HomeMy WebLinkAboutAllakaket Biomass Heat Pre-Feasibility Study 10-16-2014-BIO
Allakaket 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 1 of 12
Contents
Acknowledgements ....................................................................................................................................... 2
Community Contact Information .................................................................................................................. 2
Summary of Findings..................................................................................................................................... 2
Statement of Purpose ................................................................................................................................... 3
Community & Facility Information................................................................................................................ 3
Biomass Resource Availability ....................................................................................................................... 4
Site Control ................................................................................................................................................... 4
Permitting ..................................................................................................................................................... 4
Proposed Biomass System ............................................................................................................................ 5
Alternatives Considered ............................................................................................................................ 5
Heat Load & Biomass Requirements ............................................................................................................ 6
Opinion of Probable Cost .............................................................................................................................. 8
Financial Analysis ........................................................................................................................................ 10
Financial Summary .................................................................................................................................. 10
Benefit / Cost Model ............................................................................................................................... 10
Sensitivity Analysis .................................................................................................................................. 12
Recommendations ...................................................................................................................................... 12
Figures
Figure 1: Fuel Energy Values ......................................................................................................................... 6
Figure 2: Current Annual Fuel Use & Cost .................................................................................................... 6
Figure 3: Project Annual Fuel Use & Cost, Biomass Project .......................................................................... 6
Figure 4: Biomass Stoking Requirements & Cost .......................................................................................... 6
Figure 5: Biomass O&M Costs (non-stoking) ................................................................................................ 7
Figure 6: Force Account Summary ................................................................................................................ 8
Figure 7: Force Account Detail ...................................................................................................................... 9
Appendix
A—Biomass Technology
B – Utility Information
C – Aircraft Information
Page 2 of 12
Acknowledgements
Energy Action thanks the following representatives for their assistance with this assessment:
Melanie Wholecheese, Interim Tribal Administrator, Allakaket Village
Gale Bourne, Director of Facilities & Maintenance, Yukon-Koyukuk School District
Dave Bishop, Principal, Allakaket School
Russell Snyder, Grants Coordinator, Interior Regional Housing Authority
Steven J. Stassel, P.E., Gray Stassel Engineering
Community Contact Information
Allakaket Village
PO Box 50, Allakaket, AK 99720
P. (907) 968-2237
F. (907) 968-2233
Email: n/a
Yukon-Koyukuk School District
Gale Bourne, Director of Facilities & Maintenance
P. (907) 374-9400
gbourne@yksd.com
Summary of Findings
The Yukon-Koyukuk School District (YKSD) may be interested in a biomass heat sales agreement with a
third-party owner and operator. This is a revenue-generating opportunity for a third-party, such as the
Allakaket Village Council, the City of Allakaket, the Alatna Village Council, or a private entity.
The project building is the future Allakaket School, planned for construction in 5 – 10 years. The biomass
project would use an estimated 93 cords per year to displace about 85% of the future school’s assumed
heat load of 10,875 gallons of fuel oil. The project is considered marginally pre-feasible at this time.
If the project owner can source fuel at $265 per cord, as the Tanana Chiefs Conference reconnaissance-
level biomass resource assessment suggests, the project is considered pre-feasible.
Under the current market prices of $400 per cord and $5.69 per gallon, the project is considered
unfeasible. Sensitivity analysis indicates the project would be financially pre-feasible with the input price
of $400 per cord if the price of fuel oil rises to $6.85 per gallon or more.
When YKSD begins to actively plan the new Allakaket School, it is recommended that they review this
pre-feasibility study to consider whether assumptions have significantly changed which would impact
the pre-feasibility of the biomass heat project. It is also recommended that YKSD discuss the possibility
for third-party ownership and operation of a biomass heat project with local organizations. The project
may be an opportunity for these organizations to create revenues and community
benefits consistent with their organizational missions.
Page 3 of 12
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, Interior Regional Housing Authority, which seeks opportunities to
promote community self-sufficiency through 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.
Community & Facility Information
Allakaket Village (population 105) is an Alaska Native Village located on the south bank of the Koyukuk
River, southwest of its junction with the Alatna River, approximately 190 air miles northwest of
Fairbanks. Allakaket Village also provides the airport, electric utility, postal, and school services to
Alatna Village (population 26), which is located just west of Allakaket Village across the Koyukuk River.
The Yukon-Koyukuk School District (YKSD) will construct a new school in Allakaket in 5 – 10 years. This
new school is the project building, as explained below. YKSD is managed by a Superintendent and Board
of Education. The current Director of Facilities & Maintenance is Gale Bourne.
YKSD purchases fuel oil in Allakaket for $5.69 per gallon. Delivery is by plane only.
The current going rate for cordwood is $400 per cord (Allakaket Village Council meeting, personal
conversation, February 5, 2013). The Allakaket Village Council and City of Allakaket offices both contain
wood stoves, which are actively used for heating.
Electricity averages 92 cents per kWh (email correspondence, Gale Bourne, February 11, 2014).
Much of the town, including the existing Allakaket School, is below the 100-year flood mark of 497’. New
construction is often located on high ground in the New Allakaket Subdivision.
The project building is the future Allakaket School. This building will have the largest heat load in the
community, and new construction will offer the potential to minimize project costs by through shared
overhead expenses with the future School construction. Mr. Bourne expressed that he is interested in a
biomass energy project that meets the following standards:
Lower cost per Btu than oil
No increased maintenance costs
No inherent risk that is out of YKSD’s ability to control
It appears that a heat sales project, owned and operated by a third-party, which is separate from the
School’s energy system, may satisfy Mr. Bourne’s interest. However, the interest of a third-party to own
and operate such a system remains to be determined, as discussed in the “Recommendations” section
of this report.
The existing Allakaket School uses about 14,500 gallons of fuel oil per year (Appendix B). For the purpose
of this report, the future School is anticipated to use 75% of the existing School’s fuel usage, a total
of10,875 gallons of fuel oil. It is also assumed to be designed to heat with warm water at
120°F.
Page 4 of 12
Several buildings were considered not suitable for biomass energy assessment, including the Tribal
office, City office, and Washateria / Water Plant. The Tribal office and City office have relatively low fuel
oil consumption (<1,200 gal/ yr.), and already have operating cordwood stoves. The Washateria / Water
Plant fuel oil consumption (about 1,160 gal/ yr.) is too low to justify evaluation for biomass heat. The
Washateria /Water Plant benefits from recovered heat from the nearby AP&T power plant.
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 Allakaket
Village, and other factors. In summary, within a 5-mile radius of Allakaket Village, there are
approximately 144,000 cords of biomass, with nearly 82% of this material located on K'oyitl'ots'ina,
Limited lands. The average cost for biomass within a 5-mile radius of Allakaket 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.
Site Control
The proposed biomass project is hypothetical, and no project location has been determined. Site control
has not been evaluated for this project.
Permitting
Applicable project permitting is considered below:
The Alaska Department of Public Safety, Division of 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
million Btu/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 for to mitigate potential effects on resources.
Page 5 of 12
Proposed Biomass System
For the purpose of this report, the new school building is anticipated to use 75% of the current school’s
fuel usage. The new school building is assumed to use 10,875 gallons of fuel oil per year. It is also
assumed to be designed to heat with warm water at 120°F.
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 C.
The requirement to deliver the project equipment by plane limits the size of the boiler. The limited
boiler size increases stoking requirements, which is a major component of operating costs. The
proposed biomass system is three (3) 180,000 Btu cordwood boilers. The project would be more cost
effective with fewer, larger boilers.
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 10,875 gallons of fuel oil per year, 95% of which serves space heat load,
5% of which serves domestic hot water
Three (3) 180,000 Btu cordwood boilers with 2,940 gallons of storage total, delta T = 80°F
Maximum 4 firings per day per boiler, 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 -- $5.69/ gal
o Labor -- $20.17/ hr
Alternatives Considered
There were no alternatives considered for this project.
Page 6 of 12
Heat Load & Biomass Requirements
Figure 1: Fuel Energy Values
Figure 2: Projected Annual Fuel Use & Cost
Figure 3: Project Annual Fuel Use & Cost, Biomass Project
Figure 4: Biomass Stoking Requirements & Cost
Gross
Btu/unit
System
efficiency
Delivered
Btu/unit
Gross
$/unit
Delivered
$/MMBtu
Oil (gal)134,500 80%107,600 $ 5.69 52.88$
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
future school 10,875 5.69$ 61,879$
Total 61,879$
15%Oil
85%Biomass
9244 gallons displaced
Facility Fuel Type Units $ / unit Annual Fuel Cost
future school Biomass, 20% MC* (cord) 93.3 400$ 37,322$
future school Oil (gal)1631 5.69$ 9,282$
Total $ 46,604
Facility Total Stokings per Yr Stoking Hrs
Per Yr $ / hr Annual Stoking
Cost
future school 1893 631 20.17$ 12,726$
Page 7 of 12
Figure 5: Biomass O&M Costs (non-stoking)
Biomass size (btu)540,000
Biomass fuel Biomass, 20% MC* (cord)
Cost of Labor 20.17$
Cost of Electricity 0.83$
Number of Stokings 1893
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$
Chemicals 250$ 1 5,000$
Cost per Lifetime 8,352$
Straight-line Average Cost per Yr.418$
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$
Cost per Lifetime 2,437$
Straight-line Average Cost per Yr.122$
OTHER Yrs. To Cost
Cost over
Lifetime
Electricity 1/2 HP fan 97$ 1 1,949$
Straight-line Average Cost per Yr.97$
O&M Cost per Yr. per Boiler 637$
Number of Boilers 3
Total O&M per Yr.1,911$
Electricity -- pump 367$
2,278$ Total Annual Biomass O&M (non-stoking)
Page 8 of 12
Opinion of Probable Cost
Figure 6: Force Account Summary
Site & Foundation Work $9,973
Biomass boiler building $45,068
Biomass heat system $119,440
End-user building integration $8,374
Miscellaneous $8,700
Overhead $34,730
Freight $51,859
CONSTRUCTION SUB-TOTAL $278,143
Design & Construction Admin $22,628
Construction Management $11,314
PROJECT SUB-TOTAL $312,086
Contingency @ 20%$62,417
Admin @ 4%$12,483
TOTAL PROJECT COST $386,986
Page 9 of 12
Figure 7: 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' 45 ea $63.00 $2,835 0.50 22.50 $95 $2,138 $4,973 70.00 3150
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' 22 ea.$350 $7,700 0.3 7 $95 $627 $8,327 4 88
SIP roof -- 4' x 10' pkg 13 ea.$350 $4,550 0.75 10 $95 $926 $5,476 4 52
SIP fasteners / hardware / framing
anchors 2 lump $400 $800 0 0 $95 $0 $800 500 1000
SIP caulk, sealant, expanding foam 2 lump $250 $500 4 8 $95 $760 $1,260 150 300
Roof, frame 1 lump $900 $900 18.00 18 $95 $1,710 $2,610 400 400
Roof, Metal -- 3' x 10' Delta rib roofing 17 ea.$175 $2,975 1.00 17 $95 $1,615 $4,590 96 1632
Floor Insulation, Rigid (2"x24"x96")30 ea.$28.00 $840 0.25 8 $95 $713 $1,553 1 30
Floor system, metal 1 lump $2,400 $2,400 20.00 20 $95 $1,900 $4,300 1600 1600
Siding, Metal, plus trim -- 3' x 10' Delta
rib roofing 30 ea.$175 $5,250 1.00 30 $95 $2,850 $8,100 96 2880
Fasteners 2 lump $250 $500 0 0 $95 $0 $500 100 200
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 22 ea.$27 $594 0.33 7 $95 $690 $1,284 50 1100
Interior paint -- 5 gal 6 ea.$40 $240 4 24 $95 $2,280 $2,520 42 249
Fire protection 1 lump $250 $250 0.1 0.1 $95 $10 $260 150 150
BIOMASS HEAT SYSTEM
Boiler -- GARN 1000 3 ea.$11,000 $33,000 16 48 $95 $4,560 $37,560 2200 6600
Pipe/Valves/Ftgs/Gauges 3 lump $5,000 $15,000 54 162 $100 $16,200 $31,200 800 2400
Circ pump 4 ea.$500 $2,000 4 16 $100 $1,600 $3,600 60 240
Plate HXR, (600 MBH)2 ea.$5,000 $10,000 10 20 $100 $2,000 $12,000 250 500
Misc Strut & Pipe Hangers 1 lump $1,000 $1,000 20 20 $95 $1,900 $2,900 500 500
Tank Insulation 3 lump $1,200 $3,600 3 9 $95 $855 $4,455 50 150
Stack -- 6" dia double wall UL listed +
supporting infrastructure 3 lump $1,700 $5,100 4 12 $95 $1,140 $6,240 3.8 11
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
PEX Piping -- 2" Arctic 60 lf $25 $1,500 0.27 16 $95 $1,539 $3,039 1 78
PEX accessories -- 60 1/ft $5 $300 0.00 0 $95 $0 $300 1 60
Pipe penetration exclosure 1 lump $750 $750 3 3 $95 $285 $1,035 200 200
Temp controls 1 lump $750 $750 8 8 $100 $800 $1,550 200 200
Electrical work 1 lump $1,250 $1,250 12 12 $100 $1,200 $2,450 200 200
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 $540 $1,080 $1,080 0
Crew Per Diem 240 mn.dy.$60 $14,400 $14,400 0
Housing Rent 2 mo.$1,500 $3,000 $3,000 0
FREIGHT 29,453
Ground Freight 6,600 lb.$0.41 $2,733
Air Freight 29,453 lb.$1.40 $41,126
Air Freight Tool Mob & Demob 2 lump $2,500 $5,000
Misc Small Freight & Gold Streaks 1 lump $3,000 $3,000
CONSTRUCTION SUB-TOTAL $126,714 763 $73,340 $26,230 $51,859 $278,143
Engineering (Design & CCA)10 %$22,628
Construction Management 5 %$11,314
PROJECT SUB-TOTAL $126,714 $73,340 $60,173 $51,859 $312,086
Contingency 20 %$62,417
Admin Fee 4 %$12,483
CONSTRUCTION TOTAL $386,986
Page 10 of 12
Financial Analysis
Financial Summary
The project is considered marginally feasible at this time.
Benefit/ Cost: 0.60
Simple Payback Period: n/a
Net present value: ($146,029)
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 been adapted for 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 $218,743
NPV Capital Costs $364,772
B/C Ratio 0.60
NPV Net Benefit ($146,029)
Performance Unit Value
Displaced Petroleum Fuel gallons per year 9,244
Displaced Petroleum Fuel total lifetime gallons 184,875
Avoided CO2 tonnes per year 94
Avoided CO2 total lifetime tonnes 1,876
Proposed System Unit Value
Capital Costs $$386,986
Project Start year 2015
Project Life years 20
Displaced Heat gallons displaced per year 9,244
Heating Capacity Btu/hr 540,000
Heating Capacity Factor %85%
Parameters Unit Value
Heating Fuel Premium $ per gallon
Discount Rate % per year 3%
Crude Oil $ per barrel
Biomass
Allakaket Village
Allakaket future school_biomass
Allakaket
Allakaket, Alatna
Rural
Page 11 of 12
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 386,986$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$
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 271$ 1,451$ $2,715 $4,069 $5,516 $271 $8,713 $10,475 $12,353 $14,355 $16,487 $18,756 $21,169 $23,735 $26,462 $29,358 $32,433 $35,696 $39,157 $42,828
Transportation Savings (Costs)$ 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 $271 $1,451 $2,715 $4,069 $5,516 $271 $8,713 $10,475 $12,353 $14,355 $16,487 $18,756 $21,169 $23,735 $26,462 $29,358 $32,433 $35,696 $39,157 $42,828
Net Benefit $ per year ($386,715)$1,451 $2,715 $4,069 $5,516 $271 $8,713 $10,475 $12,353 $14,355 $16,487 $18,756 $21,169 $23,735 $26,462 $29,358 $32,433 $35,696 $39,157 $42,828
Heating Units 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
Renewable Heat gal. disp./ yr.9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244 9,244
Renewable Heat O&M (non-stoking)$ per yr.2,278$ 2,312$ 2,347$ 2,382$ 2,418$ 2,454$ 2,491$ 2,528$ 2,566$ 2,604$ 2,644$ 2,683$ 2,723$ 2,764$ 2,806$ 2,848$ 2,891$ 2,934$ 2,978$ 3,023$
Renewable Heat Stoking $ per yr.12,726$ 12,917$ 13,111$ 13,307$ 13,507$ 13,709$ 13,915$ 14,124$ 14,336$ 14,551$ 14,769$ 14,991$ 15,215$ 15,444$ 15,675$ 15,910$ 16,149$ 16,391$ 16,637$ 16,887$
Renewable Fuel Use Qty (Biomass)cords 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3 93.3
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.37,322$ 38,442$ 39,595$ 40,783$ 42,006$ 43,266$ 44,564$ 45,901$ 47,278$ 48,697$ 50,157$ 51,662$ 53,212$ 54,808$ 56,453$ 58,146$ 59,891$ 61,687$ 63,538$ 65,444$
Supplemental Fuel Qty (Oil)gal.1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631 1631
Fuel Cost $ per gal.5.69$ 5.96$ 6.25$ 6.55$ 6.86$ 7.19$ 7.54$ 7.90$ 8.28$ 8.68$ 9.09$ 9.53$ 9.99$ 10.47$ 10.97$ 11.50$ 12.05$ 12.63$ 13.23$ 13.87$
Supplemental Fuel Cost $ per yr.9,282$ 9,726$ 10,193$ 10,682$ 11,195$ 11,732$ 12,295$ 12,885$ 13,504$ 14,152$ 14,831$ 15,543$ 16,289$ 17,071$ 17,891$ 18,749$ 19,649$ 20,592$ 21,581$ 22,617$
Proposed Heat Cost $ per yr.61,607$ 63,396$ 65,245$ 67,154$ 69,125$ 71,162$ 73,265$ 75,438$ 77,684$ 80,004$ 82,401$ 84,879$ 87,440$ 90,087$ 92,824$ 95,654$ 98,580$ 101,605$ 104,734$ 107,970$
Fuel Use gal. per yr.10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875 10,875
Fuel Cost $ per gal. 5.69$ 5.96$ 6.25$ 6.55$ 6.86$ 7.19$ 7.54$ 7.90$ 8.28$ 8.68$ 9.09$ 9.53$ 9.99$ 10.47$ 10.97$ 11.50$ 12.05$ 12.63$ 13.23$ 13.87$
Fuel Cost $ per yr.61,879$ 64,847$ 67,960$ 71,222$ 74,641$ 78,224$ 81,978$ 85,913$ 90,037$ 94,359$ 98,888$ 103,635$ 108,609$ 113,823$ 119,286$ 125,012$ 131,012$ 137,301$ 143,891$ 150,798$
Base Heating Cost $ per yr.61,879$ 64,847$ 67,960$ 71,222$ 74,641$ 78,224$ 81,978$ 85,913$ 90,037$ 94,359$ 98,888$ 103,635$ 108,609$ 113,823$ 119,286$ 125,012$ 131,012$ 137,301$ 143,891$ 150,798$
Proposed
Base
Page 12 of 12
Sensitivity Analysis
Sensitivity analysis was also performed. All other variables remaining equal, the following fuel variable
results in an economically feasible project.
Sensitivity analysis was also performed for the price of cordwood. If the project owner can source fuel at
$170 per cord, as the Tanana Chiefs Conference reconnaissance-level biomass resource assessment
suggests, the project has the following economic results.
Recommendations
The biomass project for a future school is considered marginally feasible at this time. Sensitivity analysis
indicates the project will be financially pre-feasible under current assumptions if the price of fuel oil
price is $6.85 per gallon or more, or if a project owner can reliably source wood at $265 per cord or less.
Sourcing wood at $265 per cord would result in about $25,000 of revenues per year for the supplier.
When YKSD begins to actively design the future Allakaket School, it is recommended that they review
this pre-feasibility study to consider whether assumptions have significantly changed which would
impact the feasibility of the biomass project. Additionally, if YKSD anticipates reduced construction cost
through shared overhead expenses, including the ability to charter much larger plane(s), an update is
recommended.
It is also recommended that YKSD discuss the possibility for the development and operation of a
biomass heat sales project with a third-party, such as the Allakaket Village Council, the City of Allakaket,
and the Alatna Village Council. The project may be an opportunity for these organizations to create
revenues and community benefits consistent with their organizational missions.
Appendix
A—Biomass Technology
B – Utility Information
C—Aircraft Information
Fuel Oil Price per Gal, Yr. 1 6.85$
Benefit / Cost 1.25
NPV Net Benefit $91,168
Variable
Results
Cordwood, $ / cord, Yr. 1 265$
Benefit / Cost 1.25
NPV Net Benefit $89,801
Variable
Results
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.
Appendix B – Utility Receipt
B-1
Wynne,
I have quite a bit of historical fuel data. Fuel is not typically the highest cost uƟlity however.
Electricity is the highest cost.
Allakaket school currently uses an average of 52 gallons per day (total campus) or 14,500 gallons
per year. The cost is $5,69/gallon (air delivery only). Electricity runs approximately 10,398 Kwh per
month (total campus). The cost averages .92/kwh.
Gale
From: Wynne Auld [mailto:wynne@energyaction.info]
Sent: Monday, February 10, 2014 12:21 PM
To: Gale Bourne
Cc: Russell Snyder
Subject: Re: Allakaket School biomass
Hi Gale,
Thank you for the informaƟon. You can help me by helping me figure out the energy use of the
future school. Have you built other schools recently in the area? How many gallons of fuel oil
would you anƟcipate the future school using?
My assessment will focus on a biomass system serving this hypotheƟcal heat load, at current
market prices.
Thanks,
Wynne
RE: Allakaket School biomass ϐile:///C:/Users/Wynne/Google Drive/ea clients/irha/Pre‐Feasibilit...
1 of 1 7/2/2014 2:43 PM
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