. (All-time record in 2004.)

1 acre yields 400 gallons of ethanol (2.5 x 160).

One gallon net takes 3 to produce (optimistic EROEI of 1.34 to 1 so
400/4 = 100)

442 million acres x 100 = 44.2 billion gallons net return

Ethanol has less energy density 44.2/1.5 = 29.5 billion gallons net ethanol

We use 144 billion gallons of gasoline per year

29.5 is 21% of 144 billion demand.

To summarize: we could plant the entire US cropland in corn for ethanol. No more food for anyone and that would only account for 21% of our gasoline needs .

I believe the nails are all but in the coffin for corn-based ethanol. But I am hearing (from not one but numerous sources) that there are some new biotechnologies that will become commercial in the next few years that are show stoppers (from an energy and profitability standpoint). Like 10+ EROIs. I'm not sure if they are real or not because most of it is 'in the lab'. But what I am sure of, and quite concerned about, is that people need to start thinking in wide boundary terms. Will I make $$ on this biofuel at the expense of borrowing from the local and regional commons etc.? Will I get more liquid fuels but then run low on natural gas? Linkages are tighter than the market is telling us, because a)we price things at the marginal unit, so everything is copasetic until its not and b)many of the things we truly need (water quality, trees, fresh air, dolphins, etc) are not included in decisionmaking/moneymaking models.

Ya - its become evident that corn ethanol doesn't make sense as a national policy. It was a knee jerk reaction to high oil prices - we need to be smarter about large scale deployment going forward - and we need to look at the source - why do we want more and is more good for us?

It might not be corn but rather corn ears that are the problem. A friend sent me this link about tropical maize that gets very sugary in the stalk (25%) when grown at higher latitudes. There may be some evidence that Algonquin cultivated this variety for sugar. Corn does not need a lot of nitrogen until it starts to set ears.


sugary in the stalk

Such should not be shocking - cellulose (way oversimplified) is a complex sugar. And a few old references for making distilled ethynol suggest stalk from sweetcorn.

I think you're right about the nails being put in the coffin for corn ethanol. The fact that it's an ineffective oil displacement fuel is becoming widely accepted. Corn is being seen now as what the biofuels research arm of the University of Tennessee has termed a "first generation feedstock" for the ethanol infrastructure that's being built. They are hard at work developing high net energy switchgrass feedstocks that are inedible and not a food inflation problem. Even the science challenged U.S. Congress is mulling over things like all new ethanol infrastructure facilties built after 2012 being noncorn based. But all fuel crops are going to induce a huge water problem. Even without the dire need for fuel crops and the lucrative export driven economic growth they imply, the developing populations of the world are becoming desparate for water that's fit for human consumption. The U.N. estimates that 80% of the hospital beds in the world are occupied by cases of drinking bad water. There is a tandem bull market emerging in agriculture and water while everyone debates runnin' on corn sqeezins just as there was a bull market emerging in oil 4 years ago with everyone poking fun at peak oil.

I hear you, I hear you.

I think it was known from the start that corn-based ethanol wasn't a viable alternative.

When you guys over there started to crank upp production of corn-based ethanol, I had a hard time believing that people really thought it was a good idea. Political lobbying from the farmers yes, but seriously a good idea for a fuel source? Wheat has a better EROI, at least a positive one anyway. But wheat is not a really good crop for ethanol production either. Sugarcane is. Heck, sugar beets have much better yield per acre compared to corn. There is everal alternatives to corn that is better.

A cellulosic process is the only real saver for corn-based ethanol. But a true cellulosic process don't need to be based on corn, it can be based on wood, grasses whatever has the best yield locally.

A better way would be to make biogas (methane) from corn instead, it has a much better EROI. The by-product can be used as a fertilizer for the next planting. If you absolutely have to use corn for energy production.

"A joint study of the U.S. Department of Energy and the U.S. Department of Agriculture concludes that the United States could produce 60 billion gallons of ethanol by 2030 through a combination of grain and cellulosic feedstocks, enough to replace 30% of projected U.S. gasoline demand."

Hi Nate, nice article. About the part above, are you talking about the 2005 Oak Ridge National Lab report referred to as the “Billion Ton Study.” I found this quote from the ORNL web site:

Jonathan Mielenz, leader of the Bioconversion Science and Technology Group in ORNL's Biosciences Division, says, "The Billion Ton study was a critical contribution because it provided evidence for the biomass ethanol and chemical industries that a real and substantial resource base could be potentially available from which to build their businesses. This knowledge gave decision makers in government and elsewhere credible arguments to support funding and policy decisions needed for a fledgling biorefinery industry."

The study seemed to come across as a bit promotion piece meant to satisfy the desires of the administration to find 'an answer' to liquid fuel imports. Given the more recent news about biofuels, I wonder how they feel about that report now? However, they were emphasizing future cellulosic, not starch-based like today.

Furthermore, I interviewed David Fridley of the Berkeley Lab and he said their biomass numbers were highly inflated, and the logistics of using that biomass became ridiculous.

Wondering if anyone else has looked carefully at that report from your sort of perspective (which I consider sane).

And David's entire presentation is on DVD (I, editor):

Here is information (The Myths of Biofuels).

Nate…nice piece. In reading about biofuels, as a non-specialist, it seems that there is this desperate attempt to maintain liquid fuels. Why not move away from liquid fuels? Why not move away from the internal combustion engine? Why not diversify transportation with non liquid-fuel energy sources? Essentially, what we are trying to do is to preserve transportation and with that the economy. Why another liquid fuel that is only scalable if we become vastly more efficient?

Interesting to note, that for all the hype about fuel cells and liquid fuels, it’s the battery that’s dominating the short half life devices: laptops, power tools, cell phones, etc.. Still think that is the better road. The foundation is being built.

They are the best energy store we have so far and outside of some very high surface area battery or capacitor will probably remain the best for chemical energy. The constraints are pretty much set because of chemical bond energy. I can't rule out some sort of nano-tube based battery/capacitor as coming close.

However even if we stick with liquid fuels for transport we should move to fuel cells for energy conversion since they are a lot more efficient vs a internal combustion engine.

Next this is a issue only in cases that it does not make sense to use batteries for short distances or electric lines for longer distances. Electricity could fulfill a lot of our transport needs. And batteries can fill even more niches.

I think we will always use liquid fuels and probably quite a bit for other use cases that are not amendable to electrification.
1.) Airplanes
2.) Remote farms
3.) Ships (probably in conjunction with sail )

I find it a bit ironic that the off grid remote homes may eventually be one of the primary users of liquid fueled SUV/Trucks.

What we should be doing is converting extensively to electricity to minimize the number of use cases for liquid fuels. Then once they are at the minimum we can decide how to produce them in a clean manner this need not be renewable. If we have been very conservative with our liquid hydrocarbon usage then we could have had them for thousands of years which would have given us plenty of time to find replacements. So prudent use of a non-renewable resource is not all that bad.

"we should move to fuel cells for energy conversion since they are a lot more efficient vs a internal combustion engine."

Don't know the validity but this claims not:

there are a number of other systems that must be included in the overall efficiency analysis of a fuel cell-powered vehicle-the electronic inverter, motor, air compressor (fuel cells needs oxygen that must come from the air) and the energy needed to get the hydrogen fuel stored in the tank of the vehicle. These subsystems have their own efficiency conversions that calculate out as follows: Inverter 90%, motor 90%, air compressor 80% and hydrogen storage (compressed gas) at about 85%. Multiplying these efficiencies by the earlier values given for the HHV and LHV efficiencies gives us something like 14%-28% and 24-34% respectively.

Notice that even the overly-optimistic LHV efficiency falls short of some state-of-the art Diesels, natural gas and high-compression alcohol engines (40% LHV); this is a point that is often glossed over when hydrogen automotive fuel cells are discussed

Great article and just like stated, it's not only water, but arable land, fossil inputs required, biomass transport requirements and CO2/fine particle emissions.

The situation does look unsustainable for most of the current generation biofuels and even several "upcoming" processes/sources.

We just had a media 'incident' about bio-diesel in Finland surrounding Neste Oil and it's production of NExBTL (palm oil as feed).

The background situation is this. A Finnish governmental body awarded an ecological award to NExBTL biodiesel. It has been advertised and branded as "saving the climate" type of solution. Fill her up and save the world, so to speak.

Well, the truth appears to be something like this (for palm oil feed):

The axes in Finnish, but the units should speak for themselves.

Of course, water is not an issue for Finns, when:

1) Everybody thinks we already have too much of it here in Finland (really difficult to explain, but think thousands and thousands of lakes everywhere)

2) When it's produced in Indonesia, it's not our water that's lost

I'm sorry to say, but that's how people here think (not that different from other other places, is it?).

So, it's not a surprise that some enviro-orgs are trying to make a media issue out of this. Some Greenpeace activists were arrested trying to "prevent" a tanker coming to shore that was supposedly carrying palm oil from Indonesia. Well of course it was a symbolic effort, they could not have actually prevented anything, but the ensuing media battle did it's job.

Swedish gasoline distributor is giving up (for now) on Neste Oil NExBTL.

Now, that's one story.

My personal questions are, and I don't claim to have the answers:

1) should we let the perfect to be the enemy of good?

2) Should we allow unsustainable biomass using biofuel processes be started up, if they are guaranteed to switch over to sustainable feeds after a period of time (say waste fat from food processing industry, etc)?

3) Should we just abstain from all biofuel processes that are, as shown above, clearly detrimental to water reserves (not to mention having ghg emissions and other issues)? Wait for non-detrimental processes to come out of the lab?

4) If not biofuels, then what to fill the bio-fuel gap? It seems nobody is willing to ask/accept the hard questions: how can we use _less_? Who's willing to cut down on usage? How?

Now, my own stance is, that I'm not for 1st generation biofuels, but then again I don't have a constructive alternative, other than: "hey, let's all use less. A LOT less."

You can imagine how well that goes down as a solution suggestion :)

My take is that, once US sobers up on it's own production (1st gen), it'll start buying ALL biomass/biofuel it can get from Indonesia/Malaysia/Brazil/etc, regardless of water usage, emissions, certifications, etc.

Economy is just too important to sacrifice. Or that's what they say.

My personal questions are, and I don't claim to have the answers:

1) should we let the perfect to be the enemy of good?

2) Should we allow unsustainable biomass using biofuel processes be started up, if they are guaranteed to switch over to sustainable feeds after a period of time (say waste fat from food processing industry, etc)?

3) Should we just abstain from all biofuel processes that are, as shown above, clearly detrimental to water reserves (not to mention having ghg emissions and other issues)? Wait for non-detrimental processes to come out of the lab?

4) If not biofuels, then what to fill the bio-fuel gap? It seems nobody is willing to ask/accept the hard questions: how can we use _less_? Who's willing to cut down on usage? How?

Those are hard questions, but good ones. Any project should be rated on multicriteria scale across a spectrum of limiting variables (such as the ones suggested in my graph). At some threshhold, these projects are disallowed. There probably is a place for 'unsustainable' and bad environmental choices in the short run if they are linked to a long term plan which includes a change in consumption habits.

We will not find a perfect answer, but we need to be smart about using resources to find 'reasonable' answers. If people are educated about wide-boundary impacts of our energy policy, there will be that much more market disincentive to borrow from the commons as well as positive incentive to change. Heck if I didn't have an MBA, I might have been cut out for Greenpeace...;)

Nice post Nate.

The whole biofuels push is quite a spectacle.

If it weren't for Washington's willingness to dole out subsidies - and for businesses in the US to ask for them - this would not be an issue. Without federal subsidies, biorefineries wouldn't look remotely profitable with corn and oil at their current, respective prices. Corn would remain a food, and corn-derived ethanol would remain something produced locally as a fringe-fuel, which is about all it's good for.

My $0.02.


The whole biofuels push is quite a spectacle.

Ahhh, but coal and oil are biofuels too! *wink*

With its near-terminal energy returns and land requirements, ethanol is nearly totally fundamentally impossible. However it is worse. Not one industrial life-cycle energy study (including that of the grand pessimist hisself-David Pimentel) includes the energy cost to get the ethanol to the cars.

Farmers are now crying for more subsidies because they can't afford to drive ethanol tanker trucks at a profit. Crude and gasoline already have a pipeline infrastructure, but the mini ethanol plants are stranded.

You can convert cars in rural areas to run on ethanol. Wouldn't that make more sense than growing corn in Iowa and shipping it to California?

And if farmers and ethanol refineries are demanding more subsidies, it would seem a logical course of action for energy activists would be to oppose them. Ask your congressmen and senators to eliminate ALL energy-related subsidies and let the market (i.e. the collective bahavior of everyone interested in buying and selling) figure out what's worth pursuing.

My greatest fear is that people, having lived through the last few generations in a world of plenty and in which we've been able to make many BAD decisions, energetically, have become ovrconfident in our ability to manage a command or quasi-command economy. We're convinced that we can accurately choose what's worth pursuing, in essence picking "winners" out of a sea of potentials, all of which are under-researched and poorly understood.

I think the next step in human intellectual evolution will involve people developing the courage to step back and let things work themselves out in whatever way is thermodynamically most efficient. In other words, let the market do its thing, aided, as best we can manage, by full- or nearly full-cost pricing.

My eco-Libertarian pitch...;-)


Re: Ask your congressman and senators to eliminate ALL energy related subsidies.

You must be joking. The oil industry is the most powerful, profitable, heavily subsidised, and politically active industry in the country. Look at the behavior of Exxon-Mobile, it's poster child. No way are they going to allow their oil subsidies to be taken from them. Every attempt results in fierce opposition from representatives of petroleum producing states. This is the reason for ethanol subsidies. It's a case of I'll vote for your subsidies if you vote for mine.

The stake has hardly been driven into the coffin of the ethanol industry. Ethanol production is continuing to increase and while some plants are being delayed/canceled this is normal after such explosive growth. The publicly traded ethanol companies are a small part of the overall industry. Many plants are privately owned and some are coop's owned by the farmers who produce the corn. When the share price of publicly traded companies drops, it matters little to most ethanol producers. How those opposed to ethanol can expect the price of crude to rise indefinitely dragging along with it the price of gasoline and diesel and not expect to price of ethanol to eventually follow is beyond me. Even now it is obvious that ethanol is contributing to the increase in total liquids production as recently reported by the IEA. What are the motives of those who want to accelerate the post peak oil decline by opposing ethanol? Food production is said to be the reason. Corn is primarily animal feed. Feeding an energy intensive feed to animals to produce human food is a waste of energy. Humans need some animal products but mainly need vegetables and fruit.

Corn is primarily animal feed.

Goodness, you may not know what they're doing with corn these days.

Worthy film:

Not that having monocrop culture is a "good" thing (ultimately it isn't and won't be) but corn is in about as many things you probably don't think about (including almost all processed food) as petroleum is for most people.

Uses for corn:

Assuming we have a decrease in industrial agriculture with its use of fossil fuel, I think it's very likely the yields that produce such "surpluses" today (still hard to make a profit without subsidies the way it's set up) will shrink.

Well, possibly that whole "house of cards" thing will just not work, but I'm not sure about that.

Source: USDA, industry statistics.

2005-2006 U.S. Corn Use By Segment (bushels)

6.1 billion (54.5%)
2.1 billion (18.8%)
Ethanol (fuel):
1.6 billion (14.3%)
High Fructose Corn Syrup:
530 million (4.7%)
Corn Starch:
275 million (2.5%)
Corn Sweeteners:
225 million (2.0%)
190 million (1.7%)
Beverage Alcohol:
135 million (1.2%)


The notion that we have ever had a free market, or ever will have a free market, is simply delusional.

I think John Gray does a good job of addressing this issue.

(Not the "Men are from Mars, Women are from Venus" author, but the English guy -- author of "Straw Dogs" and other books.)

Wiki has a reasonable intro to John Gray here:

The Guardian has a good review of his latest book: "Black Mass: Apocalyptic Religion and the Death of Utopia.",,2126...

I don't agree with all that Gray has to say, but do think that his critique of the so-called "free market" libertarian illusion is strong.

His book "False Dawn: the Delusions of Global Capitalism" is superb. I recommend it for your Holiday -- or winter -- reading!

Don't worry, government is truly getting out of the energy bidness, and out of war as well. When they piratize the holdings of the US government and privatize the planet, the terrorists will have won!

Hello Nate,

Thxs for the keypost--great job. I am certainly not a hydrologist or geologist, but as aquifers deplete: does any kind of compaction or mineral buildup occur to reduce the aquifer porosity, permeability, and flowrates?

We have problems with soil subsidence in certain areas of the Southwest to the point of housing foundations severely cracking as the soil shifts underneath. Drilling wells deeper is commonly done to follow the depleting aquifer water level, but if widespread compaction and/or mineralization buildup around well-heads is occurring too, then we obviously have to start drilling lots and lots of more deep wells to keep even with the water depletion rate.

Do you have any data on this possible high-energy and resource input treadmill getting vastly steeper?

Also, has anyone figured out the breakeven crossover point of aquifer extraction vs desalination? For example: if the Ogallala aquifer soon requires untold thousands of superdeep wells, with vast amounts of diesel or coal-powered electrical pumping to operate: at some point it must become eco- & enviro-cheaper to desal GoM seawater, then pump it north.

By taking a combo of the top, plus deep seawater from the dead pool GoM area, it might reduce algae ocean anoxia, which enhances the fish stocks, plus provide simple recycling of the bottom NPK and trace minerals. The pipelines running north could be separated into two streams [1. clean, potable drinking water, 2. desalted, but NPK mineral rich water suitable for farming.

Of course, this would be a gargantuan project that we may or may not have the energy or wealth to do as we go postPeak, but it is inevitable that aquifers will eventually empty. As phosphorus depletes in North America: we also have to consider the energy cost of importing phosphates from Morroco and other distant points. This won't be cheap either.

From other TODer postings: it already seems politically clear that the Great Lakes watershed inhabitants will not allow their water to be pumped to geographies outside the watershed. If we are headed into another Dust Bowl: Lake Superior's water being pumped to Nebraska, Atlanta, Denver, Phx, Vegas, LA, Albequerque, El Paso, etc, would probably cause a civil war. Far better for the sunny, southern half to setup lots of wind-turbines and solar-genplants to desalinize seawater as our aquifers and rivers go dry.

Bob Shaw in Phx,Az Are Humans Smarter than Yeast?

Or just plain move. The large populations in the deserts are a result of cheap oil/electricity and not sustainable.

does any kind of compaction or mineral buildup occur to reduce the aquifer porosity, permeability, and flowrates?

Absolutely. You can recharge aquifers, but not back to what they were. The soil compacts.

Nate, thanks a bunch for the hard work, we all appreciate the effort.

What about price of this new wonder drug ethanol? Without subsidies, how much is a gallon of this stuff going to cost at the pump? Because, that's what seems to matter most to the public.
I've often wanted to stand on the side of the gridlock traffic jam interstate every morning and ask all the commuters what the price of gas would have to be before they started carpooling or taking the bus. I honestly don't have a clue, but boy would that be some facinating statistics! I say 8 bucks a gallon at least. Suburbanites are romanticaly attached to their cars you know...

Anyway, I would appreciate any cost data that some of you might have on ethanol, making sure to consider subsidies since we pay that with taxes, so we pay it either way (at least i think this is how it works).

Nate, thank you very much for calling our attention to the NAS report. This is invaluable information, particularly the comparison between corn ethanol and soybean biodiesel regarding the fertilizer and pesticide requirements of both per unit of energy gained.

Per unit of energy gained, corn ethanol and soybean biodiesel have dramatically different impacts on water quality. When fertilizer and pesticide application rates (Figure 3-1) are scaled relative to the NEB values of these two biofuels, they are seen to differ dramatically (Figure 3-5). Per unit of energy gained, biodiesel requires just 2 percent of the N and 8 percent of the P needed for corn ethanol. Pesticide use per NEB differs similarly.

This is crucial not only regarding water quality but also considering that N-providing fertilizers are produced using fossil fuels.

Thus, the NAS report could just have been titled "The case for scrapping corn ethanol and going for soybean biodiesel" (1). Taking also into account that the liquid fuel used for the very basic, critical functions is diesel, not gasoline (2), it becomes clear as water that, plainly speaking, corn ethanol is pure idiocy.

(1) I.e., until next-generation biofuels become practical and IF their impact on water quantity and quality turns out to be lower.

(2) I mean, no gasoline means it will be a pain to get to the supermarket, but no diesel means there will be no goods in the supermarket.

A site I've found that has a unique take on ethanol production is by a guy named Dave Blume.

He is coming at it as a small organic, sustanible farmer, NOT an energy corporation.

Busting the Ethanol Myths

Myth #1: It Takes More Energy to ­Produce Ethanol than You Get from It!

Most ethanol research over the past 25 years has been on the topic of energy returned on energy invested (EROEI). Public discussion has been dominated by the American Petroleum Institute’s aggressive distribution of the work of Cornell professor David Pimentel and his numerous, deeply flawed studies. Pimentel stands virtually alone in portraying alcohol as having a negative EROEI—producing less energy than is used in its production.

In fact, it’s oil that has a negative EROEI. Because oil is both the raw material and the energy source for production of gasoline, it comes out to about 20% negative. That’s just common sense; some of the oil is itself used up in the process of refining and delivering it (from the Persian Gulf, a distance of 11,000 miles in tanker travel).

The most exhaustive study on ethanol’s EROEI, by Isaias de Carvalho Macedo, shows an alcohol energy return of more than eight units of output for every unit of input—and this study accounts for everything right down to smelting the ore to make the steel for tractors.

But perhaps more important than EROEI is the energy return on fossil fuel input. Using this criterion, the energy returned from alcohol fuel per fossil energy input is much higher. In a system that supplies almost all of its energy from biomass, the ratio of return could be positive by hundreds to one.

Myth #2: There Isn’t Enough Land to Grow Crops for Both Food and Fuel!

According to the U.S. Department of Agriculture, the U.S. has 434,164,946 acres of “cropland”—land that is able to be worked in an industrial fashion (monoculture).
This is the prime, level, and generally deep agricultural soil.

In addition to cropland, the U.S. has 939,279,056 acres of “farmland.” This land is also good for agriculture, but it’s not as level and the soil not as deep.

Additionally, there is a vast amount of acreage—swamps, arid or sloped land, even rivers, oceans, and ponds—that the USDA doesn’t count as cropland or farmland, but which is still suitable for growing specialized energy crops (ethanol producing).

Of its nearly half a billion acres of prime cropland, the U.S. uses only 72.1 million acres for corn in an average year.

The land used for corn takes up only 16.6% of our prime cropland, and only 7.45% of our total agricultural land.

Even if, for alcohol production, we used only what the USDA considers prime flat cropland, we would still have to produce only 368.5 gallons of alcohol per acre to meet 100% of the demand for transportation fuel at today’s levels.

Corn could easily produce this level—and a wide variety of standard crops yield up to triple this. Plus, of course, the potential alcohol production from cellulose could dwarf all other crops.

Myth #3: Ethanol’s an Ecological ­Nightmare!

You’d be hard-pressed to find another route that so elegantly ties the solutions to the problems as does growing our own energy. Far from destroying the land and ecology, a permaculture ethanol solution will vastly improve soil fertility each year.

The real ecological nightmare is industrial agriculture. Switching to organic-style crop rotation will cut energy use on farms by a third or more: no more petroleum-based herbicides, pesticides, or chemical fertilizers. Fertilizer needs can be served either by applying the byproducts left over from the alcohol manufacturing process directly to the soil, or by first running the byproducts through animals as feed.

Myth #4: It’s Food Versus Fuel—We Should Be Growing Crops for Starving Masses, Not Cars!

Humankind has barely begun to work on designing farming as a method of harvesting solar energy for multiple uses. Given the massive potential for polyculture yields, monoculture-study dismissals of ethanol production seem silly when viewed from economic, energetic, or ecological perspectives.

Because the U.S. grows a lot of it, corn has become the primary crop used in making ­ethanol here. This is supposedly ­controversial, since corn is identified as a staple food in poverty-stricken parts of the world. But 87% of the U.S. corn crop is fed to animals. In most years, the U.S. sends close to 20% of its corn to other countries. While it is assumed that these exports could feed most of the hungry in the world, the corn is actually sold to wealthy nations to fatten their livestock. Plus, virtually no impoverished nation will accept our corn, even when it is offered as charity, due to its being genetically modified and therefore unfit for human consumption.

Also, fermenting the corn to alcohol results in more meat than if you fed the corn directly to the cattle. We can actually increase the meat supply by first processing corn into alcohol, which only takes 28% of the starch, leaving all the protein and fat, creating a higher-quality animal feed than the original corn.

Myth #5: Big Corporations Get All Those Ethanol Subsidies, and
Taxpayers Get Nothing in Return!

Between 1968 and 2000, oil companies received subsidies of $149.6 billion, compared to ethanol’s paltry $116.6 million. The subsidies alcohol did receive have worked extremely well in bringing maturity to the industry. Farmer-owned cooperatives now produce the majority of alcohol fuel in the U.S. Farmer-owners pay themselves premium prices for their corn and then pay themselves a dividend on the alcohol profit.

The increased economic activity derived from alcohol fuel production has turned out to be crucial to the survival of noncorporate farmers, and the amounts of money they spend in their communities on goods and services and taxes for schools have been much higher in areas with an ethanol plant. Plus, between $3 and $6 in tax receipts are generated for every dollar of ethanol subsidy. The rate of return can be much higher in rural communities, where re-spending within the community produces a multiplier factor of up to 22 times for each
alcohol fuel subsidy dollar.

Myth #6: Ethanol Doesn’t ­Improve Global Warming! In Fact, It ­Pollutes the Air!

Alcohol fuel has been added to gasoline to reduce virtually every class of air pollution. Adding as little as 5–10% alcohol can reduce carbon monoxide from gasoline exhaust dramatically. When using pure alcohol, the reductions in all three of the major pollutants—carbon monoxide, nitrogen oxides, and ­hydrocarbons—are so great that, in many cases, the remaining emissions are unmeasurably small. Reductions of more than 90% over gasoline emissions in all categories have been routinely documented for straight alcohol fuel.

It is true that when certain chemicals are included in gasoline, addition of alcohol at 2–20% of the blend can cause a reaction that makes these chemicals more volatile and evaporative. But it’s not the ethanol that’s the problem; it’s the gasoline.

Alcohol carries none of the heavy metals and sulfuric acid that gasoline and diesel exhausts do. And straight ethanol’s evaporative emissions are dramatically lower than gasoline’s, no more toxic than what you’d find in the air of your local bar.

As for global warming, the production and use of alcohol neither reduces nor increases the atmosphere’s CO2. In a properly designed system, the amount of CO2 and water emitted during fermentation and from exhaust is precisely the amount of both chemicals that the next year’s crop of fuel plants needs to make the same amount of fuel once again.

Alcohol fuel production actually lets us reduce carbon dioxide emissions, since the growing of plants ties up many times more carbon dioxide than is created in the production and use of the alcohol. Converting from a hydrocarbon to a ­carbohydrate economy could quickly reduce atmospheric carbon dioxide.

I wish I had more time to debate these points right now but I don't. I am a fan of permaculture but that was not the point of this post

The 'myths' are correct. It is the ludicrous challenges that are nonsense. That a new-age gardening technique would be called upon to save this industrial infrastructure is a sure sign of our desperation.

'Permaculture' is nothing more traditional agriculture wisdom packaged up pretty for 1st-world romantics. It is not a panacea but rather a call for land-redistribution and revolution.

FYI, this has been discussed here:

thank you!
i had missed that
better than I would have written even. what a community.!

He likes to site "non traditional" crops, like mesquite trees growing in the Arizona desert...

Two huge problems with this:
1. These non-traditional crops have non-trivial harvesting and processing requirements, making it very difficult to get any good data on their net energy.
2. As soon as you go into the desert, you go away from population density and hence the ability to deliver a product from land to processing center to consumer without huge losses due to transportation costs.

Also worth noting is that the mesquite tree might be 400 years old. Kinda sucks waiting for a renewable like that to replenish itself.

I think I mentioned it before, but I'll say it again: the problem is ethanol production doesn't scale.

If you're a hillbilly living in say, oh, maybe next door to Matt Simmons in North Carolina, and you've got this load of rotten apples that you could have left on the ground, and you're building a wood fire which you would have done anyway to keep warm, why not distill some apple brandy? Over 100 proof, you can put it in your car. You can neglect a lot of inputs.

But if you are collecting corn from fifty counties, brewing mash (figure more than five times the volume of eventual product), natural gas to boil off all that extra water...

tell that to the politicians that are going to overwhelmingly approve the RFS next week:

"There has been one change in the biofuels measure. While the Senate bill required that at least 3 billion gallons of "advanced biofuels" derived from sources other than corn be used starting in 2016, escalating to 21 billion gallons by 2022, new language would require that the first advanced biofuels be used in 2013. That might ease demand for corn, which has soared in price, and recognize that companies are making progress in using new feedstocks in pilot projects."

Source -todays Washington Post -Title:

"Negotiators Close In on Energy Measure Bill Raises Ethanol, Efficiency Targets; Fuel Credits for Auto Industry at Issue"

If the process, whatever process, consumes natural gas — it needs to beat the simple catalytic conversion of natgas to ethanol. We've discovered a lot of chemistry over the last 150 years and it's too bad the politicians never learned any of it.

So when replacing energy with a 'substitute', all other things do not usually remain equal. I commend the National Academy scientists for highlighting what will be a central issue in upcoming natural resource science - that of systems, and tradeoffs.

Without a doubt any signs of awareness of and concern for the long term systems impact of human economic activity on the part of individuals and institutions is welcome. However, mere cause and effect analysis concerning the consequences of specific economic choices cannot drive truly intelligent action until such time as we create social and economic institutions which are primarily committed to long term community welfare rather than to maximizing the short term accumulation of wealth by private individuals. This latter goal is, by structural necessity, the primary driver of economic activity in our current economic and financial system. Ecological intelligence is vital to our long term survival, but to be effective it must drive radical institutional change rather than being a mere guide to policy within a system private finance capitalism.

Roger, I think that I agree with you.

Unfortunately, I also think that many players do not value species survival at all: that is simply considered to be beyond our realm of concern.

Some prefer to dress up this nihilism with notions that "The Free Market" or "Democracy" or "Whatever..." will sort things out in the end if we all just fight like Hell for whatever it is that satisfies us at the time.

Even those who delude themselves into thinking that it is possible for "ecological intelligence" to drive our culture without wrenching, almost deadly transformation are nursing this kind of madness that must descend upon those who realize at some deep level they they and anyone they have ever loved are about to die due to our collective -- and frequently intentional -- ignorance.

But those who really believe in today's Totalitarian Capitalism are completely focused upon War as the primary process for gaining wealth and power.

Government has truly become one tool for shaping mass opinion, alongside the mass media. The masses of people are turned and prodded and made to cower in fear, shake with rage, and comply with messages delivered as though they bear some relation to symbols of meaning for various subgroups.

Politicians have become masters of catering to "Special Interests" -- mostly religious, some ethnic, some bearing relationships to a whole variety of ancient prejudices and fears.

People are sometimes manipulated by promises of economic well-being, and frightened with threats of terrible deprivation.

Many people are manipulated with even less tangible superstitions than their own physical well-being or security.

Weaving the religious narrative together with the economic promises and threats is the most effective way to create followers as "true believers."

It looks like we (the USA) are about to spend most of our energy on war, and some of our energy persuading ourselves that we deserve comfort and security while most others deserve swift death.

Our political and economic dallying with energy issues does not relate at all to ecological intelligence.

Rather we are driven by our need to believe that we (in the USA, in the "developed" nations) can continue living much as we are, and that we are entitled to do so, and in fact are ordained to do so.

Our political and economic systems are not capable of dealing with science or ecological information.

Indeed, they are set up to screen these things out -- look at the Tar Sands, look at Iraq, Iran.

Our economic and political systems are set up to work exactly the way a violent criminal sociopath functions. Charming, deceitful, rapacious, homicidal, and ultimately suicidal.

Not a pretty picture, but there it is.

In spite of all of the above, I remain an optimist. Love is the only thing that matters when all is said and done.

I have little choice but to embrace my absolute vulnerability in the face of global warming, resource depletion, and the increasing brutality of my own species in declaring war on the planet and ourselves.

Even so, I try to struggle along as though miracles will transform all of this into something I can deeply affirm as good.

Happy Holidays...?

To focus my above comments on the topic at hand, I suppose I am expressing my skepticism that providing more information and analysis will result in positive change in Washington DC.

The politicians in question are beholden to economic interests who have little interest in or understanding of science, and a delusional faith in the infallibility of our current economic dogma.

Even so, I am all for trying to do the right thing -- get that information out there and keep beating the drum!

You just never know what tomorrow will bring.

No need to explain. Each short paragraph was a complete gem. Thanks :)

Beggar said:
"Love is the only thing that matters when all is said and done."

I just have to comment on this statement.

Love. Its a code word at heart and used mostly to entrap people. It has lost any value whatsoever long ago. In fact some time ago it never really existed. It has found huge play beginning since about WWII and thereafter. Hollywood, advertisers and the MSM really like this world since it gives them immense power over fools.

"If you really loved me you would do thus and this." wifespeak for out for the process server

"God loves you." In fact God will and has destroyed human life and likely will in the future. No one can say what God will or won't do but He does have a history of such activity.

The advertising world is especially good at using this word to press the public into acts they feel guilty about thererby manipulating people very easily.

The Family Law attorneys make their living based on the stupidity of those who profess 'love' but later profess the opposite.

Smary idiot preachers and ministers make huge amounts of money buy 'selling' the love concept to the ignorant masses.

"But I love you."..bullshit..translated -- I will screw you over.

Parents to lovesick teenage boy. "Ohhh Johnny she is a known drug addict and has been in jail before as well as a practicing prostitute."

Johnny. "But I LOVE her"....

Parents: "ohhhh well thats different.our blessings on you"

We can forget about filial duty,responsibility, trust and many other worthwhile values when the 'love' word comes into play.

It needs to be erased from the worlds languages.


Just for the record, we people here in Denver don't need water from the Great Lakes. We have more than plenty that's produced among our 14ers.

As for the chatter about how corn get used, reality is most people eat a lot of meat. That isn't going to change anytime soon. So not only is that corn affecting food prices that way but it also does it, as we've seen today, by encouraging farmers to grow corn in lieu of other crops.

Nate, at the end, why did you mention Fischer-Tropsch as a seemingly positive step for us to take in the future? It uses enormous amounts of water and is the source of all sorts of pollution. F-T is NOT a reasonable part of the answer.

I mentioned it specifically as an example that COULD get us liquid fuels, but at a cost - a cost that is currently not counted by the market.

Limited biofuel feedstock supply?

From: American Society of Agronomy
Published November 29, 2007 08:23 AM

The United States has embarked on an ambitious program to develop technology and infrastructure to economically and sustainably produce ethanol from biomass. Corn stover, the above-ground material left in fields after corn grain harvest, has been identified as a primary feedstock. Stover and other crop biomass or residue is frequently referred to as "trash" or a waste, implying it has minimal value. However, when returned to the land, this carbon-rich material helps control erosion, replenishes soil organic matter, and improves soil quality. Organic matter in the soil retains and recycles nutrients and improves soil structure, aeration, and water exchange characteristics. In addition, organic matter is the energy source for the soil ecosystem.

"Sustainable biofuel production will require that the functions of organic matter in the soil be addressed before crop residue is removed from the land,"


What would be the impact on food and energy production without adequate water? Well, a 10 year state wide study in Missouri shows that dryland yields average more than 20% less than irrigated fields, with a high standard deviation (in drought years the yields can be over 50% less. Here is a graphic from University of Missouri:

It works the other way as well - it takes water to produce energy but it also takes energy to produce water, via pumping, irrigation, etc.

Heres another example - this time of corn yield with irrigation and without - from the state of Nebraska (pdf source)

We could replace 1/3 of our gasoline by just gasifying biomass from swithgrass and forest waste without using any additional water.