HomeMy WebLinkAboutAlatna Village Biomass Heat Pre-Feasibility Study 10-16-2014-BIO
Alatna Village
Biomass Heat Pre-Feasibility Study
Prepared for Interior Regional Housing Authority
October 16, 2014
Prepared by:
Energy Action, Wynne Auld
With Support from:
The Alaska Energy Authority
1231 W. Northern Lights #578
Anchorage, AK 99503
www.energyaction.info
(907) 744-1085
Page 2 of 15
Contents
Acknowledgements ....................................................................................................................................... 3
Community Contact Information .................................................................................................................. 3
Summary of Findings..................................................................................................................................... 3
Statement of Purpose ................................................................................................................................... 3
Community & Facility Information................................................................................................................ 4
Biomass Resource Availability ....................................................................................................................... 5
Site Control ................................................................................................................................................... 6
Permitting ..................................................................................................................................................... 6
Proposed Biomass System ............................................................................................................................ 7
Alternatives Considered ............................................................................................................................ 8
Heat Load & Biomass Requirements ............................................................................................................ 9
Opinion of Probable Cost ............................................................................................................................ 11
Financial Analysis ........................................................................................................................................ 13
Financial Summary .................................................................................................................................. 13
Benefit/ Cost Model ................................................................................................................................ 13
Recommendations ...................................................................................................................................... 15
Figures
Figure 1: Biomass Project Site Map .............................................................................................................. 8
Figure 2: Fuel Energy Values ......................................................................................................................... 9
Figure 3: Current Fuel Use & Cost ................................................................................................................. 9
Figure 4: Projected Annual Fuel Use & Cost, Biomass Project ..................................................................... 9
Figure 5: Biomass Project Stoking Requirements ......................................................................................... 9
Figure 6: Biomass O&M Costs (non-stoking) .............................................................................................. 10
Figure 7: Force Account Summary .............................................................................................................. 11
Figure 8: Force Account Detail .................................................................................................................... 12
Appendix
A—Biomass Technology
B – Utility Receipts
C – Plat Map
D – Aircraft Information
E – Site Photos
Page 3 of 15
Acknowledgements
Energy Action thanks the following representatives for their assistance with this assessment:
Michelle Sam, 2nd Chief, Alatna Village
Russell Snyder, Grants Coordinator, Interior Regional Housing Authority
Steven J. Stassel, P.E., Gray Stassel Engineering
Community Contact Information
Alatna Village
Contact: Michelle Sam, 2nd Chief
PO Box 70, Allakaket, AK 99720
P. (907) 968 2261
F. (907) 968 2305
alatnatribe@yahoo.com
Summary of Findings
Alatna Village Council and the public are interested in energy projects that displace oil with local
renewable resources and create jobs. Based on conversations at the public meeting on this topic in
spring 2014, a biomass energy project seems well-suited to the community’s interest.
The project building is the Washateria/ Water Plant. The biomass project would use an estimated 20
cords per year to displace about 85% of the building’s demand, which totals 2,315 gallons per year. The
project is considered financially unfeasible at this time, in part due to the relatively small building heat
load, the limited temperature range of the existing heat system, and the high stoking requirements due
to air freight constraints on the boiler size.
There may be an opportunity for Alatna Village Council to own and operate a biomass energy project
and sell heat as a third-party. The Allakaket School building is scheduled to be replaced in 5 – 10 years.
It appears that a heat sales project, owned and operated by a third-party, may satisfy Yukon-Koyukuk
School District’s interest in biomass energy. If the project owner can source fuel at $275 per cord, as the
Tanana Chiefs Conference reconnaissance-level biomass resource assessment suggests, the project is
considered pre-feasible. Sourcing wood at $275 per cord would result in about $25,000 of revenues per
year for the supplier. A pre-feasibility study of the project, “Allakaket Village Biomass Heat Pre-
Feasibility Study,” is publically available from the Alaska Energy Authority or Interior Regional Housing
Authority.
Statement of Purpose
Since 2008, the Alaska State Legislature has supported renewable electric and thermal energy projects
through the Renewable Energy Grant Recommendation Program, administered by the Alaska Energy
Authority. In Round 6 of the Program, the Interior Regional Housing Authority, which seeks
opportunities to promote community self-sufficiency through community energy projects, received
money to complete pre-feasibility studies of biomass heat in community buildings in seven villages. The
following pre-feasibility study has been funded through that grant.
Page 4 of 15
Community & Facility Information
Alatna Village (population 26) is an Alaska Native village located on the north bank of the Koyukuk River,
southwest of its junction with the Alatna River, approximately 190 air miles northwest of Fairbanks and
57 miles upriver from Hughes. Alatna Village is located just west of the municipal boundary of Allakaket
Village. In recent years, there has been no barge service. Imported goods and fuel are flown to the
Allakaket airport, and then transported to Alatna Village by snow machine or boat. Occasionally an ice
road is built between the communities. The Allakaket airport has a 4,000’ x 100’ gravel runway. Alatna
Village depends on Allakaket Village for airport, postal, electric, and educational services.
Alatna Village is governed by Alatna Village Council. Alatna Village Council owns and operates the
project building, which is the Washateria/ Water Plant and Clinic (“Washateria”). This building was
selected for pre-feasibility assessment because it is the largest heat load in the community. At the time
of the meeting, the Washateria manager was not present.
Fuel is purchased in Allakaket Village for $7.00 per gallon (see Appendix B). Delivery is by plane only.
Additional transportation across the river, including labor, snow machine rental, and snow machine gas
costs approximately $0.62 per gallon. These costs are well-documented in QuickBooks receipts.
However, to be included as a fuel cost, these additional fuel transportation costs would need to be
invoiced by the fuel vendor, in this case, Allakaket Village Council. The total cost is approximately $7.62
per gallon.
The current going rate for cordwood is $400 per cord. The Alatna Village Council office is primarily
heated with wood, much of which is purchased from local residents (Council meeting, personal
conversation, February 4, 2013).
Electricity is 82.85 cents per kWh, delivered by distribution lines from the AP&T power plant in Allakaket
Village (See Appendix B).
Alatna Village was relocated two miles downriver to its current location after the flood of 1994. All
buildings are located on high ground.
The Washateria was built in 2006. The approximately 2,300 ft2 building has two (2) fuel oil boilers. The
fuel oil boilers are Burnham V903A with 301,000 Btu net output. The hi / lo setting is 180/ 160°F. Three
(3) Amtrol BoilerMates model transfer heat to the potable supply. A Heliodyne solar water heater is an
additional heat source for the BoilerMates. The system is also equipped with an outdoor air reset.
The Washateria boilers provide space heating, domestic hot water, and heat to the community’s potable
water supply. In 2012, the Washateria used 2,315 gallons of fuel oil #1 (See Appendix B).
Five zones deliver heat to various end uses, which include: dryers (2), building heat (2), and hot water
generator (1). Hot water appliances include dryers, washers, faucets, cabinet unit heaters, unit heaters,
baseboard piping, radiant panel, and shell and tube heat exchangers.
Page 5 of 15
Additionally, there are valves for a future recovered heat connection on the boiler return lines, indicated
in drawings and verified in the field. There are also available breakers in the panel.
The project building is elevated off the ground. There is sufficient space on the south side of the
Washateria, near the recovered heat valves, for a biomass project building.
The Alatna Village Council Office (“Office”) is located about 400’ from the Washateria. The Office is an
approximately 1,200 ft2 log building, built in 1995. According to 2nd Chief Michelle Sam, the Office needs
to be re-leveled and the post foundation may need to be replaced. The Alatna Village Council plans to
undertake this work in summer 2014. A wood stove is the primary heat source, supplemented by a Laser
56 oil stove, which provides up to 22,000 Btu. The building is in need of weatherization and potentially a
wood stove which can supply more heat.
To the knowledge of the Alatna Village Council and the consultant, neither the Washateria nor the
Council office have ever had an energy audit conducted or undergone weatherization. However, as
mentioned, the Washateria is relatively recent construction, built in 2006.
Biomass Resource Availability
This pre-feasibility study was completed simultaneous to a reconnaissance-level biomass resource
assessment by Tanana Chiefs Conference, which will be complete in fall 2014. The draft biomass
resource assessment takes account of biomass stocking by ownership, resource distance from Alatna
Village, and other factors. In summary, within a 5-mile radius of Alatna Village, there are approximately
144,000 cords of biomass, with nearly 82% of this material located K'oyitl'ots'ina, Limited lands. The
average cost for biomass within a 5-mile radius of Alatna Village is about $121 per cord. This figure
includes harvest, stumpage, administration, and transport costs, but does not include the cost of
processing logs into cordwood or profit.
Page 6 of 15
Site Control
The proposed project site, Block 18 & 19 of Plat 2002-114 in the Fairbanks Recording District, is vested in
“Village of Alatna.” Please see Appendix C.
Permitting
Applicable project permitting is considered below:
The Alaska Department of Public Safety, Fire and Life Safety must approve the project plans
before construction is started. Mechanical and electrical review is limited to that which is
necessary to confirm compliance with fire and life safety requirements.
Commercial harvests associated with the project may or may not be required to comply with the
Alaska Forest Practices and Resources Act. While most commercial operations are required to
comply, commercial operations of minor or small scale are sometimes exempted. The Act
addresses forest management along water bodies, erosion mitigation, and reforestation.
The 40CFR63 NESHAP Rule does not apply to the project. The Rule does not apply to a hot water
heater, which is defined in Subpart 6J as a boiler with a heat input capacity is less than 1.6
MMBtu/hr and that does not generate steam.
If State or Federal money is used to construct the project, the Alaska Department of Natural
Resources Office of History and Archaeology, State Historic Preservation Office should review
project plans to determine whether historic, prehistoric, or archaeological resources are likely to
be affected. The Office also offers suggestions to mitigate potential effects on resources.
Page 7 of 15
Proposed Biomass System
The proposed system is an 180,000 Btu cordwood boiler with hydronic heat storage, to be located in a
stand-alone project building on the south side of the Washateria.
The project equipment must be suitable for delivery by plane. Contact was made with several air carriers
to identify suitable aircraft for the project, which includes the ability to accommodate the project
equipment and land at the Allakaket airport. Please see Appendix D.
Cordwood systems are not very effective when serving building heat systems that operate in a narrow
temperature range, such at 180 /160°F. The project building currently operates in this range, and the
biomass boiler operating and maintenance requirements have been modeled to maintain the existing
temperature set points.
The cost of stoking the biomass boiler would decrease if the building could operate in a wider
temperature range. Washateria staff may wish to test the existing heat system by lowering the set point
to 140°F to see if the building heat emitters can supply sufficient heat at this temperature. Alternatively,
new appliances and/or additional emitters could be installed. It may also be possible to meet heat needs
with existing equipment by changing operations, such as longer clothes dryer cycles.
The proposed site is owned and controlled by Alatna Village, has sufficient space for the project, and
offers good access to the Washateria’s mechanical room and existing supplemental heat valves.
The following assumptions were made for the purpose of completing the pre-feasibility assessment, and
are not a substitute for heat load calculations and boiler sizing to be completed by the project engineer
during project development:
Annual consumption of 2,315 gallons of fuel oil per year, 90% of which serves space heat load,
10% of which serves domestic hot water
180,000 Btu cordwood boiler with 980 gallons of water storage, delta T = 40°F
Maximum 4 stokings per day, with additional heat demand served by oil. Each firing requires 20
minutes labor
Annual inflation
o Biomass O&M and scheduled repairs – 1.5%
o Cordwood – 3%
o Oil O&M and scheduled repairs – 1.5%
o Oil – 4.8%
Input prices, year 1
o Cordwood -- $400/cord
o Oil -- $7.62/gal
o Loaded labor rate -- $20.17/ hr
Page 8 of 15
Alternatives Considered
The project could also heat the Alatna Village Council office, which uses about 700 gallons of fuel oil per
year. However, this office already has a wood stove, and is located approximately 400’ away. This
distance is considered too large to consider justify the additional capital and operating expense of
integration with the biomass boiler facility.
Figure 1: Biomass Project Site Map
Page 9 of 15
Heat Load & Biomass Requirements
Figure 2: Fuel Energy Values
Figure 3: Current Fuel Use & Cost
Figure 4: Projected Annual Fuel Use & Cost, Biomass Project
Figure 5: Biomass Project Stoking Requirements
Gross
btu/unit
System
efficiency
Delivered
btu/unit
Gross
$/unit
Delivered
$/mmbtu
Oil (gal)134,500 80%107,600 $ 7.62 70.82$
Biomass, 20% MC* (cord) 16,400,000 65%10,660,000 $ 400 37.52$
*MC is Moisture Content. Moisture in biomass fuel evaporates and absorbs energy in combustion, thereby decreasing the net
energy value of the fuel.
Facility Fuel Oil (gal)$ / gal Annual Fuel
Cost
Washateria 2,315 7.62$ 17,640$
Total 17,640$
15%Oil
85%Biomass
1968 gallons displaced
Facility Fuel Type Units $ / unit Annual Fuel Cost
Washateria Biomass, 20% MC* (cord) 19.9 400$ 7,945$
Washateria Oil (gal)347 7.62$ 2,646$
Total $ 10,591
Facility Total Stokings per Yr Stoking Hrs
Per Yr $ / hr Annual Stoking
Cost
Washateria 777 259 20.17$ 5,223$
Page 10 of 15
Figure 6: Biomass O&M Costs (non-stoking)
Equipment (Btu)180,000
Biomass Fuel cordwood
Cost of Labor 20.17$
Cost of Electricity 0.83$
Number of Stokings 777
MATERIALS
Yrs to
replacement
Replacement
Cost per lifetime
Lower Gasket 23$ 5 92$
Motor mount 27$ 10 54$
Rear cleanout gasket kit 46$ 10 92$
Manway cover gasket 19$ 10 38$
5" cleaning brush 24$ 5 96$
Motor assembly 518$ 12 863$
1/2 HP motor 331$ 12 552$
Motor mount kit 87$ 12 145$
Motor mount ring & screws 17$ 12 28$
Misc. 250$ 5 1,000$
Anode Rod 98$ 5 392$
Electricity 1/2 HP fan 40$ 1 800$
Electricity -- pump 173$ 1 3,460$
Chemicals 250$ 1 5,000$
Total Cost per Lifetime 12,612$
Straight-line Average Cost per Yr.631$
LABOR Hours labor Yrs to labor
Cost of Labor
over Lifetime
Water test and replace 0.50 1 170$
Cleanout covers and heat xger 2 1 807$
Clean blower motor 0.75 0.5 605$
Clean Ash & Combustion Air Intake 0.08 0.05 614$
Check & replace gaskets 3 5 242$
Total Cost per Lifetime 2,437$
Straight-line Average Cost per Yr.122$
752$ Total Annual Biomass O&M Cost (non-stoking)
Page 11 of 15
Opinion of Probable Cost
Figure 7: Force Account Summary
Site & Foundation Work $8,315
Biomass boiler building $42,957
Biomass heat system $58,070
End-user building integration $8,674
Miscellaneous $8,700
Overhead $35,010
Freight $43,040
CONSTRUCTION SUB-TOTAL $204,766
Design & Construction Admin $20,477
Construction Management $10,238
PROJECT SUB-TOTAL $235,481
Contingency @ 20%$47,096
Admin @ 4%$9,419
TOTAL PROJECT COST $291,996
Page 12 of 15
Figure 8: Force Account Detail
ITEM QUAN UNIT UNIT MATL UNIT LAB LAB LABOR CONTR FREIGHT TOTAL UNIT TOTAL
COST COST HRS HRS RATE COST COST COST COST WT WT(#)
SITE & FOUNDATION WORK
Site prep (layout, excavation, backfill,
compaction, grading)1 lump $5,000 $5,000 0.00 0
Wood timbers -- 8" x 8" x 8' 30 ea $63.00 $1,890 0.50 15.00 $95 $1,425 $3,315 70.00 2100
BIOMASS BOILER BUILDING W/
WOOD STORAGE
Sill plate - 2" x 6" x 20" PT 5 ea.$20 $100 0.25 1.3 $95 $119 $219 51 255
SIP exterior walls -- 4' x 10' 18 ea.$500 $9,000 0.3 5 $95 $513 $9,513 4 72
SIP roof -- 4' x 10' pkg 11 ea.$500 $5,500 0.75 8 $95 $784 $6,284 4 44
SIP fasteners / hardware / framing
anchors 1 lump $400 $400 0 0 $95 $0 $400 500 500
SIP caulk, sealant, expanding foam 1 lump $250 $250 4 4 $95 $380 $630 150 150
Roof, frame 2 lump $900 $1,800 18.00 36 $95 $3,420 $5,220 400 800
Roof, Metal -- 3' x 10' Delta rib roofing 15 ea.$175 $2,625 1.00 15 $95 $1,425 $4,050 96 1440
Floor Insulation, Rigid (2"x24"x96")19 ea.$28.00 $532 0.25 5 $95 $451 $983 1 19
Floor system, metal 1 lump $1,200 $1,200 20.00 20 $95 $1,900 $3,100 1600 1600
Siding, Metal, plus trim -- 3' x 10' Delta
rib roofing 24 ea.$175 $4,200 1.00 24 $95 $2,280 $6,480 96 2304
Fasteners 1 lump $250 $250 0 0 $95 $0 $250 100 100
Man-door w/ hardware 1 lump $780 $780 6 6 $95 $570 $1,350 75 75
Overhead garage door (10' x 10')1 lump $1,350 $1,350 6 6 $95 $570 $1,920 250 250
Drywall -- 4' x 10' + tape 25 ea.$27 $675 0.33 8 $95 $784 $1,459 50 1250
Interior paint -- 5 gal 2 ea.$40 $80 4 8 $95 $760 $840 42 83
Fire protection 1 lump $250 $250 0.1 0.1 $95 $10 $260 150 150
BIOMASS HEAT SYSTEM
Boiler -- GARN 1000 1 ea.$11,000 $11,000 16 16 $95 $1,520 $12,520 2200 2200
Pipe/Valves/Ftgs/Gauges 1 lump $5,000 $5,000 54 54 $100 $5,400 $10,400 800 800
Circ pump 2 ea.$500 $1,000 4 8 $100 $800 $1,800 60 120
Plate HXR, ( 300 MBh @ 20F)2 ea.$2,500 $5,000 2 4 $100 $400 $5,400 250 500
Misc Strut & Pipe Hangers 1 lump $1,000 $1,000 20 20 $95 $1,900 $2,900 500 500
Tank Insulation 1 lump $1,200 $1,200 3 3 $95 $285 $1,485 50 50
Stack -- 6" dia double wall UL listed +
supporting infrastructure 1 lump $1,700 $1,700 4 4 $95 $380 $2,080 3.8 4
Ventilation & Combustion Air Intake 1 lump $1,200 $1,200 3 3 $95 $285 $1,485 50 50
BTU meter 0 ea.$2,500 $0 18 0 $95 $0 $0 0 0
Electrical 1 lump $10,000 $10,000 100 100 $100 $10,000 $20,000 750 750
INTEGRATION
Artic Pipe -- 1,5" PEX 60 lf $20 $1,200 0.27 16 $95 $1,539 $2,739 1 60
PEX accessories -- 60 1/ft $5 $300 0 $95 $0 $300 1 60
Pipe penetration exclosure 1 lump $1,250 $1,250 3 3 $95 $285 $1,535 200 200
Temp controls 1 lump $750 $750 8 8 $100 $800 $1,550 200 200
Electrical work 1 lump $1,250 $1,250 13 13 $100 $1,300 $2,550 200 200
MISCELLANEOUS
Misc Hardware 1 lump $2,500 $2,500 0 0 $95 $0 $2,500 500 500
Misc Tools & Safety Gear 1 lump $1,500 $1,500 0 0 $95 $0 $1,500 1446 1446
Consumables, Gases, Etc.1 lump $2,000 $2,000 0 0 $95 $0 $2,000 1500 1500
Wood splitter 1 ea $2,700 $2,700 0 0 $95 $0 $2,700 657 657
OVERHEAD
ROW Legal Work 0 lump $0 $0 0
Rent Heavy Equip 1 lump $1,500 $1,500 0
Misc Tool Rent 1 lump $1,250 $1,250 0
Commission System & Training 20 hr 1 20 $90 $1,800 $1,800 0
Superintendent Overhd Off-Site 40 hr 1 40 $90 $3,600 $3,600 0
Superintendent Overhd On-Site 80 hr 1 80 $90 $7,200 $7,200 0
Crew Travel Time 10 hr 1 10 $90 $900 $900 0
Crew Airfares 2 trips $680 $1,360 $1,360 0
Crew Per Diem 240 mn.dy.$60 $14,400 $14,400 0
Housing Rent 2.0 mo.$1,500 $3,000 $3,000 0
FREIGHT 20,989
Ground Freight 2200 lb.$1.24 $2,733
Air Freight 20989 lb.$1.40 $29,307
Air Freight Tool Mob & Demob 2 lump $2,500 $5,000
Misc Small Freight & Gold Streaks 1 lump $6,000 $6,000
CONSTRUCTION SUB-TOTAL $81,432 564 $53,784 $26,510 $43,040 $204,766
Engineering (Design & CCA)10 %$20,477
Construction Management 5 %$10,238
PROJECT SUB-TOTAL $81,432 $53,784 57,225$ $43,040 $235,481
Contingency 20 %$47,096
Admin Fee 4 %$9,419
CONSTRUCTION TOTAL $291,996
Page 13 of 15
Financial Analysis
Financial Summary
The project is considered financially unfeasible at this time.
Benefit/ Cost: 0.32
Simple Payback Period: n/a
Net present value: ($188,452)
Benefit/ Cost Model
The following model was designed by University of Alaska Anchorage Institute of Social and Economic
Research, for use by the Alaska Energy Authority. The model has adapted to the project and completed
according to the aforementioned assumptions.
AEA B/C Model (adapted)
Project Description
Community
Nearest Fuel Community
Region
RE Technology
Project ID
Applicant Name
Project Title
Category
Results
NPV Benefits $86,783
NPV Capital Costs $275,234
B/C Ratio 0.32
NPV Net Benefit ($188,452)
Performance Unit Value
Displaced Petroleum Fuel gallons per year 1,968
Displaced Petroleum Fuel total lifetime gallons 39,355
Avoided CO2 tonnes per year 20
Avoided CO2 total lifetime tonnes 399
Proposed System Unit Value
Capital Costs $$291,996
Project Start year 2015
Project Life years 20
Displaced Heat gallons displaced per year 1,968
Heating Capacity Btu/hr 180,000
Heating Capacity Factor %85%
Parameters Unit Value
Heating Fuel Premium $ per gallon
Discount Rate % per year 3%
Crude Oil $ per barrel
Alatna Village
Alatna Washateria_biomass
Alatna
Allakaket, Alatna
Rural
Biomass
Page 14 of 15
Annual Savings (Costs)Units 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
Project Capital Cost $ per year 291,996$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$
Electric Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Heating Saving (Costs)$ per year $1,074 $1,465 $1,883 $2,329 $2,803 $3,308 $3,845 $4,416 $5,022 $5,667 $6,351 $7,076 $7,846 $8,663 $9,528 $10,444 $11,415 $12,443 $13,530 $14,681
Transportation Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Total Savings (Costs)$ per year $1,074 $1,465 $1,883 $2,329 $2,803 $3,308 $3,845 $4,416 $5,022 $5,667 $6,351 $7,076 $7,846 $8,663 $9,528 $10,444 $11,415 $12,443 $13,530 $14,681
Net Benefit $ per year ($290,922)$1,465 $1,883 $2,329 $2,803 $3,308 $3,845 $4,416 $5,022 $5,667 $6,351 $7,076 $7,846 $8,663 $9,528 $10,444 $11,415 $12,443 $13,530 $14,681
Heating Units 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
Renewable Heat gal. disp./ yr.1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968 1,968
Renewable Heat O&M (non-stoking)$ per yr.752$ 764$ 775$ 787$ 799$ 811$ 823$ 835$ 848$ 860$ 873$ 886$ 900$ 913$ 927$ 941$ 955$ 969$ 984$ 999$
Renewable Heat Stoking $ per yr.5,223$ 5,302$ 5,381$ 5,462$ 5,544$ 5,627$ 5,711$ 5,797$ 5,884$ 5,972$ 6,062$ 6,153$ 6,245$ 6,339$ 6,434$ 6,530$ 6,628$ 6,728$ 6,828$ 6,931$
Renewable Fuel Use Qty (biomass)cords 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9 19.9
Renewable Fuel Cost $ per unit 400$ 412$ 424$ 437$ 450$ 464$ 478$ 492$ 507$ 522$ 538$ 554$ 570$ 587$ 605$ 623$ 642$ 661$ 681$ 701$
Total Renewable Fuel Cost $ per yr.7,945$ 8,183$ 8,429$ 8,682$ 8,942$ 9,210$ 9,487$ 9,771$ 10,064$ 10,366$ 10,677$ 10,998$ 11,327$ 11,667$ 12,017$ 12,378$ 12,749$ 13,132$ 13,526$ 13,931$
Supplemental Fuel Qty (Oil)gal.347 347 347 347 347 347 347 347 347 347 347 347 347 347 347 347 347 347 347 347
Fuel Cost $ per gal.7.62$ 7.99$ 8.37$ 8.77$ 9.19$ 9.63$ 10.10$ 10.58$ 11.09$ 11.62$ 12.18$ 12.76$ 13.37$ 14.02$ 14.69$ 15.39$ 16.13$ 16.91$ 17.72$ 18.57$
Supplemental Fuel Cost $ per yr.2,646$ 2,773$ 2,906$ 3,046$ 3,192$ 3,345$ 3,506$ 3,674$ 3,850$ 4,035$ 4,229$ 4,432$ 4,644$ 4,867$ 5,101$ 5,346$ 5,602$ 5,871$ 6,153$ 6,449$
Proposed Heat Cost $ per yr.16,567$ 17,022$ 17,491$ 17,976$ 18,476$ 18,993$ 19,526$ 20,077$ 20,646$ 21,234$ 21,841$ 22,468$ 23,116$ 23,786$ 24,479$ 25,195$ 25,935$ 26,700$ 27,491$ 28,309$
Fuel Use gal. per yr.2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315 2,315
Fuel Cost $ per gal. 7.62$ 7.99$ 8.37$ 8.77$ 9.19$ 9.63$ 10.10$ 10.58$ 11.09$ 11.62$ 12.18$ 12.76$ 13.37$ 14.02$ 14.69$ 15.39$ 16.13$ 16.91$ 17.72$ 18.57$
Fuel Cost $ per yr.17,640$ 18,487$ 19,374$ 20,304$ 21,279$ 22,300$ 23,371$ 24,493$ 25,668$ 26,900$ 28,192$ 29,545$ 30,963$ 32,449$ 34,007$ 35,639$ 37,350$ 39,142$ 41,021$ 42,990$
Base Heating Cost $ per yr.17,640$ 18,487$ 19,374$ 20,304$ 21,279$ 22,300$ 23,371$ 24,493$ 25,668$ 26,900$ 28,192$ 29,545$ 30,963$ 32,449$ 34,007$ 35,639$ 37,350$ 39,142$ 41,021$ 42,990$
Proposed
Base
Page 15 of 15
Recommendations
Biomass heat at the Washateria is considered financially un-feasible at this time. The project does create
employment and result in operational savings, but the sum of those savings is insufficient to justify the
capital expense to develop the project.
The project also has challenges with technical feasibility, because the existing heat system operates in a
narrow temperature range, 180 / 160°F. Cordwood systems are not very effective when serving building
heat systems that operate in a narrow temperature range.
There may be an opportunity for Alatna Village Council to own and operate a biomass energy project
and sell heat as a third-party. The Allakaket School building is scheduled to be replaced in 5 – 10 years. It
appears that a heat sales project, owned and operated by a third-party, may satisfy Yukon-Koyukuk
School District’s interest in biomass energy. If the project owner can source fuel at $275 per cord, as the
Tanana Chiefs Conference reconnaissance-level biomass resource assessment suggests, the project is
considered pre-feasible. Sourcing wood at $275 per cord would result in about $25,000 of revenues per
year for the supplier. The project pre-feasibility, “Allakaket Village Biomass Heat Pre-Feasibility Study,” is
publically available from the Alaska Energy Authority (contact Biomass/CHP Program Manager, 907-771-
3068) or Interior Regional Housing Authority (contact Grants Manager, 907-452-835).
It is also recommended that Alatna Village Council proceed with plans to re-level and improve the
foundation of the Alatna Village Council Office, and to weatherize the Office. After weatherization,
Alatna Village Council may wish to upgrade the Office wood stove to better meet heat demand.
Appendix
A—Biomass Technology
B – Utility Receipts
C – Plat Map
D – Aircraft Information
E – Site Photos
A-1
A – Biomass Technology
Although humans have used wood for heat for millennia, modern high-efficiency biomass boilers have
only been in use for a few decades. Biomass boilers may use wood fuels such as cordwood, wood chips,
or wood pellets, to heat commercial buildings. Biomass boiler projects depend on sustainable forest
management, quality biomass fuel sourcing, processing, and storage, and reliable fuel handling. Biomass
boilers frequently integrate with conventional hydronic heat systems, which use water to move heat
from where it is produced to where it is needed. Small-scale biomass systems often incorporate a hot
water storage tank, which promotes efficient combustion and improves the availability of biomass heat.
To provide reliable heat, the biomass boiler, building heat distribution system, controls, and heat
emitters must be properly matched.
Sustainable
Forest
Management
Wood fuel
Processing &
Storage
Handling Combustion Thermal
Storage
Heat
Distribution
The Nature of Wood Fuels
Composition
All wood is made primarily of cellulose, hemi-cellulose, and
lignin. It is about 50% Carbon, 44% Oxygen, and 6% Hydrogen.
Theoretically, complete combustion (100% efficient) would
result in only two products: carbon dioxide and water. In
practice, biomass boilers range from about 77 -- 83% efficient.
Wood that is not completely burned become carbon monoxide
and hydrocarbons, often in the form of smoke and ash.1
Combustion
Biomass fuel undergoes fascinating changes as it burns.
Pyrolysis occurs at 500 – 600°F, in which organic gasses leave
behind charcoal solids. Primary combustion is burning of
charcoal solids.2 Secondary combustion is burning of organic
gasses. Because about 60% of the heating value is contained in
gasses, secondary combustion is essential to high efficiency
wood burning.
1 Rick Curkeet, PE, Wood Combustion Basics, EPA Burnwise Workshop 2011,
http://www.epa.gov/burnwise/workshop2011/WoodCombustion-Curkeet.pdf (June 19, 2014).
2 Curkeet, Rick.
A-2
Emissions
In wood burning, the primary emissions concern is particulate matter 2.5 microns or less in size (“PM
2.5”), which is hazardous to human health. Additionally, unburned wood signifies lost heat and potential
creosote formation. Creosote formation results in higher fuel costs, shortens the life of the boiler, and
increases other maintenance costs. Boiler manufacturers have certified emissions tests conducted
according to the ASTM E2618-13 standard that document boiler efficiency. High efficiency wood boilers
emit about 0.07 – 0.3 lbs of PM 10 per million BTU in test conditions.
Boiler manufacturers specify operating conditions for the field. One important condition is wood fuel
specifications, which include moisture content and fuel dimensions. Other important conditions for
efficient operation include proper fuel storage, routine operations and maintenance, and system design
(such as proper boiler sizing and incorporating a hot water storage tank).
One valuable source of information for seasoning cordwood in Interior Alaska is available at the Cold
Climate Housing Research Center’s (CCHRC) website.3 “Properly prepared and stored” cordwood can be
dry enough to burn safely within six weeks during the summer. In regions other than the Interior, similar
storage principles would apply, but recommended storage durations may be different. Below is a
summary of how to properly prepare and store cordwood:
Cut to stove length (two feet or shorter)
Split the wood at least once
Stack in a pile with air space between the pieces
Store wood in a shed or cover only the top of the pile with a large piece of plywood or some
waterproof tarp
Allow sun and air to reach the sides of the wood pile to help dry the wood
Season at least six weeks during the summer months
If beginning after August 1st, wait to burn until the next summer
When properly stored, more time is always better
Figure 1: Excerpt from CCHRC's Cordwood Handling Brochure
3 http://www.cchrc.org/docs/best_practices/Cordwood_Handling_Brochure.pdf
A-3
Wood Fueled Heating Systems
Below are the characteristics of cordwood, wood chip, and wood pellet boiler systems.
Advantages
Disadvantages
Cordwood
Local wood resource
Small size (less than 1 MMBTU)
Simple to operate
Higher labor costs, including hand-
feeding the boiler, manual ash
removal, and manual grate
cleaning
Labor is needed intermittently, so
someone must be available “on
site”
Typically non-pressurized, which
may require more frequent boiler
chemical additions
Pellets
Can operate unattended, and
automatically match heat load
Scalable from small to large sizes
(generally 100,000 btu – 1
MMBTU)
Relatively small footprint
Typically the most efficient
biomass combustion
Pellet fuel is typically not locally
produced, and therefore depends
on “imports”
Shipping pellets is very costly; even
a freight rate of $0.05 per lb.
results in an additional cost of
$100 per ton.
Relatively expensive wood fuel
Ash removal and grate cleaning
may be automated or manual
Chips
Can operate unattended, and
automatically match heat load
Wood chips may be the lowest
cost fuel
Local wood resource may be
available or produced
Large projects achieve economies
of scale
Creates jobs in the woods and at
the boiler plant
Large systems are expensive
Typically large sizes > 1,000,000
MMBTU
Wood chip fuel can be diverse,
which can make it difficult to meet
fuel specifications. Screens and
other devices can improve fuel
quality.
B-1
B – Utility Receipts
C‐1
C – Plat Map
D-1
Appendix D – Aircraft Information
For the purpose of this feasibility study, all project equipment should fit within a Shorts 330 Sherpa, with
a maximum cargo length of 29’, width of 75”, and height of 76”. Ravn Alaska charters the Sherpa to
Allakaket for an estimated $6,315 with a 4,800 lb. maximum payload. Up to 5,400 lbs. can be
accommodated for an additional cost.
No cordwood boilers larger than 180,000 btu were identified that would be able to fit into a Shorts 330
Sherpa, McDonnell Douglas DC 6, or Casa 212. No other aircraft that could potentially accommodate the
project equipment and land at the Allakaket Airport were identified.
E‐1
Apppendix E
E‐2
E‐3
E‐4
E‐5
E‐6
E‐7
E E‐8
E E‐9
E E‐10
E E‐11
E E‐12
E E‐13
E E‐14