Putting too much faith in any single technology to solve the world’s problems usually leads to disappointment. Artificial intelligence (AI), for example, has its uses but is overhyped and creates big problems of its own.
One technology that’s been around since the late 1800s, however, could be the key component to solving the world’s energy problems: the battery. To understand why, you need some background on the small- and large-scale roles of the battery in the energy infrastructure. First, let’s look at the energy infrastructure.
The efficiency of the electrical grid depends on the utilities’ ability to predict demand and the weather over six-month periods, and that never happens with total accuracy. The two are connected; colder-than-expected winters and warmer-than-expected summers have a huge impact on energy demand, electricity rates and grid reliability.
When more energy than needed is available to the grid, that energy is sold off to other grids at a discount. When not enough energy is available to meet demand, utilities must buy more on the spot market at a premium price. Unexpected demand can also trigger bringing so-called peaker plants online to help meet demand. These plants are typically older, fossil-fuel powered, slow to turn on and expensive to run. Utility losses from miscalculating demand find their way to ratepayers’ electric bills.
This past winter is a great example of the consequences of getting those predictions wrong. Winter was much colder than expected, which forced utilities to buy more expensive energy on the spot market. This resulted in under-collection on rates, which ratepayers will eventually have to pay.
If only there were a way to capture excess energy during low-demand times and release it when needed. Well, that’s what batteries do, and they’re becoming much better and more cost-effective at their job.
Utilities have noticed. At the large scale, utilities are rapidly deploying battery energy storage systems, or BESS. The concept is as old as the grid itself. When cities first electrified their street lamps in the late 1800s, they depended on lead-acid batteries to keep the lights on. BESS deployments today are much larger, as much as a gigawatt or more. They are designed to provide their full output to the grid for 1 to 4 hours, making the grid more resilient, but their main purpose is to allow utilities to more closely match electricity demand with supply, storing or releasing as needed.
Most use the same lithium-ion technology found in electric vehicles, or EVs, or laptops, but newer technologies are becoming available based on more common materials such as sodium and pose less of a fire risk.
U.S. utilities are expected to add 70 gigawatt-hours, or GWh, to the national grid in 2026, according to the Solar Energy Industries Association, or SEIA. That’s enough energy to power 35 to 70 million homes for an hour. By 2030, SEIA expects total BESS deployments to reach nearly 500 GWh.
Another benefit of BESS: They are often built on sites of retired power plants. This is a win for the plant owners, who get value from an otherwise difficult-to-sell asset, and the BESS developer has an ideal location with preexisting infrastructure to connect to the grid.
Large-scale battery systems, however, aren’t the only battery storage that can supply electricity to the grid. Home battery backup systems and EVs represent a growing source of potential stored electricity. Total new residential battery systems capacity was 673 megawatts in the first quarter of 2026, according to the U.S. Energy Information Administration. Not all EVs have bidirectional charging capability that would allow the grid to draw electricity, but it’s becoming a more common feature.
These small battery systems can become a distributed storage network that works much like a BESS to help flatten the peaks and valleys of electricity supply and demand. In fact, this is happening with Eversource in New Hampshire now. The utility has two incentive programs for its customers to install batteries, both requiring that the customer allow Eversource to draw electricity from their batteries during high-demand times. Customers have flexibility in setting parameters that work for their consumption patterns, and Eversource will not allow the battery charge to fall below a certain level.
The Eversource Demand Response program offers $230 per kilowatt-hour, or kWh, of storage up to a maximum of $3,000. After three years, the batteries serve only the homeowner. Only specific models from Enphase and FranklinWH are eligible. For more information, visit the Eversource Demand Response page at eversource.com/residential/save-money-energy/energy-efficiency-programs/demand-response/nhcef-home-battery.
Eversource’s ConnectedSolutions program pays customers an average of $225 per kWh used from their batteries — an average of $1,125 per year. A much wider range of batteries is eligible. Find more information here: eversource.com/residential/save-money-energy/energy-efficiency-programs/demand-response/battery-storage-demand-response.
One of my earlier columns talks about considerations when buying a home battery backup system: ledgertranscript.com/2024/06/21/michael-nadeau-prep-article-55692193/.
Programs that pay or incentivize EV owners to allow utilities to draw electricity from their vehicles are in their infancy. As more EVs with bidirectional capabilities are sold, however, those programs are likely to grow. Some work much like Eversource’s Demand Response program, where the utility pays the EV owner for electricity used or offers a reduced rate on electricity. Others focus on commercial EV fleets that have large aggregated storage at their facilities.
Grid-connected battery storage reduces the need for new power sources, enhances the reliability of the grid and improves the efficiency of electricity production no matter the source. That lowers operating costs for electricity providers and maybe — just maybe — batteries will also lower your electric bills if deployed to their full potential.
Michael Nadeau is a member of the Community Power Committee.