Transcript IDEA - Smart Solutions That Work | WM Group

The Cost of Using 1970’s Era
Design Concepts and “FEAR”in
Chilled Water Systems
Presented By: Hemant Mehta, P.E.
WMGroup Engineers, P.C.
What is the “FEAR”
• No change in design as previous design had no
complains from client
– No complain because no bench mark exists
– Fear to take the first step to change the concepts to
use state of the art technology
– Consultants sell time. Fear is any new concept will
take lots of time and it is not worth the effort
What are1970’s Era
Design Concepts?
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System Design for Peak load only
Primary/Secondary/Tertiary Pumping
5°C (42°F) supply temperature
System Balancing
Circuit Setters
Band Aid solution for any Problem
Projected Demand way above reality
Oversized chiller, pumps TDH and everything else to
cover behind
State of the Art Plant concepts
• Plant designed for optimum operation for the year. Peak
hours are less than 200 hours a year
• Variable flow primary pumping system
• 3.3°C (38°F) or lower supply temperature
• No System Balancing. Balancing is for a static system.
• No Delta P valves – No Circuit Setters
• No Band Aid solution for any Problem
• Use chilled water system diversity (0.63) to Project
Cooling Demand
• The total Chilled water pumping TDH even for a very
large system should not be more 63 meters(than 200
feet)
Selecting Equipment to Optimize Efficiency
Chiller equipment is often erroneously selected based on
peak load efficiency.
Peak load only occurs for a small number of hours of the year,
as shown on the load duration curve below:
Jeddah Airport - Cooling Load Duration Curve
16,000
14,000
Load (Tons)
12,000
10,000
8,000
6,000
4,000
2,000
0
0
1,000
2,000
3,000
4,000
5,000
Hours
6,000
7,000
8,000
The Design of the Human Body
Lungs
Brain
(Chillers)
(Building End-Users)
Heart
(Variable Volume Primary Pump)
Basic 1970’s Era Chiller Plant Design
Decoupler
Line
Chiller
Primary Pump
Secondary Pump
Building
Loads
Current Design Used on Many Large District
Chilled Water Systems
Chiller
Decoupler
Line
Primary
Pump
Secondary
Pump
Energy
Transfer
Station
Building
Pump
Building
Loads
Modern Variable Volume Primary
Chiller Plant Design
Building
Loads
Chiller
Variable Speed
Primary Pump
Lost Chiller Capacity Due to Poor ΔT
Ideal Design Conditions
150 L/sec
(2,400 gpm)
150 L/sec
(2,400 gpm)
13°C (55.5°F)
13°C (55.5°F)
No Flow
Through
Decoupler
5°C (41°F)
5°C (41°F)
150 L/sec
(2,400 gpm)
150 L/sec
(2,400 gpm)
Chiller sees a ΔT of 8°C (14.5°F) at a flow of 150 L/sec (2,400 gpm)
The chiller capacity is therefore 5,000 kW (1,450 tons)
Lost Chiller Capacity Due to Poor ΔT
Case 1: Mixing Through Decoupler Line
150 L/sec
(2,400 gpm)
75 L/sec
(1,200 gpm)
9°C (48.25°F)
13°C (55.5°F)
75 L/sec
(1,200 gpm)
at
5°C (41°F)
5°C (41°F)
5°C (41°F)
150 L/sec
(2,400 gpm)
75 L/sec
(1,200 gpm)
Chiller sees a ΔT of 4°C (7.25°F) at a flow of 150 L/sec (2,400 gpm)
The chiller capacity is therefore 2,500 kW (725 tons)
Lost Chiller Capacity Due to Poor ΔT
Case 2: Poor Building Return Temperature
150 L/sec
(2,400 gpm)
150 L/sec
(2,400 gpm)
9°C (48.25°F)
9°C (48.25°F)
No Flow
Through
Decoupler
5°C (41°F)
5°C (41°F)
150 L/sec
(2,400 gpm)
150 L/sec
(2,400 gpm)
Chiller sees a ΔT of 4°C (7.25°F) at a flow of 150 L/sec (2,400 gpm)
The chiller capacity is therefore 2,500 kW (725 tons)
Small Loss in ΔT Rapidly Reduces
Chiller Capacity
Assuming a design ΔT of 8°C
(14.4°F):
System ΔT
Chiller Capacity
8.0°C (14.4°F)
100%
7.5°C (13.5°F)
94%
7.0°C (12.6°F)
88%
6.5°C (11.7°F)
81%
6.0°C (10.8°F)
75%
5.5°C (9.9°F)
69%
5.0°C (9.0°F)
63%
4.5°C (8.1°F)
56%
4.0°C (7.2°F)
50%
Technical Paper by Erwin Hanson
(Pioneer in Chilled Water System Design)
8°
C
9°
C
11°
C
Billing Algorithm for Buildings to Give
Incentive to Owners to Improve ΔT
• Adjusted Demand Cost
Total Site
X
Demand Cost
Bldg ton-hrs
Total ton-hrs
Cost
X Penalty
Factor
• Adjusted Consumption Cost
Total Site
Electric Cost
-
Total Adjusted
Bldg Demand
Cost
X
• Total Cost = Demand + Consumption
Bldg ton-hrs
Total ton-hrs
The Design of the Human Body
Lungs
Brain
(Chillers)
(Building End-Users)
Heart
(Variable Volume Primary Pump)
History of Variable Primary Flow Projects
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King Saud University - Riyadh (1977)
Louisville Medical Center (1984)
Yale University(1988)
Harvard University (1990)
MIT(1993)
Amgen (2001)
New York-Presbyterian Hospital (2002)
Pennsylvania State Capitol Complex (2005)
Duke University (2006)
NYU Medical Center (2007)
Memorial Sloan-Kettering Cancer Center (2007)
King Saud University – Riyadh (1977)
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60,000 ton capacity with 30,000 tons for first phase
Six 5,000 ton Carrier DA chillers
Seven 10,000 GPM 240 TDH constant speed pumps
Major Problem: Too much head on chilled water pumps
Lesson Learned: Be realistic in predicting growth
Louisville Medical Center (1984)
• Existing system (1984)
– Primary/Secondary/Tertiary with 13,000 ton capacity
• Current System (2007)
– 120 feet TDH constant speed primary pumps with
building booster pumps – 30,000 ton capacity
– Changed the heads on some of the evaporator shells
to change number of passes
– Primary pumps are turned OFF during winter, Early
Spring and Late Fall. Building booster pumps are
operated to maintain flow.
Yale University (1988)
• Existing system (1988)
– Primary/Secondary/Tertiary with 10,500 ton capacity
• Current System (2007)
– 180 feet TDH VFD / Steam Turbine driven variable
flow primary pumps – 25,000 ton capacity
– Changed the heads on some of the evaporator shells
to change number of passes
Amgen (2001)
• Creation of a computerized hydraulic model of the existing
chilled water plant and distribution system
• Identification of bottlenecks in system flow
• Evaluation of existing capacity for present and future loads
• Two plants interconnected: Single plant operation for most
of the year, second plant used for peaking
• Annual Energy Cost Savings: $500,000
Additional Variable Primary
Flow Projects
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Harvard University (1990)
MIT(1993)
New York-Presbyterian Hospital (2002)
Pennsylvania State Capitol Complex (2005)
Duke University (2006)
NYU Medical Center (2007)
Memorial Sloan-Kettering Cancer Center (2007)
Duke University Background
• CCWP-1 plant was built four years ago
• CCWP-2 design was 90% complete
(Primary/Secondary pumping)
• We were retained by Duke to peer review the
design
• Peer review was time sensitive
• Plant design for CCWP-2 was modified to
Variable Primary pumping based on our
recommendations
Duke CCWP-1 Before
Duke CCWP-1 After
• Dark blue pipe replaces old primary pumps
Duke CIEMAS Building CHW System
90% closed
Triple duty valves
50% closed
Duke CIEMAS Building AHU-9
Balancing valve
50% closed
NYU Medical Center (2007)
• Plant survey and hydraulic model indicated unnecessary pumps
• 1,300 horsepower of pumps are being removed, including 11
pumps in two brand new chiller plants
• $300,000 implementation cost
• $460,000 annual energy savings
NYU Medical Center (2007)
• Plant survey and hydraulic model indicated unnecessary pumps
• 1,300 horsepower of pumps are being removed, including 11
pumps in two brand new chiller plants
• $300,000 implementation cost
• $460,000 annual energy savings
3 Pumps Removed
8 Pumps Removed
7 Pumps Removed
3 Pumps Removed
Memorial Sloan-Kettering - Before
Memorial Sloan-Kettering - After
Bypass or
removal of
pumps
Bypass
or
removal
of pump
Bypass or
removal of
pumps
Pump Cemetery
To date we have removed several hundred large
pumps from our clients’ chilled water systems
Plant Capacity Analysis -Detailed System
Analysis is a Necessity
Modern computer software allows more complex modeling of
system loads, which has proven to be very valuable to
optimize performance and minimize cost.
Return on investment to the client for detailed analysis is
typically very high.
New York Presbyterian Hospital
• Applied revolutionary control logic
Log Data
~ 20F
T
Bristol-Myers Squibb
• Biochemistry research building
• 140,000 square feet
• AHU-1 (applied new control logic)
• 100,000CFM
• AHU-2 (existing control logic
remained)
• 100,000 CFM
Bristol-Myers Squibb
• Applied revolutionary control logic
PA State Capitol Complex –
CHW ΔT
South Nassau Hospital – CHW
ΔT
Good Engineers Always Ask
“Why?”
• Why does the industry keep installing
Primary/Secondary systems?
• Why don’t we get the desired system ΔT?
• Why does the industry allow mixing of
supply and return water?
Good Engineers Always Ask
“Why?”
• Why does the industry keep installing
Primary/Secondary systems?
• Why don’t we get the desired system ΔT?
• Why does the industry allow mixing of
supply and return water?
Answer: To keep consultants like us busy!
Why change?
Reasons to Change
• The technology has changed
• Chiller manufacturing industry supports
the concepts of Variable Primary Flow
• Evaporator flow can vary over a large
range
• Precise controls provides high Delta T
Change is Starting Around the World
• Most of the large district cooling plants in Dubai currently use
Primary/Secondary pumping
• By educating the client we were able to convince them that
this is not necessary
• We are now currently designing three 40,000 ton chiller plants
in Abu Dhabi using Variable Primary Flow as part of a $6.9
billion development project
Summary
• There are many chilled water plants with significant
opportunities for improvement
• WM Group has a proven record of providing smart solutions
that work
• We will be happy to review your plant logs with no obligation
Louisville Medical Center Chilled Water Operating Data
Production
50
Cost
0.200
1985: $ 0.171/ton-hr
45
CHW Production
(million ton-hours)
35
0.150
30
2002: $0.096/ton-hr
25
0.125
20
0.100
15
10
0.075
5
0
0.050
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
Year
Cost
($/ton-hour)
0.175
40
Thank You
Hemant Mehta, P.E.
President
WMGroup Engineers, P.C.
(646) 827-6400
[email protected]
The New Royal Project
Central Energy Plant Study
By
September 16, 2008
Project Objective
Determine the Optimum Central Energy
Plant Configuration and Cogeneration
Feasibility
The New Royal Project
• A new tertiary hospital for the region
• 95,000 m2 initial area (basis of analysis)
• Disaster Recovery Consideration
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N+1
Onsite Power Generation (+/- 70% of peak demand)
Two separate central plants
Project Site
Typical Utility Tunnel
Study Approach
• Developing load profiles for Heating,
Cooling and Power
• Developing and screening of Options
• Creating a computer model for energy
cost estimate
• Performing Lifecycle Cost Analysis
• Performing Sensitivity Analysis
• Conclusions
Load Profiles
• Cooling/Heating – Daily peaks provided
by Bassett
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Cooling:
Heating:
7,400 kWt (2,100 RT)
8,000 kWt
• Power – Daily peaks provided by Bassett
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Peak demand: 4,500 kWe
Min. demand:
1,400 kWe
Cooling Loads
Daily Peak Cooling Loads (Provided by Bassett)
8,000
7,000
5,000
4,000
3,000
2,000
1,000
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Cooling Load (kWt)
6,000
11:00 PM
10:00 PM
9:00 PM
8:00 PM
7:00 PM
6:00 PM
5:00 PM
4:00 PM
3:00 PM
2:00 PM
1:00 PM
12:00 PM
11:00 AM
10:00 AM
9:00 AM
8:00 AM
7:00 AM
6:00 AM
5:00 AM
4:00 AM
3:00 AM
2:00 AM
1:00 AM
12:00 AM
Daily Cooling Load Profile
NRP Average Daily Cooling Load Profile
Max Daily
Cooling Load
Min Daily
Cooling Load
3-D Cooling Load Profile
Cooling Load Duration Curve
607 Equivalent Full-Load Hours
NRP Cooling Load Duration Curve (kWt)
8,000
7,500
2,000
7,000
6,500
6,000
5,500
4,000
3,500
1,000
3,000
2,500
2,000
500
1,500
1,000
500
0
Hours
8,500
8,000
7,500
7,000
6,500
6,000
5,500
5,000
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
0
Load (kWt)
4,500
Load (Tons)
1,500
5,000
Heating Loads
Daily Peak Heating Loads (Provided by Bassett)
9,000
8,000
6,000
5,000
4,000
3,000
2,000
1,000
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Heating Load (kWt)
7,000
11:00 PM
10:00 PM
9:00 PM
8:00 PM
7:00 PM
6:00 PM
5:00 PM
4:00 PM
3:00 PM
2:00 PM
1:00 PM
12:00 PM
11:00 AM
10:00 AM
9:00 AM
8:00 AM
7:00 AM
6:00 AM
5:00 AM
4:00 AM
3:00 AM
2:00 AM
1:00 AM
12:00 AM
Daily Heating Load Profile
NRP Average Daily Heating Load Profile
Max Daily
Heating Load
Min Daily
Heating Load
3-D Heating Load Profile
Heating Load Duration Curve
1,742 Equivalent Full-Load Hours
NRP Heating Load Duration Curve (kWt)
8,000
7,500
26,000
7,000
24,000
6,500
22,000
6,000
20,000
16,000
4,500
4,000
14,000
3,500
12,000
3,000
10,000
2,500
8,000
2,000
6,000
1,500
4,000
1,000
2,000
500
0
Hours
8,500
8,000
7,500
7,000
6,500
6,000
5,500
5,000
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
0
Load (MBH)
18,000
5,000
0
Load (kWt)
5,500
Electric Loads
Daily Peak Electric Loads (Provided by Bassett)
5,000
4,500
4,000
3,000
2,500
2,000
1,500
1,000
500
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
0
Jan
Electric Load (kWe)
3,500
11:00 PM
10:00 PM
9:00 PM
8:00 PM
7:00 PM
6:00 PM
5:00 PM
4:00 PM
3:00 PM
2:00 PM
1:00 PM
12:00 PM
11:00 AM
10:00 AM
9:00 AM
8:00 AM
7:00 AM
6:00 AM
5:00 AM
4:00 AM
3:00 AM
2:00 AM
1:00 AM
12:00 AM
Daily Electrical Load Profile
NRP Average Daily Electrical Load Profile
Max Daily
Electrical Load
Min Daily
Electrical Load
3-D Electrical Load Profile
Utility Rates
• Natural Gas:
$9.00 / GJ
• Electricity (taken from hospital bill):
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Demand Charge: $0.265641 per kVA per day
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Energy Charge:
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Based on contracted annual demand
About $10.00 per kW per month
$0.14618 / kWh (on-peak, 7 am to 10 pm)
$0.05322 / kWh (off-peak, 10 pm to 7 am and
weekends)
Fixed Charges: $27.7155 per day
•
About $830 per month
Base Option Considerations
• Minimum first cost
• Two locations
• Conventional equipment
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Electric chillers
•
Gas-fired boilers
•
Diesel emergency generators
•
No cogeneration or thermal storage
• Operational efficiency and reliability
Central Energy Plant – Base
Option
Plant
Component
East CEP
West CEP
Chiller Plant
(2) 2,500 kWt electric motor
driven, water-cooled chillers
(2) 2,500 kWt electric motor
driven, water-cooled chillers
Boiler Plant
(2) 2,750 kWt fire tube boilers
producing hot water
(2) 2,750 kWt fire tube boilers
producing hot water
Thermal
Storage
None
None
Power
Generation
(1) 2,000 kVA diesel generator
(emergency power)
(1) 2,000 kVA diesel generator
(emergency power)
Alternative Plant Considerations
• Non-Electric Chillers
•
Absorption Chillers (with or without heaters)
•
Steam Turbine Driven Chillers
•
Gas Engine Driven Chillers
• Thermal Storage
•
Ice Storage
•
Chilled Water Storage
• Cogeneration
• Geothermal
Electric vs. Non-Electric Chillers
Sample taken from another project
Hybrid Plant – Option 1A
Plant
Component
East CEP
(1) 2,650 kWt electric motor
driven, water-cooled chiller
Chiller Plant
(1) 2,450 kWt direct-fired
absorption chiller/heater
(2) 1,750 kWt fire tube boilers
producing hot water
Boiler Plant
West CEP
(1) 2,650 kWt electric motor
driven, water-cooled chiller
(1) 2,450 kWt direct-fired
absorption chiller/heater
(2) 1,750 kWt fire tube boilers
producing hot water
(1) 1,500 kWt direct-fired
(1) 1,500 kWt direct-fired
absorption chiller/heater (same absorption chiller/heater (same
unit as above)
unit as above)
Thermal
Storage
None
None
Power
Generation
(1) 2,000 kVA diesel generator
(emergency power)
(1) 2,000 kVA diesel generator
(emergency power)
Ice Storage vs. Chilled Water
Storage
• Advantages of ice storage
•
Ice storage requires less space
•
Suitable for low temperature operation
• Disadvantages of ice storage
•
Ice generation requires more energy
•
Ice storage system has a higher first cost
• Ice storage is not considered for this
project
Thermal Storage – Option 2
Plant
Component
East CEP
West CEP
Chiller Plant
(2) 1,750 kWt electric motor
driven, water-cooled chillers
(2) 1,750 kWt electric motor
driven, water-cooled chillers
Boiler Plant
(2) 2,750 kWt fire tube boilers
producing hot water
(2) 2,750 kWt fire tube boilers
producing hot water
Thermal
Storage
Power
Generation
(1) 30,000 kWt-hr chilled water storage tank connected to site
chilled water distribution system
(1) 2,000 kVA diesel generator
(emergency power)
(1) 2,000 kVA diesel generator
(emergency power)
Cogeneration Alternatives
System
Reciprocating Engines
Fuel Cells
Microturbines
Application Assessment
Suitable for high electric but low thermal loads such as NRP.
Emerging technology not for commercial use.
Limited capacity of units and requires skilled labor.
High Pressure Steam Boiler
No steam required by NRP.
and Back Pressure Turbine
High Pressure Steam Boiler
No steam required by NRP.
and Condensing Turbine
Typically for larger installations, requires skilled operators, and
Gas Turbine with HRSG
possible emissions treatment issues.
Typically for larger installations, requires skilled operators, and
Combined Cycle Generation
possible emissions treatment issues.
Engine Generator Topping
Cycle
Option 3 – Cogen w/ Gas
Engines
Plant
Component
East CEP
West CEP
Chiller Plant
(2) 1,750 kWt electric motor
driven, water-cooled chillers
(1) 1,140 kWt hot water-fired
absorption chiller
(2) 1,750 kWt electric motor
driven, water-cooled chillers
(1) 1,140 kWt hot water-fired
absorption chiller
Boiler Plant
(2) 1,750 kWt fire tube boilers
producing hot water
(2) 1,750 kWt fire tube boilers
producing hot water
Thermal
Storage
Power
Generation
None
None
(1) 2,000 kVA natural gas
generator (cogeneration)
(1) 2,000 kVA natural gas
generator (cogeneration)
(1) 2,000 kVA diesel generator
(emergency power)
(1) 2,000 kVA diesel generator
(emergency power)
* Diesel generators not required if onsite LNG storage is provided
Option 4 – Cogen & Thermal
Storage
Plant
Component
East CEP
West CEP
Chiller Plant
(2) 1,750 kWt electric motor
driven, water-cooled chillers
(1) 1,140 kWt hot water-fired
absorption chiller
(2) 1,750 kWt electric motor
driven, water-cooled chillers
(1) 1,140 kWt hot water-fired
absorption chiller
Boiler Plant
(2) 1,750 kWt fire tube boilers
producing hot water
(2) 1,750 kWt fire tube boilers
producing hot water
Thermal
Storage
Power
Generation
(1) 10,000 kWt-hr chilled water storage tank connected to site
chilled water distribution system
(1) 2,000 kVA natural gas
generator (cogeneration)
(1) 2,000 kVA natural gas
generator (cogeneration)
(1) 2,000 kVA diesel generator
(emergency power)
(1) 2,000 kVA diesel generator
(emergency power)
* Diesel generators not required if onsite LNG storage is provided
Summary of Options
Option
1
1A
2
3
4
Thermal Storage
Power
Generation
(4) 2,750 kWt boilers
None
(2) 2,000 kVA diesel
backup generators
(2) 2,450 kWt absorbers
(4) 1,750 kWt boilers, (2)
1,500 kWt absorbers
None
(2) 2,000 kVA diesel
backup generators
(4) 1,750 kWt electric
(4) 2,750 kWt boilers
Chiller Plant
Boiler Plant
(4) 2,500 kWt electric
(2) 2,650 kWt electric,
(4) 1,750 kWt electric,
(2) 1,140 kWt absorbers
(4) 1,750 kWt electric,
(2) 1,140 kWt absorbers
(4) 1,750 kWt boilers
(1) 30,000 kWt-hr
chilled water storage
None
(2) 2,000 kVA diesel
backup generators
(2) 2,000 kVA
natural gas cogen
units,
(2) 2,000 kVA diesel
backup generators
(4) 1,750 kWt boilers
(1) 10,000 kWt-hr
chilled water storage
(2) 2,000 kVA
natural gas cogen
units,
(2) 2,000 kVA diesel
backup generators
Energy Model
• Simulation of plant operation
• Calculation of total energy use (power and
fuel) and cost
Hourly Computer Model
Detailed Equipment Data
Monthly Energy Cost Summary
Monthly Energy Cost Graphs
Comparison of Annual Energy
Costs
Comparison of Annual Energy Costs
$5.0 M
$4.0 M
$4.3 M
$4.3 M
$4.2 M
$0.6 M
$0.6 M
$0.6 M
$3.0 M
$3.0 M
$2.1 M
$2.1 M
$0.9 M
$0.8 M
Option 3
Option 4
$3.0 M
$2.0 M
$3.7 M
$3.7 M
$3.6 M
$1.0 M
$0.0 M
Option 1
Option 1A
Electric Cost
Option 2
Gas Cost
Thermal Storage Economics
• Installed Cost (Opt. 1A): $1,700,000
• Annual Energy Savings:
$98,000
• Simple Payback:
17 years
Low cooling load reduces benefits of
thermal storage
25-Year Lifecycle Cost
Analysis
• Capital Cost
• Energy Cost (gas and electric)
• Maintenance and Consumables Cost
• Staffing Cost
• Economic Rates
• Discount Rate
Construction Cost Estimates
Project Cost Factors
Based on typical healthcare development
projects
• Preliminaries and Margin:
23%
• Project Contingency:
15%
• Cost Escalation to Start Date:
15%
• Consultant Fees:
10%
Total multiplier is approximately 1.8
Comparison of Initial Costs
Comparison of Initial Costs
$40 M
$35 M
Incremental Cost for Diesel Generators
$4.2 M
$30 M
$28.0 M
$25 M
$20 M
$22.9 M
$23.6 M
Option 1A
Option 2
$4.2 M
$29.5 M
$20.8 M
$15 M
$10 M
$5 M
$M
Option 1
Option 3
Option 4
Maintenance and Staffing
Costs
Option
Annual Maintenance Cost
Annual Staffing Cost
1
$84,000
$130,000
1A
$90,000
$130,000
2
$86,000
$130,000
3
$105,000
$195,000
4
$107,000
$195,000
• Options 3 and 4 also require a $240,000 engine overhaul every 5
years (included in analysis)
• Staffing cost based on $65,000 per year for each full-time staff
employee
Economic Parameters
Based on estimated government rates
• Discount Rate:
8.00%
• Gas Cost Escalation Rate:4.30%
• Electric Cost Escalation Rate:
3.40%
• Maintenance Escalation Rate:
4.00%
• Consumables Escalation Rate:
4.00%
25-Year Lifecycle Cost Analysis
Cost Summary
Option
First Cost
Annual Energy
Cost
25-Year Present Worth
Cost
1
$20,839,000
$4,345,000
$87,223,000
1A
$22,879,000
$4,311,000
$88,825,000
2
$23,558,000
$4,243,000
$88,473,000
3
$32,176,000
$2,988,000
$83,303,000
4
$33,704,000
$2,978,000
$84,722,000
Results of Lifecycle Cost
Analysis
Comparison of Present Worth Costs
$90 M
$89 M
$89 M
$88 M
$87 M
$88 M
$87 M
$86 M
$85 M
$85 M
$84 M
$83 M
$83 M
$82 M
$81 M
$80 M
Option 1
Option 1A
Option 2
Option 3
Option 4
Sensitivity Analysis
• Varying electric demand charge
• Varying gas cost
• Change economic parameters
• Carbon emission tax
• Use of geothermal energy
Thank You
Hemant Mehta, P.E.
President
WMGroup Engineers, P.C.
(646) 827-6400
[email protected]