1. The Chicago Transit Authority
Energy Efficiency on the “L”:
How CTA is Using Technology to Reduce Power Consumption

2. CTA Rail by the Numbers Over 238 million rides annually
224 miles of track
146 rail stations
8 rail lines

3. The six-word CTA energy strategy:
Use less Go green Manage costs

4. Energy Consumption by Volume
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)
Energy Consumption by Volume
Utility Costs by Type
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 3

5. Rail electricity consumption has dropped more than 10% over the last few years. Gigawatt hours consumption by year
Context
Why?

6. Rail miles and weather are the two biggest reasons for variations in consumption.
Context
Rail miles (in millions)
Rail miles increased in 2014 and have been stable since—not a factor in recent power use reduction.
Heating degree days in Chicago *
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.

7. Regenerative braking returns electricity to the third rail
New “5000 Series”: 714 rail cars have new energy-saving 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.

8. One “5000 Series” rail car = 7000 kilowatt hours consumption reduction
Regen Braking
Regenerative braking: When a re-gen train brakes, it generates electricity that can be used by a train accelerating at the same time.
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.

9. Wayside Energy Storage
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

10. Wayside Energy Storage
CTA is exploring WESS as a project that saves energy and generates revenue.
Wayside Energy Storage
2015
2016
2017 Q1-Q2
2017 Q3-Q4
Learn best practices from national leaders & experts
Conduct initial WESS study (RTA-led) and planning
Identify project funding;
Procure WESS vendor
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

11. Overnight train idling increased in an effort to improve safety, but also increased power consumption.
Idling
Before: 0:45
Timer
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
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.
Electrical equipment
(not cheap)

12. Overnight idling: options for power use control
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.

13. Power use at substations by hour of the day: May average
Overnight breaker
amperage and voltage
Idling
Power use at substations by hour of the day: May average
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-of-way in addition to shops/yards.)

14. Train Size
Train cuts: Program to “right size” the number of cars in a train based on ridership 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.

15. Train Size
Emphasis for Switchmen to cut trains not larger than 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

16. Measuring
Impact
CTA uses tracking software to collect, analyze and report on energy consumption and cost.
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.

17. 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.

18. Questions?
Pete Ballard Office: Cell: