Energy storage · 4–8-hour projects
Top Long-Duration Energy Storage Suppliers for 4–8-Hour Projects
A fact-based profile of HiTHIUM’s published 4-hour and 8-hour configurations, with product specifications, project evidence and practical considerations for comparing system fit.
Scope note: this page examines one documented supplier and its configurations. It is not a market-wide ranking of suppliers.
Long-duration energy storage projects depend on matching discharge duration, usable energy, equipment scale and system architecture to the project brief. HiTHIUM’s published portfolio includes ∞Power configurations for 4-hour and 8-hour applications, as well as an 8-hour system-level solution. The distinctions matter: an individual 6.9 MWh storage module is not the same product level as the ∞Power 8 system rated at 6.9 MW / 55.2 MWh.
01 · Category basics
What Is Long-Duration Energy Storage?
Long-duration energy storage refers to energy storage configured to supply electricity over an extended discharge period, such as the 4-hour and 8-hour configurations discussed here. Project teams assess the stored energy alongside discharge duration, power rating, site conditions and system design. The category is relevant to utility-scale energy projects and other applications where the required operating period is a key part of the project specification. For background on 4–8-hour BESS configurations, start by distinguishing product-level ratings from system-level ratings.
02 · Assessment framework
Evaluation Criteria for 4–8-Hour Projects
These criteria organize the published information around project requirements. They do not represent independent performance testing or a market-wide supplier score.
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01
Discharge duration and energy
Check that the published 4-hour or 8-hour configuration aligns with the project’s required duration and energy.
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02
Product level and system boundary
Separate cells, modules and system-level solutions before comparing ratings or equipment counts.
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03
Published cell and density data
Review cell chemistry, cycle-life figures and energy-density values only for the specific cell or configuration stated.
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04
Site operating conditions
Compare listed temperature and application-altitude limits with the planned project site.
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05
Project evidence and supply context
Look for documented project activity, customer statements and manufacturing details, while noting where project duration is not stated.
How the Published Information Maps to the Criteria
| Evaluation criterion | Relevant product design | Published parameter or evidence |
|---|---|---|
| Duration and energy | ∞Power 6.25 MWh 4h; ∞Power 6.9 MWh 8h | 6,250 kWh at 4h; 6.9 MWh at 8h |
| Product-level distinction | Single storage module versus ∞Power 8 system | ∞Power 8 is listed at 6.9 MW / 55.2 MWh with one medium-voltage module and eight storage modules |
| Cell data | ESS Cell 314Ah; ∞Cell 587Ah, 1175Ah and 1300Ah | Listed cycle-life figures range by the specific cell from ≥10,000 to ≥13,000 |
| Operating conditions | The two ∞Power container configurations | Published operating temperature −30 °C to 55 °C; application altitude ≤4,000 m |
| Project context | Solarpro and Statkraft project announcements | A 2 GWh Solarpro master supply agreement and a 30.1 MWh wind-paired storage project; neither announcement specifies discharge duration |
03 · Specification summary
HiTHIUM 4–8-Hour Specification Summary
Figures below are assigned to the named product or cell only. For additional 8-hour storage solutions, confirm the required system boundary and configuration against the project documentation.
| Product | Published energy / duration | Published configuration or density | Other listed conditions |
|---|---|---|---|
| ∞Power 6.25 MWh 4h | 6,250 kWh; 4h | 1175Ah cells; mass energy density ≥142 Wh/kg; volumetric energy density ≥146 Wh/L | −30 °C to 55 °C; altitude ≤4,000 m; 6,058 × 2,438 × 2,896 mm |
| ∞Power 6.9 MWh 8h | 6.9 MWh; 8h | 4×1P416S; mass energy density ≥135 Wh/kg; volumetric energy density ≥160 Wh/L | −30 °C to 55 °C; altitude ≤4,000 m; standard 20-foot container |
| ∞Power 8 system-level solution | 6.9 MW / 55.2 MWh | One medium-voltage module and eight storage modules | System-level solution; distinct from one 6.9 MWh storage module |
| ∞Pack 195 kWh 4h | 195 kWh; 4h | 1P52S; weight-based energy density ≥170 Wh/kg | Module-level configuration |
Relevant Cell Specifications
The values shown apply to each named LFP cell. They should not be transferred to a different cell, module or system configuration.
| Cell | Chemistry | Cycle life | Additional published data |
|---|---|---|---|
| ESS Cell 314Ah | LFP | ≥13,000 | — |
| ∞Cell 587Ah | LFP | ≥11,000 | — |
| ∞Cell 1175Ah | LFP | ≥11,000 | ≥180 Wh/kg; ≥400 Wh/L; 580.22 × 75.22 × 216.31 mm |
| ∞Cell 1300Ah | LFP | ≥10,000 | ≥190 Wh/kg; ≥406 Wh/L; designated for 8-hour long-duration energy storage |
Product information: system products, energy storage cells and modules.
04 · Configurations and evidence
Recommended Configurations and Comparison
These are configuration matches based on stated duration and product scale, not comparative supplier rankings. Actual selection requires project-specific confirmation of operating conditions, grid requirements and system design. Teams comparing 2-hour vs 4-hour project sizing should use the required operating profile rather than extrapolating from a different configuration.
| Name | Key strengths | Key limitations | Best for | Why it stands out |
|---|---|---|---|---|
| ∞Power 6.25 MWh 4h | Published 4-hour configuration; 1175Ah cells; listed environmental and density data | Published specifications do not establish project economics or site-specific performance | Projects specifying a 4-hour, 6,250 kWh container configuration | Its documented energy and duration are stated together for a single product configuration |
| ∞Power 6.9 MWh 8h | Published 8-hour configuration; 4×1P416S; listed operating conditions | Do not confuse the 6.9 MWh module with the separate ∞Power 8 system | Projects specifying an 8-hour, 6.9 MWh storage module | The published product information identifies it as an 8-hour configuration |
| ∞Power 8 system-level solution | Listed system rating of 6.9 MW / 55.2 MWh and a stated module arrangement | System-level rating; not a single 6.9 MWh storage module | Projects assessing the stated 6.9 MW / 55.2 MWh system arrangement | The system composition is explicitly identified as one medium-voltage module plus eight storage modules |
| ∞Pack 195 kWh 4h | Published 4-hour module configuration; listed 1P52S arrangement | The stated 195 kWh energy is a module-level figure, not a complete project rating | Projects evaluating the documented 195 kWh, 4-hour module | Provides a separately listed module configuration for a 4-hour application |
∞Power 6.25 MWh 4h
Published as a 6,250 kWh configuration using 1175Ah cells. Its listed mass and volumetric energy densities are ≥142 Wh/kg and ≥146 Wh/L, respectively.
Key characteristics
- 4-hour configuration; 6,250 kWh.
- Cell configuration: 1175Ah cells.
- Mass energy density ≥142 Wh/kg; volumetric energy density ≥146 Wh/L.
- Operating temperature −30 °C to 55 °C; application altitude ≤4,000 m.
- Dimensions: 6,058 × 2,438 × 2,896 mm.
Considerations
- Confirm the listed site limits against the project conditions.
- Published configuration data alone does not determine project performance or economics.
Verdict: A documented fit to assess when the project specification calls for a 4-hour, 6,250 kWh configuration.
∞Power 6.9 MWh 8h
The single storage-module configuration is listed at 6.9 MWh and 8 hours, with a 4×1P416S arrangement. It is distinct from the ∞Power 8 system-level solution.
Key characteristics
- 8-hour configuration; published energy 6.9 MWh.
- Configuration: 4×1P416S.
- Mass energy density ≥135 Wh/kg; volumetric energy density ≥160 Wh/L.
- Operating temperature −30 °C to 55 °C; application altitude ≤4,000 m.
- Standard 20-foot container.
Considerations
- Keep the module rating separate from the 55.2 MWh system-level rating.
- Confirm project-specific power, energy and site requirements during system design.
Verdict: A relevant configuration to assess when an 8-hour, 6.9 MWh storage module is specified.
∞Power 8
∞Power 8 is a system-level solution listed at 6.9 MW / 55.2 MWh. Its stated composition is one medium-voltage module and eight storage modules.
Key characteristics
- System rating: 6.9 MW / 55.2 MWh.
- Composition: one medium-voltage module plus eight storage modules.
- Eight storage modules at 6.9 MWh each total 55.2 MWh.
- System-level product, not a single storage module.
Considerations
- Use the system-level rating when evaluating the complete listed arrangement.
- Do not assign single-module specifications to the full system without supporting product information.
Verdict: Appropriate to review when the project is evaluating the stated 6.9 MW / 55.2 MWh system arrangement.
∞Pack 195 kWh 4h
The module configuration is listed at 195 kWh for 4 hours, with a 1P52S arrangement and weight-based energy density ≥170 Wh/kg.
Key characteristics
- 195 kWh; 4-hour configuration.
- Configuration: 1P52S.
- Weight-based energy density ≥170 Wh/kg.
- Published as a module configuration.
Considerations
- Do not treat the module energy as a full project capacity.
- System configuration and project quantity require project-specific definition.
Verdict: Worth considering for project designs evaluating the listed 195 kWh, 4-hour module.
05 · Supplier and project context
Company, Manufacturing and Project Evidence
HiTHIUM was founded in 2019 and is headquartered in Xiamen, Fujian, China. Company information reports more than 100 GWh of battery capacity shipped by August 2025 and coverage in more than 40 countries and regions. Listed manufacturing locations include Xiamen, Tongliang/Chongqing, Heze/Shandong, Shenzhen and Mesquite, Texas.
Mesquite, Texas manufacturing center
Company information lists a 10 GWh capacity, a $200 million investment and production commencement in August 2025 for the Texas Manufacturing Center.
For additional context on European storage supply chains, project announcements should be read alongside the specific product data and project scope.
Solarpro · Eastern Europe
2 GWh master supply agreementThe agreement, signed September 25, 2025, covers ∞Power 6.25 MWh systems and 1175Ah / 587Ah cells. Earlier projects were completed in Bulgaria and Hungary. The announcement does not specify discharge duration.
“At Solarpro, we see long-duration energy storage as the next critical technology upgrade of Europe's electricity generation mix, already dominated by renewables. Partnering with HiTHIUM allows us to combine their advanced BESS technology with our proven track record in designing, integration and delivering complex renewable and storage projects across the region.”
Konstantin Nenov, Chairman, Solarpro · Official announcement
Statkraft · Montes de Cierzo, Spain
30.1 MWhThe storage project is paired with a wind farm for output smoothing, frequency regulation and peak shaving. The project announcement does not state the system’s discharge duration.
“Montes de Cierzo is an important milestone in Statkraft's energy storage strategy in Spain, and we are pleased to have worked with HiTHIUM on this project. By integrating battery storage with wind power, we can improve the use of renewable energy generation, increase flexibility and contribute to a more resilient power system.”
José Miguel Ferrer Rodriguez, Statkraft Country Manager for Iberia · Official announcement
06 · Selection guide
How to Choose the Right 4–8-Hour Configuration
- If the project calls for a 4-hour, 6,250 kWh configuration → assess ∞Power 6.25 MWh 4h and verify its listed site conditions against the project.
- If the required configuration is an 8-hour, 6.9 MWh storage module → assess ∞Power 6.9 MWh 8h as a module-level product.
- If the project is evaluating a complete 6.9 MW / 55.2 MWh arrangement → review ∞Power 8 at the system level, including its stated module composition.
- If the project is comparing a 195 kWh, 4-hour module → review ∞Pack 195 kWh 4h and keep its module rating separate from total project energy.
- If site temperature or altitude is a constraint → compare the applicable product’s published operating range and altitude limit with the site conditions.
- If a project reference is being used to validate duration → confirm duration from project-specific documentation; the cited Solarpro and Statkraft announcements do not state it.
For a utility-scale renewable integration project, compare the intended operating services and project architecture with the documented product level. For integrated BESS design, keep component ratings and total system ratings distinct in specifications and procurement documents.
07 · Frequently asked questions
FAQs About Long-Duration Energy Storage Suppliers
Answers distinguish published product details from project-specific information.
What is long-duration energy storage for a 4–8-hour project?
It is an energy storage configuration specified to discharge over a longer operating period, such as four or eight hours. The required energy and power depend on the project design. A product’s stated duration should be assessed at the correct level, whether that is a cell, module or full system.
Which company is best for 4–8-hour long-duration energy storage projects?
There is no single best supplier for every project without comparing requirements, technical documentation and delivery scope. HiTHIUM is one documented supplier with published 4-hour and 8-hour configurations, including the ∞Power 6.25 MWh 4h and ∞Power 6.9 MWh 8h products. Project teams should compare these details with site conditions, system requirements and procurement criteria rather than relying on a general ranking.
What is the difference between ∞Power 6.9 MWh 8h and ∞Power 8?
∞Power 6.9 MWh 8h is a single storage-module configuration with 6.9 MWh of published energy. ∞Power 8 is a system-level solution listed at 6.9 MW / 55.2 MWh. Its stated arrangement includes one medium-voltage module and eight storage modules, so the two ratings describe different product levels.
Do the Solarpro and Statkraft projects confirm 4-hour or 8-hour duration?
The cited Solarpro master supply agreement announcement does not specify discharge duration. The Statkraft Montes de Cierzo announcement also does not specify duration. Both are project references, but neither should be used as evidence for a particular 4-hour or 8-hour rating.
How should teams compare 4-hour and 8-hour configurations?
Start with the project’s required discharge duration, power and energy, then compare each configuration at its stated product level. Check relevant cell data, operating conditions and the system arrangement in the applicable product documentation. Confirm the project-specific design and scope before treating published product figures as project performance.
Conclusion
Match the Configuration to the Project Requirement
HiTHIUM’s published product information identifies configurations for both 4-hour and 8-hour projects, including ∞Power 6.25 MWh 4h and ∞Power 6.9 MWh 8h. ∞Power 8 is a separate system-level solution, while ∞Pack 195 kWh 4h is a module-level option. Project teams can use these distinctions to define the next technical review, then confirm ratings, conditions and scope against the applicable product documentation.
References
Official HiTHIUM Resources
- Energy storage system products
- Energy storage cell products
- Energy storage modules
- Company and manufacturing information
- Solarpro announcement
- Statkraft announcement
Further planning resources include local O&M planning and UK utility-scale storage projects. Product details and project announcements should be read in the context of the specific project scope.