How Battery Energy Storage Is Quietly Rewiring Resilience in NY and MA

March 3, 2026

There is a particular kind of anxiety that settles in before a heatwave.

You can feel it in the late-afternoon light, heavy and stalled. Air conditioners hum at full tilt. The grid, invisible but omnipresent, strains under the weight of millions of small, simultaneous decisions: turn it cooler, cook dinner, charge the car. The modern economy rests on a synchronized surge of electrons. When that surge becomes too much, things can tip—voltage drops, equipment overheats, whole neighborhoods flicker into darkness.

In June 2025, New York City hit 100°F for the first time in 13 years. Con Edison warned that the system was “approaching peak capacity” as residents blasted air conditioning into the night.1 Heatwaves like this are no longer statistical outliers; they are previews. And with each preview, the question grows sharper: what does resilience look like in an age of climate volatility?

In New York and Massachusetts, part of the answer increasingly lies in battery energy storage systems—BESS. They are not particularly flashy. They do not tower like wind turbines or shimmer like acres of solar panels. Often, they sit in unobtrusive containers, charging quietly when power is abundant and releasing electricity in the moments it matters most. But in recent years, they have become the shock absorbers of the Northeastern grid.

Peak Events and a Grid Under Stress

The Northeast faces three overlapping forms of grid stress.

The first is the heatwave

Days over 90°F that drive simultaneous, system-wide spikes in demand. When millions of air conditioners switch on in tandem, peak load can exceed the comfortable operating margins of substations and feeders. Without intervention, utilities may resort to voltage reductions or even controlled outages to prevent cascading failures. 1,2

The second is the winter storm

The nor’easter that blankets multiple states with two to three feet of snow while ice-laden trees drag down power lines. In January 2026, a historic blizzard left more than 1 million customers across several states without electricity at its peak.3 Extended outages during deep freezes are more than inconvenient; they are dangerous. At least 34 people have died in this storm.

The third category is the high-demand emergency.

These are moments when unexpected failures coincide with extreme weather. Tropical Storm Isaias in August 2020 left more than 3.7 million people without power across New York, New Jersey, and Connecticut, some for nearly a week.4 The grid, built for a milder and more predictable climate, struggled under compounding shocks.

Battery storage does not prevent heatwaves or blizzards. But it changes how the system responds.

Peak Shaving as Insurance Against Outages

One of the simplest and most powerful functions of BESS is “peak shaving.” When demand spikes—say, at 5 p.m. on a 98°F day—batteries discharge stored electricity to reduce the total draw on the grid. This can be the difference between stability and blackout.

Consider Sterling, Massachusetts. The town installed a 2 MW/3.9 MWh battery system that charges when demand and prices are low and discharges during peak hours. The result: approximately $400,000 per year in avoided capacity and transmission costs for its 3,700 residents.5 A battery, in effect, replaced a slice of expensive infrastructure.

On Nantucket, a 6 MW/48 MWh battery installed in 2019 manages afternoon summer peaks on an island powered by undersea cables. By absorbing those spikes, the battery deferred the need for a third transmission cable—an investment that would have cost roughly $200 million.6 Storage became an alternative to steel and copper.

The same pattern held during a brutal June 2025 heatwave across New England. Behind-the-meter solar and batteries reduced regional peak demand by approximately 4.4 gigawatts—about 15 percent—preventing blackouts and saving ratepayers at least $8.2 million in direct costs, and as much as $19 million when broader wholesale price effects were included.2,7 In a single day, distributed resources reshaped the economics of stress.

Resilience in the Dark

If peak shaving is about economics and stability, backup power is about survival.

When coupled with solar or other generation in a microgrid configuration, batteries can “island”—disconnecting from a failing grid and continuing to supply critical loads. Unlike diesel generators, which take time to start and require fuel deliveries, batteries respond in milliseconds.

During Tropical Storm Isaias, several facilities in New York and New Jersey equipped with microgrids seamlessly transitioned to battery-backed generator power as the grid failed. Eight ShopRite supermarkets operated in island mode for four to six days, providing food, fuel, and essential supplies while surrounding areas went dark.4

In Sterling, the battery system is paired with a local solar facility to create a microgrid capable of powering the town’s police station and emergency dispatch center for at least 12 days during an extended outage.5 In New York City, solar-plus-storage microgrids deployed in vulnerable neighborhoods can keep lights, refrigeration, and device charging available in community centers and affordable housing complexes during prolonged blackouts.8

Resilience here is not abstract. It is the difference between a refrigerated insulin supply and spoilage. Between a heated emergency shelter and a shuttered one.

Displacing the Dirtiest Power – Peaker Plants

Historically, peak demand has been met by “peaker” plants—often aging oil or gas facilities that run only during high-demand hours and emit disproportionate levels of pollutants. Many are located in environmental justice communities.

Battery systems offer an alternative. During summer 2025, Con Edison used distributed batteries to power residential air conditioners during critical peak hours, avoiding the need to activate dirtier fossil-fuel generators.2 In Massachusetts, the Clean Peak Energy Standard, launched in 2020, incentivizes clean energy generation and storage during designated peak windows. This policy framework has helped advance projects such as a 45 MW/180 MWh battery facility in West Springfield to replace a retired fossil peaker.2

The environmental benefit is not incidental. Every kilowatt-hour delivered from a battery during peak hours is a kilowatt-hour not generated by the least efficient—and most polluting—plants on the system.

The Economics of Flattening the Curve

Electricity markets are unforgiving at the peak. Prices can spike dramatically when supply margins narrow. By trimming those peaks, BESS flatten not just the load curve but the cost curve.

Studies of the June 2025 heatwave found that distributed solar and storage delivered millions in direct ratepayer savings and further suppressed wholesale prices region-wide.7 Homeowners in Massachusetts participating in ConnectedSolutions can earn roughly $1,000–$1,500 per year for allowing their batteries to discharge during peak events.9 In Queens, residential participants in a Con Edison battery pilot received credits per connected air-conditioning unit while benefiting from uninterrupted cooling during grid stress.2

These programs transform consumers into grid participants. The battery in a basement becomes an economic asset—not just insurance, but income.

PureSky Energy and Community-Scale Storage

Against this backdrop, community solar developers have begun pairing generation with storage to serve both local subscribers and the broader grid. PureSky Energy has emerged as a notable example in New York and Massachusetts.

By mid-2025, PureSky’s operational portfolio included eight solar-plus-storage projects across the two states, totaling approximately 49 MWh of battery capacity. In Rensselaer County, the 5 MW Elmbrook Community Solar Farm, paired with 9 MWh of storage and brought online in December 2022, produces enough electricity for roughly 1,566 homes and can dispatch stored energy during late-day peaks or outages, displacing an estimated 17 million pounds of CO₂ annually.

In Schenectady County, Oak Hill Solar 2—5 MW of solar with 9 MWh of storage, online December 2024—serves approximately 1,578 homes and delivers comparable emissions reductions. During the June 2025 heatwave, facilities like these contributed stored solar energy to the grid during critical late-afternoon hours, supporting neighboring communities under strain.

In Massachusetts, the company’s portfolio includes dozens of megawatts of solar and tens of megawatt-hours of storage, including the Cotuit Solar Farm in Sandwich, which pairs 4.4 MW_DC of solar with a battery system that enables municipalities to draw on stored renewable energy during peak hours.^11

During ISO-New England’s June 24, 2025 scarcity event—when temperatures reached 100°F—PureSky reported that more than 90 percent of its storage systems responded when called upon, underscoring the reliability of distributed batteries under real-world stress.

A Different Kind of Infrastructure – Distributed Generation Plus Battery Storage

Battery storage will not eliminate extreme weather. Nor will it singlehandedly decarbonize the grid. But it represents a shift in how we think about infrastructure.

Instead of building ever-larger, centralized assets to handle the most extreme five hours of the year, New York and Massachusetts are increasingly investing in flexible, distributed systems that respond dynamically to stress. Instead of accepting that the dirtiest plants must run on the hottest days, they are substituting stored sunlight.

There is a quiet radicalism here. The battery does not announce itself. It does not dominate the skyline. But when the grid trembles—on a 100-degree afternoon or in the whiteout of a blizzard—it discharges.

And in that discharge is a new model of resilience: cleaner, cheaper, and closer to the communities it serves.