Transcript Automated Building Services

School Board of St. Lucie County
Energy Conservation Strategies
School Board of St. Lucie County Energy
Conservation Strategies
School Board of St. Lucie County, Florida
39,000 Students
47 Campuses
+6 Million Square Feet of buildings
Marty Sanders, PE
Executive Director Growth Management, Facilities & Maintenance
327 NW Commerce Park Drive
Port St. Lucie, FL 34986
(772) 340-7100
[email protected]
“A pessimist sees difficulty in every opportunity. An optimist sees opportunity
in every difficulty.“ Winston Churchill
School Board of St. Lucie County Energy
Conservation Strategies-Overview
1. Energy Advisory Committee
2. Building Automation
3. Early projects (Lighting, controls, Facility Use
Automation, Insta-hots in lieu of boilers)
4. Utility Rate Structures
5. Thermal Energy Storage
6. Cost History of plants
7. Obstacles
8. Secrets to Success
Energy Advisory Team
Team consists of District Facilities staff, engineers, architects, utility providers to
develop and advise the District with real, measurable goals to reduce total energy
consumption and create a healthier educational environment for staff and students.
Major Areas of implementation:
1. Education: improve student and staff awareness of energy conservation through
programs, training and instruction.
2. Measurement: install infrastructure to measure energy consumption before and after
changes (sub-metering).
3.
Audit: establish sites current operational condition.
4. Commission: Verify what was designed and installed.
5. Implementation: Provide controls over HVAC, lighting, water and gas infrastructure
systems.
6. New Technology and Trends: Monitoring; trend changes for estimated payback and future
energy budgeting.
Automated Building Services
Projects Resulting from Energy Advisory Committee
•
Building Automation-Controls
•
Electrical-Lighting Retrofits
•
Mechanical-HVAC (Ice Plants) & Boilers
•
Civil-Water, Sewer, Gas
•
Utilities Rate Structure-Rebates, Seasonal Demand
Automated Building Services
 Energy Manager
 Building Automation Specialist
 Building Automation Technician
 Automated Building Services provides technical support
over all Heating, Ventilation, Air Conditioning and Lighting
controls. Also manages Technical Support programs
proactively, assists with design, maintenance and
efficiency for all mechanical equipment.
Lighting Controls
• Replaced florescent T-12 with T8 or T-5
(Grainger Watt-stopper contract)
• Motion Sensors
Lighting typically 30% of Energy Cost
Ceiling Mount Motion Sensor
Wall Mount Motion Sensor
Automated Building Controls
Override System
 Coordinated Building Use and Control System for use
outside normal school hours.
 School Dude product, Facilities Direct which allows us the
ability to use one system to schedule, invoice and track all
“Overrides” .
 With this system in place we have been able to begin
integrating all three control systems (Trane, Siemens and
Delta) to work together more efficiently.
Automated Building Controls Override System
Treasure Coast High School
Facility Use Schedule
Building Automation
 Improved Building Performance
 Programming (“Sequence”) Modifications
 Chiller Plant Optimization
 Re-commissioning
 Operational Enhancements
 Command Center Console
 Training (District Power Users)
 Student and School Staff Education
 Siemens Science Days - 5th Grade Science Classes
 Energy Awareness Awards (re-introduction)
 Energy Dashboard
Building Automation
“Cruise Control”
 “Cruise Control” Programming involves a more
efficient approach to the control sequence.
 By changing the rate of response time and adding
more monitoring points to the program, we can
decrease the amount of energy it takes to provide
comfort to the classrooms.
Building Automation
BACnet
School Dude
Paging
Internet
Access
E-mail
District’s Wide Area Network
B
A
S
H
V
A
C
Energy Management Systems
35 Schools Simultaneously
Monitored and Controlled
L
I
G
H
T
I
N
G
P
O
W
E
R
Kilowatt Management Program
 Continual Monitoring of Power Consumption
 Monitoring Use of Facilities
 Comparing Use With Other Similar Campuses
 After Hour Consumption
 Reporting of Consumption via Web Server for all
Principals and Management
 New Curriculum Opportunity
Why Thermal Energy (Ice) Storage?
• Save Energy
• Save Money
• Reduce Maintenance Costs
• Assist partner, Utility in reducing
demands on grid
Thermal Energy (Ice) Storage Basics
• Purchase power at 4 cents v. 14 cents
per KWH
• Eliminates demand charge
• Minimal chiller starts v. multiple starts
• Ice melt during occupied hours w/o
chiller, handle variable demand well
Composite Cost of Power Cents per/KWH
(2010-11)
10
9
8
26% lower
Consumption
cost
20% lower
Consumption
cost
Cost Per KWH(cents)
7
6
5
4
3
2
1
0
Village Green Chiller
Village Green-School
SLW Centennial Chiller
SLW Centennial-School
Before Ice Storage
100
What is Thermal Storage?
90
Campus Load
80
70
60
50
CHILLER ON
40
30
20
CHILLER
10
SCHOOL
0
1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4
5
6 7 8 9 10 11 12
Time
After Ice Storage
100
90
Campus Load
80
ICE TANK
70
60
ICE
DISCHARGING
(SAVINGS)
50
40
30
20
CHILLER
SCHOOL
10
CHILLER
MAKING ICE
CHILLER ON
CHILLER OFF
0
1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
Time
Cost for Thermal (Ice) Storage
Bayshore Elementary School
• Ice storage cost
= $261,200
• Power CO Incentive
= $132,960
• Net Cost of Ice storage = $128,240
• Yearly Power Savings
• Simple Payback
= $ 24,869
= 5.2 years
PARTIAL THERMAL ENERGY STORAGE
SYSTEM OVERVIEW
50% CAPACITY
IN CHILLERS
•
•
•
+
50% CAPACITY
IN ICE
Chillers build ice over night.
Chillers run during the day to serve the building A/C.
Ice is used during the day to supplement for peak load
conditions above installed chiller capacity only.
PARTIAL THERMAL ENERGY STORAGE
WHEN DOES PARTIAL TES MAKE SENSE?
When the Utility Company:
•
Offers no incentives / rebates for TES
•
Provides no time of use rate structures
$
$+$
PARTIAL THERMAL ENERGY STORAGE
PEAK ELECTRIC DEMAND REDUCTION
TYPICAL ELEMENTARY SCHOOL EXAMPLE – 400 TONS A/C
Air Cooled Chillers (No
TES)
Partial TES System
+
Peak Demand = 450 KW
450KW x $6.77 per KW = $3,046
per month at peak
Peak Demand = 225 KW
225KW x $6.77 per KW = $1,523
per month at peak
Partial TES is only used to reduce peak electric demand costs.
Net reduction = $1,522 per month at peak capacity
Estimated Energy Cost Savings
= $10,000-$15,000 Annually
Ice Plant Elementary School Savings
Plant on
line
Operational
Adjustments
Utility Conservation & Consumption Reduction
Water & Sewer
• Using low flow toilets & waterless urinals
• Revise operational procedures & monitoring to help
minimize potable water usage for makeup water at chiller
plants. Sensors notify personnel immediately when an
A/C system needs maintenance thus reducing wastewater
into the local utility system.
• Use of irrigation meters or sub-meter Chiller plants to
avoid sewer charge.
• Monitoring water usage for A/C chillers, measures can be
implemented to minimize water consumption & costs.
• Using rainwater for flushing toilets, supplementing
irrigation, or possibly using for A/C chiller makeup water
can help reduce potable water consumption.
2) Gas
• School generator systems, science
classrooms, and kitchen equipment design or
convert to natural gas if available.
•
Use of bottled propane where natural gas is
not available
•
By using natural gas & propane for generators,
this eliminates environmental hazards and
cleanup associated with diesel storage tanks.
Utility Billing Structure
Two Utility Providers
•
Fort Pierce Utility Authority-no
variable rate structure.
•
Florida power & Light-Multiple rate
structures SDR, TOU, etc.
Utility Billing Structure
Seasonal Demand Rate
Peak Time
June, July, August, September
12
3
9
Demand Charges are measured
Between 3 PM and 6 PM
6
During the months of June, July, August, September FPL provides an
incentive to demand customers by measuring the electrical demand
only between 3 PM and 6 PM
What is Demand ?
We all know about KWH charges. That’s what we are
paying for on our home power bills. However when you
have larger loads, like schools , offices, there is a second
component to the bill. The demand charge.
Electric demand refers to the maximum amount of
electrical energy that is being consumed over a 30 minute
interval.
Results in program
SLW Centennial HS Ice Plant
Date
KWH /
Month
On Peak
Kwh
On Peak KW
Demnd
tot_elec_amnt
($)
02/16/10
74160
2640
34
4,709.98
01/15/10
57120
1920
41
3,515.00
12/14/09
131280
6720
605
16,138.05
11/11/09
173280
8880
758
20,835.24
10/13/09
209760
10080
610
21,875.56
09/14/09
188880
5760
792
21,809.88
08/13/09
140880
54000
864
23,226.42
07/15/09
139440
77520
862
25,269.79
06/15/09
120240
85680
826
24,328.57
05/14/09
99840
44640
576
16,925.89
04/15/09
100560
45120
576
17,084.92
03/17/09
47520
14160
679
11,441.99
Cruise
Control
32%
reduction
Ice Plant
38%
23 % Reduction in
Electrical Cost in 2
years
Obstacles to Energy Management Program
1. Convincing People that You need to Change (staff buy-in)
•
Scheduling after hours events
•
Maintenance Staff fear of TES
•
SDR hours of operation staff complaints
2. Separating fact from fiction (Snake oil salesmen)
3. Capital funding – use of planned replacement combined with
Rebates to upgrade to TES
4. FPUA no TOU rates or rebates-used load shedding on school
modernization
5. Maintaining savings over time
Secrets to Our Success
Selecting the right personnel-HVAC & Controls
experience
Collaborative Culture
• Energy Management Team Partners
• School Board & Superintendent
• Staff & Unions
Diligence in Monitoring & Making Repairs
Results—Increased Productivity, Healthier
Environments, and Better Test Scores
Questions