HomeMy WebLinkAboutIliamna Village Fesability Assessment for Biomass Heating Systems AWEDTG 07-26-2013-BIO
Feasibility Assessment for Biomass Heating Systems
Iliamna Village Office Building, Iliamna, Alaska
800 F Street, Anchorage, AK 99501
p (907) 276-6664 f (907) 276-5042
Tony SlatonBarker, PE, and
Lee Bolling, CEA
FINAL REPORT – 7/26/2013
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. i
Contents
I. Executive Summary ............................................................................................................ 1
II. Introduction ...................................................................................................................... 2
III. Preliminary Site Investigation ........................................................................................... 3
BUILDING DESCRIPTION ................................................................................................................................................... 3
EXISTING HEATING SYSTEM .............................................................................................................................................. 3
DOMESTIC HOT WATER................................................................................................................................................... 3
BUILDING ENVELOPE ....................................................................................................................................................... 3
AVAILABLE SPACE ........................................................................................................................................................... 3
STREET ACCESS AND FUEL STORAGE ................................................................................................................................... 4
BUILDING OR SITE CONSTRAINTS ....................................................................................................................................... 4
BIOMASS SYSTEM INTEGRATION ........................................................................................................................................ 4
BIOMASS SYSTEM OPTIONS .............................................................................................................................................. 4
IV. Energy Consumption and Costs ......................................................................................... 5
WOOD ENERGY ............................................................................................................................................................. 5
ENERGY COSTS .............................................................................................................................................................. 5
EXISTING FUEL OIL CONSUMPTION .................................................................................................................................... 6
BIOMASS SYSTEM CONSUMPTION ..................................................................................................................................... 6
V. Preliminary Cost Estimating ............................................................................................... 8
VI. Economic Analysis .......................................................................................................... 10
O&M COSTS .............................................................................................................................................................. 10
DEFINITIONS................................................................................................................................................................ 10
RESULTS ..................................................................................................................................................................... 12
SENSITIVITY ANALYSIS ................................................................................................................................................... 13
VII. Forest Resource and Fuel Availability Assessments ........................................................ 14
FOREST RESOURCE ASSESSMENTS .................................................................................................................................... 14
AIR QUALITY PERMITTING .............................................................................................................................................. 14
VIII. General Biomass Technology Information ..................................................................... 15
HEATING WITH WOOD FUEL ........................................................................................................................................... 15
TYPES OF WOOD FUEL .................................................................................................................................................. 15
HIGH EFFICIENCY CORD WOOD BOILERS ........................................................................................................................... 16
LOW EFFICIENCY CORD WOOD BOILERS ........................................................................................................................... 16
HIGH EFFICIENCY WOOD STOVES .................................................................................................................................... 17
BULK FUEL BOILERS ...................................................................................................................................................... 17
GRANTS ..................................................................................................................................................................... 17
Appendices
Appendix A – Site Photos
Appendix B – Economic Analysis Spreadsheet
Appendix C – Site Plan
Appendix D – AWEDTG Field Data Sheet
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. ii
Abbreviations
ACF Accumulated Cash Flow
ASHRAE American Society of Heating, Refrigeration, and Air-Conditioning Engineers
AEA Alaska Energy Authority
AFUE Annual Fuel Utilization Efficiency
AHU Air Handling Unit
ARCH Architectural
B/C Benefit / Cost Ratio
BAS Building Automation System
BTU British Thermal Unit
BTUH BTU per hour
CCF One Hundred Cubic Feet
CEI Coffman Engineers, Inc.
CFM Cubic Feet per Minute
CIRC Circulation
CMU Concrete Masonry Unit
CRAC Computer Room Air Conditioning
CWCO Cold Weather Cut Out
DDC Direct Digital Control
∆T Delta T (Temperature Differential)
ECI Energy Cost Index
ECM Energy Conservation Measure
EF Exhaust Fan
Eff Efficiency
ELEC Electrical
EPDM Ethylene Propylene Diene Monomer
EUI Energy Utilization Index
F Fahrenheit
ft Feet
GPM Gallons Per Minute
HP Horsepower
HPS High Pressure Sodium
HVAC Heating, Ventilating, and Air-Conditioning
IESNA Illuminating Engineering Society of North America
in Inch(es)
IPLC Integrated Power and Load Circuit
IRC Internal Revenue Code
kBTU One Thousand BTUs
kWh Kilowatt-Hour
LED Light-Emitting Diode
MBH Thousand BTUs per Hour
MECH Mechanical
MH Metal Halide
O&M Operations and Maintenance
MMBTU One Million BTUs
P Pump
PC Project Cost
PF Power Factor
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. iii
R R-Value
PH Phase
SC Shading Coefficient
SAT Supply Air Temperature
SF Square Feet, Supply Fan
TEMP Temperature
U U-Value
V Volts
VFD Variable Frequency Drive
W Watts
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. iv
List of Figures
Fig. 1 – Iliamna, Alaska – Google Maps ......................................................................................................... 2
Fig. 2 – Iliamna Village Council Office Building – Google Maps .................................................................... 2
List of Tables
Table 1 – Economic Evaluation Summary ..................................................................................................... 1
Table 2 – Energy Comparison ....................................................................................................................... 5
Table 3 – Existing Fuel Oil Consumption ....................................................................................................... 6
Table 4 – Proposed Biomass System Fuel Consumption .............................................................................. 7
Table 5 – Option A - Estimate of Probable Cost ............................................................................................ 8
Table 6 – Option B - Estimate of Probable Cost ............................................................................................ 9
Table 7 – Inflation rates .............................................................................................................................. 10
Table 8 – Economic Definitions ................................................................................................................... 11
Table 9 – Option A - Economic Analysis Results ......................................................................................... 12
Table 10 – Option B - Economic Analysis Results ....................................................................................... 13
Table 11 – Option A Sensitivity Analysis ..................................................................................................... 13
Table 12 – Option B Sensitivity Analysis ..................................................................................................... 13
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 1
I. Executive Summary
A preliminary feasibility assessment was completed to determine the technical and economic viability of
biomass heating systems at the Iliamna Village Office Building in Iliamna, Alaska. In the study two
options were evaluated. Both options utilize one GarnPak cord wood boiler system to offset heating oil
consumption. In Option A, the GarnPak serves only the Village Office Building. In Option B, the GarnPak
serves the Village Office Building and the adjacent shop building.
The results of the economic evaluation for both options are shown below. Both options are not
economically justified at this time, due to the fact that the benefit to cost ratio of each option is less
than 1.0. However, since the benefit to cost ratio of Option B is very close to 1.0 it may be prudent to
further study this option. Further investigation is needed to determine the actual heating oil
consumption of the shop building and to develop a more detailed cost estimate.
Economic Analysis Results Option A Option B
Project Capital Cost ($332,298) ($395,488)
Simple Payback 42.3 years 30.7 years
Present Value of Project Benefits (20 year life) $544,586 $818,146
Present Value of Operating Costs (20 year life) ($302,773) ($438,717)
Benefit / Cost Ratio of Project (20 year life) 0.73 0.96
Net Present Value (20 year life) ($90,484) ($16,059)
Year Accumulated Cash Flow is Net Positive First Year First Year
Year Accumulated Cash Flow > Project Capital Cost 25 years 21 years
Table 1 – Economic Evaluation Summary
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 2
II. Introduction
A preliminary feasibility assessment was completed to determine the technical and economic viability of
biomass heating systems for the Iliamna Village Council Office building in Iliamna, AK. The location of
the building is shown in Figures 1 and 2.
Fig. 1 – Iliamna, Alaska – Google Maps
Fig. 2 – Iliamna Village Council Office Building – Google Maps
ILIAMNA VILLAGE
OFFICE BUILDING
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 3
III. Preliminary Site Investigation
Building Description
The Iliamna Village Office Building is a 3,200 SF two story building that was built in 1988. It has two
floors of office space and a large garage bay for storing the fire engine. There are no scheduled or
planned renovations for the building. It is used by five to ten office staff during the work week from
8am to 5pm and occasionally during the weekend. It is typically used approximately 60 hours per week.
No energy audit has been conducted at the building.
Existing Heating System
The building is heated by two identical Burnham Boilers (MN: LE2-GBI2S, 1.25 GPH Firing Rate, 143 MBH
Output) that were installed in 2010. The boilers are located in the second floor boiler room. The boilers
serve three heating zones and an indirect hot water heater. One heating zone is for two unit heaters
located in the garage. The remaining zones heat the two floors of office space with baseboard radiators.
New pumps, piping and boiler controller in the boiler room appear to have been installed during the
2010 boiler replacement. The boilers appear to be sized to be fully redundant, so that one boiler can
carry the entire building heat load. This was confirmed by a heat load calculation. The combustion
efficiency of the existing fuel oil boilers is approximately 80%.
There is no routine maintenance of the boilers. The boilers appear to be in poor shape considering the
age of the boilers. The installation of the control wiring for the boilers and zone valves does not appear
to be finished. Also, the boilers were short cycling during the site visit and the Tekmar boiler control
module was reading an error message.
One 2,000 gal heating oil tank serves the boilers and is located to the north side of the building. No spill
containment is present around the tank. Fuel in the tanks is used for heating only.
Domestic Hot Water
Domestic hot water is used for hand washing and also for laundry. There are three commercial washing
machines in the building. Hot water is provided by a 50 gal Superstore indirect hot water heater, which
uses a loop from the boiler for heat.
Building Envelope
The building is a typical pre-fabricated steel frame metal warehouse building. The office space was
framed inside the originally open metal building. It is estimated that the walls have R-19 fiberglass batt
insulation and the metal hot roof has R-25 fiberglass batt insulation. The windows are double pane and
there is one arctic entry for the rear entrance.
Available Space
There is no allowable space inside the building for a wood heating system. The Village Council does not
wish to sacrifice space inside the building for a wood boiler system. The office building sits on a large
gravel pad and a second 60’x40’ shop building is approximately 80 ft to the north of the office building.
There is ample room on the gravel pad for a detached wood boiler building. The Village Council has
selected a location for the wood boiler building approximately 80ft to the west of the office building.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 4
This location can be easily accessed by a truck or forklift. This will require a buried arctic pipe between
the wood boiler building and the office building.
Street Access and Fuel Storage
The building site is situated along a paved road and a truck can easily access all sides of the building.
There is adequate space to the west side of the gravel pad for a wood boiler building and wood storage
shed.
Building or Site constraints
The site is flat with no significant site constraints. There were no wetlands or signs of historical
structures observed.
Biomass System Integration
A wood boiler system would easily be able to tie into the return line of the existing hydronic system of
the building. The existing hydronic system, baseboards and unit heaters would be used to distribute
heat around the building.
Biomass System Options
The most viable option for biomass resource is cord wood, as it is available locally in the Iliamna area.
Wood chips and wood pellets were considered, but were considered not to be viable due to the
expensive cost of shipping to Iliamna since there is no local supplier of either type of wood fuel. Chips
and pellets can only be shipped to Iliamna in two ways: 1) flown in by plane or 2) shipped by barge from
Homer to Williamsport, then trucked to Pile Bay, and finally barged across Lake Iliamna to Iliamna. Due
to these expensive shipping issues, it was determined that a cord wood boiler system would be the most
viable option for wood heating at the building.
Option A: For this study, a GarnPak cord wood boiler system is used. A GarnPak, or Garn-in-the-box, is
a pre-constructed conex that contains one Garn cord wood boiler. The GarnPak would be located in the
available space on the gravel pad 80’ west of the building and would deliver heat to the building via
buried and pre-insulated hydronic piping. The Garn boiler would deliver heat to a heat exchanger inside
the GarnPak conex, which would transfer heat to a buried 50% propylene glycol loop. This loop would
deliver heat via buried arctic pipe to a heat exchanger in the boiler room. This second heat exchanger
would transfer heat to the office building’s existing hydronic system. For this building, one Garn WHS
2000 is recommended. This size Garn will produce a similar heat output to one of the existing heating
oil boilers at 148,000 BTU/hr with a 6 hr firing frequency.
Option B: Option B includes everything in Option A and a connection to the adjacent shop building.
This option will supply heat with one Garn WHS 2000 boiler to both the Village Office Building and the
shop building. Additional buried piping will be required, as well as another heat exchanger and piping to
connect to the shop’s existing hydronic system. The shop is currently heated by a Weil-McLain Gold Oil
Boiler P-WGO-3, with 115,000 BTU/hr output. The boiler serves two radiant floor slab zones in the
building. An EnergyLogic EL-200H waste oil furnace (160,000 BTU/hr) also supplies heat when waste oil
is available.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 5
IV. Energy Consumption and Costs
Wood Energy
The gross energy content of a cord of wood varies depending on tree species and moisture content.
Black spruce, white spruce and birch at 20% moisture content have respective gross energy contents of
15.9 MMBTU/Cord, 18.1 MMBTU/cord and 23.6 MMBTU/cord, according to the UAF Cooperative
Extension. Wet or greenwood has higher moisture contents and require additional heat to evaporate
moisture before the wood can burn. Thus, wood with higher moisture contents will have lower energy
contents. Seasoned or dry wood will typically have 20% moisture content. For this study, cord wood
was estimated to have 16.0 MMBTU/cord. This is a conservative estimate based on the fact that the
community has access to both spruce and birch. To determine the delivered $/MMBTU of the biomass
system, a 75% efficiency for the Garn boiler system was assumed. This is based on manufacturer
documentation and typical operational issues which do not allow firing 100% of the time.
Energy Costs
The high price of fuel oil is the main economic driver for the use of lower cost biomass heating. Fuel oil
is shipped into Iliamna by plane and currently costs $6.75/gal. For this study, the energy content of fuel
oil is based on 134,000 BTU/gal, according to the UAF Cooperative Extension.
Cord wood is sold in Iliamna not by the cord but by the truckload. A typical truck with a 6’ bed can
deliver cord wood to a site at $200 per truckload. A truck load of wood is approximately 0.61 cords.
This is estimated to be equivalent to $330 per cord, which is used for this study.
The table below shows the energy comparison of different fuel types. The system efficiency is used to
calculate the delivered MMBTU’s of energy to the building. The delivered cost of energy to the building,
in $/MMBTU, is the most accurate way to compare costs of different energy types. As shown below,
cord wood is less than half the cost of fuel oil based on the $/MMBTU delivered to the building heat
load.
Fuel Type Units Gross
BTU/unit
System
Efficiency $/unit Delivered
$/MMBTU
Cord Wood cords 16,000,000 75% $330 $27.50
Fuel Oil gal 134,000 80% $6.75 $62.97
Electricity kWh 3,413 99% $0.69 $204.21
Table 2 – Energy Comparison
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 6
Existing Fuel Oil Consumption
The Iliamna Village Office Building uses approximately 3,440 gal of fuel oil annually for space heating
and domestic hot water. This quantity is based on available heating oil records from 2012. The annual
fuel cost, based on the current price of heating oil, is $23,220.
The heating oil consumption of the adjacent shop building is unknown. It is estimated that the shop
building consumes about 0.9 gal/SF of heating oil and waste heat oil annually. It is estimated that 80%
of the building heat is provided by heating oil, while the remaining 20% is provided by waste oil. Based
on these assumptions, it is estimated that the shop building consumes approximately 1,728 gallons of
heating oil annually. The combined annual heating oil cost of the Village Office Building and shop
building is $38,884.
Building Name Fuel Type
Avg. Annual
Consumption Net MMBTU/yr
Annual Fuel
Cost
Iliamna Village
Office Building Fuel Oil 3,440 gal 368.8 $23,220
Shop Building Fuel Oil 1,728 gal 185.2 $11,664
Total Fuel Oil 5,168 gal 554.0 $34,884
Table 3 – Existing Fuel Oil Consumption
Biomass System Consumption
For both options it is estimated that the proposed biomass system will offset 85% of heating oil
consumption for the building, or buildings. The remaining 15% of the heat for the building will come
from the existing heating oil-fired boilers.
For Option A, the proposed biomass system would have a total annual energy cost of $14,370, to serve
the Village Office Building. This annual energy cost includes wood and fuel oil costs, as well as the cost
of the additional electricity required to operate the biomass heating system. It is estimated that 3,285
kWh annually will be required to operate the system pumps required by the Garn system.
For Option B, the proposed biomass system would have a total annual energy cost of $21,016, to serve
both the Village Office Building and shop building. It is estimated that 4,106 kWh per year of electricity
will be needed for this option.
Option Fuel Type % Heating
Source
Net
MMBTU/yr
Annual
Consumption
Energy
Cost
Total Energy
Cost
Option A:
Iliamna Village
Office Building
Cord
Wood 85% 313.5 26.1 cords $8,620
$14,370
Fuel Oil 15% 55.3 516 gal $3,483
Electricity N/A N/A 3,285 kWh $2,267
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 7
Option Fuel Type % Heating
Source
Net
MMBTU/yr
Annual
Consumption
Energy
Cost
Total Energy
Cost
Option B:
Iliamna Village
Office Building
+ Shop Building
Cord
Wood 85% 470.9 39.2 cords $12,950
$21,016 Fuel Oil 15% 83.1 775 gal $5,233
Electricity N/A N/A 4,106 kWh $2,833
Table 4 – Proposed Biomass System Fuel Consumption
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 8
V. Preliminary Cost Estimating
An estimate of probable costs was completed for Option A and Option B. The cost estimate is based on
a similar GarnPak system, installed in 2012, which Coffman designed for Thorne Bay, Alaska. The
estimate includes general conditions and overhead and profit for the general contractor. A 10% remote
factor was used to account for increased shipping and installation costs in Iliamna. Engineering design
and permitting was estimated at 15% and a 10% contingency was used.
Option A – GarnPak for Village Office Building
Category Description Cost
Site Work NFS Fill $ 3,380
Site Grading $ 1,500
Traffic Protection $ 350
Subtotal $ 5,230
Mechanical Utilities Trench & Backfill $ 4,530
Buried Piping $ 10,000
Piping Allowance $ 8,000
Subtotal $ 22,530
Electrical Utilities Service Entrance $ 7,000
Conduit and Wiring $ 6,900
Fire Allowance $ 3,000
Electrical Allowance $ 12,700
Subtotal $ 29,600
Wood Boiler and Boiler Bldg GarnPak Unit $ 120,000
Installation $ 5,000
$ 125,000
Interior Mechanical & Electrical HX, Piping & Materials $ 15,000
Subtotal $ 15,000
Subtotal Material and Installation Cost
$ 197,360
General Conditions 10% $ 19,736
Subtotal $ 217,096
Overhead and Profit 10% $ 21,710
Subtotal $ 238,806
Remote Factor 10% $ 23,881
Subtotal $ 262,686
Design Fees and Permitting 15% $ 39,403
Subtotal $ 302,089
Contingency 10% $ 30,209
Total Project Cost $ 332,298
Table 5 – Option A - Estimate of Probable Cost
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 9
Option B – GarnPak for Village Office Building and Shop Building
Category Description Cost
Site Work NFS Fill $ 3,380
Site Grading $ 1,500
Traffic Protection $ 350
Subtotal $ 5,230
Mechanical Utilities Trench & Backfill $ 9,060
Buried Piping $ 20,000
Piping Allowance $ 16,000
Subtotal $ 45,060
Electrical Utilities Service Entrance $ 7,000
Conduit and Wiring $ 6,900
Fire Allowance $ 3,000
Electrical Allowance $ 12,700
Subtotal $ 29,600
Wood Boiler and Boiler Bldg GarnPak Unit $ 120,000
Installation $ 5,000
$ 125,000
Interior Mechanical & Electrical HX, Piping & Materials $ 30,000
Subtotal $ 30,000
Subtotal Material and Installation Cost
$ 234,890
General Conditions 10% $ 23,489
Subtotal $ 258,379
Overhead and Profit 10% $ 25,838
Subtotal $ 284,217
Remote Factor 10% $ 28,422
Subtotal $ 312,639
Design Fees and Permitting 15% $ 46,896
Subtotal $ 359,534
Contingency 10% $ 35,953
Total Project Cost $ 395,488
Table 6 – Option B - Estimate of Probable Cost
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 10
VI. Economic Analysis
The following assumptions were used to complete the economic analysis for the proposed biomass
system at the Iliamna Village Office Building.
Inflation Rates
Discount Rate for Net Present Value Analysis 3%
Wood Fuel Escalation Rate 3%
Fossil Fuel Escalation Rate 5%
Electricity Escalation Rate 3%
O&M Escalation Rate 2%
Table 7 – Inflation rates
The real discount rate, or minimum attractive rate of return, is 3.0% and is the current rate used for all
Life Cycle Cost Analysis by the Alaska Department of Education and Early Development. This is a typical
rate used for completing economic analysis for public entities in Alaska. The escalation rates used for
the wood, heating oil, electricity and O&M rates are based on rates used in the Alaska Energy Authority
funded 2012 biomass pre-feasibility studies. These are typical rates used for this level of evaluation and
were used so that results are consistent and comparable to the 2012 studies.
O&M Costs
Non-fuel related operations and maintenance costs (O&M) were estimated at $500 per year. This
estimate is consistent with AEA’s O&M estimates used for projects utilizing Garn cord wood boilers. For
only the first two years of service, an additional $500 per year was added to account for maintenance
staff getting used to operating the new system. O&M costs were estimated to be the same for both
Option A and Option B.
Definitions
There are many different economic terms used in this study. A listing of all of the terms with their
definition is provided below for reference.
Economic Term Description
Project Capital Cost This is the opinion of probable cost for designing and constructing the
project.
Simple Payback The Simple Payback is the Project Capital Cost divided by the first year
annual energy savings. The Simple Payback does not take into account
escalated energy prices.
Present Value of Project
Benefits (20 year life)
The present value of all of the heating oil that would have been consumed by
the existing heating oil-fired heating system, over a 20 year period.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 11
Economic Term Description
Present Value of
Operating Costs (20 year
life)
The present value of all of the proposed biomass systems operating costs
over a 20 year period. This includes wood fuel, additional electricity, and
O&M costs for the proposed biomass system to provide 85% of the building’s
heat. It also includes the heating oil required for the existing oil-fired boilers
to provide the remaining 15% of heat to the building.
Benefit / Cost Ratio of
Project (20 year life)
This is the benefit to cost ratio over the 20 year period. A project that has a
benefit to cost ratio greater 1.0 is economically justified. It is defined as
follows:
Where:
PV = The present value over the 20 year period
Reference Sullivan, Wicks and Koelling, “Engineering Economy”, 14th ed.,
2009, pg. 440, Modified B-C Ratio.
Net Present Value (20
year life)
This is the net present value of the project over a 20 year period. If the
project has a net present value greater than zero, the project is economically
justified. This quantity accounts for the project capital cost, project benefits
and operating costs.
Year Accumulated Cash
Flow > Project Capital
Cost
This is the number of years it takes for the accumulated cash flow of the
project to be greater than or equal to the project capital cost. This is similar
to the project’s simple payback, except that it incorporates the inflation
rates. This quantity is the payback of the project including escalating energy
prices and O&M rates. This quantity is calculated as follows:
Where:
J = Year that the accumulated cash flow is greater than or equal to the
Project Capital Cost.
= Project Cash flow for the kth year.
Table 8 – Economic Definitions
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 12
Results
The economic analysis for Option A and Option B was completed in order to determine the simple
payback, benefit to cost ratio, and net present value of each. The results of the proposed GarnPak cord
wood boiler system are shown below. For both options, the GarnPak would be located in the available
space on the gravel pad 80 ft west of the Iliamna Village Office Building and would deliver heat to the
building via buried hydronic piping.
Option A - Due to the high cost of the GarnPak system compared to the heating oil offset, the Option A
has a low benefit to cost ratio of 0.73 over the 20 year study period. Any project with a benefit to cost
ratio below 1.0 is typically considered not economically justified, but there may be other project
benefits that make these projects still worth pursuing. From a standpoint of looking at this project
individually and from a purely economic standpoint, this project is does not appear justified based on
this pre-feasibility study.
In order for Option A to have a benefit to cost ratio of 1.0 over the 20 year study period, the project
capital cost would need to be reduced to $241,000. However, reducing the capital cost to this level does
not appear to be possible. The GarnPak itself costs $120,000, which leaves $121,000 remaining for site
work, mechanical and electrical work, buried utilities, general conditions, overhead and profit, design
and permitting fees, and a contingency. Moving the GarnPak building closer to the Tribal Office Building
would reduce buried piping costs, however, this cost reduction may not be sufficient to make the
project cost effective.
Option A - Economic Analysis Results
Project Capital Cost ($332,298)
Simple Payback 42.3 years
Present Value of Project Benefits (20 year life) $544,586
Present Value of Operating Costs (20 year life) ($302,773)
Benefit / Cost Ratio of Project (20 year life) 0.73
Net Present Value (20 year life) ($90,484)
Year Accumulated Cash Flow is Net Positive First Year
Year Accumulated Cash Flow > Project Capital Cost 25 years
Table 9 – Option A - Economic Analysis Results
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 13
Option B – Option B increases heating oil offset by the GarnPak system by connecting both the Village
Office Building and the shop building. However, there will be the additional expense of at least 80 ft of
buried piping to connect the GarnPak to the shop building as well as an additional heat exchanger and
piping. Overall, Option B has a benefit to cost ratio of 0.96, making it not typically considered
economically justified based on the cost estimate and available heating oil offsets. Since the project has
a benefit to cost ratio close to 1.0 and the actual heating oil consumption of the shop building is not
accurately known, this option may require more study to determine cost effectiveness.
Option B - Economic Analysis Results
Project Capital Cost ($395,488)
Simple Payback 30.7 years
Present Value of Project Benefits (20 year life) $818,146
Present Value of Operating Costs (20 year life) ($438,717)
Benefit / Cost Ratio of Project (20 year life) 0.96
Net Present Value (20 year life) ($16,059)
Year Accumulated Cash Flow is Net Positive First Year
Year Accumulated Cash Flow > Project Capital Cost 21 years
Table 10 – Option B - Economic Analysis Results
Sensitivity Analysis
A sensitivity analysis was completed for both options to show how changing heating oil costs and wood
costs affect the B/C ratios of the projects. As heating oil costs increase and wood costs decrease, the
project becomes more economically viable.
Option A – B/C Ratios Wood Cost ($/cord)
$264/cord $330/cord $396/cord
Heating Oil Cost
($/gal)
$5.40/gal 0.55 0.45 0.35
$6.75/gal 0.83 0.73 0.63
$8.10/gal 1.11 1.01 0.91
Table 11 – Option A Sensitivity Analysis
Option B – B/C Ratios Wood Cost ($/cord)
$264/cord $330/cord $396/cord
Heating Oil Cost
($/gal)
$5.40/gal 0.73 0.61 0.48
$6.75/gal 1.09 0.96 0.83
$8.10/gal 1.44 1.31 1.18
Table 12 – Option B Sensitivity Analysis
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 14
VII. Forest Resource and Fuel Availability Assessments
Forest Resource Assessments
Fuel availability assessments were not available for the Iliamna area. During the site visit it was found
that the land around Iliamna village is sparsely forested, with a low density of small spruce trees. The
tree density increases as one travels north to Six Mile Lake near Nondalton. Many of the Iliamna
community harvest wood in this area, and haul wood back to Iliamna.
Per Coffman’s discussions with Mr. Will Putman with the State Forestry Service, most of the permits for
wood harvesting are owned and controlled by village corporations within the state. If harvesting is to
take place in these areas, permission will need to be obtained from the village corporation prior to
harvesting. If more than 40 acres per year or 50 cords of wood are collected per year, the harvesting is
classified as a commercial operation. For a commercial harvest, the practices outlined in the Forest
Resources and Practices Act will need to be followed. The Forest Resource and Practices Act protects the
water and habitat within the harvesting site and applies to state, federal, and native corporation land. If
less than 40 cords of wood are used per year, the use is considered as a personal use and a commercial
permit is not required.
Air Quality Permitting
Currently, air quality permitting is regulated according to the Alaska Department of Environmental
Conservation Section 18 AAC 50 Air Quality Control regulations. Per these regulations, a minor air
quality permit is required if a new wood boiler or wood stove produces one of the following conditions
per Section 18 AAC 50.502 (C)(1): 40 tons per year (TPY) of carbon dioxide (CO2), 15 TPY of particulate
matter greater than 10 microns (PM-10), 40 TPY of sulfur dioxide, 0.6 TPY of lead, 100 TPY of carbon
monoxide within 10 kilometers of a carbon monoxide nonattainment area, or 10 TPY of direct PM -2.5
emissions. These regulations assume that the device will operate 24 hours per day, 365 days per year
and that no fuel burning equipment is used. If a new wood boiler or wood stove is installed in addition
to a fuel burning heating device, the increase in air pollutants cannot exceed the following per AAC
50.502 (C)(3): 10 TPY of PM-10, 10 TPY of sulfur dioxide, 10 TPY of nitrogen oxides, 100 TPY of carbon
monoxide within 10 kilometers of a carbon monoxide nonattainment area, or 10 TPY of direct PM -2.5
emissions. Per the Wood-fired Heating Device Visible Emission Standards (Section 18 AAC 50.075), a
person may not operate a wood-fired heating device in a manner that causes black smoke or visible
emissions that exceed 50 percent opacity for more than 15 minutes in any hour in an area where an air
quality advisory is in effect.
From Coffman’s discussions with Patrick Dunn at the Alaska Department of Environmental Conservation,
these regulations are focused on permitting industrial applications of wood burning equipment. In his
opinion, it would be unlikely that an individual wood boiler would require an air quality permit unless
several boilers were to be installed and operated at the same site. If several boilers were installed and
operated together, the emissions produced could be greater than 40 tons of CO2 per year. This would
require permitting per AAC 50.502 (C)(1) or (C)(3). Permitting would not be required on the residential
wood fired stoves unless they violated the Wood-fired Heating Device Visible Emission Standards
(Section 18 AAC 50.075). The recent Garn boiler systems installed in Alaska have not needed or
obtained air quality permits.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 15
VIII. General Biomass Technology Information
Heating with Wood Fuel
Wood fuels are among the most cost-effective and reliable sources of heating fuel for communities
adjacent to forestland when the wood fuels are processed, handled, and combusted appropriately.
Compared to other heating energy fuels, such as oil and propane, wood fuels typically have lower
energy density and higher associated transportation and handling costs. Due to this low bulk density,
wood fuels have a shorter viable haul distance when compared to fossil fuels. This short haul distance
also creates an advantage for local communities to utilize locally-sourced wood fuels, while
simultaneously retaining local energy dollars.
Most villages in rural Alaska are particularly vulnerable to high energy prices due to the large number of
heating degree days and expensive shipping costs. For many communities, wood-fueled heating can
lower fuel costs. For example, cordwood sourced at $250 per cord is just 25% of the cost per MMBTU as
#1 fuel oil sourced at $7 per gallon. In addition to the financial savings, the local communities also
benefit from the multiplier effect of circulating energy dollars within the community longer, more stable
energy prices, job creation, and more active forest management.
In all of the Lake and Peninsula Communities studied, the community’s wood supply and demand are
isolated from outside markets. The local cordwood market is influenced by land ownership, existing
forest management and ecological conditions, local demand and supply, and the State of Alaska Energy
Assistance program.
Types of Wood Fuel
Wood fuels are specified by energy density, moisture content, ash content, and granulometry. Each of
these characteristics affects the wood fuel’s handling characteristics, storage requirements, and
combustion process. Higher quality fuels have lower moisture, ash, dirt, and rock contents , consistent
granulometry, and higher energy density. Different types of fuel quality can be used in wood heating
projects as long as the infrastructure specifications match the fuel content characteristics. Typically,
lower quality fuel will be the lowest cost fuel, but it will require more expensive storage, handling, and
combustion infrastructure, as well as additional maintenance.
Projects in rural Alaska must be designed around the availability of wood fuels. Some fuels can be
harvested and manufactured on site, such as cordwood, woodchips, and briquettes. The economic
feasibility of manufacturing on site is determined by a financial assessment of the project. Typically,
larger projects offer more flexibility in terms of owning and operating the wood harvesting and
manufacturing equipment, such as a wood chipper, splitter, or equipment to haul wood out of forest,
than smaller projects.
Due to the limited wood fuel demand, large financial obligations and operating complexities, it is
unlikely that the Lake and Peninsula communities in this study will be able to manufacture pellets.
However, some communities may be able to manufacture bricks or fire logs made from pressed wood
material. These products can substitute for cordwood in woodstoves and boilers, while reducing supply
pressure on larger diameter trees that are generally preferred for cordwood.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 16
High Efficiency Cord Wood Boilers
High Efficiency Low Emission (HELE) cordwood boilers are designed to burn cordwood fuel cleanly and
efficiently. The boilers use cordwood that is typically seasoned to 25% moisture content (MC) or less and
meet the dimensions required for loading and firing. The amount of cordwood burned by the boiler will
depend on the heat load profile of the building and the utilization of the fuel oil system as back up.
Three HELE cordwood boiler suppliers include Garn (www.garn.com), Greenwood
(www.greenwoodusa.com) and TarmUSA (www.woodboilers.com). All three of these suppliers have
units operating in Alaska. Greenwood and TarmUSA have a number of residential units operating in
Alaska and have models that range between 100,000 to 300,000 BTU/hr. Garn boilers, manufactured by
Dectra Corporation, are used in Tanana, Kasilof, Dot Lake, Thorne Bay, Coffman Cove and other
locations to heat homes, washaterias, schools, and community buildings.
The Garn boiler has a unique construction, which is basically a wood boiler housed in a large water tank.
Garn boilers come in several sizes and are appropriate for facilities using 100,000 to 1,000,000 BTUs per
hour. The jacket of water surrounding the fire box absorbs heat and is piped into buildings via a heat
exchanger, and then transferred to an existing building heating system, infloor radiant tubing, unit
heaters, or baseboard heaters. In installations where the Garn boiler is in a detached building, there are
additional heat exchangers, pumps and a glycol circulation loop that are necessary to transfer heat to
the building while allowing for freeze protection. Radiant floor heating is the most efficient heating
method when using wood boilers such as Garns, because they can operate using lower supply water
temperatures compared to baseboards.
Garn boilers are approximately 87% efficient and store a large quantity of water. For example, the Garn
WHS-2000 holds approximately 1,825 gallons of heated water. Garns also produce virtually no smoke
when at full burn, because of a primary and secondary gasification (2,000 ºF) burning process. Garns are
manually stocked with cordwood and can be loaded multiple times a day during periods of high heating
demand. Garns are simple to operate with only three moving parts: a handle, door and blower. Garns
produce very little ash and require minimal maintenance. Removing ash and inspecting fans are typical
maintenance requirements. Fans are used to produce a draft that increases combustion temperatures
and boiler efficiency. In cold climates, Garns can be equipped with exterior insulated storage tanks for
extra hot water circulating capacity. Most facilities using cordwood boilers keep existing oil-fired
systems operational to provide heating backup during biomass boiler downtimes and to provide
additional heat for peak heating demand periods.
Low Efficiency Cord Wood Boilers
Outdoor boilers are categorized as low-efficiency, high emission (LEHE) systems. These boiler systems
are not recommended as they produce significant emission issues and do not combust wood fuels
efficiently or completely, resulting in significant energy waste and pollution. These systems require
significantly more wood to be purchased, handled and combusted to heat a facility as compared to a
HELE system. The Alaska Department of Environmental Conservation has issued nuisance abatement
orders for air pollution for outdoor wood boilers in Fairbanks. Fairbanks is ranked number four on Time
Magazine's list of most air polluted cities in America. Additionally, several states have placed a
moratorium on installing LEHE boilers because of air quality issues (Washington). These LEHE systems
can have combustion efficiencies as low as twenty five (25%) percent and produce more than nine times
the emission rate of standard industrial boilers. In comparison, Garns can operate around 87%
efficiency.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 17
High Efficiency Wood Stoves
Newer high efficiency wood stoves are available on the market that produce minimal smoke, minimal
ash and require less firewood. New EPA-certified wood stoves produce significantly less smoke than
older uncertified wood stoves. High efficiency wood stoves are easy to operate with minimal
maintenance compared to other biomass systems. The Blaze King Classic high efficiency wood stove
(www.blazeking.com) is a recommended model, due to its built-in thermostats that monitor the heat
output of the stove. This stove automatically adjusts the air required for combustion. This unique
technology, combined with the efficiencies of a catalytic combustor with a built-in thermostat, provides
the longest burn times of any wood stove. The Blaze King stove allows for optimal combustion and less
frequent loading and firing times.
Bulk Fuel Boilers
Bulk fuel boilers usually burn wood chips, sawdust, bark or pellets and are designed around the wood
resources that are available from the local forests or local industry. Several large facilities in Tok, Craig,
and Delta Junction (Delta Greely High School) are using bulk fuel biomass systems. Tok uses a
commercial grinder to process woodchips. The chips are then dumped into a bin and are carried by a
conveyor belt to the boiler. The wood fuel comes from timber scraps, local sawmills and forest thinning
projects. The Delta Greely High School has a woodchip bulk fuel boiler that heats the 77,000 square foot
facility. The Delta Greely system, designed by Coffman engineers, includes a completely separate boiler
building which includes chip storage bunker and space for storage of tractor trailers full of chips (so
handling of frozen chips could be avoided). Woodchips are stored in the concrete bunker and augers
move the material on a conveyor belt to the boilers. The automated fuel handling requirements for bulk
fuel systems are not cost-effective for small and medium sized structures due to higher maintenance
costs and complexities. Due to these reasons, a bulk fuel boiler system is not recommended for small
rural communities in Alaska with limited financial and human resources.
Grants
There are many grant opportunities for biomass work state, federal, and local for feasibility studies,
design and construction. If a project if determined to be pursued, a thorough search of websites and
discussions with the AEA Biomass group would be recommended to make sure no possible funding
opportunities are missed. Below are some funding opportunities and existing past grants that have
been awarded.
Currently, there is a funding opportunity for tribal communities that develop clean and renewable
energy resources through the U.S. Department of Energy. On April 30, 2013, the Department of Energy
announced up to $7 million was available to deploy clean energy projects in tribal communities to
reduce reliance on fossil fuel and promote economic development on tribal lands. The Energy
Department’s Tribal Energy Program, in cooperation with the Office of Indian Energy, will help Native
American communities, tribal energy resource development organizations, and tribal consortia to install
community or facility scale clean energy projects.
http://apps1.eere.energy.gov/tribalenergy/
The Department of Energy (DOE), Alaska Native programs, focus on energy efficiency and add ocean
energy into the mix. In addition the communities are eligible for up to $250,000 in energy-efficiency aid.
The Native village of Kongiganak will get help strengthening its wind-energy infrastructure, increasing
energy efficiency and developing “smart grid technology”. Koyukuk will get help upgrading its energy
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc. 18
infrastructure, improving energy efficiency and exploring biomass options. The village of Minto will
explore all the above options as well as look for solar-energy ideas. Shishmaref, an Alaska Native village
faced climate-change-induced relocation, will receive help with increasing energy sustainability and
building capacity as it relocates. And the Yakutat T’lingit Tribe will also study efficiency, biomass and
ocean energy. This DOE program would be a viable avenue for biomass funding.
http://energy.gov/articles/alaska-native-communities-receive-technical-assistance-local-clean-energy-
development
The city of Nulato was awarded a $40,420 grant for engineering services for a wood energy project by
the United States Department of Agriculture (USDA) and the United States Forest Service. Links
regarding the award of the Woody Biomass Utilization Project recipients are shown below:
http://www.fs.fed.us/news/2012/releases/07/renewablewoods.shtml
http://www.usda.gov/wps/portal/usda/usdahome?contentid=2009/08/0403.xml
Delta Junction was awarded a grant for engineering from the Alaska Energy Authority from the
Renewable Energy Fund for $831,203. This fund provides assistance to utilities, independent power
producers, local governments, and tribal governments for feasibility studies, reconnaissance studies,
energy resource monitoring, and work related to the design and construction of eligible facilities.
http://www.akenergyauthority.org/re-fund-6/4_Program_Update/FinalREFStatusAppendix2013.pdf
http://www.akenergyauthority.org/PDF%20files/PFS-BiomassProgramFactSheet.pdf
http://www.akenergyauthority.org/RenewableEnergyFund/RFA_Project_Locations_20Oct08.pdf
The Alaska Wood Energy Development Task Group (AWEDTG) consists of a coalition of federal and state
agencies and not-for-profit organizations that have signed a Memorandum of Understanding (MOU) to
explore opportunities to increase the utilization of wood for energy and biofuels production in Alaska. A
pre-feasibility study for Aleknagik was conducted in 2012 for the AWEDTG. The preliminary costs for the
biomass system(s) are $346,257 for the city hall and health center system and $439,096 for the city hal l,
health center, and future washeteria system.
http://www.akenergyauthority.org/biomasswoodenergygrants.html
http://www.akenergyauthority.org/BiomassWoodEnergy/Aleknagik%20Final%20Report.pdf
The Emerging Energy Technology Fund grand program provides funds to eligible applicants for
demonstrations projects of technologies that have a reasonable expectation to be commercially viable
within five years and that are designed to: test emerging energy technologies or methods of conserving
energy, improve an existing energy technology, or deploy an existing technology that has not previously
been demonstrated in Alaska.
http://www.akenergyauthority.org/EETFundGrantProgram.html
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc.
Appendix A
Site Photos
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc.
1. South elevation of office building. 2. West elevation of office building.
3. North elevation of office building. 4. East elevation of office building.
5. Site entrance. Office building on left (south)
and shop building on right (north).
6. Location of GarnPak detached building,
approximately 80 ft to the right (west) of the
office building.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc.
7. Fuel tank and red conex for fire department
equipment. 8. Office building boiler room.
9. Office building boiler room. 10. Boiler (1 of 2)
11. Garage area of the office building. 12. First floor conference room in the office
building.
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc.
Appendix B
Economic Analysis Spreadsheet
Option A: Iliamna Tribal Office BuildingIliamna, AlaskaProject Capital Cost($332,298)Simple Payback = Total Project Cost / First Year Cost Savings42.3 yearsPresent Value of Project Benefits (20 year life)$544,586Present Value of Operating Costs (20 year life)($302,773)Benefit / Cost Ratio of Project (20 year life)0.73Net Present Value (20 year life)($90,484)Year Accumulated Cash Flow is Net PositiveFirst YearYear Accumulated Cash Flow > Project Capital Cost25 yearsDiscount Rate for Net Present Value Analysis3%Wood Fuel Escalation Rate3%Fossil Fuel Escalation Rate5%Electricity Escalation Rate3%O&M Escalation Rate2%YearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYear1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Existing Heating System Operating CostsExisting Heating Oil Consumption$6.753,440gal$23,220$24,381$25,600$26,880$28,224$29,635$31,117$32,673$34,307$36,022$37,823$39,714$41,700$43,785$45,974$48,273$50,686$53,221$55,882$58,676Biomass System Operating CostsWood Fuel (Delivered to site)$330.0085%26.1cord($8,613)($8,871)($9,138)($9,412)($9,694)($9,985)($10,284)($10,593)($10,911)($11,238)($11,575)($11,922)($12,280)($12,648)($13,028)($13,419)($13,821)($14,236)($14,663)($15,103)Fossil Fuel$6.7515%516gal($3,483)($3,657)($3,840)($4,032)($4,234)($4,445)($4,668)($4,901)($5,146)($5,403)($5,673)($5,957)($6,255)($6,568)($6,896)($7,241)($7,603)($7,983)($8,382)($8,801)Electricity$0.693,285kWh($2,267)($2,335)($2,405)($2,477)($2,551)($2,628)($2,706)($2,788)($2,871)($2,957)($3,046)($3,138)($3,232)($3,329)($3,429)($3,531)($3,637)($3,746)($3,859)($3,975)Operation and Maintenance Costs($500)($510)($520)($531)($541)($552)($563)($574)($586)($598)($609)($622)($634)($647)($660)($673)($686)($700)($714)($728)Additional Operation and Maintenance Costs for first 2 years($500)($510)$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0Total Operating Costs($15,363)($15,883)($15,902)($16,451)($17,020)($17,610)($18,222)($18,856)($19,514)($20,196)($20,904)($21,639)($22,401)($23,192)($24,012)($24,864)($25,748)($26,666)($27,618)($28,607)Annual Operating Cost Savings$7,857 $8,498 $9,698 $10,429 $11,204 $12,025 $12,896 $13,817 $14,793 $15,826 $16,919 $18,075 $19,299 $20,593 $21,962 $23,409 $24,938 $26,555 $28,263 $30,068Accumulated Cash Flow$7,857 $16,355 $26,053 $36,482 $47,686 $59,711 $72,607 $86,424 $101,216 $117,042 $133,961 $152,036 $171,335 $191,928 $213,890 $237,298 $262,237 $288,792 $317,055 $347,124Net Present Value($324,670) ($316,660) ($307,785) ($298,519) ($288,854) ($278,783) ($268,298) ($257,390) ($246,053) ($234,277) ($222,055) ($209,377) ($196,236) ($182,621) ($168,525) ($153,937) ($138,849) ($123,251) ($107,133) ($90,484)Energy UnitsHeating Source ProportionEconomic Analysis ResultsInflation RatesDescription Unit CostAnnual Energy Units
Option B: Iliamna Tribal Office Building and Shop BuildingIliamna, AlaskaProject Capital Cost($395,488)Simple Payback = Total Project Cost / First Year Cost Savings30.7 yearsPresent Value of Project Benefits (20 year life)$818,146Present Value of Operating Costs (20 year life)($438,717)Benefit / Cost Ratio of Project (20 year life)0.96Net Present Value (20 year life)($16,059)Year Accumulated Cash Flow is Net PositiveFirst YearYear Accumulated Cash Flow > Project Capital Cost21 yearsDiscount Rate for Net Present Value Analysis3%Wood Fuel Escalation Rate3%Fossil Fuel Escalation Rate5%Electricity Escalation Rate3%O&M Escalation Rate2%YearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYearYear1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Existing Heating System Operating CostsExisting Heating Oil Consumption$6.755,168gal$34,884$36,628$38,460$40,383$42,402$44,522$46,748$49,085$51,540$54,117$56,822$59,663$62,647$65,779$69,068$72,521$76,147$79,955$83,953$88,150Biomass System Operating CostsWood Fuel (Delivered to site)$330.0085%39.2cord($12,936)($13,324)($13,724)($14,136)($14,560)($14,996)($15,446)($15,910)($16,387)($16,879)($17,385)($17,906)($18,444)($18,997)($19,567)($20,154)($20,758)($21,381)($22,023)($22,683)Fossil Fuel$6.7515%775gal($5,231)($5,493)($5,767)($6,056)($6,359)($6,677)($7,010)($7,361)($7,729)($8,115)($8,521)($8,947)($9,395)($9,864)($10,358)($10,875)($11,419)($11,990)($12,590)($13,219)Electricity$0.694,106kWh($2,833)($2,918)($3,006)($3,096)($3,189)($3,284)($3,383)($3,484)($3,589)($3,697)($3,808)($3,922)($4,039)($4,161)($4,285)($4,414)($4,546)($4,683)($4,823)($4,968)Operation and Maintenance Costs($500)($510)($520)($531)($541)($552)($563)($574)($586)($598)($609)($622)($634)($647)($660)($673)($686)($700)($714)($728)Additional Operation and Maintenance Costs for first 2 years($500)($510)$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0$0Total Operating Costs($22,000)($22,755)($23,017)($23,818)($24,648)($25,509)($26,403)($27,329)($28,291)($29,288)($30,323)($31,397)($32,512)($33,669)($34,869)($36,116)($37,410)($38,754)($40,150)($41,599)Annual Operating Cost Savings$12,884 $13,873 $15,442 $16,565 $17,754 $19,012 $20,345 $21,756 $23,249 $24,828 $26,499 $28,266 $30,135 $32,110 $34,198 $36,405 $38,737 $41,201 $43,803 $46,551Accumulated Cash Flow$12,884 $26,757 $42,199 $58,764 $76,518 $95,530 $115,875 $137,631 $160,880 $185,709 $212,208 $240,474 $270,609 $302,720 $336,918 $373,323 $412,060 $453,261 $497,064 $543,615Net Present Value($382,980) ($369,903) ($355,771) ($341,053) ($325,739) ($309,816) ($293,274) ($276,099) ($258,281) ($239,806) ($220,662) ($200,837) ($180,317) ($159,088) ($137,137) ($114,451) ($91,014) ($66,813) ($41,833) ($16,059)Energy UnitsEconomic Analysis ResultsInflation RatesDescription Unit CostHeating Source ProportionAnnual Energy Units
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc.
Appendix C
Site Plan
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc.
Site Plan of Iliamna Village Office Building
ILIAMNA VILLAGE
OFFICE BUILDING
SHOP BUILDING
PERIMETER CHAIN
LINK FENCE
AROUND GRAVEL
PAD
PROPOSED
BURIED ARCTIC
PIPE (OPTION B)
PROPOSED GARNPAK
AND WOOD STORAGE
BUILDING
Feasibility Assessment for Biomass Heating Systems Iliamna, AK
Coffman Engineers, Inc.
Appendix D
AWEDTG Field Data Sheet