Beyond Healthier Student Transportation, Electric School Buses Support More Resilient Communities.

Remember Transformers? Trainbots and Autobots, Seacons and Decepticons? The premise behind the toy line was that they could shift from their primary function as a vehicle or device into a robot action figure and back again—a child’s fantasy that never quite arrived in the real world. Until now.

Enter the electric school bus. Paired with bidirectional charging and vehicle-to-grid (V2G) technology, it’s a key part of building reliability and resilience into the nation’s electric grids (not to mention a way to help bring down electric school bus prices). Electric school buses would fit perfectly into the Transformer universe: the humble transportation machine that also helps keep the lights on.

From Grid Reliability to Grid Resiliency

The North American Electric Reliability Corporation (NERC) defines grid reliability as a combination of grid adequacy (generating enough electricity to meet demand) and grid security (the ability of the grid to withstand disturbances). Grid resiliency goes even further, describing a grid that can adapt and remain operational despite changing environmental threats from winter storms, heat domes, wildfires, hurricanes, and other climate events, minimizing the consequences to communities. By delivering stored energy from their batteries back to the grid when it’s needed most, electric school buses can help create a more reliable and more resilient local power system.

A Reliable Grid Begins with Bidirectional Charging

A fully charged electric school bus has hidden powers no diesel or internal combustion vehicle can match. Besides emitting pollutants that actively harm children and communities, fossil fuel-powered buses are a significant capital investment that spend most of their time parked and slowly fall apart. Electric buses, on the other hand, can be useful around the clock, providing not only transportation but also serving as grid-supporting energy storage resources during their off hours.

Bidirectional charging allows energy to be taken from the bus battery and pushed back to the local grid to help alleviate spikes in demand (for instance, on a very hot afternoon when everyone wants to use their air conditioning). This extra energy is valuable to utilities, who will pay to be able to use the bus batteries at certain times. Charging the batteries when demand and electricity prices are low (overnight or midday) and discharging them when demand and prices are high (typically in the late afternoon and early evening) can help lower the total cost of ownership of electric school buses while also supporting a more reliable grid.

Electric School Buses as Grid Assets – Via the V2G Platform

Electrifying a school bus depot requires powerful infrastructure to connect EV chargers with the local utility grid. A V2G-enabled depot with bi-directional chargers and V2G management software changes that connection between the buses and local utility from a one-way flow of electrons (in which the grid charges the bus) to a two-way flow (in which the bus can feed power back to the grid).

Electric school buses’ primary job is to transport students. They can be valuable grid assets, but only when they’re not performing their main function. To ensure they are always ready to run their routes when needed, we work with technology partners like Synop and Zonar Systems to capture telemetric data on the location, charge level, and other operational information of every electric school bus we’ve deployed, 24 hours a day, seven days a week. This data keeps buses operating smoothly and determines whether a bus’s battery can be available to provide V2G services. During periods of high electricity demand, the grid may draw power from an electric bus that isn’t transporting pupils and recharge it when demand is lower, and the price of electricity is cheaper. Planned V2G events and programs from energy providers let customers like school districts opt-in at their discretion.

Building V2G Into Highland’s Offerings

When you work with Highland, our priority is to make sure your electric bus fleet operates as expected and that the buses are available to safely transport your students when needed. We only take part in V2G events that have no impact on the priority of moving students. Our platform tracks and understands the requirements of each specific route, and factors for weather, ambient temperature, and other variables. It guarantees that your buses will be charged and ready for transportation before we agree with your utility to participate in any planned discharging event. Using artificial intelligence- driven forecasting, smart charge management, fleet-wide V2G controls, and complex coordination between vehicles, utilities, and energy markets, the platform ensures that Highland delivers the maximum benefit to both you and the grid.

Once we ensure your transportation needs are met, we examine every opportunity available during off-route time for your buses to earn dollars that are factored into your contract to help keep your costs for electric buses at or below your costs to buy, operate, and maintain your diesel buses.

The Ultimate Power Trip

Can the amount of energy returned to the grid by electric school buses really make a difference?

Remarkably, the energy capacity of a single bus could meet the power demands of a residential home for 4 days (assuming an average home uses around 30 kWh per day and an average electric school bus battery capacity is 120kWh, although the Thomas Built Bus Jouley® is 201 kWh 1 ). Imagine what an entire bus depot with V2G chargers pushing power back to the grid can do. A report released in March 2022 found that if every school bus currently in operation across the United States were replaced with an electric school bus equipped with the right V2G technology, it would add more than 60 GWh to the country’s capacity to store electricity—enough to power more than 200,000 average American homes for a week. Such a fleet could also deliver 6.28 GW of instantaneous energy, equivalent to more than a million residential solar roof installations or 16 average coal power generators.

1 *Constellation Energy estimates (link) and Oak Ridge National Laboratory paper (link)

Highland Is Making It Happen Now

Highland works with schools, governments, and communities to make it simple to upgrade to electric fleets, combining industry-leading technology with financing, comprehensive services, and energy market expertise.

While others are still planning V2G programs, we have two years of experience orchestrating them. During summer 2021, in conjunction with National Grid, and Beverly Public Schools in Massachusetts, we deployed a Thomas Built Buses Saf-T-Liner C2 Jouley® electric school bus equipped with a Proterra Powered™ battery system to discharge nearly 3 MWh of electricity stored in the bus to the regional electric grid over the course of 30 events during the summer. In addition to supporting the local grid when demand for energy spiked on hot days, the initiative helped Beverly Public Schools lower the cost of their electric buses. This was the first time an electric school bus had been leveraged as a commercial energy resource in New England and was among the first instances in the nation that an electric school bus has supported the grid in this way. In the summer of 2022, we used two of Beverly’s buses to discharge more than 7 MWh of electricity to the grid over 80 hours across 32 events.

We are participating in a second commercial V2G program with Green Mountain Power in the South Burlington School District in Vermont, and a third is in development for Montgomery County Public Schools (MCPS) and Pepco in Maryland. We have also partnered with Voltus to use the MCPS electric school buses to provide synchronized reserves to support the PJM wholesale energy market.