Michigan Air Quality Division Greenhouse Gas BACT Analysis for Wolverine Power Supply Cooperative Inc. G. Vinson Hellwig, Chief Air Quality Division Michigan Department of Environmental Quality

Project consists of two 300MW (net) circulating fluidized bed (CFB) coal-fired boilers and auxiliary equipment Project site is located in Rogers City, Michigan, and would provide base load power in northern lower Michigan

BACT analysis for conventional criteria pollutants completed prior to submittal of GHG BACT analysis GHG BACT analysis submitted in March 2011 as a supplement to original BACT analysis

Step 1 - Identify control options Technologies Considered: • Carbon Capture and Sequestration (CCS) • Combined Cycle Gas Turbine (CCGT) • Pulverized Coal (sub-critical, supercritical, ultrasupercritical) • Circulating Fluidized Bed (supercritical) • Integrated Coal Gasification Combined Cycle (IGCC) • Biomass Gasification • 100% Biomass Combustion • Energy Efficiency • Combined Heat and Power (CHP)

Step 2 – Eliminate technically Infeasible Options Not feasible: • Combined Cycle Gas Turbine (CCGT) • Pulverized Coal (sub-critical, supercritical, ultrasupercritical) • Integrated Coal Gasification Combined Cycle (IGCC) • Biomass Gasification • 100% Biomass Combustion • Combined Heat and Power (CHP) CCGT – redefinition of source; lack of NG supply; limited fuel flexibility (couldn’t burn biomass); doesn’t take advantage of site specific options (limestone availability for SOx control, on-site cooling water port for solid fuel delivery, landfill for ash); high fluctuation of fuel costs; less attractive option overall PC – fuel input limitations therefore infeasible; doesn’t take advantage of site specific attributes; also could be eliminated in Step 3 due to lower ranking than CFB IGCC – determined to be cost prohibitive for criteria pollutant control; fuel input limitations therefore infeasible; no advantage in GHG emissions over other designs Biomass Gasification & 100% Biomass Combustion – limitations on biomass feedstock supply; not demonstrated at size proposed by WCEV CHP – eliminated in previous analysis because no options for nearby users of steam Most of the these technologies were eliminated is because they redefined the source, were considered to be in developmental state, or in the earlier analysis for criteria pollutants.

Step 3 – Rank Remaining Technologies Remaining Technologies: • Circulating Fluidized Bed (supercritical) • Carbon Capture and Sequestration (CCS) • Energy Efficiency • Biomass Fuel Augmentation

Supercritical Circulating Fluidized Bed Boiler Eliminated from further consideration because: • Only one supercritical CFB known to exist in world (built in 2009 in Poland) • Known supercritical CFB burns only eastern european bituminous coals • Very limited data

Carbon Capture and Sequestration Carbon Capture technologies reviewed: • Absorption • Adsorption • Physical Separation • Hybrid technologies • Biological uptake (algae farms) • Oxy-firing Absorption – typically amines, lime and other proprietary materials being investigated Adsortpion – zeolite, activated carbon Physical – mambrane technologies, cryogenic technologies Hybrid – combinations of chemical absorbents/adsorbents & physical separation Biological – algae farms with bio-engineered algae strains Oxy-firing – not really a capture technology but can be used to concentrate dilute CO2 streams

Carbon Capture and Sequestration Carbon Sequestration technologies reviewed: • Terrestrial - Offsets • Geological - Sequestration • Compression & Re-use

Carbon Capture and Sequestration CCS eliminated based on: • cost • increase in plant size to accomodate parasitic load required to operate CCS equipment Cost effectiveness was about $126/ton based on a slipstream of 5% Total add’l cost for 5% slipstream is on the order of 30% of base cost of plant Would require an increase in plant generating capacity of at least 20%

Biomass Fuel Augmentation Michigan PA 295 requires electric service providers to establish renewable energy programs 75-mile radius around site could theoretically support up to 20% biomass Feedstocks over 5% biomass can negatively affect boiler efficiencies at high moisture contents 5% biomass selected as BACT

Energy Efficiency Variable speed motors over 100 hp Thermal efficiencies Minimize pressure drops across control equipment Permit includes requirement for design specs, Energy Efficiency Plan (EEP), and output based limits Energy Efficiency selected as BACT

Questions?