The Argument for Biofuels

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Marcia Hardy
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1 The Argument for Biofuels Chris Somerville Carnegie Institution Stanford University Lawrence Berkeley National Laboratory The American Society for Cell Biology 1

2 Mean Global Energy Consumption, 1998 (Total 12.8 TW) TW Oil Gas Coal Hydro Biomass Renew Nuclear Nate Lewis, Caltech The American Society for Cell Biology 2

3 The world is warming From: Anders Röj (Volvo Inc.) Agenda 2020 Technology Summit (2004) The American Society for Cell Biology 3

4 CO 2 release rises with per capita GDP M Hoeffert The American Society for Cell Biology 4

5 Predicted increase in global mean temperature due to CO 2 accumulation The American Society for Cell Biology 5

6 Potential of carbon neutral energy sources Terrawatts ? Nuclear Hydro Tides & Wind currents Geo thermal Solar Current From: Basic Research Needs for Solar Energy Utilization, DOE 2005 The American Society for Cell Biology 6

7 TW Potential of underused renewable energy sources 0.1 Hydro Tides & currents Wind Geo thermal Solar Current use From: Basic Research Needs for Solar Energy Utilization, DOE 2005 The American Society for Cell Biology 7

8 ~26,000 km 2 of photovoltaic devices would meet US energy needs 3.3 TW Total shipped = 3 km 2 Turner, Science 285,687 The American Society for Cell Biology 8

9 Central power plants Sequestration vision Electricity & hydrogen Fossil fuel Gas & oil fields CO 2 Coal mines Deep coal beds Subterranean aquifers, oil wells Modified from Hoffert et al. Science 298,981 The American Society for Cell Biology 9

10 The Sleipner Experiment 1 million tons/y; capacity 600 B tons 7000 such sites needed The American Society for Cell Biology 10

11 Sunlight Combustion of biomass provides carbon neutral energy CO 2 Photosynthesis Combustion Polysaccharides Work (Storage) The American Society for Cell Biology 11

12 Is there enough land to produce a significant amount of biofuels? The American Society for Cell Biology 12

13 90,000 TW of energy arrives on the earths surface from the sun Water 70.9% Land 29.0% Amount of land needed for 13 TW at 1% efficiency 5% of land 650 MHa The American Society for Cell Biology 13

14 >1% yield is feasible Yield of 26.5 tons/acre observed by Young & colleagues in Illinois without irrigation Courtesy of Steve Long and Emily Heaton The American Society for Cell Biology 14

15 Land Usage Nonarable 34.4% Other crops 6.9% Forest & Savannah 30.5% Cereal 4.6% Pasture & Range 23.7% AMBIO 23,198 (Total Land surface 13,000 M Ha) The American Society for Cell Biology 15

16 Global grain production with and without yield enhancements Million Hectares Year Data from worldwatch The American Society for Cell Biology 16

17 US Biomass inventory = 1.3 billion tons Corn stover 19.9% Wheat straw 6.1% Soy 6.2% Crop residues 7.6% Grains 5.2% Perennial crops 35.2% Manure 4.1% Urban waste 2.9% Forest 12.8% From: Billion ton Vision, DOE & USDA 2005 The American Society for Cell Biology 17

18 Perennials have more photosynthesis than annuals Miscanthus x giganteus 100 PAR interception (%) Zea mays 20 Spartina cynosuroides Julian day 1993 Courtesy of Steve Long, University of Illinois Note. Annualized net photosynthesis is proportional to the area under the curve. Thus, it can be seen that the perennial crops have much higher Annualized net photosynthesis than the annual crop (Zea mays) Note from steve Long You are very welcome to make use of the mineral recycling diagram and also the Miscanthus images. We do also have images of Miscanthus and switchgrass growing side-by-side, if that is of help - let me know. There was no attachment, but we do have actual data of radiation interception by Miscanthus and by corn crops on the South Farms that demonstrate your point on radiation use (our Miscanthus typically forms a closed canopy a month or two ahead of corn and remains green and photosynthetically active until the first heavy frost - usually early November; our corn usually looses photosynthetic activity and its chlorophyll in the last week of August). I am not sure that I can obtain the data though before Tuesday, but if you need it sooner let me know; I will be in the office tomorrow. In the meantime, I have attached a figure for corn and Miscanthus radiation interception from my earlier work in the UK; corn there is very late, grown for silage and usually green until the first frost. The American Society for Cell Biology 18

19 Miscanthus: A potential energy crop Miscanthus gigantaeus The American Society for Cell Biology 19

20 Switchgrass: A potential energy crop Switchgrass (Panicum virgatum) USDA-NRCS PLANTS Database / Hitchcock, A.S. (rev. A. Chase) Manual of the grasses of the United States. USDA Misc. Publ. No Washington, DC. The American Society for Cell Biology 20

21 Harvesting Miscanthus The American Society for Cell Biology 21

22 Geographic distribution of energy crops Wright et al DOE-ORNL-EERE The American Society for Cell Biology 22

23 Annual precipitation The American Society for Cell Biology 23

24 Water and temperature limit growth Baldocchi et al SCOPE 62 The American Society for Cell Biology 24

25 Water and temperature limit growth Baldocchi et al SCOPE 62 The American Society for Cell Biology 25

26 Comments Perennial energy crops are expected to be more environmentally benign than production agriculture Low fertilizer and chemical inputs Late-harvest supports biodiversity Mixed cultures possible Many species can be used The American Society for Cell Biology 26

27 Effect of 50% stover removal on corn grain yields in eastern NE. (120kg N/ha) stover removed 50% removed Kg/Ha K. Vogel et al., unpublished The American Society for Cell Biology 27

28 Pests and pathogens may prevent large-scale cultivation of perennials Asian soy rust The American Society for Cell Biology 28

29 Many questions need answers What are the probable effects on food security? What are the tradeoffs in environmental effects? The American Society for Cell Biology 29

30 Many questions need answers What are the probable social effects in various regions of the world? What trade policies and regulations may be useful? The American Society for Cell Biology 30

31 A Vision of the Future The American Society for Cell Biology 31

Agricultural Outlook Forum Presented: March 1-2, 2007 U.S. Department of Agriculture

Agricultural Outlook Forum Presented: March 1-2, 2007 U.S. Department of Agriculture DEVELOPMENT OF CELLULOSIC BIOFUELS Chris Somerville Carnegie Institution, Stanford University Lawrence Berkeley National