Good news at years end
To provide good news at the end of the year the MTA topped out 2021 with a press release about zero emission buses (ZEB), MDOT Secretary Slater's last public announcement. There was nothing to look at, there was no electric bus in sight and just a press release that the MTA is "launching a transition plan to move to a zero emission bus fleet." Nevertheless, this announcement is worth celebrating, because it represents exactly what had been demanded at the Glasgow climate summit last year: A step from goals and commitments towards actual implementation. Per orders already put in place, Baltimore will see its first 7 electric buses in 2023.
|Unbeknownst to most: There are two full electric |
buses in Baltimore run by BGE for its employees.
The electric bus implementation follows goals established in the Regional Transportation Plan and other State commitments about carbon reduction. Transportation plays a major role in combating climate change since transportation is Maryland's largest greenhouse gas emitter. Baltimore also is a dirty air area, in technical terms, a "non attainment area under the Clean Air Act". Diesel exhaust from buses and trucks plays a major role in this.
Specifically, MTA's December announcement confirms that MTA would, indeed, comply with the Zero–Emission Bus Transition Act passed in 2020 and effective in October 2021. The Act prohibits the MTA from purchasing any more diesel buses, even if they call them "clean diesel" as they have in the past (already existing delivery contracts can continue and will extend into 2023). The law also requires MTA to provide a progress report by January 1, 2022, that report was submitted and matches the details provided by MTA in their press release. The following steps were announced:
- Seven battery electric buses will be delivered in 2023 consisting of standard 40' buses and 60' articulated buses. These buses are added to the current fleet as a pilot.
- The new Kirk Bus facility will house the new buses and provide the infratstructure needed to maintain, and charge them
- By 2026 the Kirk division will be converted to handle 100% electric buses
- Starting 2025 the Northwest Division will be retrofitted starting 2025 followed by the Eastern Division in 2026 and the Bush Division in 2028.
- By 2030 50% of the MTA bus fleet (excluding Mobility buses) is required to be ZEB
- MTA will continue to investigate the use of other ZEB options such a hydrogen fuel cell buses
The implementation steps show, that buying electric buses isn't all there is to do to get to zero emissions. Maintenance facilities need a charging infrastructure and the tools and the equipment to maintain electric buses. Charging hundreds of buses requires an upgrade of the electric grid, additional switchgear and transformers and should also include some resilience strategies for electric grid failure. Relatively long charging times will also require changes in how a bus is handled in the depot. The exchange rate of 1:1 between diesel and battery electric buses will only hold if the schedule allows enough down time for the bus to recharge in full, or if it will be charged on fast charge stations during revenue service. Downtime is also used to clean and maintain the bus, so charging and cleaning should be combined, whereby the bus would remain stationary. This is a change from today where the bus is driven through cleaning, maintenance and fueling stations. Another option would be to swap out battery packages during the stay in the depot.
|Paris has several bus routes running with full|
electric buses (Photo Philipsen)
What will happen after next year?
MTA has over 770 buses, the conversion of 50%of the fleet by 2030 requires to procure 70 electric buses a year. The current price of a battery electric bus is about $800,000 to $1million, depending on accessories, between 25-50% above the cost of standard diesel buses. Proponents of the conversion argue, that over the lifetime of a bus the reduced operating and maintenance costs of electric buses will more than return the extra initial cost. A cost benefit analysis prepared by MTA based on current known cost did not bear that out, even though operating cost of BEB is shown to be nearly half of that of diesel. but that it cannot make up for the high procurement cost. The MTA report to the State Legislature states that "Analysis provided should be considered a conservative assessment of BEB costs, as the industry in North America is still in preliminary stages of development. Production costs may decrease as production increases to meet future demand and economies of scale are achieved."
MTA's press release states that the purchase of the initial buses Low or No Emission Vehicle Program from the Federal Transit Administration, and the Volkswagen Settlement.” It isn't clear, how many buses can be purchased with those sources or how much additional capital will be needed until 2030 to fulfill the requirement for 385 electric buses at cost of at least $280 million at today's dollars. (It can be expected that the cost of battery powered buses will significantly decrease with advancing battery technology). The Maryland bill says that "the full cost of zero–emission and alternative–fuel buses purchased under this subsection shall be paid from the Transportation Trust Fund."for the "pilot program and the infrastructure for charging them will utilize grant funding from the
The MTA ZEB implementation schedule is similar to WMATA's bus fleet transition which also will also buy its first battery electric buses (BEB) for 2023 service with a goal of full conversion to ZEB by 2045. Since 2018 the only electric bus that can be spotted in Baltimore is operated by BGE to shuttle employees from the BGE headquarters in downtown. With that Maryland is far behind other large cities in Europe or North America where battery powered electric buses run revenue service on designated routes in several large cities for some time. The largest number of electric buses rolls through Chinese cities, foremost the city of Shenzhen where the entire fleet of 16,000 buses has been converted to electric in 2020.
However, experiences are not all rosy. When Albuquerque NM tried to employ the Chinese BYD buses, they decided in 2018 to return them for non compliance with their specifications, especially regarding the range which was only 177 miles instead of the specified 275 miles. Most buses do about 150 miles a day, but the electric range various widely depending on how hilly the terrain is, how much AC or heat is needed and how heavily the bus is loaded. In order to overcome the range limit, several transit agencies install charging stations at bus "layover" points, the place where one "run" ends and the next one will begin. Usually these layovers are scheduled to be about 20 minutes. Depending on the charger's capacity and the frequency of full length layovers, those stops can add enough miles to complete its daily routes without having to go to the depot. MTA has selected overhead pantograph charging as the preferred option.
|Proterra bus in Broward County 2021 (Photo: Proterra)|
The city of Duluth ran into similar problems with their US made Proterra electric buses in 2021. To fix the heating challenge, Proterra retrofitted the buses with diesel powered heaters. The electric heat pumps had reduced the range by 60%. As anyone with an electric car knows, an electric motor produces no heat and electric heat exchangers can significantly lower the battery's range capacity, which is already challenged in extreme temps. In Baltimore where buses need to master some steep hills, need extreme cooling in summer, and extreme heating on some winter days as today, the current latest model diesel and hybrid buses are powerful enough that they can heat or cool the bus, even when it is very hot or cold and when the bus is packed and has to go uphill. (older models had frequent engine overheating issues in the summer). This is an important comfort feature. Passengers can get very testy if it is too hot or too cold in the bus.
Baltimore had its own electric bus failure: The initial Charm City Circulator was an electric bus with a gas powered small "turbine" for recharging. The innovative bus failed to deliver in Baltimore's summers and got frequently stranded with the batteries depleted. The model was eventually abandoned, forcing the City to buy new buses long before it was anticipated.
|Baltimore's original electric "Eco Saver"|
Charm Circulator in 2009 (Philipsen)
It will be interesting to see how Seattle will do where King County's Metro Fleet has just finished a larger scale pilot test program for 40' electric New Flyer buses and has begun a second testing phase for 60' articulated electric buses. Seattle's transit agency also operates electric trolley buses, the oldest form of electric buses still in use in some cities such as Seattle, Vancouver and San Francisco. Trolley buses receive power from overhead wires, just like street cars. They are popular with riders for they snappy, quiet and emission free performance and have proven to be very enduring and long lasting.
The Canadian City of Winnipeg switched their battery electric buses for hydrogen fuel cell electric buses (FCEBS). Fuel cells are a widely discussed option for cleaner buses, trucks, ships and even airplanes. They use liquid hydrogen to create electricity in a fuel cell which then charges a battery. The process produces waste heat that can heat the bus without local emissions. Fuel cell buses receive their hydrogen at the depot in a process that is similar to filling a tank with diesel or CNG and have a range of 200-300 miles, sufficient for a day of service. Canada with an abundance of clean hydro electricity made by water turbines is an ideal place to use surplus electricity for generating liquid hydrogen through electrolysis. That option makes only sense as a climate change contribution if hydrogen is not generated with "dirty" electricity from coal or gas since the production of hydrogen is quite energy intensive.
The future is electric
Whatever the best technology, diesel isn't any longer it. Electric buses are now offered by the popular US bus manufacturers, including New Flyer and Nova, brands the MTA currently operates as diesels. The bodies of the BEB models aren't any longer funny looking plastic contraptions, but are essentailly identical to what people are used to in the standard 40' and 60' long versions. BEBs continually improve, are quiet and have substantially more torque than diesel buses, making them quicker and more nimble. Drivers report that they are fun to drive. Electric motors don't need an oil change, have no transmission and no complicated exhaust management which means they last longer and are much easier to
|Components of electric bus diagram (Proterra)|
maintain. With carbon based fuel prices expected to rise over time, electric buses should also be much cheaper to run than diesel buses that have a gas mileage of about 10mpg or less. The large bus facilities should be equipped with solar arrays that can feed battery back ups so that bus charging can occur even during power outages. For the case that electric buses should continue to present insurmountable technical problems in complying with the agency's specifications, the Zero Emissions Bus Transition Act provides a considerable loophole: The MTA then could buy "alternative fuel buses" which would include buses powered by natural gas, a fossil fuel.
Klaus Philipsen, FAIA
ArchPlan Inc., in collaboration with Wilson T. Ballard engineers, provided 30% design documents for the new Kirk Bus facility.
The article was updated after receiving the Zero Emissions Conversion Report to the General Assembly form MTA.