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2024-06-21 23:59:59 US/Eastern Time

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Long Operation Combatant-Naval Energy Storage System (LOC-NESS)

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Project Description

Problem Statement

Emerging U.S. Navy platforms need increased power and energy production, storage, and distribution for a range of maritime applications. These upgrades will require increases to on-board storage capacity and power conversion systems, including high-voltage alternating current (AC), medium voltage AC, and low-voltage direct current (DC) interfaces. 

Commercial power solutions hold the potential to scale modular energy storage systems, maximize efficiency of physical footprint, reduce development and sustainment costs, improve obsolescence management, decrease foreign supply chain reliance, and enable greater efficiency of electrification for shipboard power and mission systems.

Current large-scale commercial energy storage solutions require militarization and hardening improvements in order to meet Navy requirements such as shock and vibration, electromagnetic interference (EMI), performance, signature and safety specifications. Further, the Department of Defense (DoD) requires cell-to-pack supply chain security with both domestic and allied sourcing and manufacturing for sustainment of critical Naval systems.

Desired Solution Attributes 

The U.S. Navy seeks large-scale commercial solutions to provide improved energy resilience and a superior cost structure for the government. Ideal solutions will be vertically integrated, modularized energy storage and power conversion systems with associated controls, thermal management, safety protection and mitigations that have been broadly proven in complex commercial/industrial maritime environments where power surety and redundancy are mandatory.  

The prototype should be scalable to power and energy demands as platforms and their intended missions dictate. It is understood that commercial off-the-shelf (COTS) systems may not meet all desired military attributes initially, however the minimum threshold characteristics are designated below. The vendor must provide evidence (failure modes, effects and criticality analysis; test reports; independent evaluation reports) of the system in relation to identified requirements. 

Power Interfaces: 

  • The energy storage system must be able to operate under a range of charge and discharge conditions to support a broad spectrum of capabilities. Vendors should describe what interfaces their power conversion and batteries can provide natively, or what would be required to adjust and adapt to government-provided interface specifications.  
  • Navy ships distribute power as AC, including at 450VAC 60Hz, 4160VAC 60Hz, and 13800VAC 60Hz compliant to MIL-STD 1399-300-1 and MIL-STD-1399-300-2. 
  • The solution is required to input and output to: 
    • 4160VAC three-phase, three-wire, 60Hz shipboard bus. The initial use-case may not be compliant to MIL-STD-1399-300-2.
    • Low voltage direct current interface of 1000VDC. Additional interfaces include an unregulated 875VDC nominal battery interface, and regulated 850VDC in accordance with MIL-STD-1399-300-3, type II and III, respectively.

Scalable Modules:

  • The system should be designed to minimize the installed size. Physical envelope of combined energy storage and power conversion systems, including baseline cabinets, structures, and cable routing, should be described in the solution brief.
  • Low-impedance, high-power designs, capable of minimum threshold >3C, with an objective for special high rate operations of >15C. Cycle life at the battery nominal and maximum design discharge/charge rates should be provided with referenceable data.  
  • Individual modules <60VDC, minimization of parallel cells; in series at 875VDC nominal voltage, with other string configurations viable (max allowable string voltage should be reported). 

Desired Commercial Cells: 

  • Vendors should define their cell chemistry and form-factor (e.g., 4680, 46120, 26650, other), with a preference for large format designs, with modules ideally consisting of >15Ah cells.
  • Vendors should clearly define and describe their battery cell supply chain, with a preference for domestic/Allied cell suppliers, to be evaluated on a case-by-case basis. Vendors who source components/subcomponents from the People’s Republic of China are required to develop a comprehensive, phased strategy for onshoring or friendshoring their production or alternate sourcing during the prototype execution.

Energy Storage Safety:

  • The system must be capable of identifying and reporting an internal casualty event, then activate system-level and platform-level mitigations to ensure platform survivability during at-sea operations. 
  • Resistance to propagation, and system design testing and approvals for commercial use should be provided.

Integration and Maintenance Costs:

  • The energy storage system should be capable of operating for 10 years at low cyclic operation (less than one full cycle per week); modular energy storage should be replaceable to enable sustained life of the overall system beyond that term.
  • An objective of sourcing a commercial solution is to reduce the development, integration and lifecycle cost of a system. Please describe in your solution brief:
    • Cost per scalable unit (energy storage and power conversion, $/kWh and $/kW)
    • 10-year lifecycle costs (integration, maintenance events, battery replacement or upgrades) of COTS system

Execution Expectations 

The phases expected are as follows:

  1. Evaluation of complete commercial system design relative to MIL-STD requirements, listed below, and component supply chain plan (report).
  2. Design, prototyping and land-based abusive and operational acceptance testing of components to meet MIL-STD and Navy Lithium Battery Safety standards (multiple first article prototypes).
  3. Maturation of prototypes with approved supply chain and delivery of modularized energy storage system with capability of at least 4MWh and 8MW of power for shipboard integration (full system prototype).  

During the period of performance, vendor solutions and prototypes will be evaluated for compliance or deltas to the following standards, and where needed, additional engineering for acceptance:

  • MIL-S-901D, Grade B (threshold), A (Objective) shock
  • MIL-STD-167-1, required Type 1 Vibration
  • MIL-STD-741 for Airborne and Structure-borne Noise
  • MIL-STF-461F, EMI
  • MIL-DTL-2036, Enclosures for electric and electronic equipment
  • MIL-DTL-32529, Power electronic conversion equipment
  • MIL-DTL-917, Electric power equipment basic requirements
  • MIL-W-21965, Water cooling of shipboard electronic equipment

To enable use in Navy platforms and test facilities, batteries will be characterized for safety and evaluated for mitigations. Vendors may share analogous test data to other industry protocols; from these outcomes, DoD may determine additional testing and assets needed to fulfill safety assessment and certification. Testing and risk evaluation of Li-ion batteries encompass:

  • NAVSEA S9310-AQ-SAF-010 minimum threshold (Platform – Ship Criteria) for battery safety assessment 
  • NAVSEA SG270-BV-SAF-010 for battery risk mitigation

Some integration support and planning will be expected in order to understand lifecycle cost and field supportability.  

Submission Requirements

Vendors are expected to submit a solution brief for a complete system that meets the requirements outlined above. Inclusion of examples of past successful deployment of similar solutions in the commercial or public sectors is highly encouraged. Teaming with, or subcontracting, commercial partners is permitted to achieve a fully integrated system and improve battery supply chain. Preference will be given to submissions that present a comprehensive and compelling solution to the problem statement and product requirements, and robustly discuss the process to adopt a fully domestic/Allied supply chain in a cost-effective manner. 

Any resulting agreement from this solicitation will include language requiring your company to confirm compliance with Section 889 of the John S. McCain National Defense Authorization Act for Fiscal Year 2019 (Pub. L. 115-232). If you are unable to confirm compliance with the referenced law, the government will not be able to enter into an agreement with your company.

Eligibility Requirements

Awarding Instrument

This solicitation will be awarded in accordance with the Commercial Solutions Opening (CSO) process detailed within HQ0845-20-S-C001 (DIU CSO), posted to on 13 Jan 2020, updated 02 Oct 2023. This document can be found at:

Vendors are reminded that in order to utilize an Other Transaction (OT) agreement the requirements of 10 USC 4022 must be satisfied. Specifically reference 10 USC 4022(d), which requires significant contribution from a nontraditional defense contractor, all participants to be small business concerns, or at least one third of the total cost of the prototype project is to be paid out of funds provided by sources other than the federal government.

Follow-on Production

Companies are advised that any prototype Other Transaction (OT) agreement awarded in response to this Area of Interest may result in the award of a follow-on production OT agreement or contract without the use of further competitive procedures. The follow-on production OT agreement or contract will be available for use by one or more organizations in the Department of Defense and, as a result, the magnitude of the follow-on production OT agreement or contract could be significantly larger than that of the prototype OT. As such, any prototype OT will include the following statement relative to the potential for follow-on production: 

“In accordance with 10 U.S.C. § 4022(f), and upon a determination that the prototype project, or portions thereof, for this transaction has been successfully completed, this competitively awarded prototype OT agreement may result in the award of a follow-on production OT agreement or contract without the use of competitive procedures.”


Question: Do we have to present a specific cell solution in detail at the Solution Brief stage?

Answer: The cell solution should be defined as part of a vendor’s submission.

Question: Is a cylindrical cell preferred for this project?

Answer: The solicitation does not specifically require a cylindrical cell. Any mass-produced cell that has an established supply chain would be considered. Please note the expectation of maturing solutions to use domestic or Allied cell suppliers.

Question: Is the desired energy of the final system 4MWh?

Answer: Energy requirement greater or equal to 4MWh is desired. Demonstrated scalability of the proposed solution is essential.

Question: What is the desired nominal voltage of the final prototype?

Answer: The AOI provides the range of AC and DC interfaces of interest. The prototype should have a battery with a nominal voltage of ~875VDC, coupled with a converter suited for 4160VAC 60Hz.

Question: Do we need to have a cost estimation ($/kWh) at the “solution brief” stage?

Answer: Because this effort leverages commercial solutions with established manufacturing and supply chain, the $/kWh metric should demonstrate relevant scale.

Question: What is the desired duration for 15C?

Answer: A 15C discharge supports a 4 minute duration. The 15C metric is used to emphasize the requirement for batteries capable of high power. 

Question: It is referred that the system capabilities are 8MW (~2C) but simultaneously, modules capable of minimum threshold >3C. Is the standard discharge 2C or 3C?

Answer: A C-rate is not a constant power value, and thus an ~8MW constant power discharge capability may go beyond a 2C rate.

Question: Can you elaborate on the power limit of unregulated and regulated DC output?

Answer: The converters/inverters should be capable to provide 8MW at the 4160 VAC interface. The architecture and power ratings for the DC interfaces will be contingent upon battery and converter design and connectivity.

Question: What are anticipated annual quantities (modules/year, systems/year)?

Answer: DOD seeks commercialized solutions with industrial maritime application, and thus, DOD market size should not be a driver on Solution Briefs.


Question: Do you expect a Solution to include converters (850VDC) and inverters (4160VAC, 3-phase, 60Hz) as “part” of the battery system?

Answer: This solicitation is primarily looking for vertically integrated systems. Incomplete system concepts may be considered if time and resources allow, but they are less likely to be fulfill the Area of Interest.

Question: Is ~13kWh system the minimum quantum for the modular system? How do you think about modularity in terms of Energy?

Answer: Correct. Solutions based on large format cells are preferable over massively paralleled small format cells. We anticipate that large numbers of batteries and modules will need to be strung in various configurations to achieve the desired power and energy.

Question: On the AC side, is it preferred to have a number of inverters connected in parallel or we need to go to a single inverter solution?

Answer: This should be based upon traceable commercial/industrial product offerings, and not a point design.

Question: Are there any specific needs for the individual modules (e.g. Air transportable, LRU)?

Answer: Ideally, all subcomponents would be suited to fit through a 26x66” oval hatch. At this time however we have not mandated any specific geometry, form factor, weight, etc. 

Question: What is the range for the unregulated 875VDC?

Answer: Per MIL-STD-1399-300-3, type II interface:

  • Nominal load voltage: 875 VDC (Open-circuit unloaded);
  • Load normal service open-circuit voltage range, nominal state-of-charge: 844 to 936 VDC;
  • Load normal service voltage range, overcharged to discharged: 680 to 1000 VDC;
  • Load voltage transient tolerance: 650 to 1060 VDC


Question: Can you elaborate on charging process, source(s) of the system? Will charging of the battery be through 4160VAC or 875VDC or both? Will Inverters shall be bidirectional?

Answer: Charging power would be provided from a primary distribution system which is 4160 VAC that would charge the nominal 875VDC battery. The design of the system could use bidirectional converters, or a dedicated charging converter, with a high power DC-to-AC converter. The offeror should describe the charging process and approach in their commercialized design.


Question: Does the US Navy want the deliverable to include multiple individual modules <60VDC, or is a complete battery pack which has cells connected in a series string with total parallel strings acceptable?

Answer: We wish to minimize massive parallelization of small format cells. The system architect should string the battery in series and parallel to provide the correct interfaces and total energy, as well as meet the requirements of the proposed converter system.

Question: Is there interest in Kinetic Energy Storage (i.e., flywheel) solutions? 

Answer: While flywheels are of interest for some constant high power, high duty cycle operations, that does not align well to the intention of this effort, as kinetic storage will increase the challenges associated with certifying and fielding a specific design. 

Before You Submit

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Potential Follow-On Production Contract for Prototype Other Transaction Agreements

Companies are advised that any Prototype Other Transaction (OT) agreement awarded in response to this solicitation may result in the direct award of a follow-on production contract or agreement without the use of further competitive procedures. Follow-on production activities will result from successful prototype completion.

The follow-on production contract or agreement will be available for use by one or more organizations within the Department of Defense. As a result, the magnitude of the follow-on production contract or agreement could be significantly larger than that of the Prototype OT agreement. All Prototype OT agreements will include the following statement relative to the potential for follow-on production: “In accordance with 10 U.S.C. § 4022(f), and upon a determination that the prototype project for this transaction has successfully been completed, this competitively awarded Prototype OT agreement may result in the award of a follow-on production contract or transaction without the use of competitive procedures.”

2023 Other Transaction Guide

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Any agreement awarded off of this solicitation will include language requiring your company to confirm compliance with Section 889 of the John S. McCain National Defense Authorization Act for Fiscal Year 2019 (Pub. L. 115-232). If you are not able to comply with the law, the Government may not be able to award the agreement.

We Work With You

If we think there’s a good match between your solution and our DoD partners, we’ll invite you to provide us with a full proposal — this is the beginning of negotiating all the terms and conditions of a proposed prototype contract.

After a successful prototype, the relationship can continue and even grow, as your company and any interested DoD entity can easily enter into follow-on contracts.

Our Process

  1. We solicit commercial solutions that address current needs of our DoD partners.

  2. You send us a short brief about your solution.

  3. We’ll get back to you within 30 days if we’re interested in learning more through a pitch. If we're not interested, we'll strive to let you know ASAP.