Case Study: Craig Biomass Project

The City of Craig on Prince of Wales Island in Southeast Alaska installed a Chiptec boiler in 2008 to heat the municipal swimming pool as well as the adjacent Elementary School and Middle School. Approximately 750 tons of wood per year are used to heat 82,000 square feet.

This system will save approximately $100,000 in 2008/2009 school year compared to the oil consumption of the old system. The wood chips are supplied by a local saw mill as part of the waste from their mill operation. The biomass fuel includes wood chips and hog fuel (mixed sawdust, wood chips and bark). There is no available market for hog fuel. This boiler will use 2 truckloads of wood waste every two weeks. Each truck load holds 14 tons of chips.

Source: City of Craig

System Specs

  • Chiptec boiler
  • 4 million BTU per hour output
  • 150 horsepower
  • 60-ton storage bin
  • Underground piping

System Cost

  • Engineering Costs $100,000 shared by:
    • City of Craig $40,000
    • USDA Forest Service $30,000
    • AK Energy Authority$30,000
  • Construction Cost $1,500,000 shared by:
    • USDA Forest Service $117,000
    • AK Energy Authority grant $300,000
    • AK Energy Authority loan $500,000
    • NRCS grant $45,000
    • Bank Loan for City of Craig $500,000
  • Annual Operation and Maintenance Cost - Unknown
  • Wood fuel cost – Hog Fuel is free and the only cost is for hauling at $70 per truck load (14 tons per truck) and chips are sold at market rate of $30 per ton, but no haul cost ($420 per truck load)
  • Electricity cost unknown

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