Transcript Energy Efficiency on the `L` - How CTA is Using Technology to

The Chicago Transit Authority
Energy Efficiency on the “L”:
How CTA is Using Technology to Reduce Power Consumption
CTA Rail by the Numbers
•Over 238 million rides annually
•224 miles of track
•146 rail stations
•8 rail lines
The six-word CTA energy strategy:
Use less
Go green
Manage costs
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Context
With an annual cost of almost $100M per year, CTA’s energy
usage represents an opportunity for efficiency gains and savings.
2015 Energy Consumption & Cost (in $Millions)
Utility Costs by Type
Energy Consumption by Volume
Commodity
Volume
Diesel Gas
(Gallons-Millions)
16.5
Electricity – “L” Trains
(GWh)
421
Electricity – Facilities
(Bus, Rail, Maintenance,
Administration) (GWh)
135
Natural Gas (Dekatherms)
640,000
Natural
Gas, $5M
ElectricityFacilities,
$10M
Electricity
- "L"
Trains,
$30M
Water,
$1M
Diesel
Fuel,
$50M
Total: $96M
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Rail electricity consumption has dropped more than
10% over the last few years.
Context
Gigawatt hours consumption by year 2013-2016
Why?
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Rail miles and weather are the two biggest reasons for
variations in consumption.
Rail miles 2013-2016 (in millions)
Rail miles increased in 2014 and have
been stable since—not a factor in
recent power use reduction.
Context
Heating degree days in Chicago 2013-2015*
2015 had warmer weather in winter
months, a major factor in the
consumption drop…but it does not
explain everything.
*The number of degrees the average temperature in a given day is below a baseline (65 degrees). For annual values, the daily
values are summed for a year.
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New “5000 Series”: 714 rail cars have new energysaving features and technologies—half of CTA’s fleet.
Regen
Braking
LED lighting
Improved door seals
Advanced controls to
calibrate heating,
ventilation and air
conditioning
Regenerative braking
returns electricity to
the third rail
Alternating current
(AC) train motor
system uses less
energy and requires
less maintenance.
New rail cars are 5,000 pounds heavier than
older cars, but consume less energy.
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Regenerative braking: When a re-gen train brakes,
it generates electricity that can be used by a train
accelerating at the same time.
Regen
Braking
One “5000 Series” rail car = 7000 kilowatt hours consumption reduction
714 “5000 Series” rail cars = 5 million KWh reduction = $350K in savings
If trains are not braking and accelerating simultaneously, the re-gen energy is lost.
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A “wayside energy storage system” (WESS) captures
and reuses electricity that is otherwise wasted.
Wayside
Energy
Storage
Simultaneous braking and
accelerating
Energy
reused
No accelerating trains
Energy
wasted
WESS captures and stores
energy for:
• accelerating trains
• responding to energy
markets
• providing back-up power
WESS
Energy
stored
and
reused
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CTA is exploring WESS as a project that saves
energy and generates revenue.
2015
Learn best
practices from
national leaders
& experts
2016
Conduct initial
WESS study
(RTA-led) and
planning
2017 Q1-Q2
Identify project
funding;
Procure WESS
vendor
Wayside
Energy
Storage
2017 Q3-Q4
Design, install,
and operate the
WESS
• Lessons learned:
• Develop in-house expertise, conduct feasibility study to
maximize pay back.
• Plan on persistence - at least 3 years from project
inception to operation.
• CTA go/no go decision in early 2017
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Overnight train idling increased in an effort to improve
safety, but also increased power consumption.
Before:
0:45
Timer
Idling
Before September 2013,
trains had 45-minute timer
for auxiliary (“hotel”) power
before shut-off.
September 2013 train
collision in Forest Park due to
multiple, concurrent factors.
After:
4:00
Timer
Electrical
equipment
(not cheap)
Incident review led to
several practice changes to
increase safety, including
adjusting the timer to 4
hours before shut-off.
Change resulted in enhanced
safety, but more idling and
more stress on power and
way equipment.
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Overnight idling: options for power use control
Idling
• Update Standard Operating Procedures to put parameters on
when trains can idle
– Temperature
– Period of time before service
– Train cleaning performance standards
• Field observations
– Can provide justification for SOP changes, but field staff
can’t be everywhere, all the time.
• Unlike buses, there is no automated car-level communication
of power status in existing fleet.
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Overnight breaker
amperage and voltage
Power use at substations by hour of the day:
May average
3.5
Calvary Substation (Howard) Average Daily Power Use & Kilowatts
3.0
Idling
2,000
1,800
1,600
1,400
1,200
2.0
1,000
1.5
800
600
1.0
400
0.5
200
0.0
0
0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00
Amps
Voltage
kW
CTA is piloting performance measurement using substation power draw:
• Substation KW demand and amperage measured every 30 seconds, 24/7
• Data automatically transmitted and stored for analysis
• Piloting at the only two substations that exclusively power shops/yards
where idling occurs. (Other substations power stations and service right-ofway in addition to shops/yards.)
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kW/volts
amps
2.5
Train cuts: Program to “right size” the number of cars
in a train based on ridership
Train Size
QuicTrak measures how long train takes to travel over single point in track
Simple example: Schedule is for one-car train
It takes one second for one-car train to pass point in track. If one second is
measured, assume it is a one-car train  Number of cars matches schedule.
It takes two seconds for a two-car train to pass point in track. If two second duration
is measured, assume it is a two-car train  Number of cars more than schedule.
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Emphasis for Switchmen to cut trains not larger than Train Size
they need to be has produced encouraging initial results.
Total miles over schedule (“excess miles”)
Estimating miles over schedule:
Number of cars in excess of schedule
x length of run
x number of runs per day
x days in year
= total annual miles over schedule
Blue Line Pilot
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CTA uses tracking software to collect, analyze and
report on energy consumption and cost.
Measuring
Impact
•
Software uploads consumption and
cost data from hundreds of utility bills
each month.
•
Data can be summarized in the
“dashboard” or pre-defined reports, or
exported for custom analysis.
•
Invoice data can be combined with
operational information (like the
number of rail miles or 5000 Series
cars) in service to forecast future
energy use.*
•
Auditing reports help find anomalies in
invoice charges
CTA added interval module that uploads consumption data at 30-minute intervals for every
meter powering trains. This allows for granular tracking of energy initiatives.
*Regression model honed over the last 4 years has predicted electricity usage and cost within 2-3% every month. This makes
Finance people happy.
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CTA lessons learned
•
No magic bullets.
• A single initiative is unlikely to dramatically reduce energy consumption.
• But a set of modest interventions can add up to substantial efficiency and savings.
•
It’s hard to evaluate and manage what you can’t measure.
• Management sometime supports ideas, but more often supports ideas + data.
• Reliable, valid data enables focus on efforts with the best ROI
• Assembling good data is hard. Don’t invest in off-the-shelf software without dedicated
system administration and utility invoice expertise.
•
Be creative.
• Evaluate new technologies. Invest in what makes sense for you.
• Take advantage of existing technology not necessarily purposed for energy efficiency.
• Creativity innovation can attract funding for up-front investments.
•
Persistence is more important than structure.
• Some organizations have dedicated energy managers/departments. The advantage of
dedicated resources can trade-off with personnel and organizational engagement.
• CTA has informal group across departments and functions that focus on energy efficiency.
No one person is in charge; people participate because it matters to them.
• Make collective decisions then be prepared to grind it out.
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Questions?
Pete Ballard
[email protected]
Office: 312-681-3468
Cell: 773-960-4016
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