Installations of battery energy storage are rapidly accelerating across the globe. According to the International Energy Agency (IEA), 108 GW of new battery storage was deployed globally in 2025, an increase of 40% over 2024 and 11 times more than in 2021. A similar story is playing out in the US, where nearly 19 GW of new storage capacity was added last year.
The momentum driving the dramatic upswing in energy storage installations is not stalling. According to a forecast from Wood Mackenzie and the American Clean Power Association, annual installations in America will exceed 28 GW by 2031. Put simply, there is little doubt that energy storage will play an increasingly prominent role in grids across the world.
There are myriad reasons why this is happening. One is simply that energy storage is increasingly cost-competitive, with a nearly 90% reduction in the cost per kWh of lithium-ion batteries over the past 15 years, making it the most deployed new battery technology chemistry (pumped storage is the world’s most used energy storage technology). While falling costs have made energy storage financially viable, its adoption is also spurred by the many benefits it can deliver—from supporting variable renewable generation to enhancing resilience, relieving grid congestion, and reducing capacity and energy costs across the power system.
A Fast-Moving Industry with Many Questions to Answer
While demand is driving a proliferation of new projects, it’s important to remember that battery energy storage remains a rapidly evolving industry. For example, lithium-ion batteries have been the dominant battery energy storage technology, and they continue to evolve with larger-format cells and improvements in balance-of-system and safety. But other technologies, such as flow, sodium-ion, and iron-based batteries, are also maturing quickly. Substantial and ongoing efforts have been made to modernize safety codes and standards, which inevitably lag behind design changes and emerging battery chemistries and their integrated solutions. And communities and local officials responsible for project approvals may have limited access to the objective technical information needed to evaluate proposals.
According to one estimate, at least 150 local governments across 17 states have temporary moratoriums, bans, or restrictive ordinances that limit battery energy storage. Other growing pains stem from the fragmented way projects are planned, developed, built, operated, and maintained. The team that initially plans an energy storage project rarely procures the equipment, secures the necessary permits, or handles the operations and maintenance (O&M) after commissioning. Developers, utilities, regulators, and communities often have distinct and differing assumptions about how a project should move forward and the value it should create.
Scaling Energy Storage Responsibly
Demand for battery energy storage will continue to drive the development and construction of more projects. But the full benefits of the technology can be more readily achieved by sharing industry best practices and experiences, and by identifying and filling knowledge gaps. That was the rationale for the development of EPRI’s Energy Storage Roadmap in 2020. “Initially, we wanted to help bring order out of the chaos of a new industry with different technologies and multiple development steps with different teams and stakeholders,” said Eva Gardow, Technical Executive in EPRI’s Energy Storage and Distributed Generation program. “Now we are focused on refining and optimizing the roadmap to better serve the industry, utilities, and communities at each stage of a project.”
The roadmap was most recently updated in 2024 and reflects the objectives that utilities, developers, and regulators have identified as most important for projects to achieve for battery energy storage to be deployed responsibly at scale. The roadmap is organized around four future state pillars—safe, reliable, affordable, and clean—that match EPRI’s mission as an organization. Underpinning all four pillars is a commitment to innovation to advance energy storage equitably, ensuring the technology’s benefits are fully shared with the communities that host projects. For each pillar, the roadmap also identifies the vision of what success looks like and the gaps standing in the way of achieving it. Identifying the gaps builds consensus about the research initiatives needed to fill them.
EPRI is well-suited to lead this effort. EPRI has a public benefit mission, a commitment to independent research, and a longtime role as a convener of utilities, regulators, policymakers, technology providers, and other stakeholders in the battery energy storage ecosystem. This ideally positions EPRI to organize and support collective efforts to scale energy storage deployments by providing the research, insights, data analysis, and best practices that projects need to be safe, reliable, affordable, and clean. EPRI also draws on decades of research across topics ranging from performance and reliability to thermal runaway and fire risks, to technoeconomic modeling, to end-of-life management.
The roadmap is intentionally structured to be useful to companies and individuals responsible for planning, developing, building, operating, and decommissioning battery energy storage projects. “It’s aimed at providing practical tools, resources, and guides that can be applied in day-to-day processes,” Gardow said.
A Roadmap Built Around How Projects Work
To provide practical guidance, the roadmap and the gaps it highlights are organized around the real-world project life cycle phases of planning, procurement, deployment and integration, operations and maintenance, and decommissioning. The logic is straightforward: different teams own different project phases, and a gap that matters to an O&M crew may be largely irrelevant to the group handling procurement. “By splitting it up by life cycle phase, it helps departments within organizations determine which gaps might be more applicable to them for what they’re doing on a daily basis,” said Taylor Kelly, an EPRI technical leader who led the creation of the most recent version of the roadmap.
The gaps identified in the roadmap are far from abstract research questions. They represent practical opportunities to mitigate risk, improve asset reliability, lower costs, and increase certainty across all stages of project development. A closer look at each roadmap pillar illustrates both the scope of challenges projects must surmount and the concrete steps underway to address them.
Safety
The safety pillar is where some of the most active work to apply knowledge and implement solutions is underway. Community pushback is one front, often driven by uncertainty about fire risk and environmental impacts rather than informed opposition. That uncertainty is understandable, given media coverage of high-profile incidents. But the data tells a more nuanced story. Despite a roughly 65-fold increase in global battery storage deployments between 2018 and 2023, the average number of failure incidents held steady at around 10 per year. The industry has incorporated lessons from failure incidents, and the trend in safety performance is moving in the right direction.
EPRI’s nearly decade-old fire prevention and mitigation research project, which won a 2025 Chauncey Award, has produced guidance on thermal runaway characterization, failure incident response, and safe operations and maintenance practices. Current work includes an updated analysis of EPRI’s publicly accessible global failure incident database, which has become one of EPRI’s most visited online resources and is regularly referenced by researchers, regulators, and first responders. Researchers are also investigating materials that could prevent failures from propagating and cascading into large-scale fires and conducting testing to characterize the emissions battery fires produce. This information has not been well documented and is important for guiding emergency responders’ strategies.
Addressing community concerns requires more than data. A community perception survey currently underway aims to establish what the public actually understands about storage technology, with the goal of developing better educational tools for communities and local authorities.
Reliability
Because battery storage is a young grid technology, the operational history needed to understand long-term performance, degradation patterns, and meaningful end-of-life thresholds is limited. EPRI has responded to fill that gap with a benchmarking initiative called BEST Reliability, or Benchmarking Energy Storage Technology Reliability. BEST Reliability is a collaboration with energy storage owners and offtakers to collect operational data from deployed commercial systems and begin developing industry-wide performance baselines. “If we can get enough system data, we can help develop the foundation for what the expectation of performance should be,” Kelly said. “Then, as we get more systems, we can start to benchmark performance over time.”
Reliability gaps also affect asset management, operating costs, procurement, and risk allocation throughout the life cycle. Battery energy storage’s modular nature introduces a large volume of components and associated data. Finding the balance between achieving greater visibility into the system’s depth and efficiently and actively addressing maintenance tasks remains a challenge. Enhancing reliability will also de-risk and harden the asset owner in the face of vendor transitions and business changes. This helps ensure the ongoing operability of the system.
Affordability
Significant and ongoing cost reductions have dramatically improved the economics, making battery energy storage financially viable for applications ranging from firming variable renewables and reducing grid congestion to providing resilience and backup power. But affordability goes well beyond the purchase price of the technology itself. It also includes the full cost of an energy storage project across its life cycle, including installation and interconnection costs, battery degradation, O&M, and end-of-life requirements that are often ignored when a project is first planned. EPRI’s Energy Storage Integration Council (ESIC) offers 17 products and tools to improve capital efficiency, reduce soft costs, and lower O&M expenses.
New technologies add both opportunity and complexity to the affordability picture. Lithium-ion batteries dominate today’s market, but sodium-ion, zinc-based, and long-duration flow battery technologies are advancing quickly, and each has distinct cost profiles, performance characteristics, and lifecycle economics. Understanding those differences requires rigorous technoeconomic analysis that accounts for the full range of variables, from capital costs and degradation rates to the value different technologies can capture across multiple use cases.
Besides the ESIC, EPRI also developed the Distributed Energy Resource Value Estimation Tool, or DER-VETTM. This free, publicly accessible platform allows utilities, developers, and other stakeholders to calculate and optimize the value of storage and other distributed energy resources based on site-specific conditions. DER-VET was built out of necessity. “Fifteen years ago, there was no tool that could calculate the energy going in and coming out,” Gardow said. “That’s why we started building this.”
Clean
The clean pillar addresses the environmental and human health dimensions of storage deployments across the full technology life cycle, from the sustainability and social impact considerations of mining critical minerals used in battery manufacturing to the reuse, repurposing, recycling, and disposal of systems at end of life. Public and industry awareness of both the environmental benefits and challenges of battery storage is growing, and the scientific understanding of these topics is improving alongside it.
One of the most tangible environmental benefits of battery storage is its potential to reduce or replace the operation of fossil-fuel peaking generators, which tend to run during periods of high heat and pollution in densely populated areas. Plant-level data shows that replacing peaker plants with battery storage can yield very large reductions in local air emissions, including nitrogen oxides and particulate matter. One hybrid project in California’s Central Valley saw reductions of up to 78% in particulate emissions and up to 60% in greenhouse gas emissions. Replacing peaker plants with batteries can produce disproportionately large health benefits for the communities closest to those facilities.
Battery storage also has the potential to deliver more direct community benefits. When deployed in underserved communities, it can lower energy bills, improve grid resilience, and support essential services ranging from food storage to medical equipment. EPRI’s research on tangible benefits documents real-world examples of these outcomes, from households in Puerto Rico that saw electricity bills drop sharply after solar and storage installations to communities in New York and California that gained both jobs and improved grid reliability from storage deployments.
For emerging battery technologies beyond lithium-ion, important environmental gaps remain. New chemistries require fresh assessments of their life cycle impacts as designs evolve. For lithium-ion batteries, EPRI has already developed scorecards and modeling tools to characterize the environmental and health impacts of both normal and abnormal operations. These are being applied to inform storage design, codes and standards, permitting decisions, and responses to community questions.
At the end of life, few large-format battery modules in stationary or electric vehicle platforms have yet reached that point, which means recycling markets and their operating requirements are still developing. Contrary to what might be assumed, recycling capacity is not the binding constraint today. Rather, it is the volume of modules reaching end of life that remains low, and the regulatory and policy frameworks governing what happens at that stage are still taking shape in most jurisdictions. EPRI’s role is to track and inform policy development with fact-based research, while also supporting work to improve the costs and efficiency of reuse, repurposing, and recycling as those markets mature.
EPRI is continuing to pursue applied research across all four pillars. Energy storage is no longer just a promising emerging technology. It has quickly become a mainstream, viable solution that addresses many of the power industry’s most pressing challenges. But the rapid growth of battery energy storage doesn’t mean it can’t scale more efficiently, safely, and affordably in the future. “Independent research and collaboration can support the industry to achieve its potential to benefit the grid, customers, and society,” Gardow said. “Our job is to help.”
EPRI Technical Experts:
Eva Gardow and Taylor Kelly
For more information, contact techexpert@eprijournal.com.
Banner image licensed by EPRI from Adobe Stock
