BIOFUELS

1
BIOFUELS

• Peter Johnston - APS
• Daniel Musgrove Universal Entech

2
Energy Sources Covered

• Biomass
• Forest waste
• Agriculture waste
• Urban green waste
• Digester-based Biogas (i.e. Methane)
• Waste water treatment plants (WWTP)
• Concentrated Animal Feeding Operations (CAFO)
• Liquid Fuels
• Bio-ethanol
• Bio-diesel
• (Neither manufactured in Arizona today but
  coming!)

3
Biomass

• Forest and woodland waste
• 12 Million acres of forest and woodlands
• 350,000 acres managed per year
• 4.5 Million tons per year of waste
• Agriculture waste
• Cotton gin trash, orchard residue, straw
• 200,000 tons of material per year
• Urban green waste
• Primarily from Phoenix and Tucson
• 95,000 tons per year

4
Technologies

• Dedicated Systems
• Stoker boiler
• Fluidized Bed
• Pyrolysis - gasification
• Rapid Pyrolysis - bio-oil
• Integrated Systems
• Co-Firing with coal

5
Biomass - Sustainable Tonnage and MW Capacity
Source Forest Waste Agriculture Waste Urban Green Waste
Tons of material per year 4,500,000 200,000 95,000
MW 300 18 9.5
6
Biomass - Installed Cost and Operating Cost
Source Forest waste Agriculture waste Urban green waste
Installed Cost (/kW) 2,000 2,500 2,500
Operating Cost (/kWh) 0.07 0.07 0.07
7
Co-Firing with Coal

• Black Veatch, Forest Energy and EPI studies at
  APS Cholla station
• Wood pellet feedstock easiest to implement
• 58.00/kW installation cost
• 0.05/kWh OM cost

8
Biogas - Characteristics

• Anaerobic digestion of organic waste
• Microbial breakdown of solid waste in an oxygen
  starved atmosphere
• Produces a methane rich biogas
• Typically 60 CH4 and 40 CO2
• Energy content 600 Btu/scf
• (Natural gas 1,000 Btu/scf)

9
Biogas - WWTP

• Wastewater Treatment Plants
• 13 Plants in Arizona with digesters
• 1 plant gt 100 MGD influent (12MW)
• 3 plants 10 to 100 MGD influent (8MW)

10
Biogas - CAFO

• CAFOs 150 sites in Arizona
• Dairy
• 170,000 animals 17 MW
• Swine
• 135,000 animals 8 MW
• Poultry
• 3,000,000 birds 5 MW
• Beef
• 318,000 animals 30 MW

11
Biogas - Sustainable Volume and MW Capacity
Methane Source WWTP CAFO
Number of sites 13 150
SCF of methane produced per day 9 Million 24 Million
MW 20 60
12
Biogas - Installed Cost and Operating Cost
Methane Source WWTP CAFO
Installed Cost (/kW) 1,200 3,000 4,000
Operating Cost (/kWh) 0.04 0.04
13
Conclusions

• Biofuel opportunities exist in AZ
• They are not unlimited in size
• One of the lowest cost renewable energy sources
• But require a premium compared to conventional
  fossil generation
• Distributed in nature
• Take advantage of the opportunities where they
  exist
• Resources are already being accessed

14
APS - Biomass

• Eagar 3MW biomass plant
• Western Renewable Energy
• On-line February 17, 2004
• Dedication event April 24,
• Cholla 3 MW biomass project
• Chiptec gasifier technology
• Scheduled for 1st Q/2005

15
APS - Biogas

• 91st Ave WWTP
• APS/City of Mesa agreement to purchase 980,000
  Decatherns of methane
• Convert to 12MW electricity
• Pinal County CAFOs
• Discussing project with United Dairymen of
  Arizona, Arizona Cattlemans Association Pinal
  Feeding
• Central manure processing plant