Bankability of Long Duration Energy Storage (LDES)

Key Takeaways

The author has evaluated the bankability of leading LDES original equipment manufacturers (OEMs) using two criteria: financial performance and field deployment record.

In this issue, ESS emerges top in financial performance among publicly-listed pure play LDES OEMs. NGK retains the top spot in the field deployment category. These companies have a high likelihood of long-term growth and profitability.

LDES Market

Long duration energy storage (LDES) technologies are storage technologies that can deliver 10+ hours of discharge at rated power (as defined by the United States Department of Energy) more cost effectively than the dominant lithium-ion battery technology.

The LDES industry has been impacted by the prevailing policy factors in 2025 including:

• Public funding programs: at both the local and national government levels globally are subsidizing the cost of deploying LDES which promotes adoption of said technologies. Such programs include the 7.7-GW LDES Cap-and-Floor program in the United Kingdom and the California Public Utilities Commission (CPUC)’s 2-GW LDES procurement target.

• U.S. tariff hike: U.S. tariffs on lithium-ion batteries (LIBs) imported from China is estimated to range from 40.9% to 82.4% in 2026 and beyond.

• U.S. Reconciliation Bill 2025 (OBBB): the provisions of OBBB with the biggest impact on the LDES industry are the 48E credit (ITC) for standalone storage, 48E credit (ITC) for solar and wind, 45X (advanced manufacturing production) credit and Foreign Entity of Concern (FEOC) restrictions.

• Data center energy consumption growth: global energy consumption of the data center industry is expected to increase by more than 100% by 2030 to around 945 TWh. The industry is moving towards on-site power generation to improve reliability and cost.

While most of the policy changes have similar impacts on both the broader energy storage industry and the LDES sub-industry, some of them have diverging impacts on the two. For instance, the FEOC restrictions under OBBB are expected to have net negative impacts on the energy storage industry as LIB supply chains are dominated by Chinese and China-affiliated companies. However, the same provision is expected to have a net positive impact on the LDES sub-industry since it is largely dependent on domestic (U.S.) supply chains and might become more cost-competitive against LIBs.

Table 1 displays the expected impacts of the 4 factors on the growth outlook of the LDES industry.

Companies to watch

The author evaluates the competitiveness of various LDES original equipment manufacturers (OEMs) bi-annually as an indicator of their commercialization progress. As in the April 2025 issue, the author utilizes 2 metrics - financial performance and field deployment - in this August 2025 issue.

For the financial metric, the author has selected LDES manufacturers based on:

1. Listing (public vs private): the author selected publicly listed companies since public companies are mandated by law to disclose their financial performance.

2. Structure (pure play vs conglomerate): the author selected pure play energy storage companies since conglomerates do not tend to specify the financial performances of their energy storage subsidiaries/divisions.

For the field deployment metric, the author has evaluated LDES OEMs irrespective of company type. The criteria used here is:

1. Cumulative installed capacity: must exceed 1 MWh

2. Number of distinct installation sites: must exceed 1

The list of companies in the April 2025 issue was as follows:

• CellCube Energy Storage GmbH (“CellCube“)

• Dalian Rongke Power Co., Ltd (“Rongke Power“)

• Eos Energy Enterprises, Inc. (“Eos“)

• ESS Tech, Inc. (“ESS“)

• Invinity Energy Systems plc (“Invinity”)

• NGK Insulators Limited / BASF Stationary Energy Storage GmbH (“NGK“ / “BSES“)

• Sumitomo Electric Industries, Ltd. (“Sumitomo Electric“)

• VRB Energy, Inc. (“VRB Energy“)

In this August 2025 issue, the list has been updated as follows:

• Additions

  • Polar Night Energy (“Polar Night“): 3 operational projects totaling 118 MWh

As such, the company list in this August 2025 issue contains the following 9 entries: CellCube, Eos, ESS, Invinity, NGK/BASF, Polar Night Energy, Rongke Power, Sumitomo Electric and VRB Energy.

Some notable LDES OEMs such as Form Energy were not included herein due to their lack of operational pilot and commercial projects.

Additionally, the following top LDES providers did not meet the deployment threshold detailed above: Antora, Energy Dome, Energy Vault, Highview Power and Largo.

More on this in the field deployment section below.

HY 2025 Financial performance

3 of the selected companies are pure-play publicly-listed LDES OEMs and have disclosed their HY 2025 financial performance. The companies HY reports are linked in the table below. See further financial details in this LDES Tracker.

Net profit margin = (net income/revenue)*100; a measure of how much profit is generated as a percentage of the revenue.

Technological innovation yielding next generation product offerings is the main driver behind the revenue growth observed for both Eos and ESS.

• Eos continues to fine tune the manufacturing process of the Z3 BESS to achieve the targeted cost reduction.

• ESS has launched the Energy Base which marks a shift in product design from modularity to a more traditional large-scale flow battery architecture entailing scalable power stack enclosures and electrolyte tanks. ESS has recently raised $31M to sustain operations.

Invinity has introduced Endurium for its higher energy density and lower operating expenses (OpEx).

Field deployment

The table below displays the deployed capacities of 8 companies across pilot, demonstration and commercial projects. See full project details in the LDES Tracker.

Additionally, the following notable LDES OEMs were not included in the table above because they did not meet the deployment threshold:

• Antora: 1 operational pilot project rated 5 MWh

• Energy Dome: 1 operational pilot project rated 4 MWh

• Energy Vault: 1 operational commercial gravitational energy storage project rated 100 MWh

• Eos: no publicly available deployment records

• Form Energy: no operational projects

• Highview Power: 1 operational pilot project rated 15 MWh

• Largo: 1 operational commercial project rated 5.5 MWh

• BYD: 1 operational sodium-ion ESS project rated 2.3 MWh

The LDES Tracker contains further details of all the projects listed above.

Author’s take

Among the pure-play publicly-listed LDES OEMs, ESS demonstrates highest financial strength with a net loss margin of 462.5% and 677.7% revenue growth YoY. Additionally, ESS’s net income grew fastest at 49.3% YoY.

From a deployment viewpoint, NGK/BASF leads with over 5000 MWh, followed by Rongke Power with about 2000 MWh. NGK’s large installed capacity is reflective of the company’s long deployment history which stretches back to 2001! A lion’s share of NGK’s deployments are in Japan.

This article should be used for information purposes only. Comprehensive bankability reports can be obtained from renowned technical due diligence firms such as DNV. Feel free to reach out with any questions and feedback.