The new electric trains chugging up and down the San Francisco Peninsula in Caltrain’s service area will be compensated for the electricity they generate using a form of technology over 100 years old.
Power companies Peninsula Clean Energy and San Jose Clean Energy announced they will allow Caltrain to qualify for compensation starting in April 2026 for returning energy created on their trains’ regenerative braking systems back to the local grid.
In a written joint statement, the two electricity producers said this past Wednesday that Caltrain could potentially receive up to $1 million annually for returning energy. Additionally, initial estimated energy costs to operate the trains hovered around $19.5 million annually, but ever since the launch of electric service, estimates were revised to be around $15.3 million.
“Caltrain’s new electric trains don’t just use electricity — they also give some back,” said the director of San Jose Clean Energy Lori Mitchell. “Our Green Transportation program is the first in the state and one of the few in the country to give credit to public transit systems like Caltrain for the energy they return to the grid, helping them save money and reduce pollution.”
“Our partnership with Caltrain and its bold move to all-renewable and carbon-free electric rail service have already improved the quality of life for our communities and illustrates how powerful local, community-driven leadership can be in better meeting customer needs,” said Peninsula Clean Energy CEO Shawn Marshall. “And now with the new regenerative braking, their cleaner, quieter and more efficient travel will send even more emission-free power back to the larger regional grid.”
1880s innovation for the EV era
An innovation from 1886, regenerative braking recaptures the energy used to move a vehicle instead of allowing it to be lost as heat energy.
“Regenerative braking operates on the same general principle as a hybrid car,” said Caltrain spokesperson Dan Lieberman. “Whether it’s a train or a car, regenerative braking systems convert kinetic energy into energy that can be either stored or redistributed.”
In the case of Caltrain, the energy recaptured by the brakes is returned to the overhead contact system, the wires and contact point with the trains, and then routed to other trains or even returned to the public electricity grid.
“Caltrain running train service on 100% renewable energy for the first time in 161 years is a victory in and of itself,” said Caltrain Executive Director Michelle Bouchard. “But now that our partners at PCE and SJCE have agreed to compensate us for the power we return to the grid, we have yet another reason to celebrate our transition to the electric fleet.”
Assemblymember Diane Papan, D-San Mateo, introduced a bill in April to consider regenerative braking as form of renewable energy creation. If passed, it could potentially increase the amount of compensation to Caltrain by 20%.
“I’m pleased to see that the renewable energy that Caltrain is sending back to the grid is being recognized and fairly compensated,” Papan said. “This is the right thing for supporting public transit and highlighting the incredible benefits from electrification.”
Caltrain estimates over 17,000 megawatt hours are produced each year by the regenerative braking system on its vehicles. In comparison, Pacific Gas and Electric data shows that Bay Area homes used around 7,500 kilowatt hours in electricity in 2024. Through regenerative braking, roughly 2,300 houses could be powered by Caltrain’s recapture methods.