Item No. 9b_supp 
Meeting Date: January 8, 2019 
Bus Procurement Projects 
Rental Car Facility Bus Purchase 
Employee Parking Bus Purchase 
Peter Lindsay and Leslie Stanton 
January 8, 2019

Briefing Overview 
Project description 
Current bus operations 
Future needs 
Goals and objectives 
Alternatives and schedule 
Results 
Recommendation 

2

Bus Operations 


Orange route serves rental car passengers, blue route serves tenant employees 
3

Project Description 
Rental Car Facility (RCF), C800810 
Replace 5 expiring buses and add 1 spare bus 
Cost recovered through customer facility charge 
Employee Parking (EP), C800956 
Replace 11 expiring buses and add 7 buses 
Cost recovered through employee parking rate 

Airport must purchase buses to maintain service 
4

Goals and Objectives 
Port goals 
Reduce carbon emissions 
Meet growing air transportation needs 
Financial sustainability of GT operations 
Project objectives 
Maintain service 
Minimize cost 
Reduce carbon emissions 
Minimize operational impacts 
Bus fleet must meet service, financial, and environmental goals 
5

Link to Framework 
Developing a Sustainable Project Framework that
incorporates multiple sustainability goals into Port
decision-making processes 
Bus procurement project offered an opportunity to test
framework assumptions 

Bus procurement project was a real-time case study for the Sustainable Project Framework 
6

Project Alternatives 
1. Electric buses 
Requires charging infrastructure and additional buses 
FAA grant available but uncertain 
2. Refurbished CNG buses with Renewable Natural Gas (RNG) 
New drivetrain, subsystems and interior 
3. New CNG buses with RNG 
RNG is zero net carbon drop-in replacement for CNG 
Other operators currently use RNG for transportation 
Bus technologies differ in price and operational impacts 
7

Schedule 
Commission briefing & authorization          2019 Q1 
FAA grant results                             2019 Q2 
Bus/charger purchase (PO)                   2019 Q3 
Replacement buses in-use                   2021 Q4 
16 CNG buses retired (EP=11, RCF=5)         2022 Q2 

Alternative must be selected by February 2019 to avoid service gaps

Analyzing Alternatives 
Step 1: Objectives 
Maintain service 
Minimize cost 
Reduce carbon emissions 
Minimize operational impacts 
Step 2: Risks 
Fuel supply 
Maintenance requirements 
Analyzed each alternative for its ability to meet objectives and minimize risk 
9

Project Costs 
Electric w/    Refurbished
Electric                                             RNG 
grant           RNG 
Initial capital cost                                   $36.6            $25.8            $11.6            $16.8 
Average annual operational costs                $0.7            $0.7            $1.0            $1.0 
NPV of total cost of ownership (20 years)         $57.4           $46.6            $30.8           $30.0 
All costs in million USD 2018 


Electric alternative has highest long-term cost 
10

Carbon Emissions 
Refurbished
CNG          Electric                         RNG 
RNG 
Carbon emissions (tons CO2/year)         1,220              20                0                 0 

Expiring buses create 5% of Sea-Tac's Scope 1 and 2 carbon emissions 

RNG and electricity have similar carbon reduction benefits 
11

Carbon Emissions 


RNG does not add carbon to the atmosphere 
12

RNG Availability 
RNG for transportation is available 
Supported by federal incentive program 
Bipartisan support; low long-term risk 
Port is developing an RFP for RNG 
Supplies airport boilers and existing CNG bus
fleet 
Seeking 10- to 20-year term 

RNG is currently available and long-term source is likely 
13

Objectives and Risks 
Refurbished          RNG 
Objective                    Electric 
RNG 
Objectives 
Maintain service 
Minimize total cost of ownership 
Reduce carbon emissions 
Minimize operational impacts 
Risks 
Fuel supply and price 
Maintenance requirements 

New CNG buses w/ RNG meet objectives with minimal risk 
14

Recommendation 
New CNG buses fueled with RNG 
Meets objectives 
Reduces maximum amount of carbon 
Minimizes total cost of ownership 
Minimizes operational impacts 
Minimizes risk 
Less maintenance downtime than refurbished buses 
Allows EV technology to mature and prices to fall 
Port can revisit electric option prior to 12-year bus
replacement 
Recommend purchasing new CNG buses and fueling them with RNG 
15

APPENDIX 
16

NPV of Project Costs (20 years) 
Electric w/     Refurbished
Electric                                                RNG 
grant            RNG 
Total cost of ownership                       $57.4            $46.6             $30.8            $30.0 
Charger capital and installation               $10.4             $5.0              $0               $0 
Initial bus capital                                $25.2             $19.8             $10.8             $15.2 
Bus replacement                           $11.4           $11.4            $5.2             $0 
Fuel                                            $2.9              $2.9              $3.2              $3.2 
Maintenance                              $7.5            $7.5           $11.5           $11.5 
All costs in million USD 2018 

Electric alternative has highest long-term cost 
17

RNG Cost 
Federal incentives are greater than CNG
commodity price 
Other U.S. airports outside of California
have procured RNG at similar cost to CNG 


RNG price is likely similar to CNG price 
18

Project Cost Summary 
Rental Car Buses  6      Employee Parking          Totals 
new CNG buses       Buses  18 new CNG
buses 
Current Budget                     $1,800,000              $18,081,000          $19,881,000 
Budget Increase/(Decrease)         $2,603,000              ($5,646,000)          ($3,043,000) 
Revised Budget                     $4,403,000              $12,435,000          $16,838,000 


Recommended alternative results in net ~$3 million overall budget reduction

Carbon Reductions Relative to CNG 
RNG             Electric        Refurbished RNG 
Emissions reduced relative to CNG
1,220               1,200               1,220 
(tons CO2/year) 
$/ton of CO2 reduced relative to
$0                  $925                   $0 
CNG 


RNG and electricity have similar carbon reduction benefits 
20

Carbon Reductions from RNG 
Sea-Tac Scope 1+2
emissions               Natural gas is 80% of Scope 1+2
25K
emissions 
Electricity
20K
Fleet gas and diesel            RNG is zero-carbon drop-in
Bus CNG
15K                            replacement for natural gas 
Tons
CO2
10K
Natural gas boilers
5K

K
RNG for buses and boilers reduces Sea-Tac's Scope 1+2 emissions by 80% 
21

Comparable Bus Operators 
Pierce Transit: primarily CNG 
Community Transit: diesel 
Microsoft: diesel and gasoline 
Amazon: diesel 
UW: gasoline 
Children's Hospital: gas/propane bi-fuel 

With RNG, the Port would remain a regional sustainability leader 
22

Electric Utilities at Sea-Tac 


S                                                                            23 N