HomeMy WebLinkAboutTech Feasibility Study Yakutat Biomass Appendix G 2009
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TECHNICAL FEASIBILITY STUDY
A 1.0-2.0 MW
Biomass Powered Organic Rankine Cycle System
for the Village of Yakutat, AK
Prepared for
Yakutat Power Alliance
By
William M. Bilbow, Jr.
WMB Enterprises
24 December 2009
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TABLE OF CONTENTS
Executive Summary............................................................................................................ 3
Introduction......................................................................................................................... 4
Biomass & Willows............................................................................................................ 4
Willow Production Yield................................................................................................ 5
Willow Biomass Demand............................................................................................... 7
Feedstock Options........................................................................................................... 9
Biomass Binary Power Plant Overview.............................................................................. 9
Feedstock Management ................................................................................................ 10
Biomass Boiler.............................................................................................................. 10
Thermal Resource Management System ...................................................................... 11
Organic Rankine Cycle Design..................................................................................... 12
Biomass Power Plant Facility/Building........................................................................ 13
Financial Summary........................................................................................................... 13
Project Plan....................................................................................................................... 18
Recommendations............................................................................................................. 19
Peer Review...................................................................................................................... 19
References......................................................................................................................... 20
APPENDIX A................................................................................................................... 21
Woody Biomass Data ................................................................................................... 21
APPENDIX B................................................................................................................... 23
Project Gantt Chart ....................................................................................................... 24
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Executive Summary
The Yakutat Biomass Power Plant feasibility report provided here has been prepared by
WMB Enterprises for the Yakutat Power Alliance in accordance with a technical services
contract dated and approved on 4 November 2009. The purpose of this study was to
provide a technical and financial assessment of the feasibility of constructing a 1.0-2.0
MW biomass power plant and its supporting infrastructure in Yakutat to meet the local
base load power demand.
The analysis examined modular binary Organic Rankine Cycle System designs with a
maximum-continuous combined electrical capacity up to 2.0 MW. All system
configurations examined use the author’s industry experience, and the predicted
performance has been subjected to peer review from industry experts.
Based upon the recommended thermal resource temperature of 300-325 dF and
condensing temperature of 40 dF, the air or water-cooled binary Organic Rankine Cycle
system can achieve a cycle efficiency of 20%. As a result, the thermal energy required for
a sustained power production of 1.0 MW is 17,061,000 Btu/hr. This may be achieved
with 772 acres of fast-growing willows or similar biomass per year based upon a three
year rotation. Therefore, the minimum land use for willow production is 2,313 acres.
The total project cost for the design and construction of the 2.0 MW biomass power plant
including the equipment and building is estimated at $10.86M or $5,430/kW. The total
biomass power production cost will be $0.12/kWh including fuel, fuel processing, labor,
operation and maintenance. Assuming that the current diesel power production cost is
$0.30/kWh, the simple payback is 6.7 years before any incentives such as renewable
energy credits or other federal and state tax credits. The final cost will depend upon the
final system specifications and equipment selections.
The extensive research and test results in the area of fast-growing willows as a renewable
and sustainable energy source was referenced extensively, especially the work published
by SUNY ESF.
The conclusions from this feasibility study support the continued development and
commissioning of a renewable & sustainable biomass power plant in the village of
Yakutat, Alaska.
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Introduction
The specific deliverables from the technical feasibility study are to answer the following
questions:
• What is the sustainable and renewable “fast-growing” willow production demand
to support the 1.2-1.6MW power plant?
• How many acres of willows will be required on a three, four and five year
rotation?
• What would be the estimated performance of the biomass-powered Organic
Rankine Cycle power plant?
• What is the proposed configuration of the biomass power plant to best meet the
power demands of the Yakutat community?
• What is the estimated cost of the biomass boiler and integrated Organic Rankine
Cycle power plant equipment?
In addition to the contractual deliverables presented above, this report will also provide
guidance on the power plant interface requirements and representative installation costs
for guidance in the cost of site design and installation of the biomass power plant.
Biomass & Willows
Biomass has recently emerged as a viable renewable resource for combined heat and
power applications from residential to industrial. While biomass feedstock is in general a
cellulose “woody” composition, sources may vary from waste wood such as used pallets
or cardboard by-products, to forest timber and woody crops such as fast-growing
willows. Many of their attributes are common such as the fact that they are renewable,
sustainable, carbon neutral and abundant.
In this feasibility study all biomass sources are considered. However for land-use
consideration, only fast-growing willows are examined.
Fast-growing willows have been the subject of significant research from a number of
research groups such as SUNY College of Environmental Sciences & Forestry,
University of Missouri-Columbia and Washington State University – Department of
Natural Resource Sciences.
Test sites particularly in the Northeastern Unites States have shown the yield and
financial benefits of coppicing fast-growing willows.
(1) Short-Rotation Woody Energy Crops: Bioenergy and Bioproducts Feedstock, SUNY-ESF, 2006 5
4 Month old coppice willows in Tully, NY (1)
One year post-coppice growth of hybrid Salix
variety willow (1)
Willow Production Yield
The yield of fast-growing willows will depend in part on the variety. It will be important
to select a variety that is indigenous or highly adaptive to Alaska, and specifically to the
air, soil and year-round seasonal conditions in Yakutat. Most research and full-scale
demonstrations of fast-growing willows have been performed in Canada and the northern
latitudes of the lower 48 states; specifically Ontario, Alberta, WI, MN, MI, NY, VT, PA,
NJ, MD, DE and NC. Based upon the work by pioneers in this field such as SUNY ESF,
(1) Short-Rotation Woody Energy Crops: Bioenergy and Bioproducts Feedstock, SUNY-ESF, 2006 6
the variety of willow with the greatest annual yield has been the hybrid Salix. The
analysis presented in this report is based upon the demonstrations of Salix in these
northern latitudes.
The growth rate for fast-growing willows in the early years is on average approximately
6-8 ft per year. Therefore, a three year growth will produce an average height of
approximately 18-24 ft.
The annual yield of coppiced fast-growing crop willows demonstrated over more than a
decade of research is 26 to 30 tons of wet willows per acre with 45% moisture for a three
year rotation. The upper net yield limit is therefore 16.5 dry tons per acre.
Commercial combine modified for willow crops (1)
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The amount of heat, or heating value, of dry willow is 6,905 Btu/lb, similar to northern
hardwoods. This represents the amount of heat that is released for every pound of willow
biomass as a fuel source for the power plant. This heating value is lower than the average
of woody biomass in general as shown in appendix A. Therefore the system performance
per unit mass of biomass may improve with some sources with a higher heating value.
Willow Biomass Demand
The biomass power plant capacity requirement was initially defined as 1.2 MW -1.6 MW,
representing the maximum electrical demand from the community. Subsequent
discussions have suggested that the peak demand may be as high as 2.0 MW and as low
as 750 kW.
The electrical load for similar communities with light industry and significant seasonal
weather variances is 40% to 100% of maximum. Therefore, for the purpose of this
feasibility study, the “load-following” range is expected to be 600 kW to 1600 kW (40%
and 100% of 1.6 MW). The average load for the purpose of biomass resource demand
(willow) is defined as 1.0 MW.
The efficiency and power density of the Organic Rankine Cycle (ORC) improves with
working fluid temperature range across the system, namely from evaporation to
condensation. At a constant condensing temperature of 40 dF, the cycle efficiency
doubles when the resource temperature is increased from 200 dF to 300 dF. By
improving the system efficiency, the amount of dry willows is reduced in half, thus
reducing the crop land-use per MW.
The ORC power plant was examined over a range of resource conditions from 200 dF to
300 dF with an average net power of 1.0 MW. The condensing temperature was also held
constant at 40 dF.
The results of the analysis are presented in the following table.
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Estimated ORC Power Plant Cycle Efficiencies ~ f(Resource Temperature)
kW 1,000 1,000 1,000 1,000 1,000
Resource Temp degF 180 200 240 280 300
ORC Rating (thermal) Btu/hr 3,412,096 3,412,096 3,412,096 3,412,096 3,412,096
Cycle Eff Cycle Eff 0.06 0.08 0.12 0.16 0.20
Uptime Eff Uptime Eff 1.00 1.00 1.00 1.00 1.00
Hrs/yr Hrs/yr 8760 8760 8760 8760 8760
Op (hrs/yr) Op (hrs/yr) 8760 8760 8760 8760 8760
kWh/yr kWh/yr 8,760,000 8,760,000 8,760,000 8,760,000 8,760,000
Willows Rotation Yrs 3 3 3 3 3
Yield (wet tons) Tw/acre 30 30 30 30 30
%Moisture % 0.45 0.45 0.45 0.45 0.45
Yield (dry tons) Td/acre 16.5 16.5 16.5 16.5 16.5
Mass Density Lbs/cord 2,100 2,100 2,100 2,100 2,100
Heating Value Btu/cord 14,500,000 14,500,000 14,500,000 14,500,000 14,500,000
Btu/lb 6904.8 6904.8 6904.8 6904.8 6904.8
Thermal Input Btu/hr (input)56,868,267 42,651,200 28,434,133 21,325,600 17,060,480
Feedstock Lb/hr 8236.1 6177.1 4118.0 3088.5 2470.8
Ton/hr 4.12 3.09 2.06 1.54 1.24
Tons/day 98.83 74.12 49.42 37.06 29.65
Burner eff Burner eff 0.85 0.85 0.85 0.85 0.85
Net Ton/hr Net Ton/hr 4.84 3.63 2.42 1.82 1.45
Tons/yr Tons/yr 42440.1 31830.1 21220.1 15915.0 12732.0
Feedstock Demand Acres/yr 2,572 1,929 1,286 965 772
Acres/kW/yr 2.57 1.93 1.29 0.96 0.77
Total Acres 7,716 5,787 3,858 2,894 2,315
In the table above, the resource temperature is varied from 180 dF to 300 dF. At 180 dF,
the cycle efficiency is 6% with a corresponding feedstock demand for an average 1 MW
power production of 99 tons/day and requiring 2,572 acres of coppiced willows per year.
At 300 dF, the cycle efficiency is 20%, lowering the feedstock demand for the same
power to 30 tons/day and 772 acres per year. This data suggests that the power plant
efficiency improves dramatically with increased resource temperature, thus lowering the
production demand of the biomass feedstock.
kW 750 1,000 1,200 1,600 2,000
ORC Rating (thermal) Btu/hr 2,559,072 3,412,096 4,094,515 5,459,354 6,824,192
Cycle Eff Cycle Eff 0.20 0.20 0.20 0.20 0.20
Uptime Eff Uptime Eff 1.00 1.00 1.00 1.00 1.00
Hrs/yr Hrs/yr 8760 8760 8760 8760 8760
Op (hrs/yr) Op (hrs/yr) 8760 8760 8760 8760 8760
kWh/yr kWh/yr 6,570,000 8,760,000 10,512,000 14,016,000 17,520,000
Willows Rotation Yrs 3 3 3 3 3
Yield (wet tons) Tw/acre 30 30 30 30 30
%Moisture % 0.45 0.45 0.45 0.45 0.45
Yield (dry tons) Td/acre 16.5 16.5 16.5 16.5 16.5
Mass Density Lbs/cord 2,100 2,100 2,100 2,100 2,100
Heating Value Btu/cord 14,500,000 14,500,000 14,500,000 14,500,000 14,500,000
Btu/lb 6904.8 6904.8 6904.8 6904.8 6904.8
Thermal Input Btu/hr (input)12,795,360 17,060,480 20,472,576 27,296,768 34,120,960
Feedstock Lb/hr 1853.1 2470.8 2965.0 3953.3 4941.7
Ton/hr 0.93 1.24 1.48 1.98 2.47
Tons/day 22.24 29.65 35.58 47.44 59.30
Burner eff Burner eff 0.85 0.85 0.85 0.85 0.85
Net Tons/hr Tons/hr 1.09 1.45 1.74 2.33 2.91
Net Tons/day Tons/day 26.16 34.88 41.86 55.81 69.76
Tons/yr Tons/yr 9549.0 12732.0 15278.4 20371.3 25464.1
Feedstock Demand Acres/yr 579 772 926 1,235 1,543
Acres/kW/yr 1 1 1 1 1
Total Acres 1,736 2,315 2,778 3,704 4,630
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The results show that the ORC operating at 1.0 MW will require 17,060,480 Btu/hr
which is 2,471 pounds of dry willow biomass per hour or 34.9 tons per day. With a yield
of 16.5 tons per acre per year for a three year rotation, the amount of willow feedstock
required per year is 772 acres, or a total land use of 2,315 acres.
Four and five year rotations were also examined. The crop yield for the same 1.0 MW
ORC demand (acres/yr) was analyzed and is presented in the table below.
ROTATION (YRS)
PARAMETER UNITS 3 4 5
ORC Power Rating kW 1,000 1,000 1,000
Biomass Demand Btu/hr 17,060,480 17,060,480 17,060,480
Willows / Yr Acres 772 609 503
Total Land Use Acres 2,315 2,437 2,516
The results show that with a four and five year rotation, the number of acres per year is
reduced from 772 to 609 and 503 respectively. However, because the rotations are
increased, the total land use increases slightly from 2,315 acres to as much as 2,516 acres.
Therefore, from a land use standpoint, a three year rotation may be preferred. However, if
land use is not a concern, the additional growing seasons would provide substantial
margin in willow production for uncontrolled variances in the growing seasons to affect
the willow production yield.
Feedstock Options
Biomass boilers are designed with numerous configurations for various feedstock
compositions and duty. Continuous duty systems often use an automated auger-type
feeder system to provide a measured amount of slurry feedstock such as wood chips,
pellets, etc. to the primary burner. Other systems may use “batch” operation, by which a
burner is stocked manually with bulk biomass such as logs, packed cardboard, etc.
The batch operation is less efficient and requires additional labor to operate. Therefore,
the automatic feed system with slurry feedstock is recommended and is the basis for this
analysis.
Biomass Binary Power Plant Overview
The biomass power plant consists of four major subsystems; 1) feedstock management,
2) biomass boiler, 3) thermal resource management, and 4) binary Organic Rankine
Cycle (ORC) system.
The range in power demand has been specified as 750 – 2,000 kW or 2.67 times the
minimum demand, and an average demand of 1,000 – 1,200 kW. This range is critical in
designing the size and configuration of the power plant. An ORC operates efficiently
above 60% of its rated power and most efficiently above 80%. Below 60% of its rated
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power the system parasitic load becomes a more dominant factor and along with slight
decreases in aerodynamic performance the system efficiency begins to decrease, thus
requiring more feedstock per kW. Therefore, the biomass power production configuration
was evaluated with 750-2,000 kW operating range and a minimum 60% load.
The following table examines various configurations. The number of ORC systems
required is determined by considering that the combined power production is not more
than 90% of the nameplate power. The step power presented below is the minimum
specified combined power of 750 kW, and the power demand to exceed the 90% of
nameplate production and warrant augmentation of an “additional” ORC.
Examination of System Configurations
Power kW 2000 2000 2000 2000 2000 2000
ORC # 4 4 4 5 5 5
Rating kW 500 500 500 400 400 400
Step Power kW 750 900 1350 750 1080 1440
Units Required for Demand # 2 3 4 3 4 5
%Min Power % 75% 60% 68% 63% 68% 72%
Feedstock Management
The biomass feedstock to be used in this power plant is fast-growing willows which are
harvested as tall narrow trunks with minimal branch appendages. The length of the trunks
should be approximately 16-18 feet after a three year growth. The feedstock must be
processed into wood chips or pellets for use in the boiler. The biomass will have
approximately 45% moisture by weight which should be dried to approximately 10%
moisture or less. Once the biomass has been processed, the surface area is increased
significantly. Provided that the stock is held in a warm and dry environment, the moisture
release occurs very rapidly.
The feedstock management will consist of the processing, storage and automated
utilization of the feedstock for fuel to the biomass boiler. The fast-growing willows are
converted to chips or pellets, dried, and then stored before fed into the biomass boiler by
a dry feed auger system.
Biomass Boiler
The thermal energy to drive a biomass ORC power plant is generated from a biomass
boiler which takes a biomass fuel or feedstock, and efficiently converts it into thermal
energy which is captured in a thermal media for use in electricity generation or other
thermal utilization.
The principal objective of the biomass power plant is to generate the base load electricity
used in the village which ranges from 750 kW to approximately 2.0 MW with an average
demand of approximately 1.0 MW. The proposed ORC system will require 5.0 MW
thermal energy for each 1.0 MW of electrical power. Therefore, a 2.0 MW electrical load
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will require a 10.0 MW boiler to generate the required thermal energy. Boilers of this
type can be highly efficient even at loads as low as 25% of the nameplate capacity;
therefore one boiler can efficiently deliver the thermal input for the full range of electrical
demand. This will provide ease in the site design of the boiler, biomass feedstock
management and exhaust management.
The size of a biomass boiler including the feedstock supply and emissions containment
varies from approximately 200-350 SF/MWth within the 1.0-2.0 MW range among
manufacturers and models.
Thermal Resource Management System
Biomass boilers today have been designed to provide hot water or/or steam over a range
of conditions to include medium to high pressure. The biomass ORC power plant
considered at Yakutat Alaska will utilize thermal oil such as Therminol which is widely
used for process heating in a wide range of industries at temperatures approaching 500
dF. Rather than heating water, the biomass boiler will directly heat thermal oil at 20 psig
to 300-325 dF which remains in liquid state and well below its boiling point.
The thermal oil reservoir will be integral with the boiler and circulated by a liquid pump
through a closed-loop header system to each modular ORC systems in parallel. This
system design allows for expansion with additional ORC systems for electrical power
production, or future thermal utilization such as district or process heating without
disruption of the plant operation. This plant arrangement is illustrated as follows:
Biomass
Boiler
ORC
1
ORC
2
ORC
3
ORC
4
(Exp)
ORC
5
(Exp)
Thermal Resource Management Loop
The illustration above shows the thermal resource loop consisting of two headers
extending from the biomass boiler, one supply and one return, with a liquid pump on the
header return (to the boiler). Along the supply header are both bypass lines and pipe
takeoffs for each of the modular ORCs. As shown, the first three ORC are shown as the
base installation, whereas ORCs 4 & 5 are shown to illustrate how the power plant can be
expanded in the future. The actual number of ORCs in the base design will be defined in
the concept design phase.
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Organic Rankine Cycle Design
Not all Organic Rankine Cycle are the same, however they all are highly dependent upon
the temperature range over which it operates at any moment. Increasing the resource
temperature or lowering the condensing temperature improves the ORC overall cycle
efficiency. For the same resource feedstock massflow rate, this in general means greater
electricity production.
The ORC utilizes a thermal resource to evaporate a working fluid at elevated pressure,
and then expands that fluid through a turbine before it is condensed by a low temperature
heat sink. Important factors which determine the performance, size and cost are the
resource (heat) temperature, mass flow, specific heat, thermal resource composition
(constituents), as well as the condensing or heat sink temperature, mass flow and specific
heat.
Concept designs were therefore evaluated to determine the configuration that will provide
a balanced design and most favorable financial results.
The illustration above shows a central boiler and thermal resource circulation loop
integrated with a single binary Organic Rankine Cycle system. These subsystems are
described below.
The footprint of the ORC system is defined by its power density. Starting with a
reference ORC system currently in operation at Chena Hot Springs Alaska, similar
systems expanded to 1 MW were considered. The turbine, pump and heat exchanger
performance were all evaluated to project the corresponding power density. The results
are shown in the following table.
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Power Density Table
Rating (kW) L (ft) W (ft) H (ft) Sq.Ft.
Power Density
(kW / SqFt)
200 18 9 10 162 1.235
400 18 11 12 198 2.020
500 18 12 14 216 2.315
1000 24 14 16 336 2.976
As shown, the power density for the Chena systems is 1.2 kW/SqFt, whereas a 400 kW
system would increase the power density to 2.0 kW/ SqFt. The suggested modular size
for the Yakutat biomass power plant is 400-500 kW, which corresponds to power
densities of 2.0-2.3 kW/ SqFt respectively. Considering a service isle between ORC
systems, the estimated footprint for the ORCs alone for 2.0 MW of power production
with 400 kW systems is 1200-1600 SF.
Biomass Power Plant Facility/Building
The biomass power plant design will need to consider the adequate protection and
serviceability of the biomass boiler, binary ORC systems, thermal resource management
system, feedstock storage and management and switchgear or other power/grid
integration. Also considered in this report is plant support staff facilities.
The 2MW estimated building space requirements are estimated for various ORC unit
ratings as follows:
Unit Rating
(kW)
Power Density
(kW / SqFt)ORCs
Service
Space Boiler Switchgear Admin TOTAL
200 1.235 1,620 2,340 6,000 480 354 10,794
400 2.020 990 1,350 6,000 240 354 8,934
500 2.315 864 1,152 6,000 192 354 8,562
1000 2.976 672 864 6,000 96 354 7,986
Floorspace Requirement (SqFt)
Financial Summary
The total cost of the project will include development, equipment and installation. The
material cost for the power production equipment, the infrastructure equipment, and
facilities. The development and material cost of the power production equipment is well
contained here with confidence.
The integration of the system with the existing and future upgraded power production
infrastructure is dependent upon the design integration. Therefore, estimated values only
are offered here based upon previous experience.
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Description Reference Unit Qty Total
Feedstock Management 60 tons/day $80,000 1 $80,000
Biomass Boiler 40 mmBtu/hr $800,000 1 $800,000
Emissions Scrubber $160,000 2 $320,000
Thermal Resource System $160,000 1 $160,000
400kW ORC Power System $560,000 5 $2,800,000
System Piping $80,000 5 $400,000
System Control $200,000 1 $200,000
Switchgear / Transformers $60,000 5 $300,000
Other / Miscellaneous $500,000 1 $500,000
Building ($250/SF) 9000 $2,250,000 1 $2,250,000
Installation $400/kW+$50k/unit $1,050,000 1 $1,050,000
Development $2,000,000 1 $2,000,000
TOTAL $10,860,000
$/kW $5,430
2.0 MW (5x400kW) Installation
The recommended minimum installed power production to handle the base load for the
majority of the year is 1.2 MW. Again considering a modular 400 kW system, this will
consist of three (3) 400 kW ORCs with standby duty provided by other resources, such as
diesel or wave. The resulting financial summary is as follows:
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Description Reference Unit Qty Total
Feedstock Management 60 tons/day $80,000 1 $80,000
Biomass Boiler 40 mmBtu/hr $800,000 1 $800,000
Emissions Scrubber $160,000 2 $320,000
Thermal Resource System $160,000 1 $160,000
400kW ORC Power System 400 $560,000 3 $1,680,000
System Piping $80,000 3 $240,000
System Control $200,000 1 $200,000
Switchgear / Transformers $60,000 3 $180,000
Other / Miscellaneous $500,000 1 $500,000
Building ($250/SF) 9000 $2,250,000 1 $2,250,000
Installation $400/kW+$50k/unit $950,000 1 $950,000
Development $1,900,000 1 $1,900,000
TOTAL $9,260,000
$/kW $4,630
1.2 MW (3x400kW) Installation
Note that the biomass boiler has not been resized, nor has the building equipment space
been reduced. This will allow for expansion of additional 400 kW modular ORC power
systems to the fully intended capacity of 2.0 MW.
One additional scenario was examined; using the 200 kW ORC systems identical to those
at Chena Hot Springs and only modified for the alternate operating temperature range.
The building increased from approximately 9,000 SqFt to 11,000 SqFt. The resulting
financial estimate is as follows:
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Description Reference Unit Qty Total
Feedstock Management 60 tons/day $80,000 1 $80,000
Biomass Boiler 40 mmBtu/hr $800,000 1 $800,000
Emissions Scrubber $160,000 2 $320,000
Thermal Resource System $160,000 1 $160,000
200kW ORC Power System 200 $380,000 10 $3,800,000
System Piping $80,000 10 $800,000
System Control $200,000 1 $200,000
Switchgear / Transformers $60,000 10 $600,000
Other / Miscellaneous $500,000 1 $500,000
Building ($250/SF) 11000 $2,750,000 1 $2,750,000
Installation $400/kW+$50k/unit $1,300,000 1 $1,300,000
Development $1,200,000 1 $1,200,000
TOTAL $12,510,000
$/kW $6,255
2.0 MW (10x200kW) Installation
Fuel Cost
Units w/o Incentives w/ Incentives
Fuel Cost $/mmBtu $3.00 $1.80
Rating MW 1 1
kW 1000 1000
Energy Input Btu/MWh 17,060,480 17,060,480
mmBtu/MWh 17.06 17.06
Service Hrs/yr 8760 8760
mmBtu/MW 149,450 149,450
Fuel Cost $/Yr $448,349 $269,010
MWh/yr 8760 8760
$/kWh 0.0512 0.0307
Labor Cost
Units w/o Incentives
with
Incentives
People Qty 1 1
Hours Hrs 8760 8760
Rate $/hr $60.00 $60.00
Total Incremental Labor $$525,600 $525,600
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Financial Analysis
Total O&M Cost, Savings and Simple Payback
Units w/o Incentives
with
Incentives
Fuel $/kWh $0.0512 $0.0307
Labor $/kWh $0.0600 $0.0600
Maintenance $/kWh $0.0040 $0.0040
Total O&M Cost $/kWh $0.1152 $0.0947
Equivalent Diesel (Estimate) $/kWh $0.3000 $0.3000
Savings $/kWh $0.1848 $0.2053
Fuel $ $448,349 $269,010
Labor $ $525,600 $525,600
Maintenance $ $35,040 $35,040
Total $/yr $1,008,989 $829,650
Diesel Estimate $/yr $2,628,000 $2,628,000
Savings $/yr $1,619,011 $1,798,350
Simple Payback Years 6.71 6.04
The analysis is all present day and does not consider escalation for either biomass or
fossil fuel commodity pricing.
The term “Incentives” shown in the tables above denote the tax credits offered for power
generated from renewable resources and the commodity value of RECs or “Renewable
Energy Credits”. Not included above are any penalties, either current or future, for GHG
emissions that exceed legislated caps or other environmental assessments attributed to
fossil fuel based power production.
The expected simple payback is 6.7 years, assuming that the net cost for power today by
diesel generators is $0.30/kWh, including fuel, labor, operation & maintenance.
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Project Plan
A representative project plan has been considered here based upon previous relevant
experience. The plan consists of four phases as follows:
1. Concept Design
2. Detailed System Design
3. Installation & Startup
4. System Monitoring
Each phase consists of finite tasks & deliverables enumerated as line items in the Gantt
chart and may be seen in more detail in Appendix B. The dependencies among the tasks
are denoted by arrows. At the completion of each phase, a project review is suggested, by
which a detailed review of the phase deliverables are reviewed. Approval to proceed with
the next phase or redirection may be offered at this time by the governing board to the
project team.
The project plan Gantt chart is offered below and in Appendix B.
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Recommendations
The recommendations offered here for the Yakutat Biomass Power Plant are as follows:
1. Conduct a timely review & debate of the feasibility study.
2. Complete the equipment specification requirements.
3. Secure WMB Enterprises & its partners for power plant design to meet the
equipment specifications.
4. Secure an engineering firm for the site design.
5. Begin the concept design by 12 January 2010 or sooner, as per the project plan
offered here.
6. Submit the concept design of the power plant and final feedstock evaluation &
design to AEA as per Grant #2195424.
7. Secure and begin processing the land for fast-growing willow crop production at
earliest opportunity (spring thaw).
Peer Review
The report has been submitted to engineers and business leaders with direct experience in
the technologies examined in this report. The information and analysis presented here is
consistent with industry experience. Final results may vary depending upon the final
selection of the equipment and system integration.
20
References
Short-Rotation Woody Energy Crops: Bioenergy and Bioproducts Feedstock, L.P.
Abrahamson, T.A. Volk, L.B. Smart, E.H. White, T.E. Amidon and A.J.Stopavonic,
SUNY-ESF, Syracuse, NY, 2006
How to Estimate Recoverable Heat Energy in Wood or Bark Fuels, Peter J. Ince, U.S.
Department of Agriculture, Forest Service, Forest Products Laboratory, 1979
Biomass Feasibility Study for the Southwestern Vermont Medical Center, GDS
Associates Inc., NH, 2009
Willow Biomass Producer’s Handbook, SUNY-Environmental Sciences and Forestry,
NY, 2002
21
APPENDIX A
Woody Biomass Data
22
Woody Biomass Data (2)
Name Species Lb/Cord MBTU's/Cord Btu/Lbm
Alder, Red Alnus rubra 2,710 17.2 6347
Apple Malus domestica 4,100 26.5 6463
Ash, Black Fraxinus nigra 2,992 19.1 6384
Ash, Green Fraxinus pennsylvanica 2,880 19.9 6910
Ash, White Fraxinus americana 3,689 23.6 6397
Aspen, American Populus tremuloides 2,290 14.7 6419
Basswood (Linden) Tilia 2,108 13.8 6546
Beech, Blue (Ironwood) Carpinus caroliniana 3,890 26.8 6889
Beech, European Fagus sylvatica 3,757 24 6388
Birch, Black Betula lenta 3,890 26.8 6889
Birch, Gray Betula populifolia 3,179 20.3 6386
Birch, Paper (White) Betula papyrifera 3,179 20.3 6386
Birch, Yellow Betula alleghaniensis 3,689 23.6 6397
Boxelder Acer negundo 2,797 17.9 6400
Buckeye, Ohio Aesculus glabra 1,984 13.8 6956
Catalpa Catalpa speciosa 2,360 16.4 6949
Cedar, White Thuja occidentalis 1,913 12.2 6377
Cherry Prunus 3,120 20 6410
Cherry, Black Prunus serotina 2,880 19.9 6910
Coffeetree, Kentucky Gymnocladus dioicus 3,112 21.6 6941
Cottonwood Populus 2,108 13.5 6404
Elm, American Ulmus americana 3,052 19.5 6389
Elm, Red Ulmus rubra 3,112 21.6 6941
Elm, White Ulmus laevis 3,052 19.5 6389
Elm, Russian (Siberian) Ulmus laevis 3,052 19.5 6389
Fir, Balsam Abies balsamea 2,236 14.3 6395
Fir, Concolor (White) Abies concolor 2,104 14.1 6702
Fir, Douglas Pseudotsuga 2,900 18.1 6241
Hackberry Celtis occidentalis 3,247 20.8 6406
Hemlock Pinaceae tsuga 2,482 15.9 6406
Hickory, Bitternut Carya cordiformis 3,832 26.7 6968
Hickory, Shagbark Carya ovata 4,327 27.7 6402
Hop Hornbeam (Ironwood) Ostrya virginiana 4,267 27.3 6398
Juniper, Rocky Mtn Juniperus scopulorum 3,150 21.8 6921
Locust, Black Robinia pseudoacacia 3,890 26.8 6889
Locust, Honey Gleditsia triacanthos 3,832 26.7 6968
Maple, Red Acer rubrum 2,924 18.7 6395
Maple, Sugar Acer saccharum 3,757 24 6388
Mulberry Morus rubra 3,712 25.8 6950
Oak, Red Quercus rubra 3,757 24 6388
Oak, White Quercus alba 4,012 25.7 6406
Osage Orange (Hedge) Maclura pomifera 4,728 32.9 6959
Pine, Jack Pinus banksiana 2,669 17.1 6407
Pine, Norway Pinus resinosa 2,669 17.1 6407
Pine, Pitch Pinus rigida 2,669 17.1 6407
Pine, Ponderosa Pinus ponderosa 2,380 15.2 6387
Pine, Red Pinus banksian 2,380 15.2 6387
Pine, White Pinus strobus 2,236 14.3 6395
Pine, Eastern (Western) Pinus strobus 2,236 14.3 6395
Spruce Picea 2,100 14.5 6905
Spruce, Black Picea mariana 2,482 15.9 6406
Sycamore Platanus 2,808 19.5 6944
Tamarack Larix laricina 3,247 20.8 6406
Walnut, Black Juglans nigra 3,192 20.2 6328
Walnut, White (Butternut) Juglans cinerea 2,100 14.5 6905
Willow Salix 2,100 14.5 6905
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APPENDIX B
Project Plan (Viewable)
Project Plan (Viewable)
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