125kW 261kWh C&I BESS Quote: Renac’s ESS-261 Specifications

For commercial and industrial operators evaluating a 125kW 261kWh C&I BESS quote, Renac Power Technology Co., Ltd offers a purpose-built solution through its ESS-261 battery energy storage system. As industry buyers assess options, understanding the exact technical configuration, warranty terms, and real-world deployment results behind a quoted system is essential. This article reviews the ESS-261 specifications, its position within Renac’s broader RENA5000 C&I BESS Solution, and the documented project outcomes that inform pricing and selection decisions.

Why a 125kW 261kWh Configuration Matters

Commercial and industrial energy users frequently face a common set of obstacles when sourcing battery storage: customized EPC project delivery is difficult, installation cycles are long, and components sourced from multiple suppliers create after-sales responsibility shifting when problems arise. These pain points are amplified in demanding application scenarios such as off-grid paralleling, off-grid load operation, and PV-energy storage-diesel generator synergy, where system performance and battery safety become critical concerns.

Renac addresses these challenges through a turnkey, all-in-one design strategy. The ESS-261 is engineered as a C&I battery energy storage system rated at 125 kW / 261 kWh, built on an all-in-one modular platform that reduces on-site installation and commissioning complexity. This configuration is one of the core building blocks within Renac’s self-developed "5S" component architecture—PCS, BES, PVS, STS, and EMS—allowing a single provider to deliver unified control rather than requiring buyers to coordinate separate hardware from different vendors.

ESS-261 Technical Specifications

The ESS-261 is built around LFP (LiFePO4) battery technology with a rated power of 125 kW and nominal energy of 261 kWh. Key technical parameters include:

Battery and Electrical Characteristics

• Battery module nominal energy: 52.25 kWh, arranged in a 1P52S configuration across 5 modules
• Rated voltage: 832 V, with a voltage range of 650 to 949 V
• Maximum charging/discharging current: 200 A
• Rated AC power: 125 kW, with maximum AC apparent power of 138 kVA
• Rated AC voltage: 400 V, 3L/N/PE, with a range of 400 V +/- 10%
• Rated frequency: 50/60 Hz, maximum AC current of 200 A
• Adjustable power factor: 0.99 (-1 to 1)
• THDi at rated output on grid: <3%; THDv at linear load off grid: <3%
• System efficiency: 88%

Protection, Environment, and Build

• IP protection: IP54 for the system, IP55 for the battery
• Protection features: battery reverse polarity, AC overvoltage/overcurrent/short-circuit, DC/AC surge protection Type II, and emergency stop
• Ambient temperature range: -25 to +55 degrees C, with derating above 45 degrees C
• Relative humidity: 5 to 95% non-condensing
• Operation altitude: up to 4000 m, with derating above 2000 m
• Cooling method: liquid cooling
• Weight: 2600 kg; Dimensions: 1100 * 2310 * 1400 mm
• Topology: transformerless, with a 3L/N/PE output supporting 100% unbalanced load

Connectivity and Monitoring

• User interface: WEB + APP
• Communication: WiFi / 4G / Ethernet
• Communication protocols: Modbus RTU, Modbus TCP

The ESS-261 also carries recognized grid and safety regulation compliance, including IEC 61727, IEC 62116, EN50549-1, EN50549-2, EN 50549-PL for grid regulation, and CE-LVD, CE-EMC, and UN38.3 for safety regulation.

A Related Configuration: ESS-261-S

Buyers requesting a quote around the 125kW / 261kWh class may also encounter the ESS-261-S, a variant that integrates a 175 kW STS module directly into the unit. This configuration eliminates the need for an additional distribution cabinet, supports active STS switching in under 20 ms for seamless on-grid to off-grid transfer, and accommodates 110% long-term overload alongside the same 100% unbalanced load support found in the standard ESS-261. Both the ESS-261 and ESS-261-S share core attributes—125 kW rated power, 261 kWh nominal energy, LFP battery chemistry, liquid cooling, and transformerless 3L/N/PE output—while differing primarily in their switching and distribution integration capabilities.

Differentiated Value Behind the Quote

A 125kW 261kWh C&I BESS quote from Renac reflects more than a single hardware unit. The ESS-261 operates within the RENA5000 C&I BESS Solution, which combines battery storage, a PV controller, a static transfer switch, and energy management into one coordinated system for commercial and industrial energy users. This turnkey approach delivers several differentiated advantages:

• Faster deployment: All-in-one design and modular configuration reduce on-site installation and commissioning complexity, shortening project delivery timelines.
• Lower system cost: External STS design supports on-grid and off-grid parallel operation without requiring additional grid and load distribution boxes.
• One-provider accountability: Self-developed 5S components (PCS, BES, PVS, STS, EMS) enable unified control and one-stop service, avoiding the responsibility shifting common when components come from multiple suppliers.
• Reliable backup power: Active STS switching delivers transfer times under 20 ms.
• Scenario flexibility: Multiple operating modes and AC/DC coupling support PV plant retrofit, ancillary service, capacity expansion, off-grid power supply, maximum self-consumption, time-of-use (TOU) optimization, and demand management.
• Improved safety: LFP cells, BMS, and packs are manufactured by REPT, with aluminum alloy pack material providing IP67 protection and thermal propagation suppression.

Service Assurance Included in Every Quote

Any 125kW 261kWh C&I BESS quote from Renac includes a 5-year product warranty and a 10-year battery performance warranty. Cells, BMS, and packs are manufactured by REPT with quality assurance and after-sales support, reinforcing the one-stop service model. Remote firmware upgrades and settings, accessible through the configurable monitoring cloud platform and WEB + APP interfaces, further support ongoing system management after installation.

Documented Project References

Renac’s ESS-261 has been deployed in two documented 125 kW PV / 261 kWh storage projects that illustrate the configuration’s real-world application:

In the Philippines, a biodiesel refinery on Mindanao Island adopted an on/off-grid island microgrid using 125 kW PV through PVS DC/DC coupling paired with 261 kWh of storage via a single ESS-261 unit, achieving PV capacity of 125 kW and storage capacity of 261 kWh.

In Romania, a farm implemented an off-grid operation designed to supply 100% green energy, again using 125 kW PV through PVS DC/DC coupling and 261 kWh of storage from one ESS-261 unit, resulting in matching PV capacity of 125 kW and storage capacity of 261 kWh.

These cases demonstrate the ESS-261’s suitability for both on/off-grid island microgrid scenarios and standalone off-grid farm operations, aligning with Renac’s stated industry adaptation for on-grid PV+BESS, off-grid PV+BESS+diesel, and on/off-grid PV+BESS+diesel configurations.

Conclusion

For organizations seeking a 125kW 261kWh C&I BESS quote, the ESS-261 from Renac Power Technology Co., Ltd (brand name RENAC) presents a fully specified, turnkey option built on self-developed 5S components, transformerless architecture, and liquid cooling. Backed by a 5-year product warranty, a 10-year battery performance warranty, and REPT-manufactured battery components, the ESS-261 is supported by documented deployments in the Philippines and Romania that confirm its performance in both island microgrid and off-grid farm applications. Buyers comparing quotes can reference these verified specifications and project outcomes when evaluating fit for their own commercial and industrial energy storage needs.

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