King County Council is considering an ordinance that would accelerate the planned transition to a fully electric bus fleet from 2040 to 2035. Staff have warned too a rapid transition would come at a steep cost, with large near term budget investments leading to service reductions.
The cost worries take two forms. The upfront investments, particularly in charging infrastructure, are large. Battery electric buses have higher total life cycle costs than the hybrid buses they are to replace. The opportunity cost of increased expenditures on fleet replacement and charging infrastructure is less revenue available to provide service. But it gets much worse with an accelerated transition where hybrid buses are unnecessarily retired before the end of their useful life. For some of the hybrid fleet, this would also mean repayment of federal grants that helped finance their purchase.
Beyond budgetary and customer impacts, the opportunity cost of foregone service matters because transit service itself reduces carbon emissions. While Metro’s 10 million gallons of diesel annually is getting the attention of the County Council, Metro is displacing four times that much by reduced driving and congestion. It’s not apparent whether the trade-off of cleaner buses and reduced funding for service would mean more or less carbon emissions.
A Metro feasibility analysis in 2017 looked at life cycle costs of a transition to battery electric buses. Despite reduced fuel costs, Metro estimates suggest a 6% greater life-cycle cash cost for a battery bus vs diesel hybrid technologies. Even on a lengthy transition, that is about $194 million and the incremental cost is equivalent to a service reduction of 55,000 hours annually. There is however a wide range of uncertainty around those estimates because battery technology is so immature and therefore the long term costs are hard to predict. The greater life cycle costs of battery electric buses are only partly offset by reduced societal costs from emissions and noise pollution.
That was good enough to set a target of 2040 for transitioning to fully electric operations. Noting the uncertainty of the technology, and other risks to scheduling and service reliability, Metro adopted a phased approach to transitioning the fleet with continuous evaluation of the industry as the transition proceeded. The recent staff report notes “there is still much uncertainty in the feasibility and costs of achieving a ZEV fleet by 2040”.
The most recent outlook for battery electric buses is more pessimistic. At the time of the 2017 report, Metro thought it could move to 100% purchases of electric buses by 2020. Since then, expectations for availability of the needed technology have diminished. Metro does not now expect to hit this milestone until 2025.
Current fleet plans
Metro has operated 8 shorter range Proterra battery electric buses in Bellevue since 2016. Those are limited to a 25 mile range, but have performed to expectations. Metro has recently leased 10 extended range buses, both 40- and 60- foot, which claimed an extended range of 140 miles. Along with the trolley fleet, about 12% of Metro’s fleet is currently all-electric. If the extended range buses prove out, they could feasibly meet most of the needs of current operations.
The planned transition ramps up in 2021 and 2022 as Metro takes delivery of 120 electric buses which will operate out of an interim base at South campus. Up to 250 battery electric buses may be added when a new South Base annex opens in 2025. The first purpose-built electric base opens in 2030 and will bring Metro’s fleet to 51% electric once full to the planned capacity of 250-300 buses. That base will finally bring prolonged relief to the constraints on Metro’s base capacity. With more flexibility for operations, Metro expects to convert existing bases to fully electric in the 2030s.
Space and infrastructure constraints on bus bases over the next decade loom large in planning for the conversion to electric. Infrastructure for battery electric buses demands more space than hybrids. Slow- and fast-charging buses require different equipment and buses from different manufacturers do not yet use inter-operable charging infrastructure. Upgrades to the large scale power needs of battery buses are a substantial capital outlay themselves. At South Annex Base, a recent estimate is for $200 million on electrification alone to support 250 buses. The electric infrastructure is roughly as expensive as the bus.
In November, Metro briefed the County Council that the incremental cost of a full transition to electric is now expected at $1 to $2 billion, and those estimates remain uncertain.
Early fleet retirement
As the transition steps up, Metro needs to be attentive to the economic life of the existing fleet. Metro generally replaces vehicles after 14 to 16 years of operation, and federal grants programs require at least 12 years of operation. Metro uses FTA grants toward the purchase of buses and those grants must be repaid on any vehicle not kept in revenue service for at least 12 years. To attain a 100% zero-emissions fleet by 2035 while remaining compliant with federal grant conditions would require all new buses are fully electric by 2023. Given the constraints on the near-term fleet plans, Metro would need to retire some hybrid buses before they reach 12 years in service if the fleet is to be fully transitioned by 2035.
Council Member Jeanne Kohl-Welles, while advocating for an early transition, acknowledged some of the challenges at a November meeting:
“2040 was determined to be the time period in which we could possibly achieve that goal. I don’t think that we can wait that long. I understand that there are a lot of challenges here about existing buses. You can’t just throw them out or discard them or sell them even, for the investment we put into purchasing them. We also have to recognize that we are doing really well in comparison to the rest of the country, but I want for us to do more and that is what this proposal is really all about. This proposal may result in some really tough decisions being made regarding financing. This also is an ordinance, not a motion, which I am sure gives King County Metro transit some heartburn. How do we pay for all of this? But what I am asking is that we do what we can.”
The legislation was first introduced shortly before the election last October, and reintroduced by the new County Council last Tuesday. The next discussion and possible action is on Wednesday January 22.