3 Design Considerations for Electric School Bus Vehicle-to-Grid Programs

This is the third article in a three-part series examining the ways stakeholders — including state policymakers, school districts and electric utilities — can build on recent federal actions to accelerate the equitable transition to electric school buses across the U.S. Here we examine vehicle-to-grid pilot programs for early insights on design principles that help maximize the potential of the electric school bus transition.

U.S. electric utilities are poised to be a key part of the momentum to shift American school buses from diesel fuel to electricity. Federal and state-level investments, along with other funding and financing opportunities, promise to accelerate the transition, bringing health, climate and economic benefits to more communities across the country.

Beyond these benefits, utilities are exploring how electric school buses can function as giant rolling batteries to support the power grid, enabling greater renewable electricity generation and providing disaster relief, through the use of vehicle-to-grid (V2G) technologies. As shown in the map below, at least 15 utilities across 14 states have committed to pilot electric school bus V2G programs, which allow electricity to be stored in the bus batteries and later discharged onto the grid. The bus batteries’ stored power can help stabilize fluctuating energy conditions, alleviate the need to start up additional power generation sources by shaving peak energy needs and provide mobile emergency power to shelters and other essential facilities. Because school buses operate on set daily schedules and often sit idle in the summer and during portions of the school day when electricity demand is high, they are ideal for this purpose. The power they can provide to the grid or buildings could offer revenue to help pay for the buses, a win-win for schools and the utility or other entity using the electricity.

While many of the V2G pilot programs are not expected to have results for another year or more, two earlier programs shed light on how the plan can work. In 2021, electric utility National Grid successfully delivered power from one electric school bus back to the grid for more than 50 hours over the course of the summer using V2G technology during peak demand times. By using V2G when demand for electricity was at its highest and most expensive, the electric school bus helped reduce local emissions in Beverly, Massachusetts, and decreased the need to fire up costly fossil fuel “peaker” plants. Last year, electric utility Con Edison also successfully completed one of the first V2G pilot programs, testing the charging and discharging of a fleet of five school buses in partnership with White Plains School District in New York state, bus manufacturer Lion, infrastructure company Nuvve and bus contractor National Express. Con Edison was able to successfully transmit energy from the electric school buses in White Plains back into the grid, and that energy was distributed to customers directly.

As successful as these early pilots were, they and other programs also helped reveal implementation challenges that will need to be addressed in moving to larger scale efforts. In 2015, for example, the Massachusetts Department of Energy Resources deployed three electric school buses across three corresponding school districts and monitored them for about a year. Although the program sought to test the V2G application of the buses, the lack of resources and trained staff at school districts to support this phase of the pilot program prevented V2G systems from being tested. Learning and sharing lessons from early pilot programs will be essential.  

Following an in-depth review of the pilot projects in all 14 states and guided by our mission to advance an equitable electric school bus transformation, we offer utilities, regulators and related stakeholders three considerations for the design of future projects that test V2G technology with electric school buses:

1.  Does the Program Prioritize an Equity-First Approach when Selecting Partners and Locations?

Electric school buses with V2G technologies offer an opportunity to advance an equity-driven agenda given the air quality, health and resiliency benefits that may be amplified in underserved communities where residents face higher levels of pollution and are more susceptible to climate change impacts. Several proposed or deployed V2G utility programs have focused on underserved communities, identified through indicators such as the number of students eligible for free and reduced lunches or average family income. For example, the goal of a project funded by the Portland Clean Energy Fund, is to use V2G technology to create an electric school bus-based resiliency hub in a low-income community in Portland. There is a crucial need for electric utilities to continue to enhance their efforts to integrate a wide range of equity-related indicators — such as race, income level and exposure to air pollution — in program design to ensure projects directly benefit traditionally marginalized communities. This can be done throughout the program design and implementation process, from thoughtful criteria and methods for choosing school district partners to fast-tracking interconnection applications and providing technical assistance for under-resourced school districts navigating utility requirements. By prioritizing projects in marginalized communities, students and others in the community gain access to cleaner transportation and associated air quality benefits.

2. Does the Program Consider New Rates to Enable School Bus Electrification and V2G Applications?

Using electricity for powering buses typically results in significant cost savings compared to relying on diesel fuels. However, specific electricity rate designs, which can vary widely across the U.S., influence the economics of electric school buses and can be particularly important if using V2G applications. Electricity rate structures can influence when buses are charged or when it makes sense to discharge electricity. In some cases, districts may face higher costs for charging during peak usage periods. Or they may face higher demand charges if their overall power usage increases during a specific hour (or, sometimes, a 15-minute interval) during a month. Significant cost increases can be incurred if demand charges are increased. For these reasons, new rate structures may be needed to enable school districts to utilize electric school buses and to provide energy through V2G programs. Pilot programs can be used to better understand the timing and volume of electricity used by electric school buses and how to best structure rates to enable both school bus electrification and V2G applications.

3. Does the Program Help Drive Community Resilience?

Electric school buses could play a role in disaster recovery and response by providing electricity during hurricanes, fires, floods and other emergencies. With climate change, natural disasters are becoming more frequent and more intense. By 2030, floods will affect more than 145 million people, including many who live in coastal areas of the United States. During extreme weather and other emergencies, interconnected infrastructure systems can fail due to power outages that stop core community operations and expose the most vulnerable residents to disproportionately high risk.

With proper planning and infrastructure, electric school buses could provide power to school buildings that are often used as shelters or offer power to other equipment, such as cell phones, during power outages. Investing in resilient infrastructure and solutions today will be necessary to provide life-saving emergency back-up power, as these events become more common. To enhance grid resilience, electric utilities are testing the value of V2G technology or other types of integration systems, such as vehicle-to-building (V2B), during potential disasters. As these technologies become more available, the electricity stored in electric school buses can be used to balance local electric distribution systems and to provide emergency back-up power to homes and businesses. DTE Energy’s five-year electric school bus pilot program, for example, will include tests of the electric school buses’ V2G capabilities to provide backup power to buildings during emergencies.

Working Together to Pave the Way for Electric School Bus Deployment

Now is the time for utilities, manufacturers, policymakers and other stakeholders to work together to deploy electric school buses nationwide and prioritize underserved communities. V2G programs can be an important part of the transition and offer value to both the community and the grid overall, but more research on the viability, benefits and challenges with V2G technology is needed. Understanding the potential revenues from electric school bus battery storage, for instance, could help utilities and school districts better plan for upfront purchase and operational costs. Further, accurately defining the technology and associated training required for electric school bus V2G applications will be paramount. Paving the way for equitable electric school bus deployment with V2G applications calls for continued research and collaboration across diverse stakeholders.

World Resources Institute’s Electric School Bus Initiative, which aims to support an equitable transition of the U.S. school bus fleet to electric by 2030, is currently convening a working group for electric utilities interested in exploring the opportunities and challenges posed by the electric school bus transition. The topics discussed and advanced through the working group will be driven by member interest and may include vehicle-to-grid integration, including V2G technology, as well as financing, program or rate design best practices, and integrating equity-related indicators into utility programs. Please contact celina.bonugli@wri.org to learn more about the working group.

Table of Utility V2G Electric School Bus (ESB) Pilot Programs

Source: Authors

Endnote: The information presented in the map and table in this article is the result of data collected by WRI’s Electric School Bus Initiative. To the best of our knowledge, this information is up to date as of October 2021, but represent a snapshot in time. The Electric School Bus Initiative will regularly update this information. Please contact norma.hutchinson@wri.org with any corrections or additional data.