1. Particulate Matter Seminar John Kush Texas Genco Rice University Shell Center for Sustainability November 9, 2004

2. Who is Texas Genco? Texas Genco –Formerly HL&P/Reliant Energy power plants –11 facilities in TX; using natural gas, oil, coal, lignite and uranium fuels –14,400 megawatts total, 12,000 in Houston area –Created as result of Texas electric power industry restructuring –Currently a subsidiary of CenterPoint Energy; sale to GC Power Acquisition, LLC in progress

3. W. A. Parish Station

4. W. A. Parish Unit Information UnitMW YearPrimary Fuel 11851958Gas 21851958Gas 32901961Gas 45651968Gas 56901977Coal 66901978Coal 75901980Coal 86501982Coal GT131967Gas

5. W. A. Parish Coal Facts Coal Supply and Delivery –Low sulfur western coal from the Powder River Basin in Wyoming –Delivery by rail car –Approx. 27,000 tons burned per day –Approx. 10 million tons burned per year Arch Coal, Inc. Black Thunder Mine

6. W. A. Parish Station Emission Control Equipment –Baghouse systems for particulate control –Low sulfur coal (plus flue gas desulfurization system (FGD) on Unit 8) –Combustion modifications for NOx control on gas-fired Units 1-4 –Low NOx burner/overfire air systems on Units 5-8 –Selective catalytic reduction (SCR) systems installed on Units 5-8 (planned for Unit 4)

7. W. A. Parish Emission Control Equipment Baghouse systems for fly ash removal –Utilize fiberglass bags to trap fly ash –>99.9% removal efficiency –Original equipment on Unit 8; retrofit in 1988-89 on Units 5-7 to replace electrostatic precipitators Unit 5 Baghouse contains ~15,000 bags

8. W. A. Parish Emission Control Equipment Flue Gas desulfurization system (FGD) for SO2 removal on Unit 8 –Spray tower design –Limestone slurry reagent –SO2 removal of ~80% Unit 8 FGD System

9. W.A. Parish Coal Combustion Product Management Ash Uses –73% of CCPs are sold 90% of all fly ash 100% of all FGD material 25% of all bottom ash –CCPs are utilized as a concrete additive, stabilization and road base/foundation materials Ash Disposal –Ash is classified as Class II non-hazardous waste –Ash disposal in two on-site 30-acre industrial landfills. Design includes clay liner, cap, and groundwater monitoring

10. W. A. Parish NOx Control Equipment Advanced LNB/OFA systems installed on all coal units 1 st commercial installation of B&W LNBs on Unit 6 1 st commercial installation of Alstom LNB/OFA system guaranteed to meet 0.15 lb/MMBtu on WAP 7 50%-60% NOx reductions achieved

11. W. A. Parish SCR Construction

12. W. A. Parish Emission Control Equipment Coal unit SCR's –Vanadium-titanium catalyst –Aqueous NH3 reagent –80-85% reduction to meet 0.03 lb/MMBtu –All 4 SCRs operational by Spring, 2004

13. The Steady Downward March of NOx Emission Rates

14. Texas Genco Emission Reduction Results W.A. Parish Emission Reductions –Unit 8 SO2 emissions reduced by ~80% (FGD system) –Coal-unit particulate emissions reduced by >99.9% (Baghouse system) –Coal-unit NOx emissions reduced by ~90% (LNB/OFA + SCR systems) The Texas Genco system operates with one of the lowest NOx production rates in U.S. W. A. Parish coal units are now likely the lowest NOx emitting coal units in the nation.

15. Questions and Answers