Deploying Bidirectional Electric Vehicles to Support the Grid Takes a Leap Forward, Enabling Mobile Microgrids

A few years ago, the idea of using an electric vehicle (EV) to support the grid and provide backup power to homes and businesses seemed like it was a concept that belonged only in science fiction.

But with increasing demands on the grid from electrification and data center growth, EVs are gaining ground as a source of energy for supporting the grid while providing environmental and economic benefits. They could potentially lower the need to add expensive and polluting gas-fired power plants to meet peak demand.

When they’re equipped with bidirectional charging technology, EVs can both charge from and send power to the grid. This allows them to become mobile microgrids that provide battery power when the EVs are sitting idle.

In California, for example, bidirectional charging is seen as a key to meeting the state’s climate goals. Other states are embracing that idea, including New Mexico.

New V2G projects in Illinois and New Mexico

Two recently launched projects shine a light on just how far bidirectional charging has come. In Illinois, electric distribution utility ComEd announced a project that will utilize three electric buses from three school districts to test the ability of vehicle-to-grid (V2G) technologies to bolster ComEd’s grid.

The state of New Mexico has signed a $400 million deal with Nuvve Holding that provides V2G technology to help electrify New Mexico’s more than 2,000 school buses and the state’s 3,500 state-owned vehicles. The goal in New Mexico is to support New Mexico’s fleet electrification efforts, which are designed to help meet the state’s renewable energy goals.

For ComEd, the pilot project focuses on how to deploy energy stored in school bus batteries to enhance grid operations and reduce energy costs, said Sri Raghavan Kothandaraman, manager of emerging technology at ComEd. This is the first time ComEd has tested V2G technology. The effort is funded through the utility’s beneficial electrification program, which provides $15 million for pilot projects that study electrification technologies.

“We look at it as a technology demonstration of the viability of implementing V2G and showcasing the potential to leverage electric buses as storage for grid services,” Kothandaraman said.

School districts that participate in the pilot will receive participation incentives, but will not sell grid services, he said.

Identifying when it’s best to charge and discharge EVs

ComEd owns the pilot, and Nuvve is charged with the day-to-day operation of the project. With the pilot, ComEd wants to identify the V2G charging and discharging schedules that will be most useful to the utility.

Assessing the environmental benefits of using electric buses compared to other types of school buses is also a goal, Kothandaraman said. One benefit is reducing air pollution by cutting the use of diesel or gas to fuel school buses.

Yet another goal is to determine if the electric buses can provide power to the grid consistently, even during peak demand periods.

“If you want the lights to go on, buses have to be able to reliably send power back to the grid. This pilot is evaluating the capability of buses to do that,” Kothandaraman said. “It depends on demand and supply. There’s a lot of peak load in the system.”

Technical issues include communicating with chargers

The pilot will also take a look at technical issues such as identifying the hardware needed for ComEd to communicate with the chargers–and vice versa. Frequency regulation is also being studied. ComEd wants to determine if the buses can participate in markets by providing frequency regulation to help keep the grid stable.

Gregory Poilasne, CEO and founder of Nuvve Holding, said that each bus has the capability to supply 100 kWh to 300 kWh, and the buses generally will be connected to 60-kWh charging stations.

Nuvve has provided frequency regulation with EVs in Denmark for 8 years, he said. Under that energy-as-a-service program, the customers pay a flat fee monthly for a charging station and energy. Nuvve keeps the revenue from participating in grid services and other markets and takes all the risk.

In California, Nuvve aggregates power from EV batteries to participate in California’s Emergency Load Reduction Program (ELRP). The company also takes part in Connected Solutions in New England, which is a demand response program under which participants receive incentives for reducing energy use during periods of peak demand.

Getting paid to reduce carbon dioxide emissions

Ultimately, Nuvve would like to be compensated for reducing carbon dioxide emissions. It could optimize discharging energy from EVs to the grid when carbon dioxide emissions from utility power plants are highest, Poilasne said.

Nuvve would like to find a way to place a value on those emission reductions, he said.

In addition to working with ComEd, Nuvve signed a contract to help electrify New Mexico’s school buses and state-owned vehicles. Under that project, Nuvve will deploy EV charging infrastructure and develop microgrids consisting of solar and storage. They will be used to make sites as self-sustainable as possible.

“The combination of local generation and local storage working in tandem with the V2G vehicles allows us to optimize the local use of energy while potentially providing grid services,” Poilasne said.

Nuvve recently broke ground on a V2G project in Fresno, Calif. under which it will electrify the Fresno Economic Opportunities Commission’s 50-shuttle fleet, deploying 60 charging stations, 37 of which will be bidirectional. Grant funding came from the Carl Moyer Memorial Air Quality Standards Attainment Program and Pacific Gas & Electric (PG&E).

Car manufacturers now studying V2G

PG&E is also working with BMW, Ford and GM to test bidirectional charging technologies that will enable EVs to help offset some of the load growth associated with electrification.

The Nuvve and PG&E projects are just some of the efforts taking place right now to understand how EV batteries can help meet global electricity demand that’s expected to increase by an average of 3.4% annually through 2026.

Bidirectional charging is no longer seen as a wild idea, but an important tool for addressing global power demand and addressing climate change.