Adding long duration and multi-day energy storage to New York’s grid could cut system costs in 2040 by 29% and expand the grid’s energy storage capacity tenfold compared to relying solely on short-duration batteries, according to an analysis by battery storage provider Form Energy.
The Boston-based energy storage company, which manufactures multi-day batteries using iron-air technology, wrote in a recent white paper that long-duration energy storage (LDES) of 10 to 24 hours and multi-day energy storage (MDS) of greater than 24 hours can help meet the state’s decarbonization and reliability goals if they’re added to the grid.
“Broadly, our analysis found that emerging LDES and MDS technologies can drive down costs and reliably integrate renewables in New York’s clean energy future,” the company wrote. Such storage can provide flexible, dispatchable, emission-free capacity over the time scales needed to balance the variability of renewable energy on New York’s grid.
“These resources can support system resiliency during lulls in renewable generation, and extreme summer heatwaves and winter storms lasting multiple days.”
Form Energy prepared the paper to inform New York’s grid decarbonization effort, which aims to supply at least 70% of demand from renewable energy resources by 2030 and achieve a zero-emissions grid by 2040. Previous studies had found the state would need 20 to 45 gigawatts (GW) of “dispatchable emissions-free resources” (DEFRs) that can be controlled and used when needed. The new analysis sought to examine which technologies in the broad category of DEFRs would provide that service at lowest cost.
On modelling multiple scenarios of varying energy storage durations, Form Energy found that the grid could reduce system costs by 29% in 2040 by including LDES and MDS in the resource mix, compared to relying solely on short-duration lithium-ion batteries.
“In the models with only short-duration lithium-ion batteries available, over 60 GW of battery capacity is built by 2040 to shift renewable generation and meet peak demand,” writes PV Magazine. “However, this capacity only provides 538 gigawatt-hours of energy storage.”
When LDES and MDS are available, total storage capacity needs drop to around 40 GW. “But critically, total energy storage capacity grows nearly 10x to over 5,000 GWh.”
But the contribution of batteries to decarbonization outcomes relies on their placement within a larger context of policy and infrastructure, veteran climate reporter David Roberts explains for Vox. They do not inherently reduce or increase emissions on their own.
“If deployed strategically, energy storage can do all the things boosters say, making the grid more flexible, unlocking renewable energy, and reducing emissions. But only if it is deployed strategically, which it generally hasn’t been,” Roberts writes.
Batteries are often used in a way that leads to greater overall grid emissions. That’s because they are largely deployed for energy arbitrage, used to store electricity when it is cheaper to produce and then discharge it at times of higher demand. While this can lead to cost savings for consumers—and profits for energy storage providers—storing electricity is less efficient than using it directly, as some of it is lost during storage. For each unit of energy used, a greater amount needs to be produced if it is stored between production and consumption. And if that energy is produced from carbon-emitting sources, more carbon is emitted in the process.
But that outcome is not inevitable. Batteries can be deployed more strategically and deliberately to reduce emissions—if a grid’s energy sources are all zero-emission. That outcome depends on policies and infrastructure that enable battery operators to make a profit while contributing to decarbonization, Roberts says. Currently those circumstances don’t widely exist.
“There is no free-standing, financial incentive for batteries to operate in a way that reduces emissions,” Roberts said on a recent episode of the Volts podcast. “They’re simply just not incentivized to do that.”
Still, batteries can be part of longer-term planning for grid decarbonization.
“Although batteries can, in some cases, increase emissions in the short term, the research community and wider industry have shown that storage can significantly reduce emissions by enabling greater investment in renewable energy and maintaining grid reliability when fossil-fired plants retire,” one of the Form Energy white paper authors told The Energy Mix.
Form Energy’s analysis “assumes that batteries are free to operate in a way that results in the lowest costs while meeting New York’s clean energy targets,” the author added. But the researchers didn’t make any assumptions about how batteries in the model are charged, in line with the industry standard for modeling such scenarios.
“Multi-day storage can create clean, firm capacity—reducing grid emissions while maintaining grid reliability over time,” and “can also curb renewable curtailment, enabling deeper penetration of renewables in the market,” the author said.
But “near-term policy support will be needed to enable the full potential of MDS technologies.”