Item No. _8b_supp 
Meeting Date: February 26, 2019 
Bus Procurement Projects 
Rental Car Facility Bus Purchase 
Employee Parking Bus Purchase 
Peter Lindsay and Leslie Stanton 
February 26, 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 
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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 
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Goals and Objectives 
Port goals 
Reduce carbon emissions 
Meet growing air transportation needs 
Financial sustainability of ground transportation operations 
Project objectives 
Maintain service 
Minimize cost 
Reduce carbon emissions 
Minimize operational impacts 
Bus fleet must meet service, financial, and environmental goals 
5

Project Alternatives 
1.   Electric buses 
Requires charging infrastructure and additional buses 
FAA grant available but uncertain 
2.   Refurbished compressed natural gas (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 
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Schedule 
Analyze bus alternatives                      2018 Q1-Q4 
Commission authorization                   2019 Q1 
RNG Results/FAA grant results                2019 Q2 
Develop and issue bus RFP                   2019 Q1-Q2 
Place bus purchase order                     2019 Q3 
New buses in use                           2021 Q4 
Mandatory bus retirement                   2022 Q2 
Alternative must be selected by February 2019 to maintain customer service

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 
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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 
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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% 
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Carbon Emissions 
Electric       Electric  PSE     Refurbished
CNG                                                      RNG 
Green Direct       Grid Mix           RNG 
Carbon emissions
1,220              20               430               0                 0 
(tons CO2/year) 
Expiring buses create 5% of Sea-Tac's Scope 1 and 2 carbon emissions 

RNG and electricity have similar carbon reduction benefits 
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RNG Cost and Availability 
Port RFP issued Jan 12th for RNG 
Supplies airport boilers and existing CNG bus
fleet 
Seeking 10 to 20-year term 
Federal credits (RINS) support RNG for
transportation 
Bipartisan support; low long-term risk 
RINS currently greater than CNG commodity
price 
RNG is currently available and long-term source is likely 
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RNG Cost and Availability 
Other U.S. airports outside of California have procured RNG
at similar cost to CNG 
RNG Facilities as of Jan 2019 
90 in operation 
21 under construction 
41 under development 

RNG price is likely similar to CNG price for buses 
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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 
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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 next bus
replacement 
Recommend purchasing new CNG buses and fueling them with RNG 
15

APPENDIX 
16

Electric Utilities at Sea-Tac 


S                                                                            17 N

Carbon Emissions 


RNG does not add carbon to the atmosphere 
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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 
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NPV of Project Costs (20 years) 


Electric alternative has highest long-term cost 
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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 
Electric  Green     Electric  PSE
RNG 
Direct              Grid Mix 
Emissions reduced relative to CNG
1,220               1,200                790 
(tons CO2/year) 
$/ton of CO2 reduced relative to
$0                 $1,140               $1,760 
CNG 


RNG and electricity have similar carbon reduction benefits 
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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 
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