HomeMy WebLinkAboutHCSD Feasibility Wood Heating Analysis - Final
Wood Heating Feasibility Analysis
Final Report
January 9, 2011
Hydaburg City Schools
Hydaburg, Alaska
Prepared for:
Hydaburg City School District
Prepared by:
Alaska Energy Engineering LLC
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
T.R. Miles Technical Consultants
1470 SW Woodward Way Portland, OR, 97225
Tel. 503-292-0107 Fax. 503-292-2919
tmiles@trmiles.com
Alaska Energy Engineering LLC
Hydaburg City Schools 1 Wood Heating Feasibility Analysis
Table of Contents
Executive Summary .................................................................................. 1
Introduction ............................................................................................... 2
Life Cycle Cost Analysis .......................................................................... 5
Appendix A Heating System Schematic Diagrams
Appendix B Energy Analysis
Appendix C Life Cycle Cost Analysis
EXECUTIVE SUMMARY
The Hydaburg Schools campus consists of an elementary school, high school, and a gymnasium
facility, all located in close proximity. Each building has an oil-fired boiler plant that is in good
condition. The school district is interested in converting the schools to wood heating, using wood
pellets or chips, to reduce heating costs. Four wood heating options were evaluated:
• Baseline – Fuel Oil Boilers (Status Quo)
• Alternative 1 – Central Pellet Heating Plant
• Alternative 2 – Modular Pellet Heating Plant
• Alternative 3 – Distributed Pellet Heating Plants
• Alternative 4 – Central Chip Heating Plant
A long-term, stable wood fuel supply is essential to converting the facilities to wood heating.
Sealaska Corporation has committed to delivering pellets to Hydaburg bimonthly. Viking Lumber in
Craig, Alaska has committed to delivering chips to Hydaburg for $75 per ton. This price is much
higher than the $30 per ton price for current deliveries to the Craig chip boiler because of higher
transportation costs.
The wood heating analysis determined that there is little economic incentive to convert the buildings
to wood heating. Under most scenarios of modest variations in pellet costs or energy inflation, the
Baseline heating system offers the lower life cycle cost. The reason this finding differs markedly from
other regions of North America where the use of wood heating is growing is that the Hydaburg
Schools will pay higher wood energy costs and higher construction costs than comparable systems in
other locales. The findings represent the challenges of converting existing buildings in Southeast
Alaska to wood heat.
Alaska Energy Engineering LLC
Hydaburg City Schools 2 Wood Heating Feasibility Analysis
INTRODUCTION
This report presents a wood heating analysis for Hydaburg City Schools in Hydaburg, Alaska. The
analysis compares the 25-year life cycle cost of retaining the existing fuel oil heating systems with
converting to wood heating systems. The intent of this analysis is to determine the lowest cost system
for heating the schools. It is performed by Jim Rehfeldt, P.E. of Alaska Energy Engineering LLC with
technical assistance by:
• Ben Haight, P.E., Haight & Associates, Inc.
• Tom Miles, T R Miles Technical Consultants, Inc.
The Hydaburg Schools campus consists of an elementary school, high school, and a gymnasium
facility, all located in close proximity. Each building has an oil-fired boiler plant that is in good
condition. The school district is interested in converting the schools to wood heating, using wood
pellets or chips, to reduce heating costs. An option to utilize a cogeneration wood plant to generate
electricity and supply heat is also evaluated.
The options for heating the school buildings, which are defined later in greater detail, are:
• Baseline – Fuel Oil Boilers (Status Quo): This option retains the existing fuel oil boiler heating
systems located in each building.
• Alternative 1 – Central Pellet Heating Plant: This option constructs a central heating plant behind
the gymnasium and connects the buildings with direct bury hydronic piping. The plant includes a
lead pellet boiler and backup fuel oil boilers (relocated from the elementary school).
• Alternative 2 – Modular Pellet Heating Plant: This option constructs a modular pellet heating
plant behind the gymnasium, connects the buildings with direct bury hydronic piping, and retains
the existing fuel oil boiler plants as backup.
• Alternative 3 – Distributed Pellet Heating Plants: This option constructs a modular pellet heating
system for each building and retains the existing fuel oil boilers as backup.
• Alternative 4 – Central Chip Heating Plant: This option constructs a central heating plant behind
the gymnasium and connects the buildings with direct bury hydronic piping. The plant includes a
lead chip boiler and two backup fuel oil boilers (relocated from the elementary school).
The opportunity for Conversion to wood heating will present several challenges to Hydaburg Schools.
For the system to succeed, the Owner must take a more active role in keeping the system operating
optimally: monitoring the equipment daily and paying attention to the quality of the fuel supply. It
will also be important for the community to be proactive on wood supply issues to insure a long-term
fuel supply.
Hydaburg schools currently contracts for maintenance and repair of the existing fuel oil heating
systems at a rate of $80.00 per hour. Conversion to a wood heating system will require more
maintenance than needed for the existing fuel oil boilers. Contracted maintenance would be cost
prohibitive for wood heating systems that require daily operating and maintenance work, so in-house
expertise will be essential to the economics of the system.
Alaska Energy Engineering LLC
Hydaburg City Schools 3 Wood Heating Feasibility Analysis
Methodology
The heating options are evaluated using life cycle cost analysis which compares construction,
operating, and energy costs of the heating options over a 25-year period. The analysis takes into
account energy inflation and the time value of money to compare the total ownership costs of each
system.
Economic Factors
The following economic factors are used in the analysis:
• Nominal Interest Rate: The nominal rate of return on an investment, without regard to inflation,
is set at 5%.
• Inflation Rate: The average inflationary change in prices over time is set at 2% per year.
• Economic Period: Set at a 25-year economic period with construction beginning in 2011.
Fuel Oil
Fuel oil currently costs $3.22 per gallon for a seasonally adjusted blend of #1 and #2 fuel oil.
From 1992 to 2006, fuel oil inflation averaged 6.3%. During 2007/2008, prices escalated at 31%, then
deescalated at 18% per year. Since 2008, fuel oil inflation has been 7% per year. It is assumed that
fuel oil prices will inflate at 6% per year for the next 25 years. Inflating today’s cost at 6% results in a
price of $3.41 per gallon in 2011.
Wood Pellets
Pellets are a manufactured product with closest suppliers in Washington, Oregon, and British
Columbia. Benefits of using pellets for heating are:
• Pellets are comparable to fuel oil in terms of quality, prices are market-based, and the heating
systems have similar operating and maintenance requirements.
• Manufactured to established standards for heating value and moisture content.
• There is potential for local suppliers to manufacturer pellets.
Sealaska Corporation is committed to purchasing pellets from the Pacific Northwest and supplying
them to Hydaburg at a current price of $300 per short ton.
Wood pellet inflation has historically averaged 1% per year. The cost of pellets delivered to
Hydaburg will have higher transportation costs, which will inflate with general inflation and fuel oil
inflation. To account for these costs, a pellet inflation rate of 2% per year is used. Inflating today’s
cost at 2% results in a price of $306 per ton in 2011.
Wood Chips
Chips are a locally produced material derived from waste wood products, slash, or whole trees. Issues
associated with using chips are:
• Local resource likely to have greater price stability than fuel oil and pellets.
• Wood from Southeast Alaska has a high moisture content, which directly affects the heating
value of the material. The chips must be dried to acceptable standards prior to burning.
• The chips must meet quality specifications for chip size and moisture content. Chips that are too
large can jam the feeder, too small and they inhibit combustion, too wet and they can freeze to the
storage bin and reduce heating output.
Alaska Energy Engineering LLC
Hydaburg City Schools 4 Wood Heating Feasibility Analysis
The Viking Lumber Mill in Craig, Alaska currently supplies chips to the Craig chip boiler at a price
of $30 per ton. Viking has verbally committed to deliver chips to Hydaburg for $75 per ton; the
higher cost is due to increased transportation distance of 36 miles to Hydaburg.
The cost of producing wood chips is likely to inflate at the national average of 1% per year.
Transportation costs are likely to inflate at a higher rate. To account for these costs, a chip inflation
rate of 1.5% per year is used. Inflating today’s cost at 1.5% results in a price of $76.10 per ton in
2011.
Sensitivity Analysis
Energy prices will have the greatest effect on the life cycle cost of the heating systems. A sensitivity
analysis is applied to the findings to see how they change with modest changes in energy prices and
inflation. The following differences are evaluated:
• Fuel Oil Inflation: A base case of 6% per year is compared to a low case of 4% and a high case
of 8%.
• Pellet Inflation: A base case of 2% per year is compared to a low case of 1% and a high case of
4%.
• Chip Inflation: A base case of 1.5% per year is compared to a high case of 3%.
• Pellet Costs: Sealaska Corporation’s pellet distribution company is currently in its startup phase.
It is possible that high or low demand will cause them to alter their prices in the future. A base
case of $300 per ton is compared to a low case of $275 per ton and a high case of $325 per ton.
Summary of Economic and Energy Factors
The following table summarizes the economic and energy factors used in the analysis.
Summary of Economic and Energy Factors
Factor Base Case Low Case High Case
Nominal Discount Rate 5% - -
General Inflation Rate 2% - -
Fuel Oil Cost $3.22/gal - -
Chip Cost $75.00/ton - -
Pellet Cost $300/ton $275/ton $325/ton
Fuel Oil Inflation 6% 4% 8%
Pellet Inflation 2% 1% 3%
Chip Inflation 1.5% 1% 2%
Alaska Energy Engineering LLC
Hydaburg City Schools 5 Wood Heating Feasibility Analysis
LIFE CYCLE COST ANALYSIS
Cogeneration Option
The option of using a cogeneration plant utilizing wood products to produce both electricity and heat
was briefly explored, but not fully developed because of the high initial cost and the recurring annual
cost for fuel and maintenance. This type of plant burns wood products in the form of pellets, chips, or
bricks to produce gas for a reciprocating engine. The engine combined with a generator utilizing
commonly manufactured equipment produces electricity.
Typically, an engine driven generator utilizes 30 to 33 percent of the energy combusted. The
remaining energy is dissipated as heat to the radiator (35 percent), engine radiation (10 percent) and
exhaust (25 percent). Of the heat generated, approximately 60 percent of it, or 45 percent of the total
energy combusted can be recovered for heating buildings.
The math works like this based on general “rules-of-thumb”:
• 3 pounds of dry wood product will produce 1 KWh of electrical energy.
• A 100 KW generator requires combustion of 300 pounds of wood product every hour to maintain
full capacity.
• 300 pounds of dry wood product produces 1,500,000 Btu’s of energy (15,000 Btu’s per KWh).
• The waste heat provided is 675,000 Btu’s.
• One gallon of diesel (135,000 Btu’s) produces approximately 12.5 KWh with a reciprocating
engine. This equates to 10,800 Btu’s per KWh; 1,080,000 Btu’s for one hour operation at 100
KW.
• The waste heat provided from a 100 KW diesel fired engine is 486,000 Btu’s.
• The cost for fuel to power a 100 KW generator based on pellets is $46 per hour. This comes to
$0.46 per KWh bare cost for electricity.
• The comparable cost of fuel for a diesel driven generator is approximately $28 per hour for the
same production. This is $0.28 per KWh bare cost for electricity.
• The construction of a gasification type cogeneration system costs approximately $1,000,000 for a
100 KW generator ($10,000 per KW).
• Construction of a plant with diesel generators typically cost $1,000 per KW. A 100 KW unit
costs approximately $100,000.
The initial cost for a wood fuel powered generator is approximately ten times greater than a diesel
fired unit. The fuel cost for a wood fuel powered generator is approximately 1.6 times the fuel for a
diesel fired generator. Although the waste energy recoverable from a wood fired generator is greater
than that from a diesel fired generator (1.4 times), it is not adequate to offset the other costs.
Heating System Options
The schools are currently heated by individual fuel oil boiler plants. The elementary school and
gymnasium have two boilers and the high school has one. Each building has a hydronic distribution
system that supplies heating water to the building.
The alternatives consider central pellet and chip plants, a modular pellet plant and distributed modular
pellet plants. Distributed modular chip plants were not considered due to the high cost to construct
chip storage and drying systems for each building, and high operating costs.
Alaska Energy Engineering LLC
Hydaburg City Schools 6 Wood Heating Feasibility Analysis
Baseline: Fuel Oil Boilers (Status Quo)
This option retains the existing heating plants. The scope includes:
• Retain the two elementary school boilers.
• Retain the two gymnasium boilers.
• Retain the one high school boiler.
Alternative 1: Central Pellet Heating Plant
This alternative replaces the existing heating plants with a central pellet boiler plant located behind
the gymnasium. The central plant consists of a pellet boiler and two fuel oil boilers relocated from the
elementary school. The boilers are connected in a primary/secondary piping system. Distribution
piping is installed through the gymnasium with direct bury branches to the high school and
gymnasium.
It is likely that this alternative would be the optimal pellet heating plant if the campus was being
newly constructed because it centralizes and simplifies the heating system. Pellets offer a stable fuel
quality and is supplied via a keep-full contract. While operating and maintenance requirements are
higher than the Baseline, it has the least equipment of the wood heating options.
The scope includes:
• Construct a boiler room behind the gymnasium.
• Install a 1,000 MBH (300 kW) pellet boiler and auger system in the new building.
• Install a 75 ton pellet silo. A 75 ton storage capacity is required for bimonthly deliveries, which is
the delivery frequency Sealaska Corporation can initially meet.
• Remove the fuel oil boilers and fuel tanks from the high school and elementary school
• Remove the fuel oil boilers from the gymnasium.
• Relocate the elementary school boilers to the new boiler room and extend the gymnasium fuel oil
piping to the boilers.
• Connect the boilers in a primary/secondary piping system. Install distribution piping through the
gymnasium with direct bury branches to the high school and elementary school. A heat exchanger
in each boiler room separates the glycol distribution system from the building system.
Alternative 2: Modular Pellet Heating Plant
This alternative constructs a modular pellet boiler plant behind the gymnasium and retains the fuel oil
boilers in each building. Distribution piping is installed through the gymnasium with direct bury
branches to the high school and gymnasium.
This alternative reduces construction costs by using a less expensive modular pellet boiler plant and
retaining the fuel oil boiler plants in each building for backup. There is more equipment to maintain
and controls are required in each building to interface the pellet plant with the building boilers. The
scope includes:
• Construct a modular 1,000 MBH (300 kW) pellet boiler plant and auger system behind the
gymnasium.
• Install a 75 ton pellet silos. A 150 ton storage capacity is required for quarterly deliveries, which
is the delivery frequency Sealaska Corporation can meet.
Alaska Energy Engineering LLC
Hydaburg City Schools 7 Wood Heating Feasibility Analysis
• Retain the heating systems in the elementary school, gymnasium, and high school.
• Install distribution piping through the gymnasium with direct bury branches to the high school
and elementary school. A heat exchanger in each boiler room separates the glycol distribution
system from the building system.
Alternative 3: Distributed Pellet Heating Systems
This alternative constructs modular pellet boiler systems, including pellet storage, at each building.
The pellet and fuel oil boilers are connected in a primary/secondary piping configuration. A control
system operates the boilers in a lead/lag/standby configuration.
The alternative utilizes gangs of smaller, less expensive pellet boilers to heat each building and
eliminates the distribution system. The system has more equipment to maintain and higher
maintenance costs. The scope includes:
• Construct a 500 MBH (145 kW) modular pellet boiler plant and auger system with 30 ton silo for
the elementary school. Retain the fuel oil boilers for backup.
• Construct a 190 MBH (55 kW) modular pellet boiler plant and auger system with 15 ton silo for
the high school. Retain the fuel oil boiler for backup.
• Construct a 425 MBH (125 kW) modular pellet boiler plant and auger system with 30 ton silo for
the gymnasium. Retain the fuel oil boilers for backup.
Alternative 4: Central Chip Heating Plant
This alternative replaces the existing heating plants with a central chip boiler plant located behind the
gymnasium. The central plant consists of a chip boiler and two fuel oil boilers relocated from the
elementary school. The boilers are connected in a primary/secondary piping system. Distribution
piping is installed through the gymnasium with direct bury branches to the high school and
gymnasium.
This alternative represents the optimal chip heating plant for a newly constructed campus because it
centralizes and simplifies the heating system. It utilizes locally produced wood chips rather than
imported energy. The scope includes:
• Construct a boiler room behind the gymnasium.
• Install a 1,800 MBH (540 kW) chip boiler and auger system in the new building.
• Construct a chip storage bin with chip drying system supplying warm air through the bin floor.
The chip boiler has a higher capacity (540 kW) than the pellet boiler (300 kW) to supply the chip
drying system.
• Remove the fuel oil boilers and fuel tanks from the high school and elementary school
• Remove the fuel oil boilers from the gymnasium.
• Relocate the elementary school boilers to the new boiler plant and extend the gymnasium fuel oil
piping to the boilers.
• Connect the boilers in a primary/secondary piping system. Install distribution piping through the
gymnasium with direct bury branches to the high school and elementary school. A heat exchanger
in each boiler room separates the glycol distribution system from the building system.
Alaska Energy Engineering LLC
Hydaburg City Schools 8 Wood Heating Feasibility Analysis
Construction Costs
The existing fuel oil boiler heating systems (Baseline) are in good condition and do not require an
initial investment to retain them for the next 25-years.
Converting the buildings to wood heat will require an investment from $1,510,000 to $2,960,000.
This investment includes the wood heating plant, retaining backup fuel oil plants, and, for the Central
Plant options, constructing a building and installing distribution pipelines to the High School and
Elementary School.
The cost estimates are based on the work being performed by off-island contractors. Wood heating
systems are emerging systems in Southeast Alaska and the estimates recognize that bidders may
include costs for installing unfamiliar systems in a remote community.
The cost estimates also include mobilization and demobilization of equipment and personnel and
lodging and per diem. The following table summarizes the construction costs.
Construction Cost Estimates
Baseline Alternative 1 Alternative 2 Alternative 3 Alternative 4
Fuel Oil Boilers Central Pellet Modular Pellet Distributed Modular Central Chip
Cost (Status Quo) Boiler Plant Boiler Plant Pellet Boilers Boiler Plant
Mobilization $ 0 $ 200,000 $ 160,000 $ 230,000 $ 200,000
Heating Building 0 250,000 0 0 340,000
Heating Plant 0 1,680,000 1,250,000 1,280,000 2,000,000
Distribution 0 420,000 470,000 0 420,000
Total $ 0 $ 2,550,000 $ 1,880,000 $ 1,510,000 $ 2,960,000
The Baseline system requires no initial construction costs to continue heating the buildings.
Alternative 3 has the lowest wood heating construction costs because it does not have a distribution
system and uses smaller, less expensive, modular pellet boilers. The tradeoff is that there is more
installed equipment that must be maintained. This is an important factor for a rural community like
Hydaburg that does not have spare parts or expertise in close proximity.
Operating Costs
Operating costs include labor and materials to operate, maintain, and replace the heating systems over
the 25-year period. Hydaburg schools currently contracts for maintenance and repair of the existing
fuel oil heating systems at a rate of $80.00 per hour. Contracted maintenance would be cost
prohibitive for wood heating systems that require daily operating and maintenance work. It is
assumed that in-house labor at a fully loaded cost of $42.00 per hour if a wood heating system is
constructed.
Operating Labor
The existing fuel oil boilers operate the majority of the year without daily oversight. Wood boilers,
however, require daily checks.
• Fuel Oil Boilers: None
• Pellet Boiler: ½ hour per day to check boiler and auger operation.
• Chip Boiler: 2 hours daily to check boilers, clear fuel feed issues, and remove slag from grating.
Alaska Energy Engineering LLC
Hydaburg City Schools 9 Wood Heating Feasibility Analysis
Maintenance
All boilers require annual maintenance to clean the firebox, maintain burners, and check components.
• Fuel Oil Boilers: 12 hours per year to clean the tubes and tune the burner.
• Pellet Boiler: 48 hours per year to clean the tubes and maintain the boiler and augers.
• Chip Boiler: 80 hours per year to clean the tubes and maintain the boiler and augers.
• Pumps: $200 per year for maintenance and periodic replacement.
Replacement
Periodic replacement of boilers and pumps will be necessary to keep the heating systems operational.
• Fuel Oil Boiler Plants
1. Elementary School Boilers: Remaining service life of 25 years; no replacement.
2. High School Boilers: Remaining service life of 20 years; replace in Year 20.
3. High School Fuel Tank: Remaining service life of 10 years; replace in Year 10.
4. Gymnasium Boilers: Remaining service life of 10 years; replace in Year 10.
• Pellet and Chip Boiler: Expected service life of 18 years; replace in Year 18.
• Augers: Expected service life of 10 years; replace in Year 10 and Year 20.
Summary
The following table provides a comparison of operating, maintenance, and replacement costs for the
heating options.
Operating Cost Estimates
Baseline Alternative 1 Alternative 2 Alternative 3 Alternative 4
Fuel Oil Boilers Central Pellet Modular Pellet Distributed Modular Central Chip
Cost (Status Quo) Boiler Plant Boiler Plant Pellet Boilers Boiler Plant
Yearly Costs
Operating $ 0 $ 8,000 $ 8,000 $ 23,000 $ 31,000
Maintenance 6,000 10,000 11,000 21,000 11,000
Total $ 6,000 $ 18,000 $ 19,000 $ 44,000 $ 42,000
Life Cycle Cost (25-year)
Operating $ 0 $ 130,000 $ 130,000 $ 400,000 $ 540,000
Maintenance 100,000 170,000 190,000 370,000 200,000
Replacement 80,000 270,000 240,000 120,000 310,000
Total $ 180,000 $ 580,000 $ 580,000 $ 890,000 $ 1,050,000
The wood heating systems have significantly higher operating costs than the existing fuel oil boilers.
The central plant options have lower operating costs than the distributed boiler option, because it has
less equipment. The chip boiler operating costs are the greatest due to significantly higher operating
and maintenance requirements.
Alaska Energy Engineering LLC
Hydaburg City Schools 10 Wood Heating Feasibility Analysis
Energy Costs
Energy Costs
An energy analysis was performed to estimate the annual heating load and purchased energy
requirement of each heating option.
• For the pellet boiler options, it is assumed that the pellet boiler will supply 95% of the heating
load and the fuel oil boilers will supplement during cold weather and during maintenance periods.
• For the chip boiler options, it is assumed that the chip boiler will supply 90% of the heating load
and the fuel oil boiler will supplement during cold weather and during maintenance periods. It is
also assumed that 15% of the input energy will be consumed drying the chips.
• Distribution losses are assumed to be 5% for the central plant options.
The energy analysis also includes electric consumption of the boilers, augers, dryers, and induction
fans, which is a relatively minor contributor to overall energy costs. Energy analysis calculations are
provided in Appendix B. The following table summarizes the energy consumption and costs of each
option.
Energy Consumption
Fuel Oil Pellets Chips 2011 Life Cycle
Heating Option (gallons) (tons) (tons) Energy Cost Energy Cost
Baseline: Fuel Oil Boilers (Status Quo) 37,500 - - $128,000 $3,630,000
Alternative 1: Central Pellet Boiler Plant 1,970 259 - $110,000 $2,100,000
Alternative 2: Modular Pellet Boiler Plant 1,880 266 - $110,000 $2,100,000
Alternative 3: Distributed Pellet Boiler Systems 1,880 253 - $97,000 $1,830,000
Alternative 4: Central Chip Boiler Plant 3,750 - 640 $101,000 $2,040,000
The above table shows that in the first year, wood heating with pellets and chips offers an energy cost
savings of 20% and 32%, respectively. The difference becomes greater in future years due to higher
fuel oil inflation (6%) than pellet (2%) and chip (1.5%) inflation. Thus the pellet and chip systems
have life cycle energy savings of 48% and 52%, respectively. The following table illustrates how
energy costs are predicted to increase over time.
$0
$100,000
$200,000
$300,000
$400,000
$500,000
$600,000
2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034 2036
Energy Cost Comparison
Baseline: Fuel Oil Boilers (Status Quo)
Alternative 1: Central Pellet Boiler Plant
Alternative 4: Central Chip Boiler Plant
Alaska Energy Engineering LLC
Hydaburg City Schools 11 Wood Heating Feasibility Analysis
Life Cycle Cost Analysis
A life cycle cost analysis determined that the Baseline Fuel Oil Boilers (Status Quo) have a
remarkably lower life cycle cost than the wood heating options. This heating option has the lowest
construction costs and the lowest operating costs. The wood heating systems have lower energy costs,
but the energy savings could not offset their higher construction and maintenance costs.
The following table shows the life cycle cost comparison. Spreadsheets with detailed breakdowns of
the costs are included in Appendix C.
Life Cycle Cost Comparison
Baseline Alternative 1 Alternative 2 Alternative 3 Alternative 4
Fuel Oil Boilers Central Pellet Central Chip Modular Pellet Distributed Pellet
Cost (Status Quo) Boiler Plant Boiler Plant Boiler Plant Boiler Plants
Construction Costs $ 0 $ 2,550,000 $ 1,880,000 $ 1,510,000 $ 2,960,000
Annual Costs 180,000 580,000 580,000 890,000 1,050,000
Energy Costs 3,630,000 2,100,000 2,100,000 1,830,000 2,040,000
Present Worth $ 3,810,000 $ 5,230,000 $ 4,560,000 $ 4,230,000 $ 6,050,000
Alternative 3 has the lowest life cycle cost of the wood heating options. This alternative is based on
using multiple wood boilers to heat the Elementary School and Gymnasium. This increases the
amount of equipment and complexity of the system, which is never desirable in a remote community.
While the economic analysis has captured the costs associated with more equipment, there is an
added risk associated with a more complex system.
The chip option has a considerably higher life cycle cost than all the other options. This result is
somewhat counterintuitive as the chips are a local energy source and have the lowest energy cost. The
high costs of operating and maintaining a chip plant, including drying the chips, causes this option to
be cost prohibitive.
The use of wood as a heating source is increasing in North America, primarily because of energy cost
savings. The finding that there is no economic incentive for this application does not directly
challenge this trend, but does speak to significant realities of wood heating, generally in Southeast
Alaska, and specifically constructing the systems in the remote community of Hydaburg. These
realities, in the order of important are:
• Energy Costs
1. Wood pellets are 33% more expensive in Southeast Alaska and are subject to greater price
volatility due to imbedded transportation energy. In the Pacific Northwest, the delivered cost
is $200 per ton, Sealaska Corporation is quoting $300 per ton. It is also likely that pellet
inflation will be higher in Southeast Alaska due to higher transportation costs. The life cycle
cost difference, if this project was in the Pacific Northwest, is approximately $480,000.
2. Wood chips delivered by Viking Lumber to Hydaburg are 250% more expensive than the
chips delivered to Craig. This increase represents the added transportation costs to deliver to
Hydaburg (36 miles) instead of Craig (6 miles). Reducing the chip costs to $30 per ton would
decrease the life cycle cost of the chip options by $490,000.
Alaska Energy Engineering LLC
Hydaburg City Schools 12 Wood Heating Feasibility Analysis
• Construction Costs: Southeast Alaska has higher construction costs, especially in remote
communities where contractors must include shipping, transportation and per diem costs. These
higher costs must be offset by energy savings, which are reduced by higher wood energy costs.
• Existing Construction: The economics of converting to wood heat are also challenged by the
generally good condition of the existing fuel oil heating plants, which heavily favors retaining the
status quo. If this analysis was comparing new construction or if the existing heating plants were
due for replacement, the wood heating systems would compete much better.
All three of these factors result in the wood heating systems have higher life cycle costs than the
status quo.
Sensitivity Analysis
A sensitivity analysis was applied to the findings to see how modest variations in pellet prices and
energy inflation affect the findings. The table below shows the findings.
Sensitivity Analysis – Life Cycle Cost
Baseline Alternative 1 Alternative 2 Alternative 3 Alternative 4
Fuel Oil Boilers Central Pellet Modular Pellet Distributed Modular Central Chip
Case (Status Quo) Boiler Plant Boiler Plant Pellet Boilers Boiler Plant
Base Case 1 $ 3,810,000 $ 5,070,000 $ 4,420,000 $ 4,160,000 $ 5,750,000
Low Pellet Cost, 275/ton $ 3,810,000 $ 4,950,000 $ 4,310,000 $ 4,050,000 $ 5,750,000
High Pellet Cost, $325/ton $ 3,810,000 $ 5,190,000 $ 4,540,000 $ 4,270,000 $ 5,750,000
Low FO Inflation, 4% $ 2,960,000 $ 5,070,000 $ 4,420,000 $ 4,160,000 $ 5,750,000
High FO Inflation, 8% $ 4,980,000 $ 5,070,000 $ 4,420,000 $ 4,160,000 $ 5,750,000
Low Pellet Inf, 1% $ 3,810,000 $ 4,920,000 $ 4,270,000 $ 4,020,000 $ 5,750,000
High Pellet Inf, 3% $ 3,810,000 $ 5,240,000 $ 4,600,000 $ 4,320,000 $ 5,750,000
Low Chip Inf, 1% $ 3,810,000 $ 5,070,000 $ 4,420,000 $ 4,160,000 $ 5,710,000
High Chip Inf, 2% $ 3,810,000 $ 5,070,000 $ 4,420,000 $ 4,160,000 $ 5,800,000
1. Pellets @ 300/ton, Pellet Inflation @ 2%, Fuel Oil Inflation @ 6%, Chip Inflation @ 1.5%
Note: Bold indicates lowest life cycle cost
The sensitivity analysis shows that for modest changes in pellet costs or energy inflation, the Status
Quo has the lowest life cycle cost. The only scenario where this is not true is the high fuel oil inflation
case. As such, the findings are not overly sensitive to modest variations in energy costs and inflation.
To add perspective to the sensitivity analysis, the following scenarios were evaluated:
• If pellets cost $227 per ton instead of $300, the Baseline and Alternative 3 would have equivalent
life cycle costs.
• If the chips were free instead of $75 per ton, the Baseline option would still have a lower life
cycle cost than Alternative 4.
• If pellet and chip inflation was 0%, the Baseline option would still have the lowest life cycle cost.
The sensitivity analysis indicates that under moderate changes in pellet costs and energy inflation, the
Baseline system has the lowest life cycle cost.
Alaska Energy Engineering LLC
Hydaburg City Schools Wood Heating Feasibility Analysis
Appendix A
Heating System Schematic Diagrams
Alaska Energy Engineering LLC
Hydaburg City Schools Wood Heating Feasibility Analysis
Appendix B
Energy Analysis
Alaska Energy Engineering LLC CALCULATIONS
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Annual Energy Requirements
HEATING PLANT SIZING
Wood Boilers Exist
Building MBH Factor Plant MBH Plant kW Factor Wood kW
Elementary 660 69% 457 134 75% 145
High School 250 69% 173 51 75% 55
Gymnasium 570 69% 394 116 75% 125
1,480 1,024 300 325
Existing Elementary School Boiler MBH Size
Boiler 1 886 60%
Boiler 2 886 60%
1,772 120%
ENERGY ANALYSIS
Baseline: Fuel Oil Boilers (Status Quo)
Gallons LHV, kBtu/gal Gross MMBtu Efficiency Net, MMBTU
37,500 130 4,875 70% 3,413
Alternative 1: Central Pellet Boiler Plant
Heating Energy
Pellet Boiler (Lead)
Net, MMBTU % Load MMBtu/ton Net, tons Dry/Dist Efficiency Gross Tons
3,413 95% 16.0 203 5% 82% 259
Fuel Oil Boilers (lag/standby)
Net, MMBTU % Load LHV, kBtu/gal Net, gallons Dry/Dist Efficiency Gross, gallons
December 3, 2010
Central Plant Individual Bldgs
3,413 5% 130.0 1,313 5% 70% 1,969
Electric Energy MMBtu MBH Hours
Wood Boiler Hours 3,242 1,024 3,800
Equipment HP kW Annual Hours kWh
De-ashing System 0.5 0.5 365 170
Pneumatic tube cleaning system 5.0 4.7 52 242
Induced draft fan 15.0 14.0 3,800 53,149
Silo auger 5.0 4.7 3,800 17,716
Feed auger 1.5 1.4 3,800 5,315
Pumping Energy GPM Head η, pump BHP η, motor Hours kWh
Wood Boiler Pump 100 20 55% 1.2 90.0% 8,322 8,486
Fuel Oil Boiler Pump 89 20 55% 1.1 90.0% 438 397
Secondary Pumps (Average) 65 40 50% 1.8 92.0% 8,760 12,496
97,972
Page 1
Alaska Energy Engineering LLC CALCULATIONS
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Annual Energy Requirements
December 3, 2010
Alternative 2: Modular Pellet Boiler Plant
Heating Energy
Pellet Boiler (Lead)
Net, MMBTU % Load MMBtu/ton Net, tons Dry/Dist Efficiency Gross Tons
3,413 95% 16.0 203 5% 80% 266
Fuel Oil Boilers (lag/standby)
Net, MMBTU % Load LHV, kBtu/gal Net, gallons Dry/Dist Efficiency Gross, gallons
3,413 5% 130.0 1,313 0% 70% 1,875
Electric Energy MMBtu MBH Hours
Wood Boiler Hours 3,242 1,024 3,800
Equipment HP kW Annual Hours kWh
De-ashing System 0.5 0.5 365 170
Pneumatic tube cleaning system 5.0 4.7 52 242
Induced draft fan 15.0 14.0 3,800 53,149
Silo auger 5.0 4.7 3,800 17,716
Feed auger 1.5 1.4 3,800 5,315
Pumping Energy GPM Head η, pump BHP η, motor Hours kWh
Wood Boiler Pump 100 20 55% 1.2 90.0% 8,322 8,486
Secondary Pumps (Average) 65 40 50% 1.8 92.0% 8,760 12,496
97,574
Alternative 3: Distributed Pellet Boiler Systems
Heating Energy
Pellet Boiler (Lead)
Net, MMBTU % Load MMBtu/ton Net, tons Dry/Dist Efficiency Gross Tons
3,413 95% 16.0 203 0% 80% 253
Fuel Oil Boilers (lag/standby)
Net, MMBTU % Load LHV, kBtu/gal Net, gallons Dry/Dist Efficiency Gross, gallons
3,413 5% 130.0 1,313 0% 70% 1,875
Electric Energy MMBtu MBH Hours
Wood Boiler Hours 3,242 1,024 3,800
Equipment HP kW Annual Hours kWh
Pneumatic tube cleaning system 1.5 1.4 52 73
Induced draft fan 7.0 6.5 3,800 24,803
Silo auger 6.0 5.6 3,800 21,260
Feed auger 1.5 1.4 3,800 5,315
Pumping Energy GPM Head η, pump BHP η, motor Hours kWh
Wood Boiler Pump 100 20 55% 1.2 90.0% 8,322 8,486
59,936
Page 2
Alaska Energy Engineering LLC CALCULATIONS
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Annual Energy Requirements
December 3, 2010
Alternative 4: Central Chip Boiler Plant
Chip Boiler (Lead)
Net, MMBTU % Load MMBtu/ton Net, tons Dry/Dist Efficiency Gross Tons
3,413 90% 8.0 384 20% 72% 640
Fuel Oil Boilers (lag/Standby)
Net, MMBTU % Load LHV, kBtu/gal Net, gallons Efficiency Gross, gallons
3,413 10% 130.0 2,625 70% 3,750
Electric Energy MMBtu MBH Hours
Wood Boiler Hours 3,686 1,809 2,445
HP kW Annual Hours kWh
De-ashing System 0.5 0.5 365 170
Pneumatic tube cleaning system 5.0 4.7 52 242
Induced draft fan 15.0 14.0 2,445 34,201
Chip drying fan 20.0 18.7 4,380 81,687
Silo auger 5.0 4.7 2,445 11,400
Feed auger 1.5 1.4 2,445 3,420
Pumping Energy GPM Head η, pump BHP η, motor Hours kWh
Wood Boiler Pump 120 20 55% 1.5 90.0% 8,322 10,183
Fuel Oil Boiler Pump 89 20 55% 1.1 90.0% 438 397
Secondary Pumps (Average) 80 40 50% 2.2 92.0% 8,760 15,379
Total kWh 157,081
$0
$100,000
$200,000
$300,000
$400,000
$500,000
$600,000
2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034 2036
Baseline: Fuel Oil Boilers (Status Quo)
Alternative 1: Central Pellet Boiler Plant
Alternative 4: Central Chip Boiler Plant
Page 3
Alaska Energy Engineering LLC
Hydaburg City Schools Wood Heating Feasibility Analysis
Appendix C
Life Cycle Cost Analysis
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Baseline: Fuel Oil Boilers (Status Quo)
Basis
Economic Factors Energy Inflation
Study Period (years) 25 Fuel Oil 6.0%
Nominal Discount Rate 5.0% Electricity 4.0%
General Inflation 2.0% Pellets 2.0%
Real Discount Rate 2.9%
Construction Costs Qty Unit Base Cost Year 0 Cost
None 1LS 0 $0
Contingencies
General Contractor Overhead and Profit 30% $0
Owner + A/E Costs 20% $0
Estimating contingency 15% $0
Total Construction Costs $0
Operating Costs Years Qty Unit Base Cost Present Value
Fuel oil boiler maintenance, 5 @ 12 hrs/yr 1 - 25 60 hrs 80.00 $84,134
Maintenance supplies 1 - 25 1 LS 1,000.00 $17,528
Replace gymnasium boilers 10 - 10 1 LS 90,000.00 $67,352
Replace high school fuel tank 10 - 10 1 LS 15,000.00 $11,225
Replace high school boiler 20 - 20 1 LS 50,000.00 $28,002
December 3, 2010
Year
0
0
0
0
Replace high school boiler 20 20 1 LS 50,000.00 $28,002
Salvage gymnasium boilers 25 - 25 1 LS -20,000.00 ($9,690)
Salvage high school boilers 25 - 25 2 LS -15,428.57 ($14,950)
Total Operating Costs $180,000
Energy Costs Years Qty Unit Base Cost Present Value
Fuel Oil 1 - 25 37,500 gals 3.41 $3,627,959
Electricity 1 - 25 0 kWh 0.21 $0
Wood Pellets 1 - 25 0 ton 306.00 $0
Wood Chips 1 - 25 0 ton 76.10 $0
Total Energy Costs $3,630,000
$3,810,000Present Worth
Page 1
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 1: Central Pellet Boiler Plant
Basis
Economic Factors Energy Inflation
Study Period (years) 25 Fuel Oil 6.0%
Nominal Discount Rate 5.0% Electricity 4.0%
General Inflation 2.0% Pellets 2.0%
Real Discount Rate 2.9%
Construction Costs Qty Unit Base Cost Year 0 Cost
General
Mobilization / Demobilization
Vehicle ferry 12 ea 200 $2,400
Driver time 12 ea 660 $7,920
Airfare: Ketchikan to Craig 12 rt 275 $3,300
Travel time 12 ea 220 $2,640
Lodging
Room rental 3 months 2,000 $6,000
Daily travel time (Craig to Hydaburg) 360 MD 220 $79,200
Food allowance 360 MD 25 $9,000
Heating Plant
Building
Site preparation, excavation, grading, backfill 1 ls 15,000 $15,000
Building, 24x16 384 sqft 200 $76,800
December 3, 2010
Year
0
0
0
0
0
0
0
0
0
Building, 24x16 384 sqft 200 $76,800
Mechanical 1 ls 20,000 $20,000
Electrical 1 ls 30,000 $30,000
Heating Plant
Wood Heating Plant 1 ls 750,000 $750,000
Wood boiler and appurtenances
Chimney and breaching
One 75 ton silos
Ash removal system
Air compressor
Control system
Silo and feed auger system
Electrical from control panel to boiler
Startup, commissioning
Silo foundation 1 ls 10,000 $10,000
Install elementary school boilers 2 ls 6,000 $12,000
Chimneys 3 ea 4,000 $12,000
Primary heating loop, 4" 1 ls 100,000 $100,000
Primary pumps 3 ea 1,500 $4,500
Secondary pumps w/ VFD 2 ea 4,500 $9,000
Controls
Boiler controls 1 ls 8,000 $8,000
Primary pumps 6 pts 1,500 $9,000
Secondary pumps 8 pts 1,500 $12,000
Heating plant 6 pts 1,500 $9,000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Page 1
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 1: Central Pellet Boiler Plant
December 3, 2010
Construction Costs Qty Unit Base Cost Year 0 Cost
Distribution
Gymnasium
3" HS and 3" HR in Gym 400 lnft 60 $24,000
Exterior wall penetration 1 ea 4,500 $4,500
High School
Excavate and surface repairs (paving, grass, sidewalks, etc) 810 sqft 25 $20,250
Direct bury 2" HS and 2" HR 135 lnft 240 $32,400
Exterior wall penetration 1 ea 4,500 $4,500
Elementary School
Excavate and repair surfaces 900 sqft 25 $22,500
Direct bury 3" HS and 3" HR 150 lnft 280 $42,000
Exterior wall penetration 1 ea 4,500 $4,500
Buildings
Elementary School
Remove boilers (relocate to Gym Boiler Room) 2 ea 3,000 $6,000
Remove chimney and patch roof penetration 1 ea 5,000 $5,000
Remove 1,000 gallon underground fuel tank and piping 1 ea 5,000 $5,000
Reconfigure building piping, connect with HX, controls 1 ea 15,000 $15,000
High School
Remove boiler 1 ea 3,000 $3,000
Remove chimney and patch roof penetration 1 ea 3,500 $3,500
Remove 500 gallon aboveground fuel tank and piping 1 ea 1,500 $1,500
Year
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Remove 500 gallon aboveground fuel tank and piping 1 ea 1,500 $1,500
Reconfigure building piping, connect with HX, controls 1 ea 12,000 $12,000
Replace circulating pump 1 ea 2,000 $2,000
Gymnasium
Remove boilers, 568 MBH 2 ea 2,500 $5,000
Remove chimney and patch roof penetration 1 ea 5,000 $5,000
Reconfigure building piping, connect with HX, controls 1 ea 15,000 $15,000
Connect fuel oil piping to relocated boilers 1 ea 3,000 $3,000
Contingencies
General Contractor Overhead and Profit 30% $427,023
Owner + A/E Costs 20% $370,087
Estimating contingency 15% $333,078
Total Construction Costs $2,550,000
0
0
0
0
0
0
0
0
0
0
Page 2
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 1: Central Pellet Boiler Plant
December 3, 2010
Operating Costs Years Qty Unit Base Cost Present Value
Pellet boiler maintenance
Daily, 0.5 hours per day 1 - 25 183 hrs 42.00 $134,351
Annual, 3 days / 2 people 1 - 25 48 hrs 42.00 $35,336
Pellet boiler contracted maintenance 1 - 25 1 ls 5,000 $87,639
Pellet boiler replacement 18 - 18 1 ls 562,500 $333,825
Pellet boiler salvage value 25 - 25 1 ls -164,063 ($79,484)
Auger replacement 10 - 10 1 ls 15,000 $11,225
Auger replacement 20 - 20 1 ls 15,000 $8,401
Auger salvage value 25 - 25 1 ls -7,500 ($3,634)
Fuel oil boiler maintenance, 2 @ 12 hrs/yr 1 - 25 24 hrs 42.00 $17,668
Pump maintenance, 1 - 25 5 pumps 200.00 $17,528
Maintenance supplies 1 - 25 1 ls 800.00 $14,022
1 - 25 $0
Total Annual Costs $580,000
Energy Costs Years Qty Unit Base Cost Present Value
Fuel Oil 1 - 25 1,969 gals 3.41 $190,468
Electricity 1 - 25 97,972 kWh 0.24 $520,305
Wood Pellets 1 - 25 259 ton 306.00 $1,391,558
Wood Chips 1 - 25 0 ton 76.10 $0
Total Energy Costs $2 100 000Total Energy Costs $2,100,000
$5,230,000Present Worth
Page 3
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 2: Modular Pellet Boiler Plant
Basis
Economic Factors Energy Inflation
Study Period (years) 25 Fuel Oil 6.0%
Nominal Discount Rate 5.0% Electricity 4.0%
General Inflation 2.0% Pellets 2.0%
Real Discount Rate 2.9%
Construction Costs Qty Unit Base Cost Year 0 Cost
General
Mobilization / Demobilization
Vehicle ferry 9 ea 200 $1,800
Driver time 9 ea 660 $5,940
Airfare: Ketchikan to Craig 9 rt 275 $2,475
Travel time 9 ea 220 $1,980
Lodging
Room rental 2 months 2,000 $4,000
Daily travel time (Craig to Hydaburg) 270 MD 220 $59,400
Food allowance 270 MD 25 $6,750
Heating Plant
Modular Heating Plant
Module with Wood Heating Plant 1 ls 661,500 $661,500
Wood boiler and appurtenances
0
December 3, 2010
Year
0
0
0
0
0
0
0
Wood boiler and appurtenances
Chimney and breaching
One 75 ton silo
Ash removal system
Air compressor
Control system
Feed auger system
Piping and elecrical, single point connection
Startup, commissioning
Undergound heating supply and return piping 20 lnft 400 $8,000
Electrical service, 208v/ 3-phase, 45A 1 ls 15,000 $15,000
Building and silo foundation 1 ls 15,000 $15,000
Distribution
Gymnasium
3" HS and 3" HR in Gym 400 lnft 60 $24,000
Exterior wall penetration 1 ea 4,500 $4,500
0
0
0
0
0
Page 1
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 2: Modular Pellet Boiler Plant
December 3, 2010
Construction Costs Qty Unit Base Cost Year 0 Cost
High School
Excavate and surface repairs (paving, grass, sidewalks, etc) 810 sqft 25 $20,250
Direct bury 2" HS and 2" HR 135 lnft 240 $32,400
Exterior wall penetration 1 ea 4,500 $4,500
Elementary School
Excavate and repair surfaces 900 sqft 25 $22,500
Direct bury 3" HS and 3" HR 150 lnft 280 $42,000
Exterior wall penetration 1 ea 4,500 $4,500
Buildings
Elementary School
Reconfigure building piping, connect with HX, controls 1 ea 40,000 $40,000
High School
Reconfigure building piping, connect with HX, controls 1 ea 25,000 $25,000
Replace circulating pump 1 ea 2,000 $2,000
Gymnasium
Reconfigure building piping, connect with HX, controls 1 ea 40,000 $40,000
Connect fuel oil piping to relocated boilers 1 ea 3,000 $3,000
Contingencies
General Contractor Overhead and Profit 30% $313,949
Owner + A/E Costs 20% $272,089
Estimating contingency 15% $244,880
Total Construction Costs $1 880 000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Year
Total Construction Costs $1,880,000
Operating Costs Years Qty Unit Base Cost Present Value
Pellet boiler maintenance
Daily, 0.5 hours per day 1 - 25 183 hrs 42.00 $134,351
Annual, 3 days / 2 people 1 - 25 48 hrs 42.00 $35,336
Pellet boiler contracted maintenance 1 - 25 1 ls 5,000 $87,639
Pellet boiler replacement 18 - 18 1 ls 496,125 $294,433
Pellet boiler salvage value 25 - 25 1 ls -144,703 ($70,105)
Auger replacement 10 - 10 1 ls 15,000 $11,225
Auger replacement 20 - 20 1 ls 15,000 $8,401
Auger salvage value 25 - 25 1 ls -7,500 ($3,634)
Replace high school fuel tank 10 - 10 1 ls 15,000.00 $11,225
Fuel oil boiler maintenance, 5 @ 12 hrs/yr 1 - 25 60 hrs 42.00 $44,170
Pump maintenance, 1 - 25 2 pumps 200.00 $7,011
Maintenance supplies 1 - 25 1 ls 1,000.00 $17,528
Total Annual Costs $580,000
Page 2
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 2: Modular Pellet Boiler Plant
December 3, 2010
Energy Costs Years Qty Unit Base Cost Present Value
Fuel Oil 1 - 25 1,875 gals 3.41 $181,398
Electricity 1 - 25 97,574 kWh 0.23 $496,603
Wood Pellets 1 - 25 266 ton 306.00 $1,426,347
Wood Chips 1 - 25 0 ton 76.10 $0
Total Energy Costs $2,100,000
$4,560,000Present Worth
Page 3
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 3: Distributed Pellet Boiler Plants
Basis
Economic Factors Energy Inflation
Study Period (years) 25 Fuel Oil 6.0%
Nominal Discount Rate 5.0% Electricity 4.0%
General Inflation 2.0% Pellets 2.0%
Real Discount Rate 2.9%
Construction Costs Qty Unit Base Cost Year 0 Cost
General
Mobilization / Demobilization
Vehicle ferry 14 ea 200 $2,800
Driver time 14 ea 660 $9,240
Airfare: Ketchikan to Craig 14 rt 275 $3,850
Travel time 14 ea 220 $3,080
Lodging
Room rental 3.5 months 2,000 $7,000
Daily travel time (Craig to Hydaburg) 414 MD 220 $91,080
Food allowance 414 MD 25 $10,350
Buildings
Elementary School
Wood Heating Plant, 145 kW
Wood boiler and appurtenances 1 ls 128,750 $128,750
0
December 3, 2010
Year
0
0
0
0
0
0
0Wood boiler and appurtenances 1 ls 128,750 $128,750
30 ton silo 1 ls 37,500 $37,500
Piping and elecrical, single point connection 1 ls 5,000 $5,000
Building 1 ls 30,000 $30,000
Undergound heating supply and return piping 20 lnft 350 $7,000
Electrical service, 12 kW 1 ls 15,000 $15,000
Building and silo foundation 1 ls 10,000 $10,000
Reconfigure building piping, connect wood boiler, controls 1 ea 50,000 $50,000
High School
Wood Heating Plant, 55 kW
Wood boiler and appurtenances 1 ls 51,250 $51,250
15 ton silo 1 ls 25,000 $25,000
Piping and elecrical, single point connection 1 ls 5,000 $5,000
Building 1 ls 20,000 $20,000
Undergound heating supply and return piping 20 lnft 350 $7,000
Electrical service, 10 kW 1 ls 5,000 $5,000
Building and silo foundation 1 ls 10,000 $10,000
Reconfigure building piping, connect wood boiler, controls 1 ea 30,000 $30,000
Relocate 500 gallon fuel oil tank 1 ea 2,500 $2,500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Page 1
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 3: Distributed Pellet Boiler Plants
December 3, 2010
Construction Costs Qty Unit Base Cost Year 0 Cost
Gymnasium
Wood Heating Plant, 125 kW
Wood boiler and appurtenances 1 ls 128,750 $128,750
One 30 ton silo 1 ls 37,500 $37,500
Piping and elecrical, single point connection 1 ls 5,000 $5,000
Building 1 ls 30,000 $30,000
Undergound heating supply and return piping 20 lnft 350 $7,000
Electrical service, 12 kW 1 ls 5,000 $5,000
Building and silo foundation 1 ls 10,000 $10,000
Reconfigure building piping, connect wood boiler, controls 1 ea 50,000 $50,000
Contingencies
General Contractor Overhead and Profit 30% $251,895
Owner + A/E Costs 20% $218,309
Estimating contingency 15% $196,478
Total Construction Costs $1,510,000
Operating Costs Years Qty Unit Base Cost Present Value
Pellet boiler maintenance
Daily, 0.5 hours per day, each plant 1 - 25 548 hrs 42.00 $403,053
Annual, 2 days / 2 people, each plant 1 - 25 96 hrs 42.00 $70,672
Pellet boiler contracted maintenance 1-25 1ls 10,000 $175,278
Year
0
0
0
0
0
0
0
0
0
0
0
Pellet boiler contracted maintenance 1 25 1 ls 10,000 $175,278
Pellet boiler replacement 18 - 18 1 ls 154,375 $91,616
Pellet boiler salvage value 25 - 25 1 ls -30,017 ($14,543)
Replace high school fuel tank 10 - 10 1 ls 15,000.00 $11,225
Auger replacement 10 - 10 3 ea 8,000 $17,961
Auger replacement 20 - 20 3 ea 8,000 $13,441
Auger salvage value 25 - 25 3 ea -2,667 ($3,876)
Fuel oil boiler maintenance, 5 @ 12 hrs/yr 1 - 25 60 hrs 42.00 $44,170
Primary Pump maintenance 1 - 25 7 pumps 200.00 $24,539
Maintenance supplies 1 - 25 1 ls 3,500.00 $61,347
1 - 25 $0
Total Annual Costs $890,000
Energy Costs Years Qty Unit Base Cost Present Value
Fuel Oil 1 - 25 1,875 gals 3.41 $181,398
Electricity 1 - 25 59,936 kWh 0.22 $291,780
Wood Pellets 1 - 25 253 ton 306.00 $1,358,426
Wood Chips 1 - 25 0 ton 76.10 $0
Total Energy Costs $1,830,000
$4,230,000Present Worth
Page 2
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 4: Central Chip Boiler Plant
Basis
Economic Factors Energy Inflation
Study Period (years) 25 Fuel Oil 6.0%
Nominal Discount Rate 5.0% Electricity 4.0%
General Inflation 2.0% Chips 1.5%
Real Discount Rate 2.9%
Construction Costs Qty Unit Base Cost Year 0 Cost
General
Mobilization / Demobilization
Vehicle ferry 12 ea 200 $2,400
Driver time 12 ea 660 $7,920
Airfare: Ketchikan to Craig 12 rt 275 $3,300
Travel time 12 ea 220 $2,640
Lodging
Room rental 3 months 2,000 $6,000
Daily travel time (Craig to Hydaburg) 360 MD 220 $79,200
Food allowance 360 MD 25 $9,000
Heating Plant
Building
Site preparation, excavation, grading, backfill 1 ls 25,000 $25,000
Building with chip storage, 24x24,576 sqft 200 $115,200
0
0
December 3, 2010
Year
0
0
0
0
0
0
0
Building with chip storage, 24x24,576 sqft 200 $115,200
Mechanical 1 ls 20,000 $20,000
Electrical 1 ls 30,000 $30,000
Heating Plant
Wood Heating Plant 1 ls 882,000 $882,000
Wood boiler and appurtenances
Chimney and breaching
Ash removal system
Air compressor
Control system
Feed auger system
Electrical from control panel to boiler
Startup, commissioning
Chip drying system inc perforated floor 1 ls 55,000 $55,000
Install elementary school boilers 2 ls 6,000 $12,000
Chimneys 3 ea 4,000 $12,000
Primary heating loop, 4" 1 ls 100,000 $100,000
Primary pumps 3 ea 1,500 $4,500
Secondary pumps w/ VFD 2 ea 4,500 $9,000
Controls
Boiler controls 1 ls 8,000 $8,000
Primary pumps 6 pts 1,500 $9,000
Secondary pumps 8 pts 1,500 $12,000
Heating plant 6 pts 1,500 $9,000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Page 1
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 4: Central Chip Boiler Plant
December 3, 2010
Construction Costs Qty Unit Base Cost Year 0 Cost
Distribution
Gymnasium
3" HS and 3" HR in Gym 400 lnft 60 $24,000
Exterior wall penetration 1 ea 4,500 $4,500
High School
Excavate and surface repairs (paving, grass, sidewalks, etc) 810 sqft 25 $20,250
Direct bury 2" HS and 2" HR 135 lnft 240 $32,400
Exterior wall penetration 1 ea 4,500 $4,500
Elementary School
Excavate and repair surfaces 900 sqft 25 $22,500
Direct bury 3" HS and 3" HR 150 lnft 280 $42,000
Exterior wall penetration 1 ea 4,500 $4,500
Buildings
Elementary School
Remove boilers (relocate to Gym Boiler Room) 2 ea 3,000 $6,000
Remove chimney and patch roof penetration 1 ea 5,000 $5,000
Remove 1,000 gallon underground fuel tank and piping 1 ea 5,000 $5,000
Reconfigure building piping, connect with HX, controls 1 ea 15,000 $15,000
High School
Remove boiler 1 ea 3,000 $3,000
Remove chimney and patch roof penetration 1 ea 3,500 $3,500
Remove 500 gallon aboveground fuel tank and piping 1 ea 1,500 $1,500
0
0
0
0
0
0
0
0
0
0
0
0
0
Year
0
0
Remove 500 gallon aboveground fuel tank and piping 1 ea 1,500 $1,500
Reconfigure building piping, connect with HX, controls 1 ea 12,000 $12,000
Replace circulating pump 1 ea 2,000 $2,000
Gymnasium
Remove boilers, 568 MBH 2 ea 2,500 $5,000
Remove chimney and patch roof penetration 1 ea 5,000 $5,000
Reconfigure building piping, connect with HX, controls 1 ea 15,000 $15,000
Connect fuel oil piping to relocated boilers 1 ea 3,000 $3,000
Contingencies
General Contractor Overhead and Profit 30% $494,643
Owner + A/E Costs 20% $428,691
Estimating contingency 15% $385,822
Total Construction Costs $2,960,000
0
0
0
0
0
0
0
0
0
0
Page 2
Alaska Energy Engineering LLC Life Cycle Cost Analysis
25200 Amalga Harbor Road Tel/Fax: 907.789.1226
Juneau, Alaska 99801 alaskaenergy@earthlink.net
Hydaburg Schools Wood Heating Analysis
Alternative 4: Central Chip Boiler Plant
December 3, 2010
Operating Costs Years Qty Unit Base Cost Present Value
Chip boiler maintenance
Daily, 2 hours per day 1 - 25 730 hrs 42.00 $537,403
Annual, 1 week / 2 people 1 - 25 80 hrs 42.00 $58,894
Chip boiler contracted maintenance 1 - 25 1 ls 5,000 $87,639
Chip boiler replacement 18 - 18 1 ls 661,500 $392,578
Chip boiler salvage value 25 - 25 1 ls -192,938 ($93,473)
Auger replacement 10 - 10 1 ls 15,000 $11,225
Auger replacement 20 - 20 1 ls 15,000 $8,401
Auger salvage value 25 - 25 1 ls -7,500 ($3,634)
Fuel oil boiler maintenance, 2 @ 12 hrs/yr 1 - 25 24 hrs 42.00 $17,668
Pump maintenance, 1 - 25 5 pumps 200.00 $17,528
Maintenance supplies 1 - 25 1 LS 1,000.00 $17,528
1 - 25 $0
Total Annual Costs $1,050,000
Energy Costs Years Qty Unit Base Cost Present Value
Fuel Oil 1 - 25 3,750 gals 3.41 $362,796
Electricity 1 - 25 157,081 kWh 0.25 $868,979
Wood Pellets 1 - 25 0 ton 306.00 $0
Wood Chips 1 - 25 640 ton 76.10 $807,044
Total Energy Costs $2 040 000Total Energy Costs $2,040,000
$6,050,000Present Worth
Page 3