Fuel Cell Systems for Buildings

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Fuel Cell Systems for Buildings
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US Energy Use and Emissions
Total Annual US Primary Energy Use 85.8
Quadrillion Btus
Total Annual US CO2 Emissions 1460 million metric
tons
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Combined Heat Power (CHP)For Building
Applications
Simultaneous production of heat and power for
useful purposes
0.67
0.33
1
Conventional Electric Power Generation
0.2
0.4
1
0.4
Combined Heat and Power
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Fuel Cell Systems for CHP Applications in
Buildings

• Wide size range
• Excellent full and part load performance
• Minimal environmental impact
• Simple maintenance
• Site friendly

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FC System Integration for Buildings
Typical 200kWe/200kWt PAFC System
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Exhaust
Thermal Energy 40 80 C (100 175 F)
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Heat Recovery
85
42
40
100
Fuel Cell Stack Air Thermal Management
Fuel Processor
Power Conditioning
Fuel
Power
2
Heat
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5 kWe/9kWt Residential PEMFC System
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Commercially Available 200 kWe PAFC System
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Prototype 100 kWe SOFC System
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Fuel Cell CHP System Economics

• Cost of electricity (/kWh)

Maint 0.01-0.03
Capital 0.010.08
Fuel 0.06
HR Credit 0 0.03
Net cost 0.050.17


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Basis CC 500 3000/kW r 10 LF
0.5 FC 8/MCF ?E 45 ?T 40 ?A 80
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FCCHP Economics Commercial Bldgs
Basis LF 0. 5 F1 0.3 r 12 N
20 years ?E0.4 ?T0.4 ?A0.8
MC 0.01/kWh
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FC CHP Residential Buildings
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Fuel Cell/Heat Pump/Thermal Storage CHP System
Heat Loss, QL
Heat Rejection, QREJ
Residence
Thermal Storage Tank
Thermal Output
Elect Water Htg, EDW
Thm Water Htg, QDW
Exhaust Gases
QFC
Thm Space Htg, QTSH
Elect Space Htg, QESH
Heat Pump
Space Cooling, QAC
Fuel
Fuel Cell System
Supply Fan, EF
EAC
EESH
FFC
Electric Output
Lights and Appl, ELA
EFC
Electricity
Thermal Energy
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Typical House Characteristics

• Floor space 195 m2 (2100 ft2) on 1-floor
• Inside temperature 21C(70F) heating
• 24C(75F) cooling
• Unconditioned crawl and attic spaces
• 4 person family 2 daytime occupants
• Typical residential construction
• Roof (R-30) Walls (R-11) Floor (R-19)
• Double glazed windows with interior blinds
• Building infiltration medium leakage (0.8 ACH)

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Selected Locations for Analysis
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Energy Use For Peak Cooling Day
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Energy Use for Peak Heating Day
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Schematic of FC CHP System
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Total Energy System Performance
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Energy Use by Service
Atlanta
Syracuse
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Comparison of Energy and Life Cycle Costs to
Conventional Systems

• All-electric conventional system components are
• Electric heat pump
• Electric domestic water tank
• Electric and natural gas conventional system
  components are
• Electric air conditioner
• Natural gas furnace for space heating
• Natural gas fired domestic water tank
• FC CHP system components are
• Fuel cell system
• Thermal storage tank
• Electric heat pump
• Life cycle cost function is
• Life of all energy systems is 20 years
• Rate of return on capital, r, is 10 percent

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Energy Use and CO2 Emissions
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Life Cycle Costs
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Characteristics of Residential FC CHP

• Residential FC CHP system characteristics
• Fuel cell size 4-5 kWe capacity depending on
  climatic conditions
• Heat pump performance SEER of 10
• Thermal storage tank size 300-liter
• FC CHP efficiencies
• 73 percent in cold climates
• 63 percent in warmer climates.
• FC CHP reduces energy use
• FC CHP reduces emissions
• FC first cost must be reduced to 500/kWe to
  yield LCC comparable to conventional systems

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General Prospects forBuilding Fuel Cells

• Cost goals (500 - 1000/kW) are less stringent
  than for vehicles
• Weight and volume criteria are less stringent
  that for vehicles
• Suitable fuel (natural gas) is widely distributed
• Thermal energy is useful (particularly in
  residential applications)
• Some building applications already require
  back-up power source
• No regulatory mandate (like zero emissions
  vehicle mandate in California)
• Technological change in building industry is
  driven by widely dispersed stakeholders

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Integration of Vehicle and Building Systems
Hydrogen Storage and Dispensing
Hydrogen Vehicle
Electricity
Heat
Natural Gas
Hydrogen
Fuel processor
Electrolyzer
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Questions???