One of the most powerful tools in the fight against climate change is the money sitting in investment portfolios - especially the trillions of dollars invested on behalf of public retirees. That’s money that could continue to fund fossil fuel development, or help pay for climate solutions instead.

New York City has implemented an ambitious Net Zero plan for its public pensions. That plan includes divesting from some fossil fuel companies and investing billions of dollars in climate solutions. One company benefiting from that investment is NineDot Energy.

Wedged between an elementary school and a big box shopping center in the Northeast Bronx, NineDot Energy is operating a battery farm that the city’s utility company, Con Ed, can call on to help relieve the grid when it gets overstressed. “The batteries hold a combined three megawatts of battery storage. That’s enough to power about 3,000 New York City households for four hours on a hot summer day. Last summer, the battery farm was called half a dozen times, which was enough to reduce greenhouse gas emissions by a combined 24 metric tons. That’s the equivalent of nine thousand car trips on the Cross Bronx Expressway.

Currently, the city has the dirtiest energy grid in the state. More than 90% of its power comes from fossil fuels. NineDot Energy is still in growth mode, but battery farms like this could eventually help the grid transition to renewable sources, like wind and solar.

“The sun only shines when nature tells it to; the wind only blows when nature tells it to, but people use electricity when they decide to,” explained Adam Cohen, co-founder of NineDot Energy. “A battery helps mediate that process. It pulls in the extra power when it's available, and then puts it back out when people call for it.”

On a recent visit to the Bronx facility, 12-year-old Virtue Onoja showed off a mural she helped paint along with other students from the elementary school across the street, envisioning a future powered by cleaner energy.

“One thing about me, I'm definitely an artist,” she said. “I drew a clear blue sky, no pollution, no nothing [and] beautiful yellow flowers and the sun.”

There are also drawings of windmills and electric school buses. “There's still a lot of pollution, not just in the Bronx, but just in New York in general,” Onoja said. “All of this is the goal that we want to achieve.”

This is an excerpt from the latest season of How We Survive. Listen to the full episode here.