Combined Heat and Power Plants Options & Solutions Joe Riddle, PE, CEM, LEED AP Vice President AECOM Atlanta, GA
What is CHP? (or Co-Generation) Combined Heat and Power (CHP) Integrates the production of usable heat and power (electricity), in one single, efficient process. Differs from conventional electricity generation where waste heat is vented to atmosphere. On-site generation eliminates distribution losses. Combined Heat and Power Plants Options & Solutions Page 2
TYPES OF PRIME MOVERS PRIME MOVER % OF U.S. INSTALLATIONS SIZE RANGE RECIPROCATING ENGINES 51.9 1 kw 10 MW GAS TURBINE 15.8 500 kw 300 MW STEAM TURBINE 17.4 50 kw 2,000 MW MICROTURBINE 8.4 30 kw 250 kw FUELCELL + OTHER 6.5 5 kw 2 MW EPA CHP PARTNERSHIP- CATALOG OF CHP TECHNOLOGIES Combined Heat and Power Plants Options & Solutions Page 3
DOES CHP MAKES SENSE? Spark Spread Used to determine the viability of onsite generator vs. purchasing power from the electric utility. Spark Spread Difference between the current delivered electricity price ($ per kwh) and the total cost (O&M costs) to generate power with a CHP system A positive spark spread indicates that the CHP project should be considered Maintenance costs average approximately 2 cents per kwh for a reciprocating engine and 1.5 cents per kwh for a turbine Combined Heat and Power Plants Options & Solutions Page 4
DOES CHP MAKE SENSE? Spark Spread for Major U.S. Cities (2015 Rates) Location Electric Utility Price ($/kwh) Natural Gas Utility Price $/Therm $/kwh Estimated O&M Cost* ($/kwh) Phoenix, AZ 0.14 12.22 0.04 0.02 0.08 Los Angeles, CA 0.10 9.17 0.03 0.02 0.05 Jacksonville, FL 0.13 12.22 0.04 0.02 0.07 Orlando, FL 0.11 12.22 0.04 0.02 0.05 Atlanta, GA 0.08 6.11 0.02 0.02 0.04 Augusta, GA 0.08 6.11 0.02 0.02 0.04 Dublin, GA 0.08 3.06 0.01 0.02 0.05 Indianapolis, IN 0.11 9.17 0.03 0.02 0.06 Boston, MA 0.31 12.22 0.04 0.02 0.25 Charlotte, NC 0.09 9.17 0.03 0.02 0.04 Omaha, NE 0.09 6.11 0.02 0.02 0.05 Columbus, OH 0.12 9.17 0.03 0.02 0.07 Oaklahoma City, OK 0.08 6.11 0.02 0.02 0.04 Charlston, SC 0.15 15.28 0.05 0.02 0.08 Austin, TX 0.13 9.17 0.03 0.02 0.08 Salt Lake City, UT 0.12 10.69 0.04 0.02 0.07 Radford, VA 0.10 15.28 0.05 0.02 0.03 * O&M cost based on average service contract price for reciprocating engines Spark Spread ($/kwh) Combined Heat and Power Plants Options & Solutions Page 5
DOES CHP MAKES SENSE? Look for incentives Emissions reduction requirements? (Executive Orders, Coal Plant Conversion) Facilities operating over 5,000 hours per year are ideal. Will at least 50% of prime mover s waste heat be recovered? Each facility is unique and should be studied in detail. Combined Heat and Power Plants Options & Solutions Page 6
DESIGN TYPICAL CHP COMPONENTS Level 1 text 24pt Arial Level 2 bullet 20pt Arial Level 1 text 24pt Arial Level 2 bullet 20pt Arial Generator Ventilation Fans Shaft/ Vent. Silencers Heat Exchanger Emissions Control Heat Exchangers Absorption Chiller Silencer Radiators Combined Heat and Power Plants Options & Solutions Page 7
DESIGN GENERATOR OPTIONS Reciprocating Engine Good part load performance (27-41% Efficient) Operate with low pressure gas High sound power levels and emissions Steam Turbine MICROTURBINE Highest Efficiency (40+ %) Requires another steam source High Reliability Gas Turbine Power output loss at high ambient temperatures (24-36% Efficient) High first cost Low emissions Microturbine SOLAR TURBINES GAS TURBINE Combined Heat and Power Plants Options & Solutions Power output loss of at ambient temperatures above 73F (22-33% Efficient) High first cost Low emissions, sound power, and maintenance costs. Page 8
DESIGN VENTILATION & NOISE CONTROL VENTILATION SHAFT EXH. SILENCERS Level 1 text 20pt Arial VENTILATION DUCT SILENCER SHAFT Level 2 bullet 18pt Arial Level 1 text 20pt Arial EXH. SILENCERS Ventilation Shaft: 123 dbareduced to 68 dba Exhaust Silencers: 127 dbareduced to 66 dba Shaft + Duct Silencer: 117 dbareduced to 65 dba Exhaust Silencers: 125 dbareduced to 63 dba Combined Heat and Power Plants Options & Solutions Page 9
DESIGN VENTILATION Ventilation prevents overheating and sub-cooling of the equipment. Use of computational fluid dynamics (CFD) can help resolve potential issues during the design phase. CFD Image indicates potential overheating at cylinder heads INITIAL DESIGN CYLINDER HEADS GENERATOR ENGINE 3X3 FAN ARRAY Combined Heat and Power Plants Options & Solutions Page 10
DESIGN VENTILATION A wider fan arrangement provide higher ventilation air velocities across cylinder heads to prevent overheating. FINAL DESIGN CYLINDER HEADS GENERATOR ENGINE 4X2 FAN ARRAY Combined Heat and Power Plants Options & Solutions Page 11
DESIGN HXER (HEAT RECOVERY) Level 1 text 20pt Arial Level 2 bullet 18pt Arial ECONOMIZER Level 1 text 20pt Arial HRSG HRSG INDECK, Keystone Energy, LLC Duct Fired HRSG Unfired HRSG/ HRHWG Allows for more and/or higher pressure steam High pressure steam can be used to produce more electricity with steam turbine. Combined Heat and Power Plants Options & Solutions Page 12 Produces steam/or HW only when generator is operating. Option for feed water economizer.
DESIGN GAS TURBINE GENERATORS 400 psig gas 275 psig steam 7 MW Gas Turbine Gen. Duct Fired HRSG 115,000 lb./hr. 7 MW Gas Turbine Gen. 275 psig Duct Fired HRSG 115,000 lb./hr. 40 psig 2 MW Steam Turbine Gen. Combined Heat and Power Plants Options & Solutions Page 13
DESIGN ABSORPTION CHILLERS Absorption chillers use heat to drive the refrigeration cycle without the use of an electric compressor. Can use steam or hot water from HRSG. BROAD U.S.A. INC BROAD U.S.A. INC Some manufacturers have a direct engine exhaust connection. Can produce chilled or hot water. Excellent application for facilities without a summer heating load in order to recover a greater amount of waste heat. YORK, JOHNSON CONTROLS Combined Heat and Power Plants Options & Solutions Page 14
DESIGN EMISSIONS CONTROLS Non attainment areas have strict emissions requirements Area considered to have air quality worse than the National Ambient Air Quality Standards SCR OC Selective Catalyst Reduction (SCR) Utilizes urea as a reactant with NOx across the catalyst Oxidation Catalyst (OC) Used for CO control Continuous Emissions Monitoring System (CEMS) Required in environmentally sensitive areas. Collects, records, and reports emissions data Emission control will vary with fuel and prime mover. Combined Heat and Power Plants Options & Solutions Page 15
DESIGN GENERATOR CONTROL OPTIONS Generator can control all aspects relating to its operation Pumps Radiators Ventilation Fans Heaters Black-Start Island Mode Operate independently from utility power. Serve as a source of permanent power during prolonged utility outage. Minimize emergency diesel generator runtime & OM cost. Can help reduce the kw size of the emergency generators. Does not replace the need for emergency generators. Available for minimal additional cost to controls - ~$20k per generator. Combined Heat and Power Plants Options & Solutions Page 16
DESIGN UTILITY INTERCONNECT Grid-Parallel at utility voltage is required. Existing power distribution downstream from tie-in is unaffected. Existing emergency generators operate as is. Intertie circuit breaker needed between Utility and CHP Can integrate with existing switchgear Involves extensive coordination with the Utility Company Combined Heat and Power Plants Options & Solutions Page 17
Summary All facilities considering the installation of a CHP plant need to be carefully studied. Options need to be investigated and scrutinized to develop optimum solutions. Costs associated with installation, operations and maintenance need to be in a thoroughly analyzed. All CHP plant designs should be carefully coordinated with the electric utility company. A well designed CHP plant should operate year round at an overall efficiency of about 65 to 80%. Presentation Title Page 18
Thank You joe.riddle@aecom.com 678-808-8800 Combined Heat and Power Plants Options & Solutions