I have argued repeatedly on this blog that the proponents of New York’s Climate Leadership and Community Protection Act (Climate Act) need to listen to the experts. Recently Governor Hochul announced that New York would be the first state to set an electric school bus requirement. This article describes an interview with a bus electrification expert about this plan.
Everyone wants to do right by the environment to the extent that they can afford to and not be unduly burdened by the effects of environmental policies. I have written extensively on implementation of New York’s response to climate change risk because I believe the ambitions for a zero-emissions economy embodied in the Climate Act outstrip available renewable technology such that it will adversely affect reliability, impact affordability, risk safety, affect lifestyles, and will have worse impacts on the environment than the purported effects of climate change in New York. New York’s Greenhouse Gas (GHG) emissions are less than one half one percent of global emissions and since 1990 global GHG emissions have increased by more than one half a percent per year. Moreover, the reductions cannot measurably affect global warming when implemented. The opinions expressed in this post do not reflect the position of any of my previous employers or any other company I have been associated with, these comments are mine alone.
Climate Act Background
The Climate Act establishes a “Net Zero” target by 2050. The Climate Action Council is responsible for preparing the Scoping Plan that will “achieve the State’s bold clean energy and climate agenda”. They were assisted by Advisory Panels who developed and presented strategies to the meet the goals to the Council. Those strategies were used to develop the integration analysis prepared by the New York State Energy Research and Development Authority (NYSERDA) and its consultants that quantified the impact of the strategies. That analysis was used to develop the Draft Scoping Plan that was released for public comment on December 30, 2021. According to the Plan the transportation sector is responsible for 27% of current greenhouse gas emissions so strategies to electrify the sector are planned.
Zero-Emission School Buses
On April 9, 2022 New York Governor Hochul announced fiscal year 2023 investments in clean energy infrastructure, climate resiliency and preservation that New York will become the first state in the nation to set an electric school bus requirement. According to the press release:
In order to improve air quality for school-age New Yorkers, the State Budget requires that all new school bus purchases be zero-emissions by 2027 and all school buses on the road be zero-emissions by 2035. The State Budget will provide $500 million through the Environmental Bond Act to support school districts in purchases of zero-emission buses and related charging infrastructure including charging stations. Additionally, the State Budget authorizes school districts to lease or finance zero-emission buses for 12 years, more than double the current five-year limitation for diesel buses, in order to help districts meet this goal, and ensures Transportation Aid is provided on zero-emission buses and related charging infrastructure.
While doing research for this article I found a series of webinars on electric school buses put together by the Center for Transportation and the Environment (CTE). They are a “member-supported 501(c)(3) nonprofit organization that develops, promotes, and implements advanced transportation technologies, vehicles, and fuels that reduce environmental pollution and fossil fuel dependency”. “In partnership with the U.S. Departments of Defense, Energy, Interior, and Transportation, the U.S. Armed Services, and NASA, among many others”, CTE and its 89 member companies work together to improve transportation technologies and fuels while reducing their environmental impacts. Despite the fact that CTE’s primary interest is foisting their “zero-emission” transportation vision on us all, the webinars (Bus Technology, Charging Infrastructure, and Program Funding) are a useful overview of the technology needed for zero-emissions school buses.
What Do the Experts Say?
Jeff Sweet is an engineer at the Niagara Frontier Transportation Authority (NFTA). His last task before retirement is to get the first electric buses and charging infrastructure operational for NFTA. He has a lot of experience making buses work for their customers and, importantly, working with Metro Rail light rail vehicles in the NFTA. Over the past couple of years, NFTA has begun the process to add battery-electric buses (BEB) to their fleet. We recently talked about the challenges of bus electrification using the CTE webinar slides as a guide.
NFTA took the position that converting the 323 buses currently in operation to battery electric vehicles should not lower the bar. The BEBs need to achieve diesel bus efficiencies and standards of performance. The more I think about that approach the more I approve. Why should we have to accept lower performance standards especially given that New York’s GHG emissions are lower than the average annual increase in global emissions over the last 30 years.
The first webinar includes a slide that explains why electric school buses are being considered now:
- Zero criteria emissions around vulnerable populations
- Quiet operation
- Lower Greenhouse Gas emissions
- Funding availability
- Lower fuel and maintenance costs
- Vehicle availability
There are issues with each of these points. Zero emissions at the point of release ignores the environmental impacts of the materials needed for battery technology. Most of the time quiet operation is an advantage but it also means pedestrians might not hear them coming. The difference in GHG emissions when total life cycle emissions are compared is pretty small. Current funding availability only works when someone, somewhere else is paying the bill. The last two claims, lower costs and availability, are frequently pointed out by advocates. Sweet explained that electric buses don’t have transmissions so that reduces maintenance. However, he noted that the lower day-to-day maintenance costs advantage can disappear when it comes time for battery replacement. Ultimately, when everything is considered, these advantages are not as big as they appear at first glance.
The bus technology CTE presentation includes a good overview description of electric vehicle batteries. A couple of good points were made. In a series of slides the limitations of the nameplate capacity were discussed. It turns out that buses won’t move unless they have more than 5% charge, below 10% they have derated performance and that charging them over 90% reduces longevity. In other words, actual battery capacity is down 20% from the get go. In addition, there are many factors that cause batteries to age that also reduce performance. Among the factors are age since production; charging rates and number of cycles; discharging rates and number of cycles; high temperatures; cyclic depth of discharge; sitting at high state of charge; and sitting at low state of charge.
Sweet explained that those battery considerations are not the only things that school districts will have to plan for when they switch to electric buses. The specifications for buses must consider the duty cycle. It is not just range but also the bus route terrain. If the buses have routes with many hills that will affect battery use. Specifications must also consider how they will be used: how many stops, location and terrain are factors. Based on his experience NFTA is planning to use traction motors like the ones used in their trolley buses.
In order for this all to work the school districts must have specifications for the life and usage of their buses to have the batteries meet the duty cycle. Financing is another practical consideration. Sweet explained that given their high rate of use when a bus is leased there is no residual value of the bus at the end of the lease. On the other hand, car leases can have lower rates because the cars have residual value and can be sold at lease end. Ultimately, he thinks the leases will be a financing scheme for batteries.
The issue of charging is an important consideration for school districts. There are different kinds of chargers and there is a premium cost for faster charging. There also different types of charging connections. Cables are cheaper but pantograph chargers are more flexible. In addition, the power requirements must be considered. We agreed that most school district bus garages would need to upgrade their electric service to a higher capacity. For a large district getting sufficient power could mean upgrades not only to the service to the bus garage but the serving utility might also have to make changes to the electric distribution system.
New York State School Buses
My primary concern is how school bus electrification will affect New York’s Climate Act implementation. In the second CTE set of slides there is a presentation titled “White Plains Electric School Bus Vehicle to Grid (V2G) Project” that describes a pilot study with Consolidated Edison. The utility’s main concern is charging equipment. The presentation notes that it needs to meet bus needs, funding constraints, and “charge management platform compatibility”. It goes on to explain that school buses will use a mix of AC and DC charging:
- AC, Level 2 (most, but not all school buses) Slower charging, up to 22kW, cheaper, smaller
- DC, Level 3 (becoming more common) Fast charging, 50-60kW typ., expensive, big, better vehicle to grid
My ultimate concern is how much money will be needed and how much is available. The presentation states that in New York State the plan is to cover up to $120K of the cost of a Type C school bus. A commentary advocating for more funding claims that there are 45,000 school buses in New York and that the Senate budget plan proposes $1 billion for school and transit bus electrification. The following table combines that information with the costs for school buses and the costs for charging infrastructure to estimate how much money will be needed. Depending on the types of chargers used there will be a funding shortfall of between $3 and $5 billion to replace 45,000 diesel school buses.
The costs of electric buses are significantly higher than diesel buses and there is insufficient money available to cover those higher costs. As a result, the electric bus conversion is an unfunded mandate to New York schools of at least $3 billion. Furthermore, Sweet’s impression is that the manufacturers and many of the consultants don’t have the practical experience necessary to keep school districts from avoiding potential pitfalls that will further increase costs. Consequently, it is likely that this is another virtue signaling “great” idea that will end up doing more harm than good.