2016 Bowen - Burns & McDonnell presentation at Power-Gen, covering the challenges and benefits of Coal to Gas Conversion. Presented by Bowen's Ed Storrs, and Burns & McDonnell's Dary Burnett.

1. ► 2015 Historical Snapshot
► Midcontinent Independent System Operator (MISO)
► Assumes current coal unit owner considering shutdown
► 4 Alternatives evaluated:
1
Overview of Economic Analysis
Coal
Operations
Coal to Gas Conversion
New 1x1 F-Class Combined Cycle
New 1x F-Class Simple Cycle
New Reciprocating Engines Plant
COAL TO GAS CONVERSION: THE CHALLENGES AND BENEFITS
POWER-GEN NATURAL GAS – 2016 – COLUMBUS, OH

2. ► 2015 Historical Snapshot
► Midcontinent Independent System Operator (MISO)
► Assumes current coal unit owner considering shutdown
► 4 Alternatives evaluated:
2
Overview of Economic Analysis
Coal
Operations
Coal to Gas Conversion
New 1x1 F-Class Combined Cycle
New 1x F-Class Simple Cycle
New Reciprocating Engines Plant
COAL TO GAS CONVERSION: THE CHALLENGES AND BENEFITS
POWER-GEN NATURAL GAS – 2016 – COLUMBUS, OH
ECONOMIC ANALYSIS
DESIGN CONSIDERATIONS
CONSTRUCTABILITY FACTORS

3. ► 2015 Historical Snapshot
► Midcontinent Independent System Operator (MISO)
► Assumes current coal unit owner considering shutdown
► 4 Alternatives evaluated:
3
Overview of Economic Analysis
Coal
Operations
Coal to Gas Conversion
New 1x1 F-Class Combined Cycle
New 1x F-Class Simple Cycle
New Reciprocating Engines Plant
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS

4. 4
Economic Analysis Assumptions
Generic Technology Assumptions
Coal to Gas
Conversion2
1x1 F-Class
CCGT -
Natural Gas
(Fully Fired)1
1xF-Class
SCGT -
Natural Gas
Reciprocating
Engine
(6 x 18MW
Engines)
Operating Capacity (MW) 450 400 210 110
Net Plant Heat Rate, Btu/kWh
(HHV) 10,000 6,900 9,500 8,300
Fixed O&M Cost, 2015 $/kW-Year $20 $10 $9 $10
Total Variable O&M Cost,
2015$/MWh $3.00 $1.90 $1.30 $3.10
Total Project Costs, 2015 MM$ $60 $380 $130 $120
Total Project Costs, 2015 $/kW $130 $950 $610 $1,100
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS

5. 5
Locational Market Prices & Natural Gas Forecast
$1.50
$2.00
$2.50
$3.00
$3.50
$4.00
$20.00
$25.00
$30.00
$35.00
$40.00
$45.00
NaturalGasPrice($/MMBtu)
LMP($/MWh)
Locational Marginal Price Natural Gas Price
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS

6. Hourly Economic Dispatch Results
Coal to Gas
Conversion
1x1 F- Class
CCGT -
Natural Gas
(Fully Fired)
1xF-Class
SCGT -
Natural Gas
Reciprocating
Engine
(6 x 18MW
Engines)
Annual Unit Generation (MWh) 878,000 2,679,000 497,000 435,000
Avg. Capacity Factor (%) 22% 77% 27% 45%
Market Revenues ($M) $32.9 $80.1 $17.7 $15.2
Fuel Costs ($M) $24.3 $52.7 $13.0 $10.3
Variable O&M Costs ($M) $3.4 $8.0 $2.1 $1.4
Gross Margin ($M)2 $5.2 $19.4 $2.6 $3.5
Gross Margin ($/kW)2 $12 $49 $12 $31
Capital Recovery, 2015 $/kW-year $12 $84 $54 $97
Fixed O&M Cost, 2015 $/kW-Year $20 $10 $9 $10
Annual Fixed Costs, 2016 $/kW1 $32 $94 $63 $107
Implied Capacity Costs, 2016
$/kW
$20 $45 $51 $76
6
Economic Analysis Results

7. ► Overall, the Coal to Gas Conversion was a lower cost source of
capacity than other options evaluated
► Even if not considering a long-term solution, may make
economic sense for as short as 5-10 years to delay investment
in a new build option and waiting for more market certainty
► Market price exposure is a potential risk of a coal to gas
conversion, but risk is still hedged with a peaking resource
► Needs to evaluated on a case-by-case basis, but current market
conditions with low LMPs and natural gas prices often favor a
lower capital investment cost of a coal to gas conversion
7
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Economic Analysis Results

8. ► 2015 Historical Snapshot
► Midcontinent Independent System Operator (MISO)
► Assumes current coal unit owner considering shutdown
► 4 Alternatives evaluated:
8
Overview of Economic Analysis
Coal
Operations
Coal to Gas Conversion
New 1x1 F-Class Combined Cycle
New 1x F-Class Simple Cycle
New Reciprocating Engines Plant
COAL TO GAS CONVERSION: THE CHALLENGES AND BENEFITS
POWER-GEN NATURAL GAS – 2016 – COLUMBUS, OH
ECONOMIC ANALYSIS
DESIGN CONSIDERATIONS
CONSTRUCTABILITY FACTORS

9. ► NFPA requirements for
Gas Conversion
• Area classification
• BMS compliance requirements
► Fuel Gas Piping System
• Pressure reducing station
• Burner Connection
► Boiler modifications
• Surface area modifications
• Flue gas recirculation
• NOx and CO
9
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Design
Considerations

10. ► Area Classification
• Gas supply piping and gas train components that contain the gas and
prevent it from entering surrounding electrical components are considered
closed piping systems
• There is a risk that these systems can be opened and release gas to the
atmosphere through the burner or vent through operation of valves.
• However, in the case of release through the burner, there is already an
ignition source present (the pilot / igniters) that cannot be removed.
• Mitigating the associated risks of such operation is achieved though
designing the systems and associated safety provisions per applicable NFPA
codes (such as NFPA 8506) to operate safely and reliably provided they are
maintained regularly.
• Relative to the vent, the risk is mitigated through terminating the vent at a
safe location outside the building.
1 0
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Design Considerations
NFPA Requirements

11. ► Area Classification
• Natural gas is lighter than air leading to dissipation of a leak from the closed
piping system.
• The boiler enclosure needs to have adequate ventilation.
► Needs to be reviewed closely with operations
► Some plants don’t use their ventilation system all year around.
► Whenever gas is in the building the ventilation system needs to be in
service to meet NFPA.
► Change in operation standards for most plants
1 1
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Design Considerations
NFPA Requirements

12. ► BMS Requirements
• All BMS controls should be within the same cabinet.
• Many BMS systems don’t comply
• The existing DCS cabinets may not have the I/O space to comply
► Ignitors
• Natural Gas Burners require one ignitor for each burner
• Coal units can use one ignitor to light two burners
• Modifications will be required for compliance.
1 2
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Design Considerations
NFPA Requirements

13. ►Model FLY Through
1 3
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Design Considerations
Fuel Gas Piping Systems

14. ►Pressure Reducing Station
• Location of the station
• Station can be loud
►Burner Connection
• Flex Hose Connection
• Boiler deformation over time
• Flexibility in the pipe design
1 4
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Design Considerations
Fuel Gas Piping Systems

15. ► Boiler modifications
• Capacity Installation – Low Cost Option
► Only install gas piping
► Make surface area modifications
► Higher heat rate
• Full Capacity Installation – High Cost Option
► Flue gas recirculation installation
► Better heat rate
► Potential draft system modifications
1 5
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Design Considerations
Boiler Modifications

16. ► Other Potential Boiler modifications
► NOx and CO catalyst
► Bottom Ash system modifications
► Back pass vibration potential
► FGD Bypass
1 6
Design Considerations
Boiler Modifications
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS

17. ► 2015 Historical Snapshot
► Midcontinent Independent System Operator (MISO)
► Assumes current coal unit owner considering shutdown
► 4 Alternatives evaluated:
1 7
Overview of Economic Analysis
Coal
Operations
Coal to Gas Conversion
New 1x1 F-Class Combined Cycle
New 1x F-Class Simple Cycle
New Reciprocating Engines Plant
COAL TO GAS CONVERSION: THE CHALLENGES AND BENEFITS
POWER-GEN NATURAL GAS – 2016 – COLUMBUS, OH
ECONOMIC ANALYSIS
DESIGN CONSIDERATIONS
CONSTRUCTABILITY FACTORS

18. ► Project work in an active
facilities
► Work is very outage-based
► The most efficient pipe routings
are already taken
► Spaces for work and equipment
are crowded
► Emergent work is a factor
1 8
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Constructability

19. ► Eliminate variables and risk
► Free time for emergent work
certain to surface in an
existing facility
► Examples
• Valve Trains / Burner Management I/O
complete before outage
• Electrical Marshalling Cabinets
• FGR Ductwork outside boiler building
1 9
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Constructability
Moving work out of outage

20. ► Clearly delineate lines of
demolition
► Demo = cost + risk
► Some Abandoned Processes
• FGD / Precip
• Coal Conveyors
• Wastewater processes
• Associated pipe, equip., buildings, etc.
2 0
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Constructability
Demolition

21. ► Locate as much of the
ductwork as possible outside
the boiler building
► Use of bottom supported
ductwork is significantly faster
than top (hangar) supported
ductwork
► Consider production changes of
duct segments as work areas
become more crowded
2 1
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Constructability
FGR Ductwork

22. ► Unknown conditions in an
existing plant
► Due to thermal expansion and
contraction wind boxes may be
damaged over time
► Extensive repairs required for
installation of tight tolerance
burner nozzles
2 2
ECONOMIC ANALYSIS DESIGN CONSIDERATIONS CONSTRUCTABILITY FACTORS
Constructability
Emergent Work

23. ► 2015 Historical Snapshot
► Midcontinent Independent System Operator (MISO)
► Assumes current coal unit owner considering shutdown
► 4 Alternatives evaluated:
2 3
Overview of Economic Analysis
Coal
Operations
Coal to Gas Conversion
New 1x1 F-Class Combined Cycle
New 1x F-Class Simple Cycle
New Reciprocating Engines Plant
COAL TO GAS CONVERSION: THE CHALLENGES AND BENEFITS
POWER-GEN NATURAL GAS – 2016 – COLUMBUS, OH
► Cost effective, quickly
implemented solution for
utility in today’s market
► Modification to existing,
active facility comes with a
variety of additional
engineering and construction
considerations that should be
factored during evaluation of
a utility’s alternatives
Conclusions

24. 2 4