1. Alternative Energy Nuclear Justin Borevitz 1/10/07 Just let it happen
I like it warm
do polar bears?
Just use methane
Just invade Iran
Just invaded Somalia
Alternative Energy
Nuclear
Justin Borevitz 1/10/07
More corn for ethanol
I like to eat corn anyhow
Just drill in the Artic
Just gasify coal
Just buy a hybrid
“I’m done”
Just put CO2 underground

2. The Energy Problem
How will society meet growing energy demands in a sustainable manner?
Fossil-fuels currently supply ~80% of world energy demand.

3. Are Biofuels the Answer?...

4. Biofuels as an Alternative
Biofuels are not THE answer to sustainable energy, but biofuels may be part of the answer
Biofuels may offer advantages over fossil fuels, but the magnitude of these advantages depends on how a biofuel crop is grown and converted into a usable fuel

5. Analysis of Alternative Biofuels
“First generation” biofuels: food-based biofuels that are currently commercially available:
Corn-grain ethanol
Soy Biodiesel
“Second generation” biofuels: cellulosic biofuels of the future
Diverse prairie biomass

6. Biofuels.. Renewable/sustainable?
Fossil fuel subsidy?
Soil fertility subsidy?
Water subsidy?
Land use subsidy?
Biodiversity/ecological subsidy?
Farmer subsidy?
Civil/ social subsidy?

7. Biofuels.. Carbon neutral?
Fossil fuel subsidy?
Fertilizer, pesticide, plant, harvest, process
Soil fertility source or sink?
Land use
from conservation (eg rainforest), CO2 sinks
from food production
Carbon cost processing
Investment in time
Investment in $$

8. Biofuels saves us Corn based ethanol subsidized at $0.51 on the dollar
Corn for corn $0.50 on the dollar
$500M DOE research funding
All arable US land to ethanol, 1/3 of foreign oil. Food?
Iowa $1B in 4 ethanol distillers

9. Evolution of Ecosystems
Niche colonization, spatial temporal
Synergistic interactions among kingdoms
Local and regional adaptation, within and between species

10. Prairie disturbance Large herbivores Early Man/woman’s fire
Colonial man’s plow,
Now industrial man’s intensive agriculture
Next post industrial man/woman’s harvest of biomass?

11. C4 and C3 grasses Plant Physiology How would both help?
cool season warm season

12. How Much Do They Supply? Corn grain ethanol (2005):
14.3% of the US corn harvest was used to produce 1.48x1010 L of ethanol annually
Energetically equivalent to 1.72% of US gasoline use
Soy biodiesel (2005)
1.5% of the US soybean harvest produced 2.56x108 L of biodiesel annually
0.09% of US diesel use

13. But How Much Could They Supply?
Devoting all US corn and soybean production to biodiesel and ethanol would generate:
12% of US gasoline consumption
6% of US diesel consumption
In terms of net energy gain:
2.4% of US gasoline consumption
2.9% of US diesel consumption

14. Food vs. Fuel: Impact on Corn Prices

19. Ethanol Demand and Corn Prices
Large increase in demand for corn for ethanol production
Production capacity over 5 billion gallons
Projected to increase to over 9 billion gallons with current plants under construction
Corn prices in January 2007 topped $4/bushel
Price has doubled since early 2006

20. Are Biofuels Cost Competitive?
In 2005, neither biofuel was cost-competitive with petroleum – but as petroleum prices increased the gap closed
Ethanol:
Estimated ethanol production cost in 2005 was $0.46 per gasoline energy equivalent L
Wholesale gasoline prices averaged $0.44/L in 2005
Soy biodiesel
Estimated soybean biodiesel production cost in 2005 was $0.55 per diesel EEL,
Diesel wholesale prices averaged $0.46/L in 2005
Recent price effects unfavorable for biofuels:
Lower fossil-fuel prices
Higher corn prices

21. Summary
Corn grain ethanol and soy biodiesel can make up only a small portion of fuel supply
Subsidize environmentally friendly biofuels
Subsidy for corn grain ethanol does not appear justified
Subsidy for soy biodiesel may be justified
Should look to other sources

22. Second Generation Biofuels: Cellulosic Feedstock…
Switchgrass Wheat Straw Hybrid Poplar Corn Stalks

23. University of Minnesota Initiative for Renewable Energy and the Environment
Morris Project
“Empowering the Countryside with Renewable Energy” Greg Cuomo & Mike Reese

24. Fermentor: The workhorse
Bio-based methods for
Materials
Energy

25. The Next Generation of Biofuels: Greenhouse-Neutral Biofuels from
High-Diversity Low-Input
Prairie Ecosystems by
David Tilman
University of Minnesota
This has happened because of the incredible and recent dominance of humans on earth. Without ever planning for our impacts, we have come to dominate the earth – to own and determine the fate of every acre of land on its surface. This has occurred because of the dramatic recent rise in population and in per capita consumption.
Why are humans now dominating global ecosystems? In essence, it comes from two major human needs: food and energy. I won’t talk today about energy use and global climate change because you are likely familiar with it and because many scientists working on global change believe that there is another issue that looms as large over humanity as climate change – and that is the impacts of global agricultural expansion. The best estimates are that. In 50 years, the earth will have 3 billion more people, each earning the projected 50% increase in global human population and increased per capita income during the coming 50 years will lead to at least a doubling in global demand for food by 2050.
Photo credit: USDA, ARS, IS Photo Unit Image Number K1443-2; Ripening wheat on the Palouse hills of Washington. Photo by Doug Wilson.

26. Learning from Current Biofuels:
Ethanol from Corn and Biodiesel from Soybeans

27. legumes
Symbiotic relationship with rhizobium bacteria to fix nitrogen,
even Word knows this “a soil bacterium that forms nodules on the roots of legumes such as beans and clover and takes up nitrogen from the atmosphere. Genus: Rhizobium”

28. Low Input High Diversity
Species Functional type
Lupinis perennis Legume
Andropogon gerardi C4 grass
Schizachyrium scoparium C4 grass
Sorghastrum nutans C4 grass
Solidago rigida Forb
Amorpha canescens Woody legume
Lespedeza capitata Legume
Poa pratensis C3 grass
Petalostemum purpureum Legume
Monarda fistulosa Forb
Achillea millefolium Forb
Panicum virgatum switchgrass! C4 grass
Liatris aspera Forb
Quercus macrocarpa Woody
Koeleria cristata C3 grass
Quercus elipsoidalis Woody
Elymus canadensis C3 grass
Agropyron smithii C3 grass

29. Experimental Design Been running since 1994
m x 9m plots, in 1 location in Minnesota
1, 2, 4, 8, or 16 perennial grassland/ savanna species.
from a set of 18 perennials: 4 C4, 4 C3 grasses, 3 herbaceous and 1 woody/shrubby legume, 4 non-legume herbaceous forbs, and 2 oak species
Watered initially, weeded 3-4 times (to maintain low diversity, like a crop), burned each Spring (which killed the woody species, or plots were left (152 plots) out as not measures of annual biomass)

30. Net Energy Balance of Corn Ethanol and Soybean Biodiesel

31. Environmental effects…
Fertilizer use
Pesticide application

32. Environmental effects of ethanol and biodiesel
Greenhouse gasses
reduced by both relative to gasoline and diesel combustion

33. Current and Maximal Potential Production of Food-Based Biofuels:
Current US Biofuel
Production (2005)
Devoting entire US crop production to biofuel
Corn grain ethanol
1.7% of gasoline usage
14% of corn harvest
12.0% of gasoline usage
100% of corn harvest
2.4% Net Energy Gain
Soybean biodiesel
0.1% of diesel usage
1.5% of soybean harvest
6.0% of diesel usage
100% of soybean harvest
2.9% Net Energy Gain
Renewable fuels standard 4.5%
Value also as biofuel additives. Soybean biodiesel blended at low levels. Ethanol at low levels.

34. Toward better biofuels:
1) Biomass feedstock producible with low inputs (e.g., fuel, fertilizers, and pesticides)
2) Producible on land with low agricultural value
3) Conversion of feedstock into biofuels should require low net energy inputs

35. The Cedar Creek Biodiversity Experiment Plus, 70 Plots with 32 Species
Established to study the fundamental impacts of biological diversity on ecosystem functioning
352 Plots
9 m x 9 m
Random Compositions
1, 2, 4, 8, or 16 Species
Plus, 70 Plots with 32 Species
(1994-Present)

36. High Diversity Grasslands Produce 238% More Biofuel Each Year Than Monocultures
Switchgrass

37. Current and future biofuels

38. Full cost accounting for Corn EtOH

39. Use of full cost accounting
To compare alternative energy sources, we should consider the full costs not just the direct costs
Energy sources that have lowest full cost to produce a unit of energy are the most desirable (i.e., greatest net benefit)
Challenge: estimating major external costs for alternative sources of energy

40. Importance of inclusion of external costs
Including external costs makes any particular energy source look less attractive
What is of importance is not cost estimate of any particular source, but the comparison across sources
Not including external costs unfairly penalizes renewable sources of energy because of the generally high external costs of fossil-fuel use

41. Diverse Prairies Remove & Store Carbon

42. Diverse plots store C in Roots

43. Diverse plots store more C in Soil

44. High-Diversity
Prairie Biofuels
Are Carbon
Negative
3.3 t/ha C Storage
0.3 t/ha Fossil C
Net Storage of
3.0 t/ha of CO2
Less CO2 in
Atmosphere
After Fuel Growth
And Use than Before

45. LIHD: Potential Global Effects?
May Meet 15% to 20% of
Global Electricity & Trans. Fuel Demand
Greenhouse Gas Impact per Hectare:
2.3 t ha yr-1 of C net displacement of fossil fuel by biomass
+ 1.1 t ha yr-1 of C sequestration in soil and roots
= 3.4 t ha yr-1 total net reduction in atmosphere C loading
Degraded Land Base:
(51.0 x 108 ha globally of agricultural land)
0.7 x 108 ha abandoned - US
+ 1.2 x 108 ha abandoned - other OEDC nations
+ 3.0 x 108 in non-OEDC nations
= 4.9 x 108 current total agric degraded land
3.4 t ha yr-1 x 4.9 x 108 ha = 1.7 x 109 t/yr reduction in C (as CO2) input into atmosphere
Potential of a 24% Reduction in CO2 Emissions

46. Low-Input High-Diversity Biofuels
Can be produced on degraded agricultural lands, sparing native ecosystems & food production
Negative net CO2 emissions (carbon sinks)
Highly sustainable and stable fuel supply
Cleaner rivers and groundwater
More energy per acre than food-based biofuels

47. Fig. 1. Effects of plant diversity on biomass energy yield and CO2 sequestration for low-input perennial grasslands. (A) Gross energy content of harvested above ground biomass (2003–2005 plot averages) increases with plant species number. (B) Ratio of mean biomass energy production of 16-species (LIHD) treatment to means of each lower diversity treatment. Diverse plots became increasingly more productive over time. (C) Annual net increase in soil organic carbon (expressed as mass of CO2 sequestered in upper 60 cm of soil) increases with plant diversity as does (D) annual net sequestration of atmospheric carbon (as mass of CO2) in roots of perennial plant species. Solid curved lines are log fits; dashed curved lines give 95% confidence intervals for these fits. [View Larger Version of this Image (156K JPEG file)]

48. Fig. 2. NEB for two food-based biofuels (current biofuels) grown on fertile soils and for LIHD biofuels from agriculturally degraded soil. NEB is the sum of all energy outputs (including coproducts) minus the sum of fossil energy inputs. NEB ratio is the sum of energy outputs divided by the sum of fossil energy inputs. Estimates for corn grain ethanol and soybean biodiesel are from (14).

49. Fig. 3. Environmental effects of bioenergy sources
Fig. 3. Environmental effects of bioenergy sources. (A) GHG reduction for complete life cycles from biofuel production through combustion, representing reduction relative to emissions from combustion of fossil fuels for which a biofuel substitutes. (B) Fertilizer and (C) pesticide application rates are U.S. averages for corn and soybeans (29). For LIHD biomass, application rates are based on analyses of table S2 (10).

50. * We assume that producing seed for planting prairies requires twice the energy used to produce prairie biomass, and that two or three hectares can be planted from the seeds harvested from each hectare of degraded or fertile prairie, respectively. We divide this total energy input over an assumed 30 year life of the prairie. † We assume 30.5 L ha-1 of diesel are used in the first year for spraying, disking, planting, and mowing (S16), and that diesel releases 36.6 MJ L-1. We distribute this total energy input over a 30 year life of the prairie. Annual fuel use for mowing, baling, an`d fertilizing is 13.8 L ha-1. ‡
We estimate the weight of equipment used in production (i.e., boom sprayer, tandem disk, notill drill, rotary mower/conditioner, hay merger, large rectangular baler, 75 hp tractor, 130 hptractor, pull spreader, loader, and bale spike) to be 3.6 × 104 kg. We assume for purposes of calculating the embodied energy of each piece of machinery that it consist entirely of steel and that it takes 25 MJ kg-1 to produce steel (S17, S18) with an additional 50% for assembly (S19).
We distribute this over a 30 year life of the prairie and a 240 ha size of the farm.
We assume a first year 2.24 kg ha-1 application rate of glyphosate, which requires 475 MJ/kg to produce and distribute (S20). We divide this energy input over an assumed 30 year life of theprairie. We assume phosphorus fertilizer, which takes 9.2 MJ/kg to produce and transport (S21), is applied every three years at a rate of 7.4 kg ha-1 yr-1 on degraded prairie and 12.0 kgha-1 yr-1 on fertile prairie to replace phosphorus removed in harvested biomass. || The 2004 U.S. per capita energy use was 3.58 × 105 MJ (S22, S23). We assume household size of 2.5 people (S24), 50% of farm household labor devoted to farming (S25), and a 240 ha farm.
¶ We estimate 24 and 38 L ha-1 of diesel is used to move bales onto and off of tractor trailers for degraded and fertile prairies, respectively (S16). We assume bales weigh 680 kg, each tractor trailer can haul 27 bales, and bales are transported an average of 40 km to their point of end use. With an average fleet efficiency of 2.2 km/L (S26), 36.4 L of diesel are used in a single round trip to haul the bales produced on 4.9 ha of degraded prairie or 3.0 ha of fertile prairie.

51. * Although we have data on biomass production on fertile soils for prairie, we do not have comparable data on LIHD carbon storage in such soils, and thus do not present this case in this table.
† Values are from (S27).
‡ This includes diesel used for producing prairie seed, planting and harvesting, and transporting bales. Diesel life cycle GHG emissions are 3.01 × 103 g CO2 eq. L-1 (S28). We also include GHG release in pesticide production, sustaining farm households, and producing farm capital and machinery by assuming they require use of an amount of diesel equivalent to the energy expenditure of these inputs.
§This value is the amount of fossil fuels each use of biomass displaces (energy equivalent) multiplied by the life cycle GHG emissions of the displaced fossil fuels. We assume ethanol displaces gasoline (life cycle GHG emission = 96.9 g CO2 eq. MJ-1) (S28), biomass-generated electricity displaces coal-generated electricity (life cycle GHG emission = g CO2 eq. MJ-1) (S29), and synfuel displaces 38% gasoline and 62% diesel (life cycle GHG emission = 82.3 g CO2 eq. MJ-1) (S14, S28).

52. Burgeoning real estate market in Greenland

53. Final Thought
“Agriculturalists are the de facto managers of the most productive lands on Earth. Sustainable agriculture will require that society appropriately rewards ranchers, farmers and other agriculturalists for the production of both food and ecosystem services.” (Tilman et al. Nature 2003)