HomeMy WebLinkAboutLower Kalskag Final Report 2013
Pre-Feasibility Assessment for
Integration of Wood-Fired Heating Systems
Draft Report
July 16, 2013
Village of Lower Kalskag
Lower Kalskag, Alaska
Presented by
CTA Architects Engineers
Nathan Ratz
R&M Engineering-Ketchikan, Inc.
Trevor Sande
For
Village of Lower Kalskag
In partnership with
Fairbanks Economic Development Corporation
Alaska Wood Energy Development Task Group
Funded by
Alaska Energy Authority and U.S. Forest Service
306 W. Railroad, Suite 104
Missoula, MT 59802
406.728.9522
www.ctagroup.com
CTA Project: FEDC_LWRKALSKAG
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers i
Draft Report July 16, 2013
TABLE OF CONTENTS
1.0 Executive Summary .................................................................................................... 1
2.0 Introduction ................................................................................................................. 4
3.0 Existing Building Systems ........................................................................................... 4
4.0 Energy Use ................................................................................................................. 5
5.0 Biomass Boiler Size .................................................................................................... 6
6.0 Wood Fuel Use ........................................................................................................... 7
7.0 Boiler Plant Location and Site Access ........................................................................ 9
8.0 Integration with Existing Heating Systems .................................................................. 9
9.0 Air Quality Permits .................................................................................................... 10
10.0 Wood Heating Options .............................................................................................. 10
11.0 Estimated Costs ........................................................................................................ 11
12.0 Economic Analysis Assumptions .............................................................................. 11
13.0 Results of Evaluation ................................................................................................ 12
14.0 Project Funding ......................................................................................................... 13
15.0 Summary ................................................................................................................... 13
16.0 Recommended Action ............................................................................................... 14
Appendixes
Appendix A: Preliminary Estimates of Probable Cost ................................................... 2 page
Appendix B: Cash Flow Analysis ................................................................................ 7 pages
Appendix C: Site Plan ................................................................................................... 1 page
Appendix D: Air Quality Report ................................................................................. 22 pages
Appendix E: Wood Fired Heating Technologies ......................................................... 4 pages
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 1 of 14
Draft Report July 16, 2013
1.0 Executive Summary
The following assessment was commissioned to determine the preliminary technical and
economic feasibility of integrating a wood fired heating system at the following 9 buildings
in Lower Kalskag, Alaska: Zachar Levi Elementary School, Lower Kalskag Health Clinic,
Village of Lower Kalskag Tribal Office, Lower Kalskag City and Community Hall, Village of
Lower Kalskag Tribal House, St. Seraphim of Sarov Church, St. Seraphim of Sarov Parish
House, Lower Kalskag Post Office, and Lower Kalskag Pump House.
The following tables summarize the current fuel use and the potential wood fuel use:
Table 1.1 - Annual Fuel Use Summary
Fuel Avg. Use Current Annual
Facility Name Type (Gallons) Cost/Gal. Cost
School Fuel Oil 15,000 $4.38 $65,700
Pump House Fuel Oil 2,750 $4.15 $11,413
Tribal Office Fuel Oil 600 $6.75 $4,050
City/Comm. Hall Fuel Oil 1,750 $6.75 $11,813
Post Office Fuel Oil 1,500 $6.75 $10,125
Health Clinic Fuel Oil 800 $6.75 $5,400
Church Fuel Oil 500 $6.75 $3,375
Parish House Fuel Oil 500 $6.75 $3,375
Tribal House Fuel Oil 550 $6.75 $3,713
Table 1.2 - Annual Wood Fuel Use Summary
Chipped/
Fuel Cord Wood Ground
Oil Wood Pellets Wood
(Gallons) (Cords) (Tons) (Tons)
School (S) 15,000 154.2 140.6 194.0
Pump House (P) 2,750 28.3 25.8 35.6
Tribal Office (TO) 600 6.2 5.6 7.8
City/Community Hall (CCH) 1,750 18.0 16.4 22.6
Post Office (PO) 1,500 15.4 14.1 19.4
Health Clinic (HC) 800 8.2 7.5 10.3
Church (CH) 500 5.1 4.7 6.5
Parish House (H) 500 5.1 4.7 6.5
Tribal House (TH) 550 5.7 5.2 7.1
S + P 17,750 182.5 166.4 229.6
P + TO + CCH + PO 6,600 67.9 61.9 85.4
HC + CH + H + TH 2,350 24.2 22.0 30.4
S+P+TO+CCH+PO+HC+CH+H+TH 23,950 246.3 224.5 309.7
The wood heating system options reviewed were:
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 2 of 14
Draft Report July 16, 2013
Cord Wood Boiler Options:
C.1.A: School Only, A freestanding building with interior cordwood storage,
70% fuel oil offset.
C.1.B: School Only, A freestanding building with interior cordwood storage,
50% fuel oil offset.
C.2.A: School and Pump House, A freestanding building with interior cordwood
storage, 70% fuel oil offset.
C.2.B: School and Pump House, A freestanding building with interior cordwood
storage, 50% fuel oil offset.
C.3: Health Clinic Only, A freestanding building with interior cordwood storage,
70% fuel oil offset.
Wood Stove Options:
D.1.A: Tribal Office, One freestanding wood stove, 30% fuel oil offset.
D.1.B: Tribal Office, One freestanding wood stove, 50% fuel oil offset.
D.2: Comm/City Hall, Two freestanding wood stoves, 30% fuel oil offset.
Table 1.3 - Economic Evaluation Summary
Lower Kalskag Biomass Heating Systems
Year 1 NPV NPV
20
Yr
30
Yr
Project Operating 20 yr 30 yr B/C B/C ACF ACF YR
Cost Savings at 3% at 3% Ratio Ratio YR 20 YR 30 ACF=PC
C.1.A $285,000 $80 $234,072 $543,293 0.82 1.91 $355,658 $1,022,698 19
C.1.B $285,000 -$3,849 $104,759 $298,745 0.37 1.05 $168,687 $587,931 24
C.2.A $475,000 $2,068 $304,916 $680,309 0.64 1.43 $458,572 $1,267,975 21
C.2.B $475,000 -$172 $208,395 $484,949 0.44 1.02 $316,980 $913,553 24
D.1.A $8,100 -$1,013 -$12,055 -$11,461 -1.49 -1.41 -$15,567 -$14,048 >30
D.1.B $8,100 -$2,171 -$28,575 -$31,178 -3.53 -3.85 -$37,560 -$42,671 >30
D.2 $16,200 $257 $21,993 $48,574 1.36 3.00 $32,971 $90,274 15
There is potential to use wood fired heating systems in Lower Kalskag. The cord wood hot
water boiler systems only made sense for the school and water plant, because of the
larger fuel oil use of those facilities. The fuel oil use of the remaining buildings was
relatively low and the potential savings of switching to wood would not pay for the
additional capital costs of integrating hot water heat into the buildings.
With the current economic assumptions, the economic viability of the cord wood boiler
options is poor as none of the options meet the minimum requirement of the 20 year B/C
ratio exceeding 1.0. However, additional economic sensitivity analysis was performed,
and if the fuel oil prices for the school reach and/or exceed $5.00 per gallon, the 20 year
B/C ratio does exceed 1.0 for the school only option (C.1.A). The difficulty for any school
project with cord wood is that the school district does not have the personnel to constantly
tend the fire to obtain the maximum amount of savings. This may then be a potential local
business opportunity. A local person or company could perhaps make an agreement with
the school district to provide heat to the school. A BTU meter could be installed on the hot
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 3 of 14
Draft Report July 16, 2013
water provided to the school, and this contractor would get paid by the BTU delivered.
There may be enough income to leverage a loan to purchase the equipment and construct
a small cord wood boiler plant to serve the school.
Options to install EPA certified wood stoves in the buildings with smaller fuel oil loads were
investigated. Installing two new wood stoves in the Community/City Hall building appears
to be economically viable. With the current economic assumptions, the economic viability
of the wood stove options for the Tribal Office and other smaller buildings is poor as none
of the options meet the minimum requirement of the 20 year B/C ratio exceeding 1.0.
However, additional economic sensitivity analysis was performed, and the wood stove
options are very sensitive to labor costs. If the labor cost to tend to the fire was a task
given to existing employees, and this did not have to be an additional cost to the project
economics, the cash flow analysis shows the 20 year B/C ratio will exceed 1.0 for even the
lower 30% fuel oil offset option (basically tending the fire for typical business hours).
The cord wood fuel source would benefit the community because the fuel is a renewable
resource, has a lower energy cost, and the money paid for the fuel would remain in the
local community and economy.
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 4 of 14
Draft Report July 16, 2013
2.0 Introduction
The following assessment was commissioned to determine the preliminary technical and
economic feasibility of integrating a wood fired heating system at the following 9 buildings
in Lower Kalskag, Alaska: Zachar Levi Elementary School, Lower Kalskag Health Clinic,
Village of Lower Kalskag Tribal Office, Lower Kalskag City and Community Hall, Village of
Lower Kalskag Tribal House, St. Seraphim of Sarov Church, St. Seraphim of Sarov Parish
House, Lower Kalskag Post Office, and Lower Kalskag Pump House.
3.0 Existing Building Systems
The Zachar Levi Elementary School is a single story wood framed building constructed
around 1983. The building is supported by piles and is elevated approximately four feet
above native grade. The facility is approximately 8,700 square feet and is heated by two
143,000 Btu/hr output fuel oil fired hot water boilers. Domestic hot water is provided by a
50 gallon, 152,000 Btu/hr input, fuel oil fired water heater. The boilers were installed last
year and are in good condition. The water heater appears to be approximately 15 years
old and is in fair condition. The heating system infrastructure is original to the building and
appears to be in fair condition. A heating and ventilating air handling unit with a hot water
coil serves the gym/multi-purpose room.
The Lower Kalskag Health Clinic is a single story wood framed building constructed in
2000. The building is supported by piles and is elevated approximately four feet above
native grade. The facility is approximately 1,400 square feet and is primarily heated by a
119,000 Btu/hr output fuel oil fired furnace. A 43,000 Btu/hr output Monitor fuel oil fired
heater is located in the waiting area and provides supplemental heat in extremely cold
temperatures and as a back up if the furnace is not operational. Domestic hot water is
provided by a 50 gallon, 152,000 Btu/hr input, fuel oil fired water heater. The existing
furnace and water heater are original to the building and appear to be in good condition.
The Monitor heater is approximately 10 years old and appears to be in fair condition. The
heating system infrastructure is original to the building and appears to be in good
condition.
The Village of Lower Kalskag Tribal Office is a single story log building approximately 14
years old. The building is supported by piles and is elevated approximately four feet
above native grade. The facility is approximately 865 square feet and is heated by a
43,000 Btu/hr output Monitor fuel oil fired heater. The Monitor heater is original to the
building and appears to be in good condition. There is no domestic water heater for this
building.
The Lower Kalskag City and Community Hall is a single story wood framed building
constructed in the mid 1950’s. The building is supported by piles and is elevated
approximately four feet above native grade. The facility is approximately 1,100 square
feet and is heated by two fuel oil fired heaters. One side of the building houses the City of
Lower Kalskag offices and the other side is the community hall. The City side is served by
a 18,000 Btu/hr output heater, and the community hall side is served by a 43,000 Btu/hr
output heater. There is no domestic water heater for this building. The age of the heaters
is unknown and they appear to be in fair condition.
The Village of Lower Kalskag Tribal House is a single story wood framed building
approximately 16 years old. The building is supported by piles and is elevated
approximately five feet above native grade. The facility is approximately 670 square feet
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 5 of 14
Draft Report July 16, 2013
and is heated by a 40,000 Btu/hr output Toyostove fuel oil fired heater. The Toyo heater is
original to the building and appears to be in good condition. The domestic water heater is
fuel oil fired, but was not accessible to collect the product data.
The St. Seraphim of Sarov Church is a single story wood framed building constructed in
the mid 1970’s. The facility is approximately 1050 square feet and is heated by a 40,000
Btu/hr output Toyostove fuel oil fired heater and a wood stove. The age of the Toyo
heater is unknown and it appears to be in fair condition. There is no domestic water
heater for this building.
The St. Seraphim of Sarov Parish House is a single story log building approximately 20
years old. The facility is approximately 960 square feet and is heated by a 43,000 Btu/hr
output Monitor fuel oil fired heater and a wood stove. The age of the Monitor heater is
unknown and it appears to be in poor condition. It was reported that both the Montior
heater and the wood stove need to operate at the same time to provide enough heat in
extremely cold weather. There is no domestic water heater for this building.
The Lower Kalskag Post Office is a single story wood framed building constructed in
approximately 2000. The building is supported by piles and is elevated approximately five
feet above native grade. The facility is approximately 728 square feet and is heated by
two 43,000 Btu/hr output Monitor fuel oil fired heaters. One heater can heat the entire
building and the second heater is for back up purposes only. The Monitor heaters are
original to the building and appear to be in good condition. The domestic water heater is a
2.5 gallon point of use type electric heater, rated at 1500 watts.
The Pump House is the community water plant and houses equipment required to store,
treat, heat, and pump the community water system. The building is a wood framed
building constructed in 1985 and is approximately 1,500 square feet. The building is
supported by piles and is elevated approximately three feet above native grade. The
facility is heated by two 242,000 Btu/hr output fuel oil fired hot water boilers and a 37,000
Btu/hr output Monitor fuel oil fired heater. The boilers are primarily used for heating the
community water system and generally are not needed until the outside air temperature
falls to -20 deg. F and below. The Monitor heater provides heat for the building at all other
times. A small electric domestic hot water is located over the toilet room, but it appears it
is not used very frequently. The age of the boilers is unknown, but they appear to be
approximately 10 years old or less and are in good condition.
4.0 Current Heating Energy Use
Fuel oil usage for each building was reported and the following table summarizes the data:
Table 4.1 - Annual Fuel Use Summary
Fuel Avg. Use Current Annual
Facility Name Type (Gallons) Cost/Gal. Cost
School Fuel Oil 15,000 $4.38 $65,700
Pump House Fuel Oil 2,750 $4.15 $11,413
Tribal Office Fuel Oil 600 $6.75 $4,050
City/Comm. Hall Fuel Oil 1,750 $6.75 $11,813
Post Office Fuel Oil 1,500 $6.75 $10,125
Health Clinic Fuel Oil 800 $6.75 $5,400
Church Fuel Oil 500 $6.75 $3,375
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 6 of 14
Draft Report July 16, 2013
Table 4.1 - Annual Fuel Use Summary
Parish House Fuel Oil 500 $6.75 $3,375
Tribal House Fuel Oil 550 $6.75 $3,713
5.0 Biomass Boiler Size
The following table summarizes the connected load of fuel fired boilers and heaters:
Table 5.1 - Connected Boiler Load Summary
Likely
Peak System
Output Load Peak
MBH Factor MBH
School Boiler 1 Fuel Oil 143 1.00 143
Boiler 2 Fuel Oil 143 1.00 143
Total 286
Pump House Boiler 1 Fuel Oil 242 0.50 121
Boiler 2 Fuel Oil 242 0.50 121
Monitor Fuel Oil 37 0.00 0
Total 242
Tribal Office Monitor Fuel Oil 43 1.00 43
City/Comm Hall Monitor Fuel Oil 18 1.00 18
Monitor Fuel Oil 40 1.00 40
Total 58
Post Office Monitor Fuel Oil 43 0.50 22
Monitor Fuel Oil 43 0.50 22
Total 43
Health Clinic Furnace Fuel Oil 119 1.00 119
Monitor Fuel Oil 43 0.00 0
Total 119
Church Toyo Fuel Oil 40 1.00 40
Parish House Monitor Fuel Oil 43 1.00 43
Wood Stove Wood 25 1.00 25
Total 68
Tribal House Toyo Fuel Oil 40 1.00 40
Total Of All Buildings 1304 939
Typically a wood heating system is sized to meet approximately 85% of the typical annual
heating energy use of the building. The existing heating boilers would be used for the
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 7 of 14
Draft Report July 16, 2013
other 15% of the time during peak heating conditions, during times when the biomass
boiler is down for servicing, and during swing months when only a few hours of heating
each day are required. Recent energy models have found that a boiler sized at 50% to
60% of the building peak load will typically accommodate 85% of the boiler run hours.
6.0 Wood Fuel Use and Cost
The only type of wood fuel currently available in the area is cord wood harvested from the
local forest land. Napaimute Enterprises is doing commercial logging in the area, with a
large portion of the wood being sent to Bethel, but wood is also sent up river and down
river to other communities. Cord wood is also collected and cut up by private individuals
for use in residential wood stoves. It appears there is sufficient local forest resources to
support any potential wood fired boiler project in Lower Kalskag.
Although cord wood is the only fuel type currently available in the area, the cost and
amount of chipped/ground wood fuel will be shown for comparison purposes only.
The estimated amount of wood fuel needed was calculated and is listed below:
Table 5.2 - Proposed Biomass Boiler Size
Likely Biomass
System Biomass Boiler
Peak Boiler Size
MBH Factor MBH
School (S) 286 0.6 172
Pump House (P) 242 0.6 145
Tribal Office (TO) 43 0.6 26
City/Community Hall (CCH) 58 0.6 35
Post Office (PO) 43 0.6 26
Health Clinic (HC) 119 0.6 71
Church (CH) 40 0.6 24
Parish House (PH) 68 0.6 41
Tribal House (TH) 40 0.6 24
S + P 528 0.6 317
P + TO + CCH + PO 386 0.6 232
HC + CH + PH + TH 267 0.6 160
S+P+TO+CCH+PO+HC+CH+PH+TH 939 0.6 564
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 8 of 14
Draft Report July 16, 2013
Table 6.1 - Annual Wood Fuel Use Summary
Chipped/
Fuel Cord Wood Ground
Oil Wood Pellets Wood
(Gallons) (Cords) (Tons) (Tons)
School (S) 15,000 154.2 140.6 194.0
Pump House (P) 2,750 28.3 25.8 35.6
Tribal Office (TO) 600 6.2 5.6 7.8
City/Community Hall (CCH) 1,750 18.0 16.4 22.6
Post Office (PO) 1,500 15.4 14.1 19.4
Health Clinic (HC) 800 8.2 7.5 10.3
Church (CH) 500 5.1 4.7 6.5
Parish House (H) 500 5.1 4.7 6.5
Tribal House (TH) 550 5.7 5.2 7.1
S + P 17,750 182.5 166.4 229.6
P + TO + CCH + PO 6,600 67.9 61.9 85.4
HC + CH + H + TH 2,350 24.2 22.0 30.4
S+P+TO+CCH+PO+HC+CH+H+TH 23,950 246.3 224.5 309.7
The amount of wood fuel shown in the table is for supplanting the entire amount of fuel oil
and is for comparison purposes only. It is extremely unlikely that wood fuel will be able to
completely replace the entire amount of fuel oil use. The moisture content of the wood
fuels and the overall wood burning system efficiencies were accounted for in these
calculations. The existing fuel oil boilers were assumed to be 80% efficient. Cord wood
was assumed to be 20% moisture content (MC) with a system efficiency of 65%. Wood
pellets were assumed to be 7% MC with a system efficiency of 70%. Chipped/ground fuel
was assumed to be 30% MC with a system efficiency of 65%.
The unit fuel costs for fuel oil and the different wood fuel types were calculated and
equalized to dollars per million Btu ($/MMBtu) to allow for direct comparison. The
Delivered $/MMBtu is the cost of the fuel based on what is actually delivered to the heating
system, which includes all the inefficiencies of the different systems. The Gross $/MMBtu
is the cost of the fuel based on raw fuel, or the higher heating value and does not account
for any system inefficiencies. The following table summarizes the equalized fuel costs at
different fuel unit costs:
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 9 of 14
Draft Report July 16, 2013
Table 6.2 - Unit Fuel Costs Equalized to $/MMBtu
Net
Gross System System
Delivered Gross
Fuel Type Units Btu/unit Efficiency Btu/unit $/unit $/MMBtu $/MMBtu
Fuel Oil gal 134500 0.8 107600 $4.38 $40.71 $32.57
$6.75 $62.73 $50.19
$7.00 $65.06 $52.04
Cord Wood cords 16173800 0.65 10512970 $300.00 $28.54 $18.55
$400.00 $38.05 $24.73
$500.00 $47.56 $30.91
Chips tons 10800000 0.65 7020000 $150.00 $21.37 $13.89
$200.00 $28.49 $18.52
$250.00 $35.61 $23.15
7.0 Boiler Plant Location and Site Access
None of the existing boiler or mechanical rooms are large enough to fit a new biomass
boiler so a new stand alone boiler plant would be required. The best location for a plant
near the school would be just north of the school generator building. The best location for
a plant near the health clinic would be just east of the clinic building. See Appendix C for a
site plan of the proposed boiler plant locations.
Any type of biomass boiler plant will require access by delivery vehicles. For cord wood
systems this would likely be pick-up trucks, trucks with trailers, snow machines or ATV’s.
The existing roads near the buildings are large enough to accommodate any type of
delivery vehicle that would be used for wood delivery.
8.0 Integration with Existing Heating System
Integration of a wood fired heating system varies from facility to facility. For the school
and the pump house, integration of a wood fired hot water boiler system would be
relatively straight forward. The field visit confirmed the location of the boiler rooms in order
to identify an approximate point of connection from a biomass boiler to the existing
buildings. Piping from the biomass boiler plant would likely be run below ground to the
buildings in arctic pipe and extend up to the boiler room. Once the hot water supply and
return piping enters the existing boiler room it would be connected to existing supply and
return pipes in appropriate locations in order to utilize the existing pumping systems within
the building. The wood heating system would inject heat into the existing heating hot
water system. Because the school has a kitchen that is used extensively, it is likely to
have a significant domestic hot water load, so a double wall heat exchanger would be
installed in the boiler room of the school and piped into the existing domestic water heater
system so that the wood fired boiler could heat the domestic hot water.
Integration of a wood fired boiler system in the health clinic would require the installation of
a hot water heating coil in the existing furnace system. The field visit confirmed the
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 10 of 14
Draft Report July 16, 2013
location of the mechanical room in order to identify an approximate point of connection
from a biomass boiler to the existing building. Piping from the biomass boiler plant would
likely be run below ground to the buildings in arctic pipe and extend up to the mechanical
room. Once the hot water supply and return piping enters the existing boiler room it would
be connected to the new heating coil installed in the ductwork from the furnace. Installing
a wood stove in the clinic would be difficult because of lack of space, unless the wood
stove could replace the existing Monitor heater.
Integration of a wood fired hot water heating system in the Tribal Office, the City and
Community Hall, the Tribal House, the Church, the Parish House, and the Post Office
would require the installation of a hot water unit heaters or hot water baseboard elements.
Because of the relatively low fuel oil use at these buildings, the capital cost of adding the
new heating equipment would not be economically viable. A better option for these
buildings would be to install an EPA certified wood stove. With the exception of the Post
Office, all of these buildings appear to have room to install a new wood stove next to the
existing fuel oil fired heaters.
For the school and the water plant, the existing hot water heating system appears to be
designed for a heating supply water temperature of 180 deg. F. Perimeter finned tube
heating elements are the primary devices used to heat the spaces. Heat emanates from
these elements via radiation and natural convection. Because of this, the performance of
the heating elements is greatly influenced by heating water supply temperature. At 140
deg. F heating water supply temperature, the heat output of these elements is
approximately 50% of their output at 180 deg F. Wood chip and wood pellet boilers can
consistently produce and maintain 180 deg. F water because the fuel is automatically and
mechanically fed into the boiler. However, it can be difficult for manually fed cord wood
systems to maintain this temperature unless they are continuously tended to and wood is
constantly fed into the boiler. For this reason, cord wood boilers should be coupled with
thermal storage tanks, so the boiler can be loaded, it can burn the wood hot and fast, and
the water can be heated and “stored” in the tank. In this scenario as long as the boiler is
checked and tended to regularly (3 to 5 times a day depending on heating load) a
consistent 140 deg. F supply temperature generally can be maintained. A very basic and
preliminary building heat load analysis was performed and it appears that a 140 deg. F
heating water supply temperature could provide sufficient heat for the building down to
approximately 22 deg. F outside air temperature, which would cover approximately 70% of
the heating hours over the course of a year.
9.0 Air Quality Permits
Resource System Group (RSG) has done a preliminary review of potential air quality
issues in the area and has found no significant concerns. The proposed boiler size at this
location is small enough that the boiler is not likely to require any State or Federal permits.
See the air quality memo in Appendix D for more detailed information including design
criteria that has been suggested to minimize emissions and maximize dispersion.
10.0 Wood Heating Options
The technologies available to produce heating energy from wood based biomass are
varied in their approach, but largely can be separated into three types: cord wood, wood
pellet and wood chip/ground wood fueled. See Appendix E for summaries on these types
of systems.
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 11 of 14
Draft Report July 16, 2013
A cord wood boiler system and a wood stove are the only viable options at this time in
Lower Kalskag. Three cord wood boiler options were developed, all with sub options of
offsetting 70% of the current fuel oil usage and two with sub options of offsetting 50% of
the current fuel oil usage. Two wood stove options were also developed, one for the Tribal
Office and one for the Community/City Hall.
The 70% offset comes from the assumption that 140 deg. F water can be constantly
produced by the cord wood boilers, and this heating water temperature can heat the
building for 70% of the heating hours (see water temperature discussion in section 8.0).
This would require significant time to tending the boilers so they could operate 7 days a
week, 24 hours per day. This time has been accounted for in the cash flow analysis. The
50% offset assumes a little less tending time.
For the wood stoves, the 30% offset is based on the amount of heating hours that could be
offset during normal business hours, Monday through Friday, 7:30 a.m. to 5:30 p.m., so
that tending the fire would only have to occur during normal business hours. To achieve
the 50% offset, additional time is required to tend the fire on evenings or weekends.
An EPA certified wood stove is assumed to be used. The EPA certification ensures a
wood stove is well designed to have good combustion efficiency and low emissions.
The options reviewed were:
Cord Wood Boiler Options:
C.1.A: School Only, A freestanding building with interior cordwood storage,
70% fuel oil offset.
C.1.B: School Only, A freestanding building with interior cordwood storage,
50% fuel oil offset.
C.2.A: School and Pump House, A freestanding building with interior cordwood
storage, 70% fuel oil offset.
C.2.B: School and Pump House, A freestanding building with interior cordwood
storage, 50% fuel oil offset.
C.3: Health Clinic Only, A freestanding building with interior cordwood storage,
70% fuel oil offset.
Wood Stove Options:
D.1.A: Tribal Office, One freestanding wood stove, 30% fuel oil offset.
D.1.B: Tribal Office, One freestanding wood stove, 50% fuel oil offset.
D.2: Comm/City Hall, Two freestanding wood stoves, 30% fuel oil offset.
11.0 Estimated Costs
The total project costs are at a preliminary level and are based on RS Means and recent
biomass project construction cost data. The estimates are shown in Appendix A. These
costs are conservative and if a deeper level feasibility analysis is undertaken and/or further
design occurs, the costs may be able to be reduced.
12.0 Economic Analysis Assumptions
The cash flow analysis assumes fuel oil at $4.38/gal for the school, $4.15/gal for the pump
house, and $6.75/gal for the remaining buildings; electricity at $0.30/kwh, and cord wood
delivered at $300/cord. The fuel oil and electricity costs are based on the costs reported
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 12 of 14
Draft Report July 16, 2013
by the facility and by the State of Alaska. Cord wood pricing is based on what was
reported in the community.
It is assumed that the wood boiler and wood stove options would supplant the estimated
fuel oil heating use as indicated in the option description, and the existing heating systems
would heat the remaining portion. Each option assumes the total project can be funded
with grants and non obligated capital money. The following inflation rates were used:
O&M - 2% Fossil Fuel – 5%
Wood Fuel – 3% Discount Rate for NPV calculation – 3%
The fossil fuel inflation rate is based on the DOE EIA website. DOE is projecting a slight
plateau with a long term inflation of approximately 5%. As a point of comparison, oil prices
have increased at an annual rate of over 8% since 2001.
The analysis also accounts for additional electrical energy required for the wood fired
boiler system as well as the system pumps to distribute heating hot water to the building.
Wood fired boiler systems also will require more maintenance, and these additional
maintenance costs are also factored into the analysis.
13.0 Results of Evaluation
The following table summarizes the economic evaluation for each option:
Table 13.1 - Economic Evaluation Summary
Lower Kalskag Biomass Heating Systems
Year 1 NPV NPV
20
Yr
30
Yr
Project Operating 20 yr 30 yr B/C B/C ACF ACF YR
Cost Savings at 3% at 3% Ratio Ratio YR 20 YR 30 ACF=PC
C.1.A $285,000 $80 $234,072 $543,293 0.82 1.91 $355,658 $1,022,698 19
C.1.B $285,000 -$3,849 $104,759 $298,745 0.37 1.05 $168,687 $587,931 24
C.2.A $475,000 $2,068 $304,916 $680,309 0.64 1.43 $458,572 $1,267,975 21
C.2.B $475,000 -$172 $208,395 $484,949 0.44 1.02 $316,980 $913,553 24
D.1.A $8,100 -$1,013 -$12,055 -$11,461 -1.49 -1.41 -$15,567 -$14,048 >30
D.1.B $8,100 -$2,171 -$28,575 -$31,178 -3.53 -3.85 -$37,560 -$42,671 >30
D.2 $16,200 $257 $21,993 $48,574 1.36 3.00 $32,971 $90,274 15
The benefit to cost (B/C) ratio takes the net present value (NPV) of the net energy savings
and divides it by the estimated construction cost of the project. A B/C ratio greater than or
equal to 1.0 indicates an economically advantageous project.
Accumulated cash flow (ACF) is another evaluation measure that is calculated in this
report and is similar to simple payback with the exception that accumulated cash flow
takes the cost of financing and fuel escalation into account. For many building owners,
having the accumulated cash flow equal the project cost within 15 years is considered
necessary for implementation. If the accumulated cash flow equals project cost in 20
years or more, that indicates a challenged project. Positive accumulated cash flow should
also be considered an avoided cost as opposed to a pure savings.
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 13 of 14
Draft Report July 16, 2013
See Appendix D for the full cash flow spread sheets for each option.
14.0 Project Funding
The Village of Lower Kalskag can pursue a biomass project grant from the Alaska Energy
Authority. See the following website for more information:
http://www.akenergyauthority.org/refund7.html
The Village of Lower Kalskag could also enter into a performance contract for the project.
Companies such as Siemens, McKinstry, Johnson Controls and Chevron have expressed
an interest in participating in funding projects of all sizes throughout Alaska. This allows
the facility owner to pay for the project entirely from the guaranteed energy savings, and to
minimize the project funds required to initiate the project. The scope of the project may be
expanded to include additional energy conservation measures such as roof and wall
insulation and upgrading mechanical systems.
15.0 Summary
There is potential to use wood fired heating systems in Lower Kalskag. The cord wood hot
water boiler systems only made sense for the school and water plant, because of the
larger fuel oil use of those facilities. The fuel oil use of the remaining buildings was
relatively low and the potential savings of switching to wood would not pay for the
additional capital costs of integrating hot water heat into the buildings.
With the current economic assumptions, the economic viability of the cord wood boiler
options is poor as none of the options meet the minimum requirement of the 20 year B/C
ratio exceeding 1.0. However, additional economic sensitivity analysis was performed,
and if the fuel oil prices for the school reach and/or exceed $5.00 per gallon, the 20 year
B/C ratio does exceed 1.0 for the school only option (C.1.A). The difficulty for any school
project with cord wood is that the school district does not have the personnel to constantly
tend the fire to obtain the maximum amount of savings. This may then be a potential local
business opportunity. A local person or company could perhaps make an agreement with
the school district to provide heat to the school. A BTU meter could be installed on the hot
water provided to the school, and this contractor would get paid by the BTU delivered.
There may be enough income to leverage a loan to purchase the equipment and construct
a small cord wood boiler plant to serve the school.
Options to install EPA certified wood stoves in the buildings with smaller fuel oil loads were
investigated. Installing two new wood stoves in the Community/City Hall building appears
to be economically viable. With the current economic assumptions, the economic viability
of the wood stove options for the Tribal Office and other smaller buildings is poor as none
of the options meet the minimum requirement of the 20 year B/C ratio exceeding 1.0.
However, additional economic sensitivity analysis was performed, and the wood stove
options are very sensitive to labor costs. If the labor cost to tend to the fire was a task
given to existing employees, and this did not have to be an additional cost to the project
economics, the cash flow analysis shows the 20 year B/C ratio will exceed 1.0 for even the
lower 30% fuel oil offset option (basically tending the fire for typical business hours).
Pre-Feasibility Assessment for Village of Lower Kalskag
Integration of Wood-Fired Heating Systems Lower Kalskag, Alaska
CTA Architects Engineers Page 14 of 14
Draft Report July 16, 2013
The cord wood fuel source would benefit the community because the fuel is a renewable
resource, has a lower energy cost, and the money paid for the fuel would remain in the
local community and economy.
16.0 Recommended Action
Pursue investigating purchasing wood stoves for the Community/City Hall and purchasing
cord wood to heat the building and determine best location to store wood. Determine if
tending the wood stoves could be integrated into existing employee jobs, and if so,
investigate purchasing wood stoves for those facilities.
Re-evaluate the economics of a cord wood boiler plant to serve the school when school
fuel prices reach $5.00/gallon.
APPENDIX A
Preliminary Estimates of Probable Cost
Preliminary Estimates of Probable Cost
Biomass Heating Options
Lower Kalskag, AK
Option C.1 Cord Wood Boiler School Only
Biomass Boiler Building Including Wood Storage Area: $55,000
Cord Wood Boiler and Thermal Storage Tank: $19,000
Stack:$5,000
Mechanical/Electrical within Boiler Building: $25,000
Underground Piping $25,000
School Integration $25,000
Subtotal:$154,000
40% Remote Factor $61,600
Subtotal:$215,600
Design Fees, Building Permit, Miscellaneous Expenses 15%: $32,340
Subtotal:$247,940
15% Contingency:$37,191
Total Project Costs 285,131$
Option C.2 Cord Wood Boiler School & Pump House
Biomass Boiler Building Including Wood Storage Area: $55,000
(2) Cord Wood Boilers and Thermal Storage Tank: $34,000
Stack:$8,000
Mechanical/Electrical within Boiler Building: $25,000
Underground Piping $85,000
School Integration $25,000
Pump House Integration $25,000
Subtotal:$257,000
40% Remote Factor $102,800
Subtotal:$359,800
Design Fees, Building Permit, Miscellaneous Expenses 15%: $53,970
Subtotal:$413,770
15% Contingency:$62,066
Total Project Costs 475,836$
Preliminary Estimates of Probable Cost
Biomass Heating Options
Lower Kalskag, AK
Option C.3 Cord Wood Boiler Health Clinic
Biomass Boiler Building Including Wood Storage Area: $55,000
Cord Wood Boiler and Thermal Storage Tank: $19,000
Stack:$5,000
Mechanical/Electrical within Boiler Building: $25,000
Underground Piping $18,000
Health Clinic Integration $15,000
Subtotal:$137,000
40% Remote Factor $54,800
Subtotal:$191,800
Design Fees, Building Permit, Miscellaneous Expenses 15%: $28,770
Subtotal:$220,570
15% Contingency:$33,086
Total Project Costs 253,656$
Option D.1 Wood Stove
Wood Stove $3,800
Stack:$1,500
Subtotal:$5,300
40% Remote Factor $2,120
Subtotal:$7,420
10% Contingency:$742
Total Project Costs 8,162$
Option D.2 Wood Stove
(2) Wood Stoves $7,600
Stack:$3,000
Subtotal:$10,600
40% Remote Factor $4,240
Subtotal:$14,840
10% Contingency:$1,484
Total Project Costs 16,324$
APPENDIX B
Cash Flow Analysis
Village of Lower Kalskag Biomass Heating System Option C.1.ALower Kalskag, AlaskaCord Wood Boiler School OnlyDate: July 15, 2013 70% OffsetAnalyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSSchoolTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$4.38 Estimated Average Annual Fuel Usage:15,00015,000Annual Heating Costs:$65,700 $0 $0 $0 $65,700ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):2,017,500,000 0 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):1,614,000,000 0 0 0 1,614,000,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800Cords of wood fuel to supplant net equivalent of 100% annual heating load.154Cords of wood fuel to supplant net equivalent of 85% annual heating load.13025 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$285,000 Project Financing InformationPercent Financed0.0%Est. Pwr Use 2900 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 14.0 40 560 $20.00 $11,200Amount of Grants$285,000 Other 0.0 40 0 $20.00 $01st 2 Year Learning 2.0 40 80 $20.00 $1,600Interest Rate5.00%Term10Annual Finance Cost (years)$0 3,570.3 years Net Benefit B/C Ratio$543,293 $258,293 1.91$234,072 -$50,9280.82Year Accumulated Cash Flow > 0#N/AYear Accumulated Cash Flow > Project Capital Cost19Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $4.38 15000 gal $65,700 $68,985 $72,434 $76,056 $79,859 $83,852 $88,044 $92,446 $97,069 $101,922 $107,018 $112,369 $117,988 $123,887 $130,082 $166,021 $211,889 $270,430Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 70% 107 cords $32,240 $33,207 $34,204 $35,230 $36,287 $37,375 $38,496 $39,651 $40,841 $42,066 $43,328 $44,628$45,967 $47,346 $48,766 $56,533 $65,538 $75,976Small load existing fuel$4.38 30% 4500 gal $19,710 $20,696 $21,730 $22,817 $23,958 $25,156 $26,413 $27,734 $29,121 $30,577 $32,106 $33,711 $35,396 $37,166 $39,024 $49,806 $63,567 $81,129Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$11,200 $11,424 $11,652 $11,886 $12,123 $12,366 $12,613 $12,865 $13,123 $13,385 $13,653 $13,926 $14,204 $14,488 $14,778 $16,316 $18,014 $19,889Additional Operation and Maintenance Costs First 2 years$1,600 $1,632Additional Electrical Cost $0.300$870 $896 $923 $951 $979 $1,009 $1,039 $1,070 $1,102 $1,135 $1,169 $1,204 $1,240 $1,278 $1,316 $1,526 $1,769 $2,050Annual Operating Cost Savings$80$1,130$3,925$5,173$6,512$7,947$9,483$11,126$12,883$14,759$16,763$18,900$21,180$23,609$26,197$41,839$63,002$91,385Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow80 1,130 3,925 5,173 6,512 7,947 9,483 11,126 12,883 14,759 16,763 18,900 21,180 23,609 26,197 41,839 63,002 91,385Accumulated Cash Flow80 1,210 5,135 10,308 16,820 24,767 34,250 45,375 58,258 73,017 89,780 108,681 129,861 153,470 179,667 355,658 625,8251,022,698Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
Village of Lower Kalskag Biomass Heating System Option C.1.BLower Kalskag, AlaskaCord Wood Boiler School OnlyDate: July 15, 2013 50% OffsetAnalyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSSchoolTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$4.38 Estimated Average Annual Fuel Usage:15,00015,000Annual Heating Costs:$65,700 $0 $0 $0 $65,700ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):2,017,500,000 0 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):1,614,000,000 0 0 0 1,614,000,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800Cords of wood fuel to supplant net equivalent of 100% annual heating load.154Cords of wood fuel to supplant net equivalent of 85% annual heating load.13025 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$285,000 Project Financing InformationPercent Financed0.0%Est. Pwr Use 2900 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 14.0 40 560 $20.00 $11,200Amount of Grants$285,000 Other 0.0 40 0 $20.00 $01st 2 Year Learning 2.0 40 80 $20.00 $1,600Interest Rate5.00%Term10Annual Finance Cost (years)$0 -74.1 years Net Benefit B/C Ratio$298,745 $13,745 1.05$104,759 -$180,2410.37Year Accumulated Cash Flow > 08Year Accumulated Cash Flow > Project Capital Cost24Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $4.38 15000 gal $65,700 $68,985 $72,434 $76,056 $79,859 $83,852 $88,044 $92,446 $97,069 $101,922 $107,018 $112,369 $117,988 $123,887 $130,082 $166,021 $211,889 $270,430Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 50% 77 cords $23,029 $23,720 $24,431 $25,164 $25,919 $26,697 $27,497 $28,322 $29,172 $30,047 $30,949 $31,877 $32,833 $33,818 $34,833 $40,381 $46,813 $54,269Small load existing fuel$4.38 50% 7500 gal $32,850 $34,493 $36,217 $38,028 $39,929 $41,926 $44,022 $46,223 $48,534 $50,961 $53,509 $56,185 $58,994 $61,944 $65,041 $83,010 $105,945 $135,215Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$11,200 $11,424 $11,652 $11,886 $12,123 $12,366 $12,613 $12,865 $13,123 $13,385 $13,653 $13,926 $14,204 $14,488 $14,778 $16,316 $18,014 $19,889Additional Operation and Maintenance Costs First 2 years$1,600 $1,632Additional Electrical Cost $0.300$870 $896 $923 $951 $979 $1,009 $1,039 $1,070 $1,102 $1,135 $1,169 $1,204 $1,240 $1,278 $1,316 $1,526 $1,769 $2,050Annual Operating Cost Savings-$3,849-$3,179-$789$28$908$1,855$2,873$3,966$5,138$6,394$7,739$9,177$10,716$12,359$14,114$24,788$39,349$59,007Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow(3,849) (3,179) (789)28 908 1,855 2,873 3,966 5,138 6,394 7,739 9,177 10,716 12,359 14,114 24,788 39,349 59,007Accumulated Cash Flow(3,849) (7,028) (7,817) (7,790) (6,882) (5,027) (2,154)1,812 6,949 13,343 21,082 30,259 40,975 53,334 67,448 168,687 334,535 587,931Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
Village of Lower Kalskag Biomass Heating System Option C.2.ALower Kalskag, AlaskaCord Wood Boiler School & Pump HouseDate: July 15, 2013 70% OffsetAnalyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSSchool Pump HouseTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$4.38 $4.15 Estimated Average Annual Fuel Usage:15,000 2,75017,750Annual Heating Costs:$65,700 $11,413 $0 $0 $77,113ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):2,017,500,000 369,875,000 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):1,614,000,000 295,900,000 0 0 1,909,900,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800 Cords of wood fuel to supplant net equivalent of 100% annual heating load.182Cords of wood fuel to supplant net equivalent of 85% annual heating load.15425 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$475,000 Project Financing InformationPercent Financed0.0%Est. Pwr Use 3200 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 14.0 40 560 $20.00 $11,200Amount of Grants$475,000 Other 0.0 40 0 $20.00 $01st 2 Year Learning 2.0 40 80 $20.00 $1,600Interest Rate5.00%Term10Annual Finance Cost (years)$0 229.7 years Net Benefit B/C Ratio$680,309 $205,309 1.43$304,916 -$170,0840.64Year Accumulated Cash Flow > 0#N/AYear Accumulated Cash Flow > Project Capital Cost21Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $4.38 15000 gal $65,700 $68,985 $72,434 $76,056 $79,859 $83,852 $88,044 $92,446 $97,069 $101,922 $107,018 $112,369 $117,988 $123,887 $130,082 $166,021 $211,889 $270,430Displaced heating costs $4.15 2750 gal $11,413 $11,983 $12,582 $13,211 $13,872 $14,566 $15,294 $16,059 $16,861 $17,705 $18,590 $19,519 $20,495 $21,520 $22,596 $28,839 $36,806 $46,975Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 70% 127 cords $38,151 $39,295 $40,474 $41,688 $42,939 $44,227 $45,554 $46,921 $48,328 $49,778 $51,272 $52,810$54,394 $56,026 $57,707 $66,898 $77,553 $89,905Small load existing fuel$4.38 30% 4500 gal $19,710 $20,696 $21,730 $22,817 $23,958 $25,156 $26,413 $27,734 $29,121 $30,577 $32,106 $33,711 $35,396 $37,166 $39,024 $49,806 $63,567 $81,129Small load existing fuel$4.15 30% 825 gal $3,424 $3,595 $3,775 $3,963 $4,162 $4,370 $4,588 $4,818 $5,058 $5,311 $5,577 $5,856 $6,149 $6,456 $6,779 $8,652 $11,042 $14,093Small load existing fuel$0.00 30% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 30% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$11,200 $11,424 $11,652 $11,886 $12,123 $12,366 $12,613 $12,865 $13,123 $13,385 $13,653 $13,926 $14,204 $14,488 $14,778 $16,316 $18,014 $19,889Additional Operation and Maintenance Costs First 2 years$1,600 $1,632Additional Electrical Cost $0.300$960 $989 $1,018 $1,049 $1,080 $1,113 $1,146 $1,181 $1,216 $1,253 $1,290 $1,329 $1,369 $1,410 $1,452 $1,683 $1,951 $2,262Annual Operating Cost Savings$2,068$3,337$6,366$7,864$9,469$11,186$13,023$14,987$17,084$19,323$21,711$24,258$26,971$29,861$32,937$51,504$76,568$110,127Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow2,068 3,337 6,366 7,864 9,469 11,186 13,023 14,987 17,084 19,323 21,711 24,258 26,971 29,861 32,937 51,504 76,568 110,127Accumulated Cash Flow2,068 5,405 11,772 19,636 29,104 40,291 53,314 68,301 85,385 104,708 126,419 150,676 177,648 207,508 240,446 458,572 788,324 1,267,975Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
Village of Lower Kalskag Biomass Heating System Option C.2.BLower Kalskag, AlaskaCord Wood Boiler School & Pump HouseDate: July 15, 2013 50% OffsetAnalyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSSchool Pump HouseTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$4.38 $4.15 Estimated Average Annual Fuel Usage:15,000 2,75017,750Annual Heating Costs:$65,700 $11,413 $0 $0 $77,113ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):2,017,500,000 369,875,000 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):1,614,000,000 295,900,000 0 0 1,909,900,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800 Cords of wood fuel to supplant net equivalent of 100% annual heating load.182Cords of wood fuel to supplant net equivalent of 85% annual heating load.15425 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$475,000 Project Financing InformationPercent Financed0.0%Est. Pwr Use 3200 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 14.0 40 560 $20.00 $11,200Amount of Grants$475,000 Other 0.0 40 0 $20.00 $01st 2 Year Learning 2.0 40 80 $20.00 $1,600Interest Rate5.00%Term10Annual Finance Cost (years)$0 -2,763.6 years Net Benefit B/C Ratio$484,949 $9,949 1.02$208,395 -$266,6050.44Year Accumulated Cash Flow > 02Year Accumulated Cash Flow > Project Capital Cost24Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $4.38 15000 gal $65,700 $68,985 $72,434 $76,056 $79,859 $83,852 $88,044 $92,446 $97,069 $101,922 $107,018 $112,369 $117,988 $123,887 $130,082 $166,021 $211,889 $270,430Displaced heating costs $4.15 2750 gal $11,413 $11,983 $12,582 $13,211 $13,872 $14,566 $15,294 $16,059 $16,861 $17,705 $18,590 $19,519 $20,495 $21,520 $22,596 $28,839 $36,806 $46,975Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 50% 91 cords $27,251 $28,068 $28,910 $29,777 $30,671 $31,591 $32,539 $33,515 $34,520 $35,556 $36,623 $37,721 $38,853 $40,018 $41,219 $47,784 $55,395 $64,218Small load existing fuel$4.38 50% 7500 gal $32,850 $34,493 $36,217 $38,028 $39,929 $41,926 $44,022 $46,223 $48,534 $50,961 $53,509 $56,185 $58,994 $61,944 $65,041 $83,010 $105,945 $135,215Small load existing fuel$4.15 30% 825 gal $3,424 $3,595 $3,775 $3,963 $4,162 $4,370 $4,588 $4,818 $5,058 $5,311 $5,577 $5,856 $6,149 $6,456 $6,779 $8,652 $11,042 $14,093Small load existing fuel$0.00 30% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 30% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$11,200 $11,424 $11,652 $11,886 $12,123 $12,366 $12,613 $12,865 $13,123 $13,385 $13,653 $13,926 $14,204 $14,488 $14,778 $16,316 $18,014 $19,889Additional Operation and Maintenance Costs First 2 years$1,600 $1,632Additional Electrical Cost $0.300$960 $989 $1,018 $1,049 $1,080 $1,113 $1,146 $1,181 $1,216 $1,253 $1,290 $1,329 $1,369 $1,410 $1,452 $1,683 $1,951 $2,262Annual Operating Cost Savings-$172$768$3,444$4,564$5,765$7,052$8,430$9,903$11,478$13,161$14,957$16,872$18,915$21,091$23,409$37,414$56,348$81,728Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow(172)768 3,444 4,564 5,765 7,052 8,430 9,903 11,478 13,161 14,95716,872 18,915 21,091 23,409 37,414 56,348 81,728Accumulated Cash Flow(172)596 4,039 8,603 14,369 21,421 29,851 39,754 51,233 64,393 79,350 96,222 115,137 136,228 159,636 316,980 558,605 913,553Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
Village of Lower Kalskag Biomass Heating System Option C.3Lower Kalskag, AlaskaCord Wood Boiler Health ClinicDate: July 15, 2013 70% OffsetAnalyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSClinicTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$6.75 Estimated Average Annual Fuel Usage:800800Annual Heating Costs:$5,400 $0 $0 $5,400ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):107,600,000 0 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):86,080,000 0 0 0 86,080,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800 Cords of wood fuel to supplant net equivalent of 100% annual heating load.8Cords of wood fuel to supplant net equivalent of 85% annual heating load.725 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$253,000 Project Financing InformationPercent Financed0.0%Est. Pwr Use 1700 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 14.0 40 560 $20.00 $11,200Amount of Grants$253,000 Other 0.0 40 0 $20.00 $01st 2 Year Learning 2.0 40 80 $20.00 $1,600Interest Rate5.00%Term10Annual Finance Cost (years)$0 -22.5 years Net Benefit B/C Ratio-$204,690 -$457,690 -0.81-$156,268 -$409,268-0.62Year Accumulated Cash Flow > 031Year Accumulated Cash Flow > Project Capital Cost31Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $6.75 800 gal $5,400 $5,670 $5,954 $6,251 $6,564 $6,892 $7,237 $7,598 $7,978 $8,377 $8,796 $9,236 $9,698 $10,183 $10,692 $13,646 $17,416 $22,227Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 70% 6 cords $1,719 $1,771 $1,824 $1,879 $1,935 $1,993 $2,053 $2,115 $2,178 $2,244 $2,311 $2,380 $2,452 $2,525 $2,601 $3,015 $3,495 $4,052Small load existing fuel$6.75 30% 240 gal $1,620 $1,701 $1,786 $1,875 $1,969 $2,068 $2,171 $2,280 $2,393 $2,513 $2,639 $2,771 $2,909 $3,055 $3,207 $4,094 $5,225 $6,668Small load existing fuel$0.00 30% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 30% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 30% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$11,200 $11,424 $11,652 $11,886 $12,123 $12,366 $12,613 $12,865 $13,123 $13,385 $13,653 $13,926 $14,204 $14,488 $14,778 $16,316 $18,014 $19,889Additional Operation and Maintenance Costs First 2 years$1,600 $1,632Additional Electrical Cost $0.300$510 $525 $541 $557 $574 $591 $609 $627 $646 $665 $685 $706 $727 $749 $771 $894 $1,037 $1,202Annual Operating Cost Savings-$11,249-$11,383-$9,850-$9,946-$10,038-$10,126-$10,210-$10,288-$10,362-$10,430-$10,492-$10,547-$10,595-$10,635-$10,666-$10,674-$10,356-$9,584Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow(11,249) (11,383) (9,850) (9,946) (10,038) (10,126) (10,210) (10,288) (10,362) (10,430) (10,492) (10,547) (10,595)(10,635) (10,666) (10,674) (10,356) (9,584)Accumulated Cash Flow(11,249) (22,633) (32,483) (42,429) (52,467) (62,593) (72,802) (83,091) (93,453) (103,883) (114,375) (124,921) (135,516) (146,151) (156,817) (210,280) (262,848) (312,524)Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
Village of Lower Kalskag Biomass Heating System Option D.1.ALower Kalskag, AlaskaCord Wood Stove 30% OffsetDate: July 15, 2013 Analyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSTribal OfficeTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$6.75 Estimated Average Annual Fuel Usage:600600Annual Heating Costs:$4,050 $0 $0 $0 $4,050ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):80,700,000 0 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):64,560,000 0 0 0 64,560,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800 Cords of wood fuel to supplant net equivalent of 100% annual heating load.6Cords of wood fuel to supplant net equivalent of 85% annual heating load.525 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$8,100 Project Financing InformationPercent Financed0.0%Est. Pwr Use 250 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 2.0 40 80 $20.00 $1,600Amount of Grants$8,100 Other 0.0 40 0 $20.00 $01st 2 Year Learning 0.0 40 0 $20.00 $0Interest Rate5.00%Term10Annual Finance Cost (years)$0 -8.0 years Net Benefit B/C Ratio-$11,461 -$19,561 -1.41-$12,055 -$20,155-1.49Year Accumulated Cash Flow > 031Year Accumulated Cash Flow > Project Capital Cost31Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $6.75 600 gal $4,050 $4,253 $4,465 $4,688 $4,923 $5,169 $5,427 $5,699 $5,984 $6,283 $6,597 $6,927 $7,273 $7,637 $8,019 $10,234 $13,062 $16,670Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 30% 2 cords $553 $569 $586 $604 $622 $641 $660 $680 $700 $721 $743 $765 $788 $812 $836 $969 $1,124 $1,302Small load existing fuel$6.75 70% 420 gal $2,835 $2,977 $3,126 $3,282 $3,446 $3,618 $3,799 $3,989 $4,189 $4,398 $4,618 $4,849 $5,091 $5,346 $5,613 $7,164 $9,143 $11,669Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$1,600 $1,632 $1,665 $1,698 $1,732 $1,767 $1,802 $1,838 $1,875 $1,912 $1,950 $1,989 $2,029 $2,070 $2,111 $2,331 $2,573$2,841Additional Operation and Maintenance Costs First 2 years$0 $0Additional Electrical Cost $0.300$75 $77 $80 $82 $84 $87 $90 $92 $95 $98 $101 $104 $107 $110 $113 $132 $152 $177Annual Operating Cost Savings-$1,013-$1,003-$991-$977-$962-$944-$923-$900-$875-$846-$815-$780-$742-$700-$655-$361$69$681Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow(1,013) (1,003) (991) (977) (962) (944) (923) (900) (875) (846) (815) (780) (742) (700) (655) (361)69 681Accumulated Cash Flow(1,013) (2,015) (3,006) (3,984) (4,945) (5,889) (6,812) (7,712) (8,587) (9,433) (10,248) (11,028) (11,770) (12,471)(13,126) (15,567) (16,145) (14,048)Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
Village of Lower Kalskag Biomass Heating System Option D.1.BLower Kalskag, AlaskaCord Wood Stove 50% OffsetDate: July 15, 2013 Analyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSTribal OfficeTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$6.75 Estimated Average Annual Fuel Usage:600600Annual Heating Costs:$4,050 $0 $0 $0 $4,050ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):80,700,000 0 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):64,560,000 0 0 0 64,560,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800 Cords of wood fuel to supplant net equivalent of 100% annual heating load.6Cords of wood fuel to supplant net equivalent of 85% annual heating load.525 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$8,100 Project Financing InformationPercent Financed0.0%Est. Pwr Use 250 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 4.0 40 160 $20.00 $3,200Amount of Grants$8,100 Other 0.0 40 0 $20.00 $01st 2 Year Learning 0.0 40 0 $20.00 $0Interest Rate5.00%Term10Annual Finance Cost (years)$0 -3.7 years Net Benefit B/C Ratio-$31,178 -$39,278 -3.85-$28,575 -$36,675-3.53Year Accumulated Cash Flow > 031Year Accumulated Cash Flow > Project Capital Cost31Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $6.75 600 gal $4,050 $4,253 $4,465 $4,688 $4,923 $5,169 $5,427 $5,699 $5,984 $6,283 $6,597 $6,927 $7,273 $7,637 $8,019 $10,234 $13,062 $16,670Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 50% 3 cords $921 $949 $977 $1,007 $1,037 $1,068 $1,100 $1,133 $1,167 $1,202 $1,238 $1,275 $1,313 $1,353 $1,393 $1,615 $1,873 $2,171Small load existing fuel$6.75 50% 300 gal $2,025 $2,126 $2,233 $2,344 $2,461 $2,584 $2,714 $2,849 $2,992 $3,141 $3,299 $3,463 $3,637 $3,818 $4,009 $5,117 $6,531 $8,335Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$3,200 $3,264 $3,329 $3,396 $3,464 $3,533 $3,604 $3,676 $3,749 $3,824 $3,901 $3,979 $4,058 $4,140 $4,222 $4,662 $5,147$5,683Additional Operation and Maintenance Costs First 2 years$0 $0Additional Electrical Cost $0.300$75 $77 $80 $82 $84 $87 $90 $92 $95 $98 $101 $104 $107 $110 $113 $132 $152 $177Annual Operating Cost Savings-$2,171-$2,164-$2,154-$2,140-$2,124-$2,103-$2,079-$2,052-$2,019-$1,983-$1,941-$1,894-$1,842-$1,784-$1,720-$1,291-$641$305Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow(2,171) (2,164) (2,154) (2,140) (2,124) (2,103) (2,079) (2,052) (2,019) (1,983) (1,941) (1,894) (1,842) (1,784) (1,720) (1,291) (641)305Accumulated Cash Flow(2,171) (4,335) (6,488) (8,629) (10,752) (12,856) (14,935) (16,987) (19,006) (20,989) (22,930) (24,824) (26,666) (28,450) (30,170) (37,560) (42,168) (42,671)Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
Village of Lower Kalskag Biomass Heating System Option D.2Lower Kalskag, AlaskaCord Wood Stove 30% OffsetDate: July 15, 2013 Analyst: CTA Architects Engineers - Nathan Ratz EXISTING CONDITIONSCom/City HallTotalExisting Fuel Type:Fuel Oil Fuel Oil Fuel Oil Fuel OilFuel Units:gal gal gal galCurrent Fuel Unit Cost:$6.75 Estimated Average Annual Fuel Usage:1,7501,750Annual Heating Costs:$11,813 $0 $0 $0 $11,813ENERGY CONVERSION (to 1,000,000 Btu; or 1 dkt)Fuel Heating Value (Btu/unit of fuel):134500 134500 134500 134500Current Annual Fuel Volume (Btu):235,375,000 0 0 0Assumed efficiency of existing heating system (%):80% 80% 80% 80% Net Annual Energy Produced (Btu):188,300,000 0 0 0 188,300,000WOOD FUEL COSTCord Wood$/cord: $300.00Assumed efficiency of wood heating system (%): 65% PROJECTED WOOD FUEL USAGEEstimated Btu content of wood fuel (Btu/cord) - Assumed 20% MC, 6,700 Btu/lb x 28.4 lb/cf x 85 cf16,173,800 Cords of wood fuel to supplant net equivalent of 100% annual heating load.18Cords of wood fuel to supplant net equivalent of 85% annual heating load.1525 ton chip van loads to supplant net equivalent of 85% annual heating load.N/A Project Capital Cost-$16,300 Project Financing InformationPercent Financed0.0%Est. Pwr Use 250 kWh Type Hr/Wk Wk/Yr Total Hr Wage/Hr TotalAmount Financed$0 Elec Rate $0.300 /kWh Biomass System 2.0 40 80 $20.00 $1,600Amount of Grants$16,300 Other 0.0 40 0 $20.00 $01st 2 Year Learning 0.0 40 0 $20.00 $0Interest Rate5.00%Term10Annual Finance Cost (years)$0 63.5 years Net Benefit B/C Ratio$48,574 $32,274 2.98$21,993 $5,6931.35Year Accumulated Cash Flow > 0#N/AYear Accumulated Cash Flow > Project Capital Cost15Inflation FactorsO&M Inflation Rate2.0%Fossil Fuel Inflation Rate5.0%Wood Fuel Inflation Rate3.0%Electricity Inflation Rate3.0%Discount Rate for Net Present Value Calculation 3.0%Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year Year YearCash flow Descriptions Unit Costs HeatingSource ProportionAnnual Heating Source VolumesHeating Units 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30Existing Heating System Operating CostsDisplaced heating costs $6.75 1750 gal $11,813 $12,403 $13,023 $13,674 $14,358 $15,076 $15,830 $16,621 $17,452 $18,325 $19,241 $20,203 $21,214 $22,274 $23,388 $29,850 $38,096 $48,622Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Displaced heating costs $0.000 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Biomass System Operating CostsWood Fuel ($/ton, delivered to boiler site)$300.00 30% 5 cords $1,612 $1,660 $1,710 $1,761 $1,814 $1,869 $1,925 $1,983 $2,042 $2,103 $2,166 $2,231 $2,298 $2,367 $2,438 $2,827 $3,277 $3,799Small load existing fuel$6.75 70% 1225 gal $8,269 $8,682 $9,116 $9,572 $10,051 $10,553 $11,081 $11,635 $12,217 $12,828 $13,469 $14,142 $14,849$15,592 $16,372 $20,895 $26,668 $34,035Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Small load existing fuel$0.00 15% 0 gal $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0 $0Additional Operation and Maintenance Costs$1,600 $1,632 $1,665 $1,698 $1,732 $1,767 $1,802 $1,838 $1,875 $1,912 $1,950 $1,989 $2,029 $2,070 $2,111 $2,331 $2,573$2,841Additional Operation and Maintenance Costs First 2 years$0 $0Additional Electrical Cost $0.300$75 $77 $80 $82 $84 $87 $90 $92 $95 $98 $101 $104 $107 $110 $113 $132 $152 $177Annual Operating Cost Savings$257$351$453$561$677$801$933$1,074$1,224$1,384$1,555$1,736$1,930$2,135$2,353$3,666$5,426$7,770Financed Project Costs - Principal and Interest0000000000 Displaced System Replacement Costs (year one only)0Net Annual Cash Flow257 351 453 561 677 801 933 1,074 1,224 1,384 1,555 1,736 1,9302,135 2,353 3,666 5,426 7,770Accumulated Cash Flow257 608 1,061 1,622 2,298 3,099 4,032 5,105 6,329 7,714 9,26811,005 12,935 15,070 17,423 32,971 56,377 90,274Additional Power UseAdditional MaintenanceSimple Payback: Total Project Cost/Year One Operating Cost Savings:Net Present Value (30 year analysis):Net Present Value (20 year analysis):
APPENDIX C
Site Plan
APPENDIX D
Air Quality Report
Resource Systems Group, Inc.
55 Railroad Row
White River Junction, VT 05001
TEL 802.295.4999 | FAX 802.295.1006
www.rsginc.com
Transportation &
Environment Practice
Air Quality Feasibility Report
For the:
FEDC Pre‐Feasibility Studies
on Wood‐Fired Heating
Projects
Prepared for:
CTA Architects Engineers
Missoula, MT
July, 2013
Prepared by:
RSG, Inc.
Alaska 2013 Air Quality Pre‐Feasibility Study
Page i
TABLE OF CONTENTS
1.0 INTRODUCTION ......................................................................................... 1
2.0 EQUIPMENT DESCRIPTION ............................................................................ 1
3.0 SITE DESCRIPTIONS .................................................................................... 2
3.1 Emmonak ................................................................................................................................................. 2
3.2 Koyuk ........................................................................................................................................................ 2
3.3 Lower Kalskag........................................................................................................................................... 2
3.4 Tuntutuliak ............................................................................................................................................... 2
4.0 METEOROLOGICAL CONDITIONS .................................................................... 3
5.0 REGULATORY CONSIDERATIONS ..................................................................... 4
6.0 DESIGN & OPERATION RECOMMENDATIONS .................................................... 4
LIST OF FIGURES
Figure 1: Wind Speed Data from Bethel, AK .......................................................................................................... 3
Figure 2: Wind Speed Data from Nome, AK ........................................................................................................... 3
Alaska 2013 Air Quality Pre‐Feasibility Study
Page 1
1.0 INTRODUCTION
At the request of CTA, RSG has completed an air quality pre‐feasibility study of implementing biomass
energy systems in Emmonak, Koyuk, Lower Kalskag, and Tuntutuliak, Alaska. These systems will displace
fossil fuel used in these locations and therefore displace fossil fuel‐related emissions.
This report is broken into the following sections:
Equipment description
Site descriptions
Meteorological conditions
Regulatory considerations
Design and operation recommendations
2.0 EQUIPMENT DESCRIPTION
The following details were provided for the boilers being considered. Equipment vendors have not been
selected.
Emmonak
o Fuel: cord wood likely, wood chips also possible.
o Heating capacity: 250,000 Btu/hr output.
Koyuk
o Fuel: cord wood.
o Heating capacity: 150,000 Btu/hr output.
Lower Kalskag
o Fuel: cord wood.
o Heating capacity.
Alternative A: one boiler at 625,000 Btu/hr output.
Alternative B: one boiler at 250,000 Btu/hr output coupled with several high
efficiency wood stoves.
Tuntutuliak
o Fuel: cord wood
o Heating capacity: 125,000 Btu/hr
3 July 2013
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3.0 SITE DESCRIPTIONS
Descriptions of each site are provided below. USGS maps, aerial photography, and site maps are provided
in the Appendix.
3.1 Emmonak
Emmonak is a small village located near the west coast of Alaska, on the north bank of the Kwiguk Pass of
the Yukon River. The area is relatively flat. No significant air pollution sources were identified in the
review for this site. One biomass plant is being considered for this site at the Emmonak Corporate Store
and Offices Building.
3.2 Koyuk
Koyuk is a small village located near the west coast of Alaska. It is situated on the north bank of the Koyuk
River at Koyuk Inlet. The village is bordered by hills to the north and flat terrain to the south. The land
slopes downhill from north to south, with ground elevation ranging from approximately 100 feet to 15
feet. No significant air pollution sources were identified in the review for this site. One Biomass plant is
being considered for this site at the Kiniaq Building.
3.3 Lower Kalskag
Lower Kalskag is a small inland village located on the western bank of the Kuskowim River. The site is
relatively flat. No significant air pollution sources were identified in the review for this site. Two biomass
plants are considered for this site. One at the school and one near the clinic.
3.4 Tuntutuliak
Tuntutuliak is a relatively small inland village located on the northern bank of the Kinak River. The site is
relatively flat. No significant air pollution sources were identified in the review for this site. One biomass
plant is being considered for this site at the Community Hall.
Alaska 2013 Air Quality Pre‐Feasibility Study
Page 3
4.0 METEOROLOGICAL CONDITIONS
Meteorological data from Bethel and Nome, AK, were reviewed to develop an understanding of weather
conditions which will affect the dispersion of emissions. Bethel is the closest weather station
approximating climactic conditions in the Emmonak, Lower Kalskag, and Tuntutuliak. Nome is the closest
weather data approximating Koyuk. The data indicates calm winds occur approximately only 10% of the
year. This suggests there will be minimal time periods when thermal inversions and therefore poor
emission dispersion conditions can occur.1
Figure 1: Wind Speed Data from Bethel, AK
Figure 2: Wind Speed Data from Nome, AK
1 See: http://climate.gi.alaska.edu/Climate/Wind/Speed/Annette/ANN.html
3 July 2013
Page 4
5.0 REGULATORY CONSIDERATIONS
The size of the proposed boilers will not trigger state or federal permitting requirements. Hot water
boilers burning wood which are less than 1.6 MMBtu/hr heat input are below the threshold for EPA
boiler requirements. More information about EPA boiler requirements can be obtained here:
http://www.epa.gov/boilercompliance/
6.0 DESIGN & OPERATION RECOMMENDATIONS
These design and operation recommendations are based on the assumption that state‐of‐the‐art
combustion equipment is installed. The following are suggested for designing this project:
Burn natural wood, whose characteristics (bark content, species, geometry) optimizes
combustion in the equipment selected for the project.
Burn seasoned cord wood. Burning wet wood generates excess emissions.
Do not install a rain cap above the stack. Rain caps obstruct vertical airflow and reduce
dispersion of emissions.
In situations where there are clusters of buildings, consider constructing the stack to at least 1.5
times the height of the tallest roofline of the adjacent building. Hence, a 20 foot roofline would
result in a minimum 30 foot stack. Special attention should be given to this in Koyuk due to the
moderate slopes present.
Operate and maintain the boiler according to manufacturer’s recommendations.
Perform a tune‐up at least every other year as per manufacturer’s recommendations.
Conduct regular observations of stack emissions. If emissions are not characteristic of good
boiler operation, make corrective actions.
More information can be found about controlling wood boiler emissions can be obtained in a report
written by RSG called “Emission Controls for Small Wood‐Fired Boilers”. The report can be downloaded
here: http://www.wflccenter.org/news_pdf/361_pdf.pdf.
APPENDIX A
EMMONAK SITE INFORMATION
APPENDIX B
KOYUK SITE INFORMATION
00.510.25
Miles I
Koyuk Aerial Photography MAP
APPENDIX C
LOWER KALSKAG SITE INFORMATION
00.510.25
Miles I
Lower Kalskag Aerial Photo MAP
APPENDIX D
TUNTUTULIAK SITE INFORMATION
APPENDIX E
Wood Fired Heating Technologies
WOOD FIRED HEATING TECHNOLOGIES
CTA has developed wood-fired heating system projects using cord wood, wood pellet
and wood chips as the primary feedstock. A summary of each system type with the
benefits and disadvantages is noted below.
Cord Wood
Cord wood systems are hand-stoked wood boilers with a limited heat output of 150,000-
200,000 British Thermal Units per hour (Btu/hour). Cord wood systems are typically
linked to a thermal storage tank in order to optimize the efficiency of the system and
reduce the frequency of stoking. Cord wood boiler systems are also typically linked to
existing heat distribution systems via a heat exchanger. Product data from Garn, HS
Tarm and KOB identify outputs of 150,000-196,000 Btu/hr based upon burning eastern
hardwoods and stoking the boiler on an hourly basis. The cost and practicality of stoking
a wood boiler on an hourly basis has led most operators of cord wood systems to
integrate an adjacent thermal storage tank, acting similar to a battery, storing heat for
later use. The thermal storage tank allows the wood boiler to be stoked to a high fire
mode 3 times per day while storing heat for distribution between stoking. Cord wood
boilers require each piece of wood to be hand fed into the firebox, hand raking of the
grates and hand removal of ash. Ash is typically cooled in a barrel before being stock
piled and later broadcast as fertilizer.
Cordwood boilers are manufactured by a number of European manufacturers and an
American manufacturer with low emissions. These manufacturers currently do not
fabricate equipment with ASME (American Society of Mechanical Engineers)
certifications. When these non ASME boilers are installed in the United States,
atmospheric boilers rather than pressurized boilers are utilized. Atmospheric boilers
require more frequent maintenance of the boiler chemicals.
Emissions from cord wood systems are typically as follows:
PM2.5 >0.08 lb/MMbtu
NOx 0.23 lb/MMbtu
SO2 0.025 lb/MMbtu
CO2 195 lb/MMbtu
Benefits:
Small size
Lower cost
Local wood resource
Simple to operate
Disadvantages:
Hand fed - a large labor commitment
Typically atmospheric boilers (not ASME rated)
Thermal Storage is required
Page 1
Wood Pellet
Wood pellet systems can be hand fed from 40 pound bags, hand shoveled from 2,500
pound sacks of wood pellets, or automatically fed from an adjacent agricultural silo with
a capacity of 30-40 tons. Pellet boilers systems are typically linked to existing heat
distribution systems via a heat exchanger. Product data from KOB, Forest Energy and
Solagen identify outputs of 200,000-5,000,000 Btu/hr based upon burning pellets made
from waste products from the western timber industry. A number of pellet fuel
manufacturers produce all tree pellets utilizing bark and needles. All tree pellets have
significantly higher ash content, resulting in more frequent ash removal. Wood pellet
boilers typically require hand raking of the grates and hand removal of ash 2-3 times a
week. Automatic ash removal can be integrated into pellet boiler systems. Ash is
typically cooled in a barrel before being stock piled and later broadcast as fertilizer.
Pellet storage is very economical. Agricultural bin storage exterior to the building is
inexpensive and quick to install. Material conveyance is also borrowed from agricultural
technology. Flexible conveyors allow the storage to be located 20 feet or more from the
boiler with a single auger.
Emissions from wood pellet systems are typically as follows:
PM2.5 >0.09 lb/MMbtu
NOx 0.22 lb/MMbtu
SO2 0.025 lb/MMbtu
CO2 220 lb/MMbtu
Benefits:
Smaller size (relative to a chip system)
Consistent fuel and easy economical storage of fuel
Automated
Disadvantages:
Higher system cost
Higher cost wood fuel ($/MMBtu)
Page 2
Page 3
Wood Chip
Chip systems utilize wood fuel that is either chipped or ground into a consistent size of
2-4 inches long and 1-2 inches wide. Chipped and ground material includes fine
sawdust and other debris. The quality of the fuel varies based upon how the wood is
processed between the forest and the facility. Trees which are harvested in a manner
that minimizes contact with the ground and run through a chipper or grinder directly into
a clean chip van are less likely to be contaminated with rocks, dirt and other debris. The
quality of the wood fuel will also be impacted by the types of screens placed on the
chipper or grinder. Fuel can be screened to reduce the quantity of fines which typically
become airborne during combustion and represent lost heat and increased particulate
emissions.
Chipped fuel is fed from the chip van into a metering bin, or loaded into a bunker with a
capacity of 60 tons or more. Wood chip boilers systems are typically linked to existing
heat distribution systems via a heat exchanger. Product data from Hurst, Messersmith
and Biomass Combustion Systems identify outputs of 1,000,000 - 50,000,000 Btu/hr
based upon burning western wood fuels. Wood chip boilers typically require hand raking
of the grates and hand removal of ash daily. Automatic ash removal can be integrated
into wood chip boiler systems. Ash is typically cooled in a barrel before being stock piled
and later broadcast as fertilizer.
Emissions from wood chip systems are typically as follows:
PM2.5 0.21 lb/MMbtu
NOx 0.22 lb/MMbtu
SO2 0.025 lb/MMbtu
CO2 195 lb/MMbtu
Benefits:
Lowest fuel cost of three options ($/MMBtu)
Automated
Can use local wood resources
Disadvantages:
Highest initial cost of three types
Larger fuel storage required
Less consistent fuel can cause operational and performance issues
Page 4
Wood Stove
Wood stove systems are typically cast iron, hand-stoked wood heaters with a limited
output range of 10,000 – 50,000 BTU/hour. Wood stove systems are stand-alone
systems that heat a space or building and are required to be hand-fed. As these
systems are hand-fed, stoking is required. New wood stoves are feature improved
safety and efficiency over older models. Wood stoves are either catalytic or non-
catalytic combustion. Catalytic wood stoves are cleaner burning and more efficient than
non-catalytic wood stoves. However, catalytic wood stoves have a ceramic catalytic
piece which requires maintenance and eventual replacement. Wood stoves should be
EPA certified. For more information on wood stoves and a list of EPA certified wood
stoves, go to this website: http://www.epa.gov/burnwise/woodstoves.html
Wood stoves burn cord wood in smaller sizes than the cord wood boilers. Each piece of
wood must be hand fed into the stove, hand raking of the grate, and hand removal of
ash. Ash is typically cooled in a barrel before being stock piled and later broadcast as
fertilizer.
Emissions from wood stove systems are typically as follows:
PM2.5 >0.08 lb/MMbtu
NOx 0.23 lb/MMbtu
SO2 0.025 lb/MMbtu
CO2 195 lb/MMbtu
Benefits:
Small size
Local wood resource
Simple to operate
Optional cooking appliance
Disadvantages:
Equipment sits in the space being heated
Catalytic systems require maintenance
Non-catalytic systems are not as efficient as catalytic systems