1. Southern Company Biomass Co-firing Research

2. Global climate change Renewable portfolio standards “Green Power” sales Renewable Energy Drivers

3. Solar and Wind Renewable Options

4. Southern Company Participants Doug Boylan, Jack Eastis, Ann Jones, & Rust Felix Southern Company Bill Zemo Alabama Power Kathy Russell Georgia Power

5. Switchgrass Co-firing Sponsors and Participants Southern Company Auburn University EPRI Southern Research Institute Wilson Farms Sunbelt Expo U.S. DOE McBurney

6. Plant Staff – Gadsden and Mitchell

7. Biomass Co-firing Technologies Co-milling - mix biomass with coal and introduce into the furnace through the coal handling system Simple procedure Reduced capital cost Reduced transport cost Considerable system experience Direct injection - introduce ground biomass pneumatically into the furnace through dedicated burners Higher co-firing percentages Direct biomass control

8. Sawdust Co-firing - Minimal Impact Measured

9. Woodchip Co-milling

10. Long Fibers Trapped in Riffles

11. Co-Milling Switchgrass and Coal Coal does not flow when mixed with low percentages of grass

12. Improved efficiency Reduced plant capital Possible NOx reductions Reduced transportation Reduced labor Reduced dust Pellet Co-firing – Potential Advantages

13. Cubing Setup - Switchgrass farm in Lincoln, AL

14. Cubes sensitive to Moisture Binder type and percentage Grass type and rate

15. Mitchell – Cube Combustion One week of testing completed Cubes pulverize well Cubes burn fairly well SO 2 reduced, NOx ? Serious bunker issues – Rat-holing

16. Tubgrinder Metering Bin Transport Fan 3 Levels of coal at each corner Boiler Pneumatic Transport Lines Upper Grass Burner Lower Grass Burner (not connected) Switchgrass Bales Upper Grass Burner Switchgrass Co-firing Schematic

17. Gadsden

18. Gadsden – Grinding Facilities

20. Gadsden In Action

21. % Coal Reduction with Switchgrass Cofiring

22. Grass on Coal Rate (klb/hour) Time Carbon Dioxide Reduction

23. SO 2 Reductions SO 2 (lb/MMBtu) (70% auger speed) Time Grass on 5:488:1210:3613:0015:24

24. NOx Reductions??? Grass on NOx (lb/MMBtu) Time 5:488:1210:3613:0015:24

25. Switchgrass Co-firing and Boiler Efficiency (Full Load - 7% by heat input)

26. Cement and Ash Tests ASTM specifications exclude biomass ash with coal ash for cement Conducted tests with University of Alabama in Birmingham to evaluate effect of wood ash on cement properties Coordinating efforts with ASTM

27. SCR Catalyst Effects SCR (Selective Catalytic Reduction) is NOx emission control device Catalyst is affected by biomass ash Pilot study at Plant Gadsden with EPRI

28. 1.Direct injection with grass was technical success 2.Co-milling reduced emissions, but a little less efficient 3.Cubes have problems 4.Wood must be fairly fine to co- fire 5.Biomass cannot be co-fired at some units for technical and cost reasons at this time 6.Research is on-going at Southern Company to address these issues Conclusions

29. Questions?