HomeMy WebLinkAboutVillage of Kaltag Biomass Energy Preliminary Fesability Assessment 08-19-2012-BIO1
Dalson Energy Inc.
308 G St. Ste 303
Anchorage, Alaska 99501
907-277-7900
8/19/2012
Preliminary Feasibility Assessment
This preliminary feasibility assessment considers the potential for
heating community buildings in Kaltag with woody biomass from
regional forests and river logs.
Biomass Energy Native Village of Kaltag
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 2
Table of Contents
Project Summary .................................................................................................................................................................. 3
Summary of Findings .......................................................................................................................................................... 5
Wood fuel supply in Kaltag ................................................................................................................................................ 6
Biomass Energy Operations and Maintenance ................................................................................................................ 7
Biomass Harvest Plan ...................................................................................................................................................... 7
Operations Plan ................................................................................................................................................................ 9
Community Facilities Information .................................................................................................................................... 9
Tribal Buildings ................................................................................................................................................................ 9
Tribal Building .............................................................................................................................................................. 9
City Buildings ................................................................................................................................................................. 10
City Office ................................................................................................................................................................... 10
Washateria/Waterplant ............................................................................................................................................ 10
Community Hall ........................................................................................................................................................ 10
Firehall ......................................................................................................................................................................... 11
Clinic ............................................................................................................................................................................ 11
School ................................................................................................................................................................................... 11
Recommended technology and fuel requirements ....................................................................................................... 12
Washateria/Waterplant ................................................................................................................................................ 12
Tribal and City Office Cluster ...................................................................................................................................... 12
Kaltag School .................................................................................................................................................................. 13
Initial investment ............................................................................................................................................................... 14
City & Tribal Office Cluster .......................................................................................................................................... 15
Waterplant/ Washateria ............................................................................................................................................... 16
Kaltag School .................................................................................................................................................................. 17
Financial Analysis .............................................................................................................................................................. 18
Operating Costs & Annual Savings ............................................................................................................................. 19
City and Tribal Office ................................................................................................................................................ 19
Washateria/ Waterplant ........................................................................................................................................... 22
Kaltag School .............................................................................................................................................................. 25
Life cycle cost analysis (LCCA) for School ............................................................................................................. 28
Summary of Financial Analysis ............................................................................................................................... 29
Conclusion .......................................................................................................................................................................... 30
Supplement: Community Wood Heating Basics ........................................................................................................... 32
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 3
Wood fuel as a heating option ......................................................................................................................................... 32
The nature of wood fuels .................................................................................................................................................. 32
The basics of wood-fueled heating .................................................................................................................................. 33
Available wood heating technology ................................................................................................................................ 36
Cordwood Boilers .......................................................................................................................................................... 36
Bulk Fuel Boilers ............................................................................................................................................................ 36
District heat loops .......................................................................................................................................................... 37
Figure 1: Land Ownership Surrounding Kaltag, AK ...................................................................................................... 6
Figure 2: Biomass stock and annual allowable cut surrounding Kaltag, AK .............................................................. 7
Figure 3: Illustration of Unmanaged Wood Harvesting Efforts .................................................................................... 8
Figure 4: Illustration of Planned Wood Harvest by Harvest Area and Time Period. ................................................ 8
Figure 5: Kaltag Washateria ................................................................................................................................................ 9
Figure 6: Kaltag community buildings. Washateria/ waterplant (8), City Hall (14), Tribal Hall (15), Clinic (12),
Community Hall (13), Fire Hall (10), School (18). ........................................................................................................... 9
Figure 7: Kaltag Washateria/ Waterplant Gallons of Fuel by Month.................................................................................... 10
Figure 8: Cordwood ............................................................................................................................................................... 32
Figure 9: Wood briquettes, as a substitute for cordwood. Cross sections of these briquettes make “wafers” which can be
automatically handled in biomass boiler systems. ............................................................................................................... 32
Figure 10: Ground wood chips used for mulch. .................................................................................................................... 32
Figure 11: Wood pellets ........................................................................................................................................................ 32
Project Summary
Interior Regional Housing Authority (IRHA) and Tanana Chiefs Conference (TCC) contracted Dalson
Energy to do a Pre-Feasibility Study for biomass heating of community buildings in the Native
Village of Kaltag.
Dalson Energy biomass specialists Thomas Deerfield and Wynne Auld visited the community on
June 15, 2012 for the initial assessment. Deerfield and Auld made their assessment based on available
data, interviews with local stakeholders and authorities, observations, and research and review of
previous studies done in Kaltag.
It was noted that there are several other studies and reports that address various aspects of biomass
energy in Kaltag, including Forestry Resource assessments done by TCC Forester Will Putman and
DNR Division of Forestry. Clare Doig of Forest and Land Management Inc. is also completing a forest
management plan for the regional corporation, Gana’A-Yoo. These studies are the foundation for
further evaluation of community heating with woody biomass in Kaltag, as exercised in this pre-
feasibility assessment.
This report was prepared by Thomas Deerfield, Wynne Auld, Louise Deerfield, and Clare Doig.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 4
Contact and interviews with the following individuals in Kaltag assisted in some of the information
gathering. Their contact information is as follows:
City - City of Kaltag
P.O. Box 9
Kaltag, AK 99748
Phone 907-534-2301
Fax 907-534-2236
Jackie Nicholas, City Manager, jdsnicholas@hotmail.com
Tommy Neglaska, Washateria Manager, tommyneglaska@yahoo.com
Tribe-- Kaltag Village, federally-recognized
P.O. Box 129
Kaltag, AK 99748
Phone 907-534-2224
Fax 907-534-2299
E-mail kaltag@aitc.org
Anne Esmailka, Tribal Administrator
Violet Burnham, Mayor and Kaltag Rep. for Gana’a’Yoo Natural Resources Committee
School—Kaltag School
PO Box 30
Main Street
Kaltag, AK 99748
Phone: (907) 534-2204
Fax: (907) 534-2227
Gale Bourne, YKSD Facilities, gbourne@yksd.com
Nancy Mason, Principal/Teacher, nmason@yksd.com
Bernice Moore, Secretary, bmoore@yksd.com
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 5
Summary of Findings
The three projects examined are (1) Kaltag School, (2) Washateria/ Waterplant, and (3) City & Tribal
Office Cluster. All of the candidate facilities identified could be served by HELE (high efficiency, low
emission) cordwood boiler systems; or, alternatively, the the Kaltag School could be served by a
wood chip system.
There is strong technical feasibility for all projects examined. All projects could be heated by a
cordwood boiler, with the Washateria and School projects being containerized units and the City and
Tribal Office being a boiler installed in in the existing building. All projects would require a new fuel
storage room.
Alternatively, the Kaltag School could be heated by a semi-automated wood chip system instead of a
cordwood boiler. The feasibility of this technology is subject to a Harvest Plan and Operations Plan,
as well as the preferences of the School administration and maintenance personnel.
The project’s success is critically dependent on a Biomass Harvest Plan and an Operations Plan. The
need for these project Plans are discussed in this Pre-Feasibility Analysis.
Dalson Energy provides this report to IRHA and TCC, and those agencies will determine the next
steps forward.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 6
Wood fuel supply in Kaltag
Kaltag, with a population of 205 (2011 Alaska Census Estimate), is located 75 miles west of Galena
and 335 miles west of Fairbanks.
In 1990 Tanana Chiefs Conference completed a timber inventory of the ANCSA Native village lands
around Kaltag. The village corporation, GANA-A'YOO, Limited, owns approximately 115,000 acres,
of which approximately 23,000 acres are forested, holding an estimated 47.835 million cubic feet of
saw timber and pole timber. Much of this material could be considered woody biomass suitable for
wood fueled heating systems. Doyon, Limited, the regional corporation, is the other major landowner
in the region, as indicated by Figure 1: Land Ownership Surrounding Kaltag, AK.
While these inventory figures indicate a substantial timber resource, sites supporting tree growth are
widely distributed and may be difficult to access because of the area characteristics and the lack of
existing roads. The Village is located along a major river system with expansive low elevation
wetlands, resulting in widely distributed higher elevation sites that support tree growth.
Figure 1: Land Ownership Surrounding Kaltag, AK
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 7
Figure 2: Biomass stock and annual allowable cut surrounding Kaltag, AK from TCC Inventory
The community of Kaltag also practices river logging. Dependability and volume of river-caught logs
have not been documented.
Community leaders in Kaltag suggested that firewood is the main residential heating fuel in Kaltag.
The current market price, determined by TCC, is $275 per cord. There are 62 homes in Kaltag, using
an estimated average of 5 – 7 cords per year.
If the projects described in this study were undertaken, the community of Kaltag would harvest up to
290 additional cords and/or up to 150 green tons of wood per year, increasing their annual volume
by about 50% from currently estimated usage.
Biomass Energy Operations and Maintenance
Biomass Harvest Plan
Wood cutting is a subsistence activity in almost all interior villages adjacent to forest land. This
subsistence resource must be carefully managed or biomass energy projects may be detrimental to
the Community.
If biomass harvests are unmanaged, the natural tendency is to harvest the most accessible wood
supply first, as illustrated below. The effect is increased scarcity and rising harvest cost, and,
consequently, biomass fuel costs, for both the project and household woodcutters. This puts
community members’ energy security and the project’s success at risk.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 8
The project’s success depends on a well-developed and executed Harvest Plan. The Harvest Plan
accounts for the biomass harvests over the project lifetime, at least 20 years. It may also designate
areas for Personal Use (household wood cutting). The Harvest Plan also describes how who is
responsible for executing the Harvest Plan, and how access will be managed. Please see figure below.
Because the project’s success is critically dependent on a Biomass Harvest Plan, the Consultant strongly
recommends developing this Plan prior to project development.
In Kaltag, harvest of Cottonwood for cordwood and/or Black Spruce for wood chips would not be
expected to interfere with the supply of personal-use firewood, since these species are not preferred
for home heating.
Figure 3: Illustration of Unmanaged Wood Harvesting Efforts
Figure 4: Illustration of Planned Wood Harvest by Harvest Area and Time Period.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 9
Operations Plan
In many Villages biomass boiler projects will
depend on collaboration among a variety of
entities, including contract wood cutters,
forest landowners, the boiler technician,
building owners and operators, and various
governmental entities.
A plan for collecting biomass, paying wood
suppliers, allocating costs among heat users,
and operating and maintaining the boiler
and heat distribution system is crucial to the
project’s success. Persons responsible for
each task must be identified.
Because the project’s success is critically
dependent on an Operations Plan, the
Consultant strongly recommends developing
this Plan prior to project development.
Community Facilities Information
The community buildings in Kaltag considered for
biomass heating are Tribal building, City Building,
Washateria/Water-plant, and Kaltag School. The
City and Tribal buildings are considered a cluster
and evaluated as a single heat plant. The Clinic,
Fire-hall, and Community Hall are adjacent to this
cluster, but were not considered for biomass
heating, for reasons discussed below.
Tribal Buildings
Tribal buildings include the Tribal Building.
Tribal Building
The Tribal Building also uses one (1) Buderus Boiler with a capacity of 120,000 btu/hr to heat about
3,500 sq. ft via hydronic baseboard heaters. The building has four zones. There is also an addition to
the North side of the building that houses the boiler room. While the addition to the North side does
not appear to be heated, it houses a separate boiler room that was observed to be extremely warm
inside. There also may be maintenance issues with the controls, as the consultant observed that the
boiler was firing even though it was over 65°F outside.
Figure 5: Kaltag Washateria
Figure 6: Kaltag community buildings. Washateria/ waterplant
(8), City Hall (14), Tribal Hall (15), Clinic (12), Community Hall
(13), Fire Hall (10), School (18).
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 10
City Buildings
City Buildings include the City Office, Washateria/Water-plant, Fire-hall, Community Hall, and
Clinic.
City Office
The City Building uses one (1) Buderus Boiler with a capacity of 106,000 btu/hr to heat 3,300 sq. ft.
The City Building used 775 gallons in FY 2012. The building was reportedly recently weatherized.
Washateria/Waterplant
The Washateria/Water-plant is a single heating system providing space and domestic hot water for
the Washateria as well as water heating for residences for a portion of uptown. The Washateria/
Water-plant is heated with three boilers: two (2) Weil McClain 76 model boilers, 416,000 BTU; and
one (1) Weil McClain 213,000 BTU boiler. Heat loads often require one large and the small boiler to
fire. The heat distribution system is in its second year of operation and is performing well.
The Washateria/Water-plant was operated by Tommy Neglaska at the time of consultant’s visit. Mr.
Neglaska meticulously maintained the facility and kept records of the fuel consumption. The fuel
consumption for 2012 follows:
Figure 7: Kaltag Washateria/ Waterplant Gallons of Fuel by Month
Community Hall
The Community Hall is heated only for events. It holds a Toyo-stove and a woodstove. Because it is
not heated regularly, it was not considered for biomass heating.
Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May TOTAL
131 77 232 220 330 687 654 919 792 812 561 381 5,796
Washateria/
Waterplant
(gallons fuel oil #1)
0
200
400
600
800
1000
Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr MayGallons fuel Oil #1 Kaltag Washateria/Waterplant
Gallons fuel oil by month
Series1
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 11
Firehall
The Fire-hall is usually rented out and used by the Iditarod Race Organizers. However, the City has
decided to close the Fire-hall this winter to reduce utility costs. Last year, the Fire-hall used 875
gallons of fuel oil. Because the Fire-hall is not expected to have any heat demand in the near future, it
was not considered for biomass heating.
Clinic
A new Clinic is planned in Kaltag. Given the biomass resource base and local climatic conditions, it is
strongly recommended that a biomass heating system, along with passive solar design, super-
insulation, and protected artic entry be considered for the building design.
This Clinic may also have the ability to cost-effectively integrate a District Heating system. The
Consultants recommend that the designers of the Clinic consider clustering heat loads when
designing the building. The location of the Clinic has already been chosen. Because a new Clinic is
planned in Kaltag, the existing Clinic was not considered for biomass heating.
School
The Kaltag School was not toured during this visit, but information was gathered from the YKSD
Facilities Department. The Kaltag School is a new school building with a newly engineered heating
system. The School has a separate boiler building housing five (5) fuel oil boilers. Over the past five
years, the School and adjacent buildings (such as teacher housing) have averaged 19,000 gallons per
year of oil. The heat is distributed via hydronic heat pipes, and converted to hot air for heating some
areas. Over the past five years, the average price per gallon was $3.10; AEA has projected the cost per
gallon in 2012 to be $4.10 per gallon.
Mr. Bourne of YKSD Facilities Department stressed the important of reliability from any heating
source.
Building Name Tribal
Office City Office Washateria/
Waterplant School
Annual Gallons (Fuel Oil #1) 775 gal/yr 1,294 gal/ yr 5,796 19,000 gal/ yr
Building Usage
During
workdays
only. No
weekends.
During
workdays only.
No weekends.
Seven days
per week.
During the
School year
Heat Transfer Mechanism Hydronic Hydronic Hydronic Hydronic
Heating infrastructure need
replacement? No No Unknown No
Maximum cords to heat the
building 17 49 160
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 12
Recommended technology and fuel requirements
The suggested system design for all three projects is a pre-fabricated, modular, containerized wood
biomass boiler unit. The suggested unit has been shown to be reliable and highly efficient. Because it
is modular, it has a lower installation cost and offers financing advantages. Either cordwood or wood
chips may be recommended as the system fuel, as described below.
From initial surveys of the Kaltag area, it appears that Cottonwood and Black Spruce are relatively
abundant species, although neither is preferred for personal-use cordwood for home heating.
Cordwood could be manufactured from Cottonwood, using chainsaws and a log splitter. Chips could
be manufactured from Black Spruce trees using a hand-fed chipper. If the harvest were properly
planned, use of these fuels would not threaten the supply of cordwood available for home heating.
Washateria/Waterplant
For the Washateria/ Water-plant, a containerized HELE (high efficiency, low emissions) cordwood
boiler is suggested. These types of systems are produced by GARN, TARM USA and others. These
units have 120,000 – 700,000 BTU/hr output capacity and store 415,000 or more BTU in hot water
tanks. One such unit, the GarnPac, has an output of about 350,000 BTU output and is currently being
employed in Thorne Bay.
This type of system is recommended because it has demonstrated reliability, uses an accessible fuel
(cordwood), and meets the heat load requirements of the Washateria/ Water-plant.
Other communities operating HELE cordwood boilers of a similar size, such as Dot Lake and Ionia,
report 2 cordwood stokings per day and 0.125 – 0.5 FTE 1 (Full-time equivalent employee) per boiler.
The Washateria/ Water-plant heat load is an estimated 150,000 – 275,000 btu/hr during the heating
season. Correct boiler sizing could be subject to further feasibility study.
For the purposes of this study, Dalson Energy modeled a biomass boiler capacity of 350,000 btu/hr
for the Washateria / Water-plant, serving 90% of the heat load.
Tribal and City Office Cluster
The Tribal and City Office Cluster load is quite small, requiring only the equivalent of about 17 cords
per year. Because the existing fuel oil usage is relatively small, the amount of savings from using
biomass (cordwood) are also relatively small.
The City and Tribal Office Cluster heat load is an estimated 50,000 – 105,000 btu/hr during the
heating season. Correct boiler sizing could be subject to further feasibility study.
For the purposes of this study, Dalson Energy modeled a pre-fabricated, containerized cordwood
boiler with a capacity of 120,000 btu/hr for the Tribal & City Office Cluster.
1 Nicholls, David. 2009. Wood energy in Alaska—case study evaluations of selected facilities. Gen. Tech. Rep. PNW-GTR-793. Portland,
OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 33 p.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 13
Kaltag School
The Kaltag School’s heat load is the largest of any of the community buildings. The heat load is an
estimated 200,000 btu/hr – 1,000,000 btu/hr.
The Kaltag School could employ a cordwood boiler system, a small wood chip system, or a wood
pellet system, depending on user’s preferences and access to biomass. Pellets would need to be
imported from outside the Village, but woodchips and cordwood could be procured from local
forests given an effective Harvesting Plan and investment in the appropriate equipment.
One challenge is that wood chip systems are operationally more complex than wood pellet or
cordwood systems, because they require multi-step wood fuel manufacturing. They also require
more machinery to process fuel. To produce woodchips, the Community would need an effective
way of harvesting, processing, and handling chips. Trees could be hand-felled and hand-fed into a
grinder and then automatically fed into a storage bin or chip van. Saw log or cordwood quality
segments could be separated and merchandised separately. Screens would be utilized to control chip
size and consistency. Additionally, woodchip storage would need to be managed with a bobcat or
other loading device to improve airflow and decrease moisture content.
While the chip processing and handling infrastructure is more expensive, the Community would
benefit from automated boiler operation and reduced operating costs, as well decreased pressure on
the Cordwood supply and access to a wider range of tree species and sizes.
If a cordwood boiler were employed, the system could use up to 160 cords per year of Cottonwood
and other available species.
If a wood chip boiler were employed, the system could use up to 250 tons of 40% MC chips.
To complete this prefeasibility analysis, the Consultant has chosen a representational boiler, a 350
BTU/hr containerized cordwood boiler. Running at maximum capacity, this boiler would offset only
a portion of the load of the School (estimated 40-50%). However, with an effective fuel harvesting and
operations plan, it would probably be the most reliable wood heating system available to the
Community. Also, an effective fuel harvesting and procurement plan could prioritize fuels that do
not interfere with cordwood gathering.
The buildings’ existing Fuel Oil infrastructure would be retained to meet peak demand and as back
up in every project building.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 14
Initial project development costs for a wood heating system costs may include:
Capital costs: boiler, hydronic pipe and other hardware, wood storage shelter, fuel-handling
equipment, shipping costs.
Engineering: storage design, plumbing integration, fuel-handling infrastructure.
Permitting: no permits required. In lieu of permits, all regulations must be met.
Installation: Site work, installation, and integration into existing system.
Fuel storage: storage building, firewood chutes, or preparation of existing storage room.
System building: (if required).
Ongoing operational costs may include:
Financing: Principal and interest payments from project debt, or profits from project equity
investment. In Village projects, financing costs likely do not apply.
Wood fuel purchases.
Amortization costs: capital equipment and other infrastructure.2 When projects are grant
financed, amortization does not apply.
Operations and Maintenance (O&M) labor.
Fossil fuel purchases and labor.3
Initial investment
The City and Tribal Office Cluster has an estimated Capitalization Cost of $249,000.
The Waterplant/ Washateria has an estimated Capitalization Cost of $257,000.
The Kaltag School has an estimated Capitalization Cost of $277,000. This is for a system that will
offset 40 % of the School’s fuel oil consumption.
2 Cash and accrual basis are two different accounting methods for project investment. Accrual accounting amortizes
project investment over the project lifetime (“lifecycle costs”). This method results in monies to reinvest in new
equipment at the end of its lifetime. Cash basis is simply on the dollars spent to operate, maintain, and finance the project.
8 The existing oil heat infrastructure will be retained for supplement heat and back-up. Therefore, the fossil fuel system
has ongoing O&M costs, albeit lower than if used as the primary heat source.
Fuel Consumption
Assumptions:
16.00 MMBTU/ Cord Cottonwood
0.1350 MMBTU per gallon Oil #1
10.32 MMBTU per ton of chips
Annual
Gallons
Annual
MMBTU
Annual Cords
(maximum)
Annual wood chip
demand
(maximum)
Cluster: City and Tribal Office 2,069 279 17 27
Washateria/ Waterplant 5,800 783 49 76
School 19,000 2,565 160 249
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 15
See charts below for cost estimates and sources. Full feasibility analysis and/or bids would provide
more detailed numbers.
City & Tribal Office Cluster
Biomass System
Rating -- Btu/hr 120,000
Btu stored 160,000
footnote notes
$ 7,560 (14 cds @ 20 sq. ft. / cd.)
Pre-Fabricated Boiler System
Base price A 93,000$
Shipping to hub B 20,000$
Bush delivery B 10,000$
Plumbing and electrical B 2,500$
B 4,500$
Building integration B 30,000$ $15,000 per building
Heat loop 6,600$ $33 per ft, 200 ft.
Subtotal-B&E Costs 167,560$
Contingency -- 20% 33,512$
Grand Total 201,072$
Soft Costs $
B 16,086$ 8% of B&E
B 12,064$ 6% of B&E
B pre-approved
Equipment Commissioning and Training B 4,000$
Construction Management B 16,086$ 8% B&E
Subtotal -- Soft Costs 48,236$
Recommended Project Budget -- Design and Construction Co 249,308$
footnote
A Based on quotes from viable suppliers
B Estimate
A/E Design Services
Fire Marshall Plan Review
Building and Equipment Costs (B&E) $
Fuel Storage Building
(fabricated building, gravel pad, $27/sf)
Site Prep
Project Management
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 16
Waterplant/ Washateria
Biomass System
Rating -- Btu/hr 350,000
Btu stored 415,000
footnote notes
$ 21,060 (39 cds @ 20 sq. ft. / cd.)
Pre-Fabricated Boiler System
Base price A 100,000$
Shipping to Hub B 20,000$
Bush Delivery B 10,000$
Plumbing and electrical B 2,500$
B 4,500$
Integration (Wash + Waterplant)B 15,000$
Subtotal-B&E Costs 173,060$
Contingency -- 20% 34,612$
Grand Total 207,672$
Soft Costs $
B 16,614$ 8% of B&E
B 12,460$ 6% of B&E
B pre-approved
Equipment Commissioning and Training B 4,000$
Construction Management B 16,614$ 8% B&E
Subtotal -- Soft Costs 49,688$
Recommended Project Budget -- Design and Construction Cost 257,360$
footnote
A Based on quotes from viable suppliers
B Estimate
Fire Marshall Plan Review
Building and Equipment Costs (B&E) $
Fuel Storage Building
(fabricated building, gravel pad, $27/sf)
Site Prep
Project Management
A/E Design Services
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 17
Kaltag School
Initial investment: Kaltag School
Biomass System
Rating -- Btu/hr 350,000
Btu stored 415,000
footnote notes
C $ 24,300 (45 cds @ 20 sq. ft. / cd.)
Pre-Fabricated Boiler System
Base price A 100,000$
Shipping to Hub B 20,000$
Bush Delivery B 10,000$
Plumbing and electrical B 2,500$
B 4,500$
Integration B 15,000$
Subtotal-B&E Costs 176,300$
Contingency -- 20% 35,260$
Grand Total 211,560$
Soft Costs $
15,000$
B 16,925$ 8% of B&E
B 12,694$ 6% of B&E
B pre-approved
Equipment Commissioning and Training B 4,000$
Construction Management B 16,925$ 8% B&E
Subtotal -- Soft Costs 65,543$
Recommended Project Budget -- Design and Construction Costs 277,103$
footnote
A Based on quotes from viable suppliers
B Estimate
C 64 cords total consumption throughout year. Inventory management with 19 cords stored offsite.
A/E Design Services
Fire Marshall Plan Review
Building and Equipment Costs (B&E) $
Fuel Storage Building
(fabricated building, gravel pad, $27/sf)
Site Prep
Fuel procurement plan
Project Coordination
18
Financial Analysis
The following financial analyses make use of AEA’s financial Benefit: Cost model.
Please note that the market price for household cordwood is reportedly determined by the TCC price,
currently $300/cord. In the course of modeling this project, Dalson Energy has used $250/cord to
represent the price per cord of Cottonwood and other non-preferred species, which is estimated to be
more accessible than White Spruce and other preferred species.
For each building, Dalson Energy estimated the percentage of heating oil offset by considering a
heating degree day model of the buildings’ energy load. For the Kaltag School, a single 350,000
btu/hr boiler was assumed to offset 40-50% of the School’s heating oil.
19
Operating Costs & Annual Savings
City and Tribal Office
Project Description
Community
Nearest Fuel Community
Region
RE Technology
Project ID
Applicant Name
Project Title
Category
Results
NPV Benefits $71,126
NPV Capital Costs $242,046
B/C Ratio 0.29
NPV Net Benefit ($170,921)
Performance Unit Value
Displaced Electricity kWh per year -
Displaced Electricity total lifetime kWh -
Displaced Petroleum Fuel gallons per year 6,003
Displaced Petroleum Fuel total lifetime gallons 64,685
Displaced Natural Gas mmBtu per year -
Displaced Natural Gas total lifetime mmBtu -
Avoided CO2 tonnes per year 61
Avoided CO2 total lifetime tonnes 657
Proposed System Unit Value
Capital Costs $249,308$
Project Start year 2013
Project Life years 25
Displaced Electric kWh per year -
Displaced Heat gallons displaced per year 1,655
Displaced Transportation gallons displaced per year 0.00
Renewable Generation O&$ per BTU
Electric Capacity kW 0
Electric Capacity Factor %0
Heating Capacity Btu/hr.120,000
Heating Capacity Factor %86
Base System Unit Value
Diesel Generator O&M $ per kWh 0.033$
Diesel Generation Efficien kWh per gallon
Parameters Unit Value
Heating Fuel Premium $ per gallon 2.00$
Transportation Fuel Premi $ per gallon 1.00$
Discount Rate % per year 3%
Crude Oil $ per barrel EIA Mid
Natural Gas $ per mmBtu ISER - Mid
Kaltag
Rural
Woody biomass heat
Village of Kaltag
Kaltag City and Tribal Hall Wood Heat
20
Annual Savings (Costs)Units 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
Entered Value Project Capital Cost $ per year 249,308$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$
Electric Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Heating Saving (Costs)$ per year ($138)$3,317 $3,391 $3,498 $3,648 $3,786 $3,915 $4,029 $4,130 $4,199 $4,269 $4,325 $4,372
Transportation Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Total Savings (Costs)$ per year ($138)$3,317 $3,391 $3,498 $3,648 $3,786 $3,915 $4,029 $4,130 $4,199 $4,269 $4,325 $4,372
Net Benefit $ per year ($249,446)$3,317 $3,391 $3,498 $3,648 $3,786 $3,915 $4,029 $4,130 $4,199 $4,269 $4,325 $4,372
Annual Savings (Costs)Units 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 PV
Entered Value Project Capital Cost $ per year -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ $242,046
Electric Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Heating Saving (Costs)$ per year $4,406 $4,420 $4,413 $4,392 $4,354 $4,296 $4,220 $4,144 $4,062 $3,988 $9,332 $9,202 $71,126
Transportation Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Total Savings (Costs)$ per year $4,406 $4,420 $4,413 $4,392 $4,354 $4,296 $4,220 $4,144 $4,062 $3,988 $9,332 $9,202 $71,126
Net Benefit $ per year $4,406 $4,420 $4,413 $4,392 $4,354 $4,296 $4,220 $4,144 $4,062 $3,988 $9,332 $9,202 ($170,921)
Heating Units 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
Renewable Heat gallons displaced 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655
Entered Value Renewable Heat Scheduled Rep$ per year 300$ 303$ 306$ 309$ 312$ 315$ 318$ 322$ 325$ 328$ 331$ 335$ 338$
Entered Value Renewable Heat O&M $ per year 7,563$ 7,639$ 7,715$ 7,792$ 7,870$ 7,949$ 8,028$ 8,109$ 8,190$ 8,272$ 8,354$ 8,438$ 8,522$
Entered Value Renewable Fuel Use Quantity (Bcords 14 14 14 14 14 14 14 14 14 14 14 14 14
Entered Value Renewable Fuel Cost $ per unit $250.00 $253 $255 $258 $260 $263 $265 $268 $271 $273 $276 $279 $282
Total Renewable Fuel Cost $ per year 3,491$ 3,535$ 3,570$ 3,606$ 3,642$ 3,679$ 3,715$ 3,752$ 3,790$ 3,828$ 3,866$ 3,905$ 3,944$
Remaining Fuel Oil (supplemen gallons remaining 414 414 414 414 414 414 414 414 414 414 414 414 414
Total Fuel Cost (supplement)$ per year 2,567$ 2,608$ 2,642$ 2,682$ 2,730$ 2,777$ 2,822$ 2,864$ 2,904$ 2,938$ 2,973$ 3,005$ 3,036$
Proposed Heat Cost $ per year 13,921$ 14,085$ 14,233$ 14,389$ 14,555$ 14,719$ 14,884$ 15,047$ 15,209$ 15,366$ 15,525$ 15,683$ 15,840$
Fuel Use gallons per year 2,069 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609
Fuel Cost $ per gallon $6.20 $6.30 $6.38 $6.48 $6.60 $6.71 $6.82 $6.92 $7.02 $7.10 $7.18 $7.26 $7.34
Entered Value Fuel Scheduled Repairs $ per year 200$ 202$ 204$ 206$ 208$ 210$ 212$ 214$ 217$ 219$ 221$ 223$ 225$
Entered Value Fuel O&M $ per year 750$ 758$ 765$ 773$ 780$ 788$ 796$ 804$ 812$ 820$ 828$ 837$ 845$
Fuel Cost $ per year 12,833$ 16,442$ 16,655$ 16,909$ 17,214$ 17,508$ 17,790$ 18,058$ 18,310$ 18,526$ 18,744$ 18,948$ 19,141$
Base Heating Cost $ per year 13,783$ 17,402$ 17,624$ 17,887$ 18,203$ 18,506$ 18,799$ 19,076$ 19,339$ 19,565$ 19,793$ 20,008$ 20,212$
Proposed
Base
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 21
Heating Units 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 PV
Renewable Heat gallons displaced 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655 1,655
Entered Value Renewable Heat Scheduled Rep$ per year 341$ 345$ 348$ 352$ 355$ 359$ 362$ 366$ 370$ 373$ 377$ 381$ $5,813
Entered Value Renewable Heat O&M $ per year 8,607$ 8,694$ 8,780$ 8,868$ 8,957$ 9,047$ 9,137$ 9,228$ 9,321$ 9,414$ 9,508$ 9,603$ $146,536
Entered Value Renewable Fuel Use Quantity (Bcords 14 14 14 14 14 14 14 14 14 14 14 14
Entered Value Renewable Fuel Cost $ per unit $285 $287 $290 $293 $296 $299 $302 $305 $308 $311 $314 $317
Total Renewable Fuel Cost $ per year 3,983$ 4,023$ 4,063$ 4,104$ 4,145$ 4,187$ 4,228$ 4,271$ 4,313$ 4,357$ 4,400$ 4,444$
Remaining Fuel Oil (supplemen gallons remaining 414 414 414 414 414 414 414 414 414 414 414 414
Total Fuel Cost (supplement)$ per year 3,065$ 3,090$ 3,111$ 3,129$ 3,145$ 3,158$ 3,167$ 3,176$ 3,185$ 3,195$ 4,227$ 4,227$
Proposed Heat Cost $ per year 15,997$ 16,151$ 16,303$ 16,454$ 16,603$ 16,750$ 16,895$ 17,041$ 17,188$ 17,339$ 18,512$ 18,655$ $272,203
Fuel Use gallons per year 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609 2,609
Fuel Cost $ per gallon $7.41 $7.47 $7.52 $7.56 $7.60 $7.63 $7.65 $7.68 $7.70 $7.72 $10.21 $10.21
Entered Value Fuel Scheduled Repairs $ per year 228$ 230$ 232$ 235$ 237$ 239$ 242$ 244$ 246$ 249$ 251$ 254$ $3,875
Entered Value Fuel O&M $ per year 854$ 862$ 871$ 879$ 888$ 897$ 906$ 915$ 924$ 934$ 943$ 952$ $14,531
Fuel Cost $ per year 19,322$ 19,479$ 19,613$ 19,731$ 19,832$ 19,910$ 19,966$ 20,026$ 20,080$ 20,145$ 26,650$ 26,650$ $324,923
Base Heating Cost $ per year 20,403$ 20,571$ 20,715$ 20,845$ 20,957$ 21,046$ 21,114$ 21,186$ 21,250$ 21,327$ 27,845$ 27,856$ $343,329
Proposed
Base
22
Washateria/ Waterplant
Project Description
Community
Nearest Fuel Community
Region
RE Technology
Project ID
Applicant Name
Project Title
Category
Results
NPV Benefits $212,483
NPV Capital Costs $249,864
B/C Ratio 0.85
NPV Net Benefit ($37,381)
Performance Unit Value
Displaced Electricity kWh per year -
Displaced Electricity total lifetime kWh -
Displaced Petroleum Fuel gallons per year 6,003
Displaced Petroleum Fuel total lifetime gallons 145,000
Displaced Natural Gas mmBtu per year -
Displaced Natural Gas total lifetime mmBtu -
Avoided CO2 tonnes per year 61
Avoided CO2 total lifetime tonnes 1,472
Proposed System Unit Value
Capital Costs $257,360$
Project Start year 2013
Project Life years 25
Displaced Electric kWh per year -
Displaced Heat gallons displaced per year 5,220
Displaced Transportation gallons displaced per year 0.00
Renewable Generation O&$ per BTU
Electric Capacity kW 0
Electric Capacity Factor %0
Heating Capacity Btu/hr.350,000
Heating Capacity Factor %86
Base System Unit Value
Diesel Generator O&M $ per kWh 0.033$
Diesel Generation Efficien kWh per gallon
Parameters Unit Value
Heating Fuel Premium $ per gallon 2.00$
Transportation Fuel Premi $ per gallon 1.00$
Discount Rate % per year 3%
Crude Oil $ per barrel EIA Mid
Natural Gas $ per mmBtu ISER - Mid
Washateria/ Waterplant
Kaltag
Rural
Woody biomass heat
Village of Kaltag
23
Annual Savings (Costs)Units 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
Entered Value Project Capital Cost $ per year 257,360$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$
Electric Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Heating Saving (Costs)$ per year $9,455 $9,746 $9,940 $10,213 $10,589 $10,937 $11,262 $11,554 $11,813 $11,997 $12,182 $12,338 $12,468
Transportation Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Total Savings (Costs)$ per year $9,455 $9,746 $9,940 $10,213 $10,589 $10,937 $11,262 $11,554 $11,813 $11,997 $12,182 $12,338 $12,468
Net Benefit $ per year ($247,905)$9,746 $9,940 $10,213 $10,589 $10,937 $11,262 $11,554 $11,813 $11,997 $12,182 $12,338 $12,468
Annual Savings (Costs)Units 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 PV
Entered Value Project Capital Cost $ per year -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ $249,864
Electric Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Heating Saving (Costs)$ per year $12,572 $12,626 $12,628 $12,600 $12,533 $12,417 $12,256 $12,099 $11,926 $11,774 $24,504 $24,216 $212,483
Transportation Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Total Savings (Costs)$ per year $12,572 $12,626 $12,628 $12,600 $12,533 $12,417 $12,256 $12,099 $11,926 $11,774 $24,504 $24,216 $212,483
Net Benefit $ per year $12,572 $12,626 $12,628 $12,600 $12,533 $12,417 $12,256 $12,099 $11,926 $11,774 $24,504 $24,216 ($37,381)
Heating Units 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
Renewable Heat gallons displ 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220
Entered Value Renewable Heat Scheduled Rep$ per year 500$ 505$ 510$ 515$ 520$ 526$ 531$ 536$ 541$ 547$ 552$ 558$ 563$ 569$
Entered Value Renewable Heat O&M $ per year 12,361$ 12,485$ 12,610$ 12,736$ 12,863$ 12,992$ 13,122$ 13,253$ 13,385$ 13,519$ 13,654$ 13,791$ 13,929$ 14,068$
Entered Value Renewable Fuel Use Quantity (Bcords 44 44 44 44 44 44 44 44 44 44 44 44 44 44
Entered Value Renewable Fuel Cost $ per unit $250.00 $253 $255 $258 $260 $263 $265 $268 $271 $273 $276 $279 $282 $285
Total Renewable Fuel Cost $ per year 11,011$ 11,121$ 11,232$ 11,345$ 11,458$ 11,573$ 11,688$ 11,805$ 11,923$ 12,043$ 12,163$ 12,285$ 12,407$ 12,531$
Remaining Fuel Oil (supplementgallons rema 580 580 580 580 580 580 580 580 580 580 580 580 580 580
Total Fuel Cost (supplement)$ per year 3,597$ 3,655$ 3,702$ 3,759$ 3,827$ 3,892$ 3,955$ 4,014$ 4,070$ 4,119$ 4,167$ 4,212$ 4,255$ 4,295$
Proposed Heat Cost $ per year 27,469$ 27,766$ 28,054$ 28,354$ 28,668$ 28,982$ 29,296$ 29,608$ 29,920$ 30,227$ 30,536$ 30,846$ 31,155$ 31,464$
Fuel Use gallons per y 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800
Fuel Cost $ per gallon 6.20$ 6.30$ 6.38$ 6.48$ 6.60$ 6.71$ 6.82$ 6.92$ 7.02$ 7.10$ 7.18$ 7.26$ 7.34$ 7.41$
Entered Value Fuel Scheduled Repairs $ per year 200$ 202$ 204$ 206$ 208$ 210$ 212$ 214$ 217$ 219$ 221$ 223$ 225$ 228$
Entered Value Fuel O&M $ per year 750$ 758$ 765$ 773$ 780$ 788$ 796$ 804$ 812$ 820$ 828$ 837$ 845$ 854$
Fuel Cost $ per year 35,974$ 36,552$ 37,025$ 37,589$ 38,269$ 38,921$ 39,550$ 40,143$ 40,705$ 41,185$ 41,669$ 42,123$ 42,553$ 42,954$
Base Heating Cost $ per year 36,924$ 37,512$ 37,994$ 38,568$ 39,257$ 39,919$ 40,558$ 41,162$ 41,734$ 42,224$ 42,719$ 43,183$ 43,623$ 44,035$
Proposed
Base
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 24
Heating Units 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 PV
Renewable Heat gallons displ 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220 5,220
Entered Value Renewable Heat Scheduled Rep$ per year 569$ 575$ 580$ 586$ 592$ 598$ 604$ 610$ 616$ 622$ 629$ 635$ $9,688
Entered Value Renewable Heat O&M $ per year 14,068$ 14,209$ 14,351$ 14,494$ 14,639$ 14,786$ 14,933$ 15,083$ 15,234$ 15,386$ 15,540$ 15,695$ $239,497
Entered Value Renewable Fuel Use Quantity (Bcords 44 44 44 44 44 44 44 44 44 44 44 44
Entered Value Renewable Fuel Cost $ per unit $285 $287 $290 $293 $296 $299 $302 $305 $308 $311 $314 $317
Total Renewable Fuel Cost $ per year 12,531$ 12,657$ 12,783$ 12,911$ 13,040$ 13,171$ 13,302$ 13,435$ 13,570$ 13,705$ 13,843$ 13,981$
Remaining Fuel Oil (supplemen gallons rema 580 580 580 580 580 580 580 580 580 580 580 580
Total Fuel Cost (supplement)$ per year 4,295$ 4,330$ 4,360$ 4,386$ 4,409$ 4,426$ 4,439$ 4,452$ 4,464$ 4,478$ 5,925$ 5,925$
Proposed Heat Cost $ per year 31,464$ 31,771$ 32,075$ 32,378$ 32,681$ 32,980$ 33,279$ 33,580$ 33,883$ 34,192$ 35,936$ 36,236$ $535,479
Fuel Use gallons per y 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800 5,800
Fuel Cost $ per gallon 7.41$ 7.47$ 7.52$ 7.56$ 7.60$ 7.63$ 7.65$ 7.68$ 7.70$ 7.72$ 10.21$ 10.21$
Entered Value Fuel Scheduled Repairs $ per year 228$ 230$ 232$ 235$ 237$ 239$ 242$ 244$ 246$ 249$ 251$ 254$ $3,875
Entered Value Fuel O&M $ per year 854$ 862$ 871$ 879$ 888$ 897$ 906$ 915$ 924$ 934$ 943$ 952$ $14,531
Fuel Cost $ per year 42,954$ 43,304$ 43,600$ 43,864$ 44,088$ 44,261$ 44,387$ 44,520$ 44,638$ 44,783$ 59,245$ 59,245$ $729,556
Base Heating Cost $ per year 44,035$ 44,396$ 44,703$ 44,978$ 45,213$ 45,397$ 45,535$ 45,679$ 45,809$ 45,966$ 60,440$ 60,452$ $747,962
Proposed
Base
25
Kaltag School
Project Description
Community
Nearest Fuel Community
Region
RE Technology
Project ID
Applicant Name
Project Title
Category
Results
NPV Benefits $414,583
NPV Capital Costs $269,032
B/C Ratio 1.54
NPV Net Benefit $145,551
Performance Unit Value
Displaced Electricity kWh per year -
Displaced Electricity total lifetime kWh -
Displaced Petroleum Fuel gallons per year 6,003
Displaced Petroleum Fuel total lifetime gallons 475,000
Displaced Natural Gas mmBtu per year -
Displaced Natural Gas total lifetime mmBtu -
Avoided CO2 tonnes per year 61
Avoided CO2 total lifetime tonnes 4,821
Proposed System Unit Value
Capital Costs $277,103$
Project Start year 2013
Project Life years 25
Displaced Electric kWh per year -
Displaced Heat gallons displaced per year 7,600
Displaced Transportation gallons displaced per year 0.00
Renewable Generation O&$ per BTU
Electric Capacity kW 0
Electric Capacity Factor %0
Heating Capacity Btu/hr.350,000
Heating Capacity Factor %86
Base System Unit Value
Diesel Generator O&M $ per kWh 0.033$
Diesel Generation Efficien kWh per gallon
Parameters Unit Value
Heating Fuel Premium $ per gallon 2.00$
Transportation Fuel Premi $ per gallon 1.00$
Discount Rate % per year 3%
Crude Oil $ per barrel EIA Mid
Natural Gas $ per mmBtu ISER - Mid
Kaltag School
Kaltag
Rural
Woody biomass heat
Village of Kaltag
26
Units 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
Project Capital Cost $ per year 277,103$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$
Electric Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Heating Saving (Costs)$ per year $19,196 $19,675 $20,011 $20,465 $21,068 $21,632 $22,162 $22,644 $23,080 $23,406 $23,735 $24,022 $24,273
Transportation Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Total Savings (Costs)$ per year $19,196 $19,675 $20,011 $20,465 $21,068 $21,632 $22,162 $22,644 $23,080 $23,406 $23,735 $24,022 $24,273
Net Benefit $ per year ($257,907)$19,675 $20,011 $20,465 $21,068 $21,632 $22,162 $22,644 $23,080 $23,406 $23,735 $24,022 $24,273
Units 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 PV
Project Capital Cost $ per year -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ -$ $269,032
Electric Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Heating Saving (Costs)$ per year $24,484 $24,625 $24,691 $24,712 $24,678 $24,574 $24,405 $24,242 $24,056 $23,902 $42,504 $42,153 $414,583
Transportation Savings (Costs)$ per year $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0
Total Savings (Costs)$ per year $24,484 $24,625 $24,691 $24,712 $24,678 $24,574 $24,405 $24,242 $24,056 $23,902 $42,504 $42,153 $414,583
Net Benefit $ per year $24,484 $24,625 $24,691 $24,712 $24,678 $24,574 $24,405 $24,242 $24,056 $23,902 $42,504 $42,153 $145,551
Heating Units 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
Renewable Heat gallons displ 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600
Entered Value Renewable Heat Scheduled Rep$ per year 500$ 505$ 510$ 515$ 520$ 526$ 531$ 536$ 541$ 547$ 552$ 558$ 563$
Entered Value Renewable Heat O&M $ per year 12,361$ 12,485$ 12,610$ 12,736$ 12,863$ 12,992$ 13,122$ 13,253$ 13,385$ 13,519$ 13,654$ 13,791$ 13,929$
Entered Value Renewable Fuel Use Quantity (Bcords 64 64 64 64 64 64 64 64 64 64 64 64 64
Entered Value Renewable Fuel Cost $ per unit $250 $253 $255 $258 $260 $263 $265 $268 $271 $273 $276 $279 $282
Total Renewable Fuel Cost $ per year 16,031$ 16,192$ 16,353$ 16,517$ 16,682$ 16,849$ 17,017$ 17,188$ 17,360$ 17,533$ 17,708$ 17,886$ 18,064$
Remaining Fuel Oil (supplemen gallons rema 11400 11400 11400 11400 11400 11400 11400 11400 11400 11400 11400 11400 11400
Total Fuel Cost (supplement)$ per year 70,708$ 71,844$ 72,773$ 73,882$ 75,218$ 76,499$ 77,735$ 78,903$ 80,006$ 80,950$ 81,902$ 82,794$ 83,638$
Proposed Heat Cost $ per year 99,600$ 101,026$ 102,246$ 103,649$ 105,283$ 106,865$ 108,405$ 109,879$ 111,292$ 112,549$ 113,817$ 115,029$ 116,194$
Fuel Use gallons per y 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000
Fuel Cost $ per gallon 6.20$ 6.30$ 6.38$ 6.48$ 6.60$ 6.71$ 6.82$ 6.92$ 7.02$ 7.10$ 7.18$ 7.26$ 7.34$
Entered Value Fuel Scheduled Repairs $ per year 200$ 202$ 204$ 206$ 208$ 210$ 212$ 214$ 217$ 219$ 221$ 223$ 225$
Entered Value Fuel O&M $ per year 750$ 758$ 765$ 773$ 780$ 788$ 796$ 804$ 812$ 820$ 828$ 837$ 845$
Fuel Cost $ per year 117,846$ 119,741$ 121,289$ 123,136$ 125,363$ 127,498$ 129,559$ 131,504$ 133,343$ 134,916$ 136,503$ 137,991$ 139,396$
Base Heating Cost $ per year 118,796$ 120,700$ 122,258$ 124,115$ 126,351$ 128,497$ 130,567$ 132,523$ 134,372$ 135,955$ 137,552$ 139,051$ 140,467$
Proposed
Base
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 27
Heating Units 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 PV
Renewable Heat gallons displ 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600 7,600
Entered Value Renewable Heat Scheduled Rep$ per year 569$ 575$ 580$ 586$ 592$ 598$ 604$ 610$ 616$ 622$ 629$ 635$ $9,688
Entered Value Renewable Heat O&M $ per year 14,068$ 14,209$ 14,351$ 14,494$ 14,639$ 14,786$ 14,933$ 15,083$ 15,234$ 15,386$ 15,540$ 15,695$ $239,497
Entered Value Renewable Fuel Use Quantity (Bcords 64 64 64 64 64 64 64 64 64 64 64 64
Entered Value Renewable Fuel Cost $ per unit $285 $287 $290 $293 $296 $299 $302 $305 $308 $311 $314 $317
Total Renewable Fuel Cost $ per year 18,245$ 18,428$ 18,612$ 18,798$ 18,986$ 19,176$ 19,367$ 19,561$ 19,757$ 19,954$ 20,154$ 20,355$
Remaining Fuel Oil (supplementgallons rema 11400 11400 11400 11400 11400 11400 11400 11400 11400 11400 11400 11400
Total Fuel Cost (supplement)$ per year 84,427$ 85,115$ 85,697$ 86,215$ 86,656$ 86,995$ 87,243$ 87,505$ 87,738$ 88,023$ 116,448$ 116,448$
Proposed Heat Cost $ per year 117,310$ 118,326$ 119,240$ 120,093$ 120,873$ 121,555$ 122,148$ 122,759$ 123,344$ 123,985$ 152,770$ 153,133$ $1,993,748
Fuel Use gallons per y 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000 19,000
Fuel Cost $ per gallon 7.41$ 7.47$ 7.52$ 7.56$ 7.60$ 7.63$ 7.65$ 7.68$ 7.70$ 7.72$ 10.21$ 10.21$
Entered Value Fuel Scheduled Repairs $ per year 228$ 230$ 232$ 235$ 237$ 239$ 242$ 244$ 246$ 249$ 251$ 254$ $3,875
Entered Value Fuel O&M $ per year 854$ 862$ 871$ 879$ 888$ 897$ 906$ 915$ 924$ 934$ 943$ 952$ $14,531
Fuel Cost $ per year 140,712$ 141,859$ 142,828$ 143,692$ 144,426$ 144,992$ 145,405$ 145,841$ 146,229$ 146,704$ 194,080$ 194,080$ $2,389,925
Base Heating Cost $ per year 141,794$ 142,951$ 143,931$ 144,806$ 145,551$ 146,128$ 146,553$ 147,001$ 147,400$ 147,887$ 195,274$ 195,286$ $2,408,331
Proposed
Base
28
Life cycle cost analysis (LCCA) for School
District:Yukon Koyukuk
School:Kaltag School
Project: Kaltag School chip boiler
Project No. NA
Study Period:20
Discount Rate: 3.50%
Alternative #1 (low)Alternative #2 (high)
Initial Investment Cost 332,195$ 398,508$
O&M and Repair Cost 588,985$ 914,198$
Replacement Cost 121,621$ 133,783$
Residual Value (78,655)$ (86,521)$
Total Life Cycle Cost 964,146$ 1,359,967$
GSF of Project 14,749 14,749
Initial Cost/ GSF 22.52$ 27.02$
LCC/ GSF 65.37$ 92.21$
Life Cycle Costs of Project Alternatives
YEAR 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Discount Rate 3.50%
Gen'l Inflation for O&M 1.50%
NPV
O&M $588,985 36,457$ 37,003$ 37,558$ 38,122$ 38,694$ 39,274$ 39,863$ 40,461$ 41,068$ 41,684$ 42,309$ 42,944$ 43,588$ 44,242$ 44,906$ 45,579$ 46,263$ 46,957$ 47,661$ 48,376$
Replacement $121,621 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 242,000$
Residual $78,655 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 156,508$
Discount Rate 3.50%398,508$
Gen'l Inflation for O&M 1.50%
NPV
O&M $914,198 40,102$ 40,102$ 40,704$ 41,314$ 41,934$ 42,563$ 43,201$ 43,849$ 44,507$ 45,175$ 45,852$ 46,540$ 47,238$ 47,947$ 48,666$ 49,396$ 50,137$ 50,889$ 51,652$ 52,427$
Replacement $133,783 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 266,200$
Residual $86,521 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 172,159$
Alt. 1
Alt 2
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 29
Summary of Financial Analysis
Estimated System Description
(abbreviated)
NPV Benefits PV B/C Ratio Simple
Payback
Kaltag City and
Tribal Office
One (2) 120,000 btu containerized
cordwood boiler
$71,000 $249,000 0.29 75
Kaltag
Washateria/
Waterplant
One 350,000 btu containerized
cordwood boiler
$212,400 $257,300 0.85 26.5
Kaltag School One 350,000 btu containerized
cordwood boiler, offsetting 40%
of fuel oil load
$414,500 $277,000 1.54 14.1
30
Conclusion
The village of Kaltag has significant opportunities for biomass heating, owing to the high cost of fuel
oil, community capacity for operating and maintaining heating systems, and existing heat loads that
could be adequately served by containerized biomass heating units. One of the most significant assets
to any potential biomass project is the dedicated services of maintenance personnel in the
Community.
There is strong technical feasibility for biomass heating of the Washateria and Kaltag School. All
projects could be heated by containerized cordwood boiler systems. All projects would require a new
fuel storage room. Additionally, the Kaltag School could be heated by a semi-automated wood chip
system instead of a cordwood boiler. The feasibility of this technology is subject to a Harvest Plan
and Operations Plan, as well as the preferences and capacity of the School administration and
maintenance personnel.
Of the projects identified, the Kaltag School appears to have the strongest financial feasibility, based
on amount of heating oil usage.
Additionally, because the project’s success is critically dependent on both Harvest and Operations
Plan, Dalson Energy strongly recommends developing these Plans prior to project development.
Finally, Dalson Energy recommends that a request in any grant application include funding for O&M
training from the system manufacturer for the first two years of operation. This training would
improve the efficiency of O&M and also offer the opportunity to train new maintenance personnel if
necessary.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 31
Consultant/Authors of this report:
Dalson Energy is a Renewable Energy Consulting and Technology Research firm based in
Anchorage. Dalson staff and partners have decades of experience in construction project
management, project development consulting and renewable energy technology research. Dalson
teams with licensed engineers, architects and designers in Alaska, Canada and Lower 48.
Dalson Energy has worked with Alaska Energy Authority, Alaska Center for Energy & Power,
University of Alaska Fairbanks, Washington State CTED (Community Trade & Economic
Development) and California Energy Commission on biomass energy technology research.
Dalson’s President, Thomas Deerfield, has been involved in biomass energy RD&D since 2001,
winning grants and managing projects with NREL (National Renewable Energy Labs), USFS (US
Forest Service), and CEC (California Energy Commission).
Thomas managed the field-testing of biomass CHP systems, including the first grid-connected
biomass gasification CHP system in the US. (2007). Thomas coordinated the design and creation of
the first prototype Biomass “Boiler in a Box” in Alaska, in 2010. That Garn-based system is now
deployed in Elim, in the Bering Sea region.
Thomas founded Shasta Energy Group (SEG), a 501c3 nonprofit, and managed wind energy research,
biomass energy feasibility studies, energy efficiency for buildings, and hydronic heating system
research design and development (RD&D). He also initiated a rural economic development think
tank and has engaged his writing skills to assist many other renewable energy project initiatives.
Wynne Auld is a Biomass Energy Specialist with Dalson Energy. She focuses on assessing and
developing woody biomass energy projects. Over the past few years, she has supported the business
development of integrated biomass energy campuses in Oregon and Idaho, especially related to their
energy initiatives. Her efforts have included marketing Campus biomass heating products to major
wholesalers and retail buyers, and planning and developing Campus sort yards and small-scale CHP.
Wynne also specializes in assisting commercial and municipal building managers in assessing the
feasibility of biomass heating, and implementing their projects. She works to ensure vibrant rural
communities through sustainable natural resource utilization.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 32
Supplement: Community Wood Heating Basics
Wood fuel as a heating option
When processed, handled, and combusted appropriately, wood fuels are
among the most cost-effective and reliable sources of heating fuel for
communities adjacent to forestland.
Compared to other heating energy fuels, wood fuels are characterized by
lower energy density and higher associated transportation and handling
costs. This low bulk density results in a shorter viable haul distance for
wood fuels compared to fossil fuels. However, this “limit” also creates an
advantage for local communities to utilize locally-sourced wood fuels,
while simultaneously retaining local energy dollars and exercising local
resource management.
Most Interior villages are particularly vulnerable to high energy prices
because the region has over 13,500 heating degree days 4 (HDD) per year –
160% of Anchorage’s HDDs, or 380% of Seattle’s HDDs. For many
communities, wood-fueled heating lowers fuel costs. For example,
cordwood sourced at $250 per cord is just 25% of the cost per MMBTU as
fuel oil #1 sourced at $7 per gallon. Besides the financial savings, local
communities benefit from the multiplier effect of circulating fuel money
in the community longer, more stable energy prices, job creation, and
more active forest management.
In all the Interior villages studied, the community’s wood supply and
demand are isolated from outside markets. Instead, the firewood market
is influenced by land ownership, existing forest management and ecological
conditions, local demand and supply, and the State of Alaska Energy
Assistance program.
The nature of wood fuels
Wood fuels are specified by moisture content, granulometry, energy density,
ash content, dirt and rocks, and fines and coarse particles. Each of these
characteristics affects the wood fuel’s handling characteristics, storage requirements, and combustion
process. Fuels are considered higher quality if they have lower moisture, ash, dirt, and rock contents;
consistent granulometry; and higher energy density.
4 Heating degree days are a metric designed to reflect the amount of energy needed to heat the
interior of a building. It is derived from measurements of outside temperature.
Figure 11: Wood pellets
Figure 10: Ground wood chips
used for mulch.
Figure 9: Wood briquettes, as a
substitute for cordwood. Cross
sections of these briquettes make
“wafers” which can be
automatically handled in biomass
boiler systems.
Figure 8: Cordwood
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 33
Many types of fuel quality can be used in wood heating projects so 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 interior Alaska must be designed around the availability of wood fuels. Some fuels can be
manufactured on site, such as cordwood, woodchips, and briquettes. The economic feasibility of
manufacturing on site can be determined by a financial assessment of the project; generally speaking,
larger projects offer more flexibility in terms of owning and operating harvesting and manufacturing
equipment, such as a wood chipper, than smaller projects.
It is unlikely that interior communities will be able to manufacture pellets, from both a financial,
operational, and fuel sourcing perspective. However, some interior communities may be able to
manufacture bricks or firelogs made from pressed wood material. These products can substitute for
cordwood in woodstoves and boilers, while reducing supply pressure on larger diameter trees than
are generally preferred for cordwood. At their simplest, brick presses are operated by hand, but
require chipped, dry fuel.
The basics of wood-fueled heating
Biomass heating systems fit into two typical categories: first, stoves and fireplaces that heat space
directly through convection and radiation by burning cordwood or pellets; second, hydronic systems
where the boiler burns cordwood, woodchips or pellets to heat liquid that is distributed to radiant
piping, radiators or heat exchangers. The heated liquid is distributed out to users, then returned to
the heat source for re-heating.
Hydronic systems are appropriate for serving individual buildings, or multiple buildings with
insulated piping called heat loops. Systems that serve multiple buildings are called district heating
loops. District heating is common in Europe, where larger boilers sometimes serve entire villages.
Biomass boilers are dependent on the compatibility of the chosen fuel, handling system, and
combustion system. General categories for typically available biomass fuel systems follow:
Batch load solid chunk boiler
Semi-automated or fully-automated chipped or ground biomass boilers
Fully-automated densified-fuel boiler, using pellets, bricks, or pucks
The system application is typically determined by size of heat load, available wood fuels, and
available maintenance personnel. General categories for heat load and wood fuel follow:
Loads < 1 MMBTU often use cordwood or pellet boilers
Loads > 1MMBTU often use pellet or woodchip boilers
Loads > 10MMTU often use hog-fuel (mixed ground wood)
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 34
Each wood fuel type has different handling requirements and is associated with different emission
profiles. For example, industrial systems greater than 10 MMBTU often require additional particulate
and emission controls because of the combustion properties of hog-fuel.
One category of system that is particularly appropriate for remote rural communities is cordwood
boilers. Cordwood boilers are batch-loaded with seasoned cordwood. A significant advantage to
cordwood is that very little infrastructure is needed to manufacture or handle the heating fuel. At its
most basic, cordwood can be “manufactured” with a chainsaw (or handsaw) and an ax, and residents
of rural communities are often accustomed to harvesting wood to heat their homes and shops.
Harvesting in most Interior villages is accomplished with ATV’s, river skiffs, sleds and dog teams,
and snow machines. Since cordwood systems are batch loaded by hand, they do not require
expensive automated material handling systems. Covered storage is required; such storage may be as
simple as an existing shed or a vented shipping container, rather than newly constructed storage
structures.
Challenges to cordwood include higher labor costs associated with manual loading. Some LEHE (low
efficiency, high emission) technologies such as Outdoor Wood Boilers (OWBs) have been criticized
for their high emissions and excessive wood consumption.
Cordwood systems are typically less than 1 MMBTU. However, if needed, some types of cordwood
boilers can be “cascaded,” meaning multiple boilers can meet heat demand as a single unit. However,
above a certain heat load, automated material handling and larger combustion systems become
viable.
Woodchip systems can be automated and thereby less labor intensive. However, woodchip systems
have significantly higher capital costs than both cordwood and pellet systems. Additionally, a
reliable stream of woodchips typically depends on a regionally active forest products manufacturing
base in the area, and active forest management. In most Interior communities, institutional heating
with woody biomass does not justify the purchase of log trucks, harvesting, handling, and
manufacturing equipment.
Pellet systems are the most automated systems, and have lower capital equipment costs than
woodchip systems. Lower costs are due to the smaller size of required infrastructure and simplified
handling and storage infrastructure. However, pellet fuel and other densified fuels tend to be more
expensive than other wood fuels, and require reliable access to pellet fuels.
For any system, the mass of feedstock required annually is determined by three parameters:
1) Building heat load
2) Net BTU content of the fuel
3) Efficiency of the boiler system
Building heat loads are determined by square footage, orientation and usage, as well as energy
efficiency factors such as insulation, moisture barriers and air leakage. Usage is particularly
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 35
important because it influences peak demand. For example, a community center which is used only a
few times per month for events, and otherwise kept at a storage temperature of 55 d. F, would have a
much different usage profile than a City Office which is fully occupied during the work day and
occasionally during evenings and weekends.
Building heat load analysis, including the building usage profile, is a particularly important part of
boiler right-sizing. A full feasibility analysis would conduct analyses that optimize the return on
investment (ROI) of systems. Typically, optimizing a biomass project’s ROI depends on a
supplementary heating system, such as an oil fired system, to meet peak demand and prevent short-
cycling of the biomass boiler. Full feasibility analyses may not be necessary for small projects,
especially for those employing cordwood boilers.
Biomass boiler efficiencies vary from 60% to 80%, depending on the manufacturer and the field
conditions of the equipment. The efficiency is strongly influenced by the BTU value and MC
(moisture content) of the fuel. Wood fuels with greater than 50% MC generally result in lower
efficiency systems, because some energy is used to drive off moisture from the fuel during the
combustion process. The reduction in energy output is mathematically equal; 50% MC generally
means 50% reduction in potential BTU value.
Like other combustion-based energy systems, woody biomass boilers produce emissions in the
combustion process. Compared to fossil fuels (coal, natural gas, and fuel oil), wood fuel emissions
are low in nitrogen oxides (NOx); carbon monoxide (CO, a product of incomplete combustion); sulfur
dioxide (SO2); and mercury (Hg). Because these compounds are all products of the forest and CO
would release naturally during the process of decay or wildfire, they generally do not concern
regulatory agencies. For emission control agencies, the real interest is particulate matter (PM)
emissions, which affect the air quality of human communities. Some wood systems are extremely
sophisticated, producing less than 0.06 lb/ MMBTU of PM.
Effective methods of PM control have been developed to remove most of the particles from the
exhaust air of wood combustion facilities. These include introduction of pre-heated secondary air,
highly controlled combustion, and PM collection devices.
Biomass boiler systems typically integrate a hot water storage tank, or buffer tank. The storage tank
prevents short cycling for automated boilers and improves efficiency and performance of batch-fired
systems, by allowing project buildings to draw on the boiler’s hot water long after the combustion
process. The GarnPac boiler design incorporates hot water storage into the boiler jacket itself, storing
approximately 2,200 gallons of hot water. Other boilers are typically installed with a separate hot
water storage tank.
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 36
Available wood heating technology
This section will focus generally on manufacturers of the types of technology discussed previously.
Cordwood Boilers
High Efficiency Low Emission (HELE) cordwood boilers are designed to burn cordwood fuel cleanly
and efficiently.
Cordwood used at the site will ideally be seasoned to 25% MC (moisture content) and meet the
dimensions specified by the chosen boiler. The actual amount of cordwood used would depend on
the buildings’ heat load profile, and the utilization of a fuel oil system as back up.
The following table lists three HELE cordwood boiler suppliers, all of which have units operating in
Alaska. Greenwood and TarmUSA, Inc. have a number of residential units operating in Alaska, and
several GARN boilers, manufactured by Dectra Corporation, are used in Tanana, Kasilof, Dot Lake,
Thorne Bay and other locations to heat homes, Washaterias, and Community Buildings.
HELE Cordwood Boiler Suppliers
Vendor Btu/hr ratings Supplier
Tarm
100,000 to 198,000 Tarm USA www.tarmusa.com
Greenwood 100,000 to 300,000 Greenwood www.greenwoodusa.com
GARN 250,000 to 700,000 Dectra Corp. www.dectra.net/garn
Note: These lists are representational of available systems, and are not inclusive.
Bulk Fuel Boilers
The term “bulk fuel” refers to systems that utilize wood chips, pellets, pucks, or other loose
manufactured fuel. Numerous suppliers of these boilers exist. Since this report focuses on village-
scale heating, the following chart outlines manufacturers of chip and pellet fuel boilers < 1 MMBTU.
HELE Bulk Fuel Boiler Suppliers
Vendor Btu/hr ratings Supplier
Froling 35,800 to 200,000; up to 4 can be cascaded as
a single unit at 800,000 BTU
Tarm USA www.tarmusa.com
KOB 512,000 – 1,800,000 BTU (PYROT model) Ventek Energy Systems Inc.
peter@ventekenergy.com
Binder
34,000 BTU – 34 MMBTU BINDER USA
contact@binder-boiler.com
Note: These lists are representational of available systems, and are not inclusive
Dalson Energy, Inc. – Kaltag Preliminary Feasibility Assessment 37
The following is a review of Community Facilities being considered for biomass heating. The
subsequent section will recommend a certain type of biomass heating technology, based on the
Facility information below.
District Heat Loops
District heat loops refers to a system for heating multiple buildings from a central power plant. The
heat is transported in a piping system to consumers in the form of hot water or steam.
These are the key factors that affect the cost of installing and operating a district heating system 5:
• Heat load density.
• Distance between buildings. Shorter distances between buildings will allow use of smaller
diameter (less expensive) pipes and lesser pumping costs.
• Permafrost. In the Interior, frozen soil could affect construction costs and project feasibility.
Aboveground insulated piping may be preferred to underground piping, such as the
cordwood system recently installed in Tanana, Alaska.
• Piping materials used. Several types of tubing are available for supply and return water. Pre-
insulated PEX tubing may be the preferred piping material for its flexibility and oxygen
barrier.
• District loop design. Water can be piped in one direction (i.e., one pipe enclosed) or two
directions (two pipes enclosed) for a given piping system. Design affects capital costs and
equality of heat distribution.
• Other considerations. Pump size, thermal load (BTUs per hour), water temperature, and
electrical use are other variables.
For the purposes of this study, the consultants have chosen to estimate the costs of district heat loops
using the RET Screen, a unique decision support tool developed with the contribution of numerous
experts from government, industry, and academia. The software, provided free-of-charge, can be
used worldwide to evaluate the energy production and savings, costs, emission reductions, financial
viability and risk for various types of Renewable-energy and Energy-efficient Technologies (RETs),
including district heat loops from biomass.
5 Nicholls, David; Miles, Tom. 2009. Cordwood energy systems for community heating in Alaska—an
overview. Gen. Tech. Rep. PNW-GTR-783. Portland, OR: U.S. Department of Agriculture, Forest
Service, Pacific Northwest Research
Station. 17 p.