EcoSTORE Mega –
A Fully-Integrated Sub-5MW Battery Energy Storage System (BESS)
EcoSTORE MEGA™ is a sub-5MW battery energy storage system integrated in Australia for Australian conditions and delivering a reliable, high-performance solution tailored to local network realities. The EcoSTORE MEGA will allow network operators to alleviate network constraints on high voltage feeders and substations, enable more CER connections, and reduce reliance on large-scale generation solutions.
Fully integrated and customised by EcoJoule Energy, EcoSTORE MEGA combines world-leading technology with local integration and delivery, as well as deep control and power electronics expertise. The result is a utility-scale energy storage system purpose-built to meet Australia’s unique operational, regulatory, and commercial requirements.
Built using high-efficiency LFP batteries and high-performance power conversion and control technology, EcoSTORE MEGA offers proven, predictable operation and bankable reliability. Its modular, integrated architecture simplifies grid compliance, enables scalable deployment, and allows developers and utilities to expand capacity over time without disruption.
EcoSTORE MEGA™ is built on advanced global engineering solutions integrated and optimised by EcoJoule Energy for the unique demands of Australia.
EcoSTORE MEGA is a modular, utility-grade battery energy storage system engineered and integrated by EcoJoule Energy for grid-following (GFL) and grid-forming (GFM) applications. The MEGA brings together two best-in-class technologies from the world’s leading providers – Hitachi Energy(PCS) and EVE Energy (BESS). The system integrates world-leading 5 MWh LFP battery containers with Hitachi Energy bi-directional power conversion systems and a centralised power plant controller to deliver precise active and reactive power control.
A standard 4.98MW/5MWh block architecture supports energy durations from 10 to 20 MWh using a common PCS platform. EcoSTORE MEGA is designed to meet Australian and international safety and grid-compliance standards, delivering high efficiency, fast control response, and long-term operational reliability.
The EcoJoule Advantage
EcoJoule Energy combines deep local power electronics expertise, proven system integration, and long-term onshore support to deliver utility-scale battery energy storage solutions that perform. As grid conditions grow more complex and technology evolves at a rapid pace , successful projects depend on more than high-quality components. They need an experienced local partner who understands how technology, networks, compliance, and operations intersect in real-world Australian deployments.
Through local engineering, EcoJoule Energy ensures each EcoSTORE MEGA solution aligns with Australian standards, network expectations, and operating environments from the start. This approach reduces delivery risk, accelerates grid connection, and improves long-term asset performance.
Why local expertise and integration matter.
- Deep understanding of Australian grid behaviour, standards, and regulatory frameworks
- Proven system-level integration that reduces technical and delivery risk
- Faster grid connection and commissioning through local stakeholder engagement
- Onshore engineering, commissioning, and operational support throughout the asset life
- Single point of accountability for system performance, compliance, and reliability
A Bigger, Better Battery
The EcoSTORE MEGA is built around EVE Energy’s “Mr Giant” 5 MWh battery containers. Mr Giant is a cutting-edge large-scale energy storage solution designed to meet the growing demand for long-duration, high-capacity battery systems in utility, commercial, and industrial applications.
At its core is a 5 MWh containerised energy storage system that integrates EVE’s ultra-large-capacity 628 Ah battery cells into a streamlined architecture that optimises energy density while simplifying installation and system design. The system has demonstrated stable performance with high round-trip efficiency (greater than 95 %)
This configuration positions Mr Giant as a flagship in EVE’s portfolio of energy storage products, helping to support renewable energy integration, peak shaving, and grid stability amid increasing penetration of solar and wind power.
Battery Specification
Standard 20HC container adopting Mr Giant (628Ah) large battery cell with 1P52S through-type pack design
| Item | Specification |
|---|---|
| System Type | S556H201 (0.5P) |
| Battery Cell | MB56 (628Ah) |
| Configuration | 6 * 1P416S |
| Rated Energy/kWh | 5,015.961 |
| Nominal Voltage/V | 1,331.2 |
| Voltage Range/V | 1,164.8 – 1,497.6 |
| Duration/h | ≥2 |
| Thermal Management | Liquid Cooling |
| Dimension (W/D/H)/mm | 6,058 x 2,438 x 2,896 |
| Weight | ≤43 tonne |
| Operation Temperature/C | -30℃ – 55℃ |
| IP Level | IP55 |
| Corrosion Resistance Level | -C4 (C5 optional) |
| Noise level/db@1m | ≤ 75 ( ≤ 65 with noise attenuator) |
| Certifications | UN3536, UL9540, NFPA 68/69/855, IEC61000, IEC62477, IEC62933 AS/NZS 3000/3008/5139 |
Advanced PCS Tailored For <5MW Deployments
EcoSTORE MEGA’s Power Converter System (PCS) utilises the WD4 family of power conversion systems developed by Hitachi Energy. This compact, modular solution is ideal for the sub-5 MW market, offering high performance, flexibility, and seamless integration into Australian distribution networks.
- Power Range: Tailored for sub 5 MW deployments.
- Wide DC Input Range: Supports up to 1500 Vdc nominal (1550 Vdc max), with 6000 A max input current.
- Bidirectional DC/AC Conversion: Full four-quadrant operation for active and reactive power control.
- Advanced Cooling: A high-efficiency liquid-cooling system ensures reliable performance in extreme Australian climates.
- Grid Compliance: Meets stringent global and Australian grid codes, with Grid-Following (GFL) and Grid-Forming (GFM) capabilities.
- Remote Control & Monitoring: Supports Modbus/TCP and integration with SCADA and Power Plant Controllers.
- Rugged Design: IP65-rated, fully sealed enclosures for harsh outdoor environments, including high temperatures and dust.
- Fast installation with plug-and-play busbar connections
- Easy maintenance via front and rear access
- High reliability in remote and off-grid environments
- Support for ancillary services: frequency response, ramp rate control, and optional STATCOM functionality
- Bidirectional plug-and-play converter designed for BESS integration and compatible with a range of leading battery manufacturers.
The WD4 PCS is supplied as part of a skid-mounted package, incorporating the required RMU/MV protection and the system auxiliary power supply.
The Hitachi WD4 PCS is built for Australia’s harsh conditions.
- Internal electronics and components are coated to resist corrosive, salt-intensive conditions.
- Sealing elements and standard enclosures with IP65-rated protection against rain and moisture.
- Ability to perform in high altitude mountain regions up to 4000 MASL.
- Liquid cooling system, combined with filters and enhanced protection, prevents dust ingress.
- Low temperature and reduced noise kits (optional)
PCS Technical Specifications
| Item | Specification |
|---|---|
| Ground-fault monitoring | Yes |
| Insulation monitoring | Yes |
| Lightning protection | Yes |
| Nominal AC Voltage 1 | 710 |
| Max AC Voltage Range | 85%-115% |
| Rated apparent AC current [A] @ 95ºF/35ºC | 3 x 1,500 |
| Rated AC power. Pmax@ 95ºF/35ºC [kW] 2 | 4,980 |
| Rated AC power. Pmax@122ºF/50ºC [kW] 2 | 4,980 |
| Maximum output current | 4,614 |
| Total Current Demand Distortion (TDD) | <3% |
| Power factor | Adjustable |
| AC Cabinet | Integrated |
| AC/DC Efficiency: Maximum Peak | European Efficiency | CEC Efficiency 3 | 98,84 / 98,5 / 98,5 (7) |
| Voltage range [Vdc] | 987-1,550 |
| Voltage range @ full power [Vdc] | 987-1,550 |
| Max. DC voltage [Vdc] | 1,500 |
| Operation ambient temperature (without derating) | [5ºF, 140ºF] / [-15ºC, 55ºC] (>95ºF/ >50ºC) |
| Maximum relative humidity (storage humidity without condensation) | 100% (85%) |
| Max. altitude above sea level allowed (without derating) [masl] | 4,000 (1,000) |
| Dimensions (W x D x H) [mm] | 6,500 x 1,120 x 2,460 mm |
| Protection degree (Outdoor model) 4 | IP65 |
| Directives applied for static inverters construction and design 5 | IEEE 1547-2018, UL 1741 – SA & SB, IEC 62477 IEC 62109-1, IEC 62109-2, IEC62109 IEC 60529 CE Marking NEC Compliance IEC 61000-3-4, IEC 61000-3-11, IEC 61000-3-12, IEC 61000-6-4 |
| Procedures for measuring efficiency | IEC61683 CEC requirements |
| EMC regarding immunity, interference, voltage varia-tions, and flicker | UNE EN61000-4-2:2010 UNE EN61000-4-3:2007 UNE EN61000-4-4:2013 UNE EN61000-4-5:2015 UNE EN61000-4-6:2014 UNE EN61000-4-8:2011 |
| 1. Other voltage configurations are possible on request 2. At nominal AC voltage, f= 50 Hz, VDC < 1500 V and cos ϕ = 1 3. Self-consumption is not considered in the efficiency measurement. 4. IP65 for power electronics and control devices 5. Other applicable standards/grid codes are possible |
Power Plant Controller
The Hitachi Energy Power Plant Controller (PPC) is the intelligent core of the EcoSTORE MEGA. Acting as the central brain of the power plant, the PPC precisely manages active and reactive power, voltage and frequency support, FCAS response, and market dispatch through a VPP interface. Built on Hitachi Energy’s deep power systems expertise, the PPC delivers reliable, future-ready control at the Point of Interconnection (POI), ensuring optimal performance, compliance, and flexibility in even the most demanding grid environments.
Smarter Power for a Smarter Grid
EcoJoule Energy delivers intelligent, Australian-made power management systems that improve energy quality, reliability, and efficiency.
Resilience Where It Matters Most
Our technology enhances grid stability and performance, particularly in fringe-of-grid and renewable-heavy networks.
Designed for the Energy Transition
We support utilities and communities in their transition to a cleaner, more distributed energy future.