San Diego Gas & Electric (SDG&E) announced it has successfully deployed a bidirectional charging setup that enables eight electric school buses in the Cajon Valley Union School District to put electricity back on the grid. The collaboration with technology company Nuvve is the first vehicle-to-grid (V2G) project to become operational in the nation.
The Dept. of Energy announced its vehicle-to-everything (V2X) initiative in April, and SDG&E is a signatory to the departments MOU. As part of the five-year pilot project, SDG&E installed six 60-kW bidirectional DC fast chargers at Cajon Valley’s bus yard in El Cajon, California.
“This pilot project is a great example of our region being at the forefront of testing and adopting innovative technologies to reduce greenhouse gas emissions and strengthen the electric grid,” SDG&E Vice President of Energy Innovation Miguel Romero said. “Electric fleets represent a vast untapped energy storage resource and hold immense potential to benefit our customers and community not just environmentally, but also financially and economically.”
On average, cars are parked 95% of the time. California is home to 1.1 million EVs, the largest concentration of EVs in the nation. Starting in 2035, all new cars and passenger trucks sold in California are required to be zero-emissions. Many local agencies and local companies are working to transition to electric fleets under SDG&E’s Power Your Drive for Fleets program, which provides infrastructure support. In addition to Cajon Valley, SDG&E is also working with San Diego Unified and Ramona Unified School Districts on V2G projects.
“Pilots like these are critical to advancing industry knowledge and commercialization of new technologies that help create jobs and build a clean energy future,” said Office of Technology Transitions Commercialization Executive Rima Oueid. “I am thrilled to see this project go live less than three months after the DOE launched our V2X initiative, validating the value of public-private partnership.”
With the bidirectional chargers now in operation, Cajon Valley can participate in SDG&E’s new Emergency Load Reduction Program (ELRP), which pays business customers $2/kWh if they export energy to the grid or reduce energy use during grid emergencies.
“We jumped at the opportunity to be part of this pilot project because of its potential to help us build a healthier community and better serve our students,” said Assistant Superintendent Scott Buxbaum. “If we are able to reduce our energy and vehicle maintenance costs as a result of this project, it frees up more resources for our schools and students.”
V2G technology works by allowing batteries onboard vehicles to charge up during the day when energy, particularly renewable energy such as solar is abundant. The batteries then discharge clean electricity back to the grid during peak hours or other periods of high demand.
“School buses are an excellent use case for V2G,” said Nuvve Co-Founder, Chair and CEO Gregory Poilasne. “They hold larger batteries than standard vehicles and can spend peak solar hours parked and plugged into bi-directional chargers. Nuvve’s technology enables the grid to draw energy from a bus when it is needed most, yet still ensuring the bus has enough stored power to operate when needed.”
News item from SDG&E
There has been some bad press on EV bus fires over the last few months. The LION seems to have three battery chemistries it uses, (LTO), (LFP) and NCM. The NCM would be the most energy dense, but is also the most likely to fail into thermal run away. (LFP) has a better chemistry that does not easily fail into thermal run away and one would almost have to put a torch to (LTO) for the battery to ignite. The LTO would be the longest lasting battery chemistry in a V2X set up, but again the LTO battery is not as energy dense as LFP that could also work well for V2X systems operations. It will be interesting to see what the long term effects of using the battery pack as a “fuel tank” for a BEV school bus and as a participant in grid services when the vehicle isn’t picking up or delivering students to school.