Nineteen battery storage projects totaling nearly 2,400 megawatts are proposed across the Bronx, Brooklyn, Queens, and Staten Island. They’ve been proposed to help meet New York State’s six-gigawatt energy storage goal, a program the state says will store renewable generation “for the times it is needed most,” firming intermittent solar and wind into steady power.

That belief that batteries store renewable energy is the basis for nearly everything that follows. It’s the basis for a subsidy program modeled on renewable energy credits and collected from every electric bill in the state, with nearly a third of the money steered to projects in New York City. In the city itself, batteries share a property tax abatement with rooftop solar, administered under a single “solar electric generating system and electric energy storage equipment” program. And every one of them can claim the federal government’s “Clean Electricity Investment Credit.” It’s the language borough presidents and council members repeat when these projects are announced.

None of those benefits, state or federal, is conditioned on where the electricity actually comes from. So it’s worth asking the question the incentives never ask: when these batteries charge, what generates the power going into them?

In New York City, the answer, overwhelmingly, is natural gas, 92% of the time (according to NYISO’s own marginal-emissions data), the highest share in the state. Not just now, but likely for the lifetime of these projects: our modeling finds New York would need five to nine times all the solar it has ever built before charging windows are even half renewable.

Zone-by-zone breakdown

Every battery on the map charges from the same place: the grid of the zone it sits in. Batteries earn their money by buying power when it’s cheapest and selling it back when it’s expensive, so we pulled a full year of NYISO real-time price data and found the four cheapest hours of every single day in every zone. Those are the hours a battery operator charges. Then we asked what was actually setting the price in those hours, because on a power grid, new demand isn’t served by the average of everything running. It’s served by whatever plant ramps up next. At two in the morning, that is not solar.

The chart below shows the answer for each zone, hour by hour across 365 days: the share of charging hours where gas plants set the price, the share where zero-carbon resources did (hydro, wind, nuclear surplus), and the share too close to call, which we count against our own case. And you don’t have to take our word for the method. NYISO, the grid operator, publishes its own measure of exactly this, the marginal emission rate, which it says is “[r]elevant for near-term consumption decisions” like charging. Each zone’s bar carries NYISO’s number alongside ours. The two agree within a few points everywhere.

What they told you

These battery systems help us bring more clean, renewable energy onto the City grid, typically charging up overnight, when our regular grid is actually less dirty than during the day, and when it has excess energy available, and then discharging during high-demand hours as a replacement for peaker plants.

Costa Constantinides, Former NYC Council Member, Queens — amNewYork op-ed, June 21, 2025

NYPA has signed two term sheets with developers of battery energy storage projects for the Harlem River and Gowanus power plants, and is in active negotiations on three more term sheets for the Brentwood, Hellgate and Pouch power plants. … These battery storage facilities will provide safe, dispatchable, emissions-free power to help meet the future reliability of New York City’s electric system.

Justin E. Driscoll, President & CEO, New York Power Authority — Prepared testimony to the NYS Assembly Ways and Means and Senate Finance Committees, January 28, 2025

The advent of large-scale energy storage technology also greatly increases our opportunities to integrate clean, renewable power into the mix and transition to a low-carbon future.

Matthew Ketschke, President, Con Edison of New York — Con Edison press release, June 20, 2023

Battery storage will play a significant role in advancing New York City’s just transition to a clean energy future and will help to replace dependency on highly pollutive peaker plants that emit dangerous pollutants – ultimately creating a brighter and healthier future for all New Yorkers.

Andrew Kimball, President & CEO, NYC Economic Development Corporation — NYCEDC press release, May 16, 2024

I commend the NYCEDC and the NYCIDA for taking decisive steps to bolster our city’s green economy by facilitating projects like this one that produce clean and renewable energy.

Donovan Richards, Queens Borough President — NYCEDC press release, May 16, 2024

This initiative, led by the NYCEDC and NYCIDA, is a testament to our dedication to clean and renewable energy systems.

James F. Gennaro, NYC Council Member; Chair, Committee on Environmental Protection, Resiliency & Waterfronts — NYCEDC press release, May 16, 2024

Methodology

NYISO real-time zonal prices and fuel mix, 12 complete months, every day's 4 cheapest hours classified by what set the price; corroborated by NYISO's Implied Marginal Emission Rates (report P-72) and EPA CAMD plant-level hourly data. Confirmed-gas figures are floors; ceilings including ambiguous hours are shown on the map. Zero-carbon charging hours are real, counted, and disclosed on every project marker.

Come make sense of the grid with us

Everything comes down to how the electric grid actually works. On Thursday, August 20, we're bringing Meredith Angwin, a.k.a. "The Electric Grandma," one of the first women to run projects at the Electric Power Research Institute, to Ulster County for a plain-English crash course: why bills are rising, how the grid keeps the lights on, and which power sources you can actually count on.

Understanding Energy: A Civic 101 Crash Course
Aug 20, 6–8 pm | M. Clifford Miller Middle School, Lake Katrine | $15

Info & Tickets