Both the US and global energy storage markets have experienced rapid growth over the last year and are expected to continue expanding rapidly in order to support grid resiliency. Through 2035, global energy storage installations are expected to reach a capacity of 2 terawatts, which is eight times the capacity level reached in 2025.[1] The global market is forecast to experience an annual growth rate of 23%, led by China and the United States, despite policy uncertainty in both countries.[2] During 2025 alone, global energy storage installations jumped by 46% to a total installed capacity of 106 gigawatts (GW).[3]
The rapid growth in the energy storage market is similarly driving demand for project financing. As with any other project-financed asset class, lenders will analyze both the amount and probability of receiving cashflows generated by energy storage systems. Energy storage resources present a distinct set of challenges given their unique nature: unlike conventional or renewable generation, energy storage resources must be charged with electric power, which will sometimes (but not always) be provided by the offtaker, and are also subject to unique technical challenges such as degradation and augmentation.
Further, energy storage resources are limited in their ability to dispatch by the number of megawatts (MW) that can be used to charge the project (which may vary depending on the state of charge of the project) as well as the total number of megawatt hours (MWh) that can be stored. Energy storage resources are typically capable of providing capacity and other ancillary services, thus making them stronger candidates for multiple revenue streams than traditional generation. Each of these revenue streams will be subject to lender analysis. Moreover, there are certain additional considerations when structuring a project-financed transaction for an energy storage project, as set forth below.
TECHNOLOGY RISKS
While lithium-ion batteries remain the most widespread technology used in energy storage systems, these systems also use hydrogen, compressed air, and other battery technologies. Moreover, the energy storage industry continues to explore new technologies that can provide longer-duration storage to satisfy different market needs. Project finance lenders view all of these newer technologies as having increased risk due to a lack of historical data. As a result, a primary focus for lenders in their due diligence of an energy storage project will be evolving technology risks.
Much of the lenders’ diligence on technology risks will be covered by a report from an independent engineer, who will examine the project’s ability to satisfy the commissioning testing requirements and minimum performance requirements under the applicable offtake agreements.
For energy storage projects using lithium-ion batteries, lenders will expect a robust review from the independent engineer on capacity degradation and safety issues tied to overheating. Fires resulting from battery thermal runaway have become one of the biggest challenges for energy storage project developers and lenders. Project companies can mitigate degradation concerns by securing performance guarantees, equipment warranties, and/or an operations and maintenance (O&M) agreement (which may include obligations for periodic augmentation of the batteries) to ensure that equipment will be replaced or otherwise maintained at a minimum capacity.
In particular, performance guarantees and equipment warranties mitigate technology risks by shifting these risks away from the project company to the technology vendors. Performance guarantees and equipment warranties provide assurances to the lenders that the applicable equipment will perform at the projected levels set forth in the lenders’ financial models. Pre-agreed and priced augmentation schedules also mitigate the risk of future price changes in the relevant equipment.
Lenders will also assess the value of any performance guarantees and equipment warranties based on a few different factors.
First, any performance guarantees and equipment warranties should be assigned to the project company upon or prior to the operation of the project so that the project company is able to directly enforce these performance guarantees and equipment warranties.
Second, any performance guarantees and equipment warranties should be given by creditworthy counterparties. Given the everchanging landscape of energy storage technologies, some equipment and service providers will be new entrants and may not have strong financials, which may limit the benefit of any such performance guarantees and equipment warranties.
If an equipment or service provider has a weaker balance sheet, this weakness can be offset by securing letters of credit from the provider or a guaranty from a parent entity with a significant balance sheet. Recent bankruptcies and restructurings of key suppliers have had a ripple effect in the market, and lenders have been seeking replacement O&M and warranty providers for affected suppliers.
CONSTRUCTION RISKS
It is fairly common to see multiple equipment supply, construction, and installation contracts rather than one turnkey engineering, procurement, and construction (EPC) contract for energy storage projects. Lenders tend to prefer fixed-price turnkey EPC contracts so that there is a single contractor, which shifts some of the construction risk from the project company to the EPC contractor. An energy storage project with a split EPC structure will require additional diligence by the lenders to address any additional risk exposure. In particular, lenders will want to review the applicable contracts to ensure that they work together correctly from a timing and technical perspective.
For example, a balance of plant (BoP) contractor must have the site ready (including complying with any technical specifications from the equipment provider) before the batteries will be delivered onsite. If the contracts do not align, the risk of resulting delays will be borne by the project company and therefore the lenders. Moreover, the lenders will expect that project costs will be fixed at the time of closing of the project financing and, if the construction costs are subject to change, the lenders will require that there are sufficient reserves for potential cost increases. The lenders will typically require a collateral assignment of any construction contracts in accordance with a customary collateral assignment agreement.
In addition, for the US market a number of executive orders have been issued that impose tariffs since the change of administration in January 2025. There is risk that additional tariffs may be imposed, existing tariffs increased, or other trade barriers put in place. These developments have affected and are expected to continue to affect the supply chains related to renewable energy projects, including energy storage projects. This has resulted in a heightened focus by lenders in their due diligence process on the supply contracts to understand any additional risk to increased costs resulting from tariffs.
OPERATING RISKS
As a general matter, lenders will conduct diligence to understand the energy storage project’s operating limitations and O&M costs. Lenders will look for an O&M agreement for the project with an experienced operator that will ensure that the project will be operated within the project’s operating limitations.
Any such agreement would typically be included in the collateral package pursuant to a customary collateral assignment agreement. To the extent that there are project degradation issues or other anticipated major maintenance costs such as the augmentation of battery systems, lenders may require the project company to establish O&M reserves to ensure sufficient funds will be on hand to cover these anticipated maintenance costs.
Lenders will also look for confirmation that the project company has sufficient rights to the system’s software and any other IP rights, which is critical to the daily operations of the energy storage project. More specifically, the project company will need to evidence that the system’s software can be accessed by the project company if the operator is replaced or by the lenders if the lenders exercise remedies and take ownership of the project. This can be evidenced with transferable software licenses or technology escrow agreements.
REVENUE STREAMS
As with all project finance transactions, project companies must show that the project can support a steady and reliable stream of cashflows. Traditionally, energy storage projects have had long-term offtake agreements that can cover payments for delivered energy, capacity, or ancillary services, or a combination of the foregoing. These projects will have long-term predictable revenue streams. Lenders may be willing to finance merchant cashflows, but with less leverage and subject to detailed market studies, cash sweeps, and other lender protections.
Energy storage projects with contracted cashflows can employ several different revenue structures, including offtake agreements for standalone storage projects, which typically provide either capacity-only payments or payments for capacity plus variable O&M costs; offtake agreements for renewables-plus-storage projects, which typically provide payments for delivered energy or energy plus capacity; and build-transfer agreements, which typically provide payment for title to the energy storage project upon substantial completion and operation of the project (or after mechanical completion and prior to the project being placed in service for tax purposes if tax credits are involved).
Lenders may be willing to finance merchant cashflows for energy storage projects subject to less leverage and cash sweeps. For energy storage projects with merchant cashflows (whether in whole or in part), lenders will focus on understanding the markets, running model sensitivities, and preparing for all reasonably foreseeable scenarios that would affect cashflows.
Notably, the available revenue streams for merchant cashflows in the United States differ significantly based on the location of the energy storage projects and the applicable market forecasts. Moreover, lenders may be sensitive to tightening margins in specific markets as the penetration of energy storage systems increases, as is the case in Texas.
In order to offset the reduced leverage provided for merchant cashflows, developers may seek a mix of contracted and merchant cashflows. In Texas, some energy storage projects utilize hedge agreements that provide some sort of revenue floor, together with market reports about future power prices. In California, some energy storage projects can contract for energy and resource adequacy, which provides projects with a contracted revenue stream.
Developers may seek portfolio financing as an alternative to single-project financing. Portfolio financing can mitigate the risks associated with any single project since the lenders will not be wholly dependent on a single project; however, portfolio financing can also be challenging from a diligence and structuring point of view.
UNDERWRITING TAX EQUITY INVESTMENTS
The One Big Beautiful Bill Act (OBBBA), enacted in July 2025, amended the federal clean energy tax incentives established under the Inflation Reduction Act; however, energy storage projects (whether built on a standalone basis or paired with a renewable energy generation project) in the United States remain eligible for investment tax credits for projects where construction begins prior to 2033.
As such, lenders are willing to provide bridge capital that is underwritten based on the receipt of proceeds from an anticipated tax equity investment or purchase of tax credits, similar to traditional renewable energy projects. Certain tax equity structures involve both an equity investment as well as the future sale of tax credits, and these additional features may add complexity to the structure of the bridge debt, which may include both tax equity bridge loans and tax credit transfer bridge loans.
As with other renewable energy projects, the addition of construction bridge debt provides an additional source of capital to pay construction costs while also adding complexity to the project financing of an energy storage project. The OBBBA tightened domestic content and “Foreign Entity of Concern” requirements affecting eligibility of certain projects using foreign-sourced equipment or having certain ties to prohibited foreign entities.
As a result, lenders will conduct additional diligence on the tax equity documents and often require the delivery of an interparty agreement with the applicable tax equity investor or tax credit purchaser. Project owners must satisfy the federal prevailing wage and apprenticeship requirements to be eligible for the full base investment tax credits.
Despite global shifts in policy in 2025, causing lenders to undertake additional diligence before financing an energy storage project, the project finance market for energy storage has grown and is continuing to grow alongside the rapid transition to less carbon-intensive resources.
Explore Other Chapters in the Report
Prefer to read by topic? Explore the individual chapters below:
Utility-Scale Energy Storage Procurements in 2026: Contracting and Risk Allocation
A practical guide to utility-scale energy storage procurement in 2026, covering PPAs, EPCs, BTAs, battery supply agreements, financeability terms, tariffs, UFLPA, FEOC, and change-in-law risk.
Federal Regulatory Outlook for Electric Storage, QFs, and Inverter-Based Resources
FERC’s evolving rules for energy storage, QFs, and inverter-based resources, including Orders 841 and 2222, co-location, data center interconnection, and reliability standards.
State Energy Storage Policy Trends for 2026
State energy storage policy outlook for 2026, including procurement mandates, incentive programs, IRP reforms, DER aggregation, and safety standards shaping deployment.
How ‘FEOC’ Rules Are Reshaping Energy Storage Tax Credit Eligibility
How FEOC restrictions affect energy storage tax credits, including ITC eligibility, 45X credits, foreign entity rules, supply chain sourcing, and compliance risks.
Tariffs and Trade Risk in Energy Storage Projects: 2026 and Beyond
2026 outlook on tariffs and trade risk for battery energy storage projects, covering supply chain scrutiny, AD/CVD investigations, Section 232 actions, and BESS procurement strategies.
EU and UK Energy Storage Regulation in 2026 and Beyond
Outlook for EU and UK energy storage regulation in 2026, covering batteries rules, critical raw materials, net-zero policy, permitting, and UK storage reforms.
The Next Phase of Battery Storage Investment in 2026 and Beyond
Battery energy storage investment outlook for 2026, covering project M&A, investor diligence trends, supply chain risk, and renewable portfolio integration.