Helios Co., Ltd. Launches Low-Voltage Aggregation Service to Bundle Multiple Low-Voltage Battery Storage Facilities as Virtual Batteries

Helios Co., Ltd. (headquartered in Shibuya-ku, Tokyo; hereinafter 'Helios') has begun accepting orders for its 'Low-Voltage Aggregation Service,' which bundles multiple low-voltage battery storage systems into a virtual battery on the cloud, enabling them to be managed as a control unit equivalent to high-voltage battery storage facilities. The service will be rolled out gradually, following software development, connection verification, project-specific configuration checks, equipment procurement, and communication testing. Helios currently provides monitoring services for approximately 600 power generation sites nationwide, totaling about 2.5 GW, primarily focusing on extra-high-voltage and high-voltage solar power plants. Leveraging its expertise in monitoring and control technologies developed through its power plant monitoring systems, EMS, VPP systems, and DER control terminals, as well as its EMS development capabilities compatible with multiple aggregators, Helios will establish a control and data integration platform to operate clusters of low-voltage battery storage facilities as market-participating aggregation units.

Additionally, drawing on its experience in providing control devices for solar power plants that comply with output control requirements from power transmission and distribution companies, Helios is expanding its coordinated control capabilities for sites where batteries and PV systems are co-located, implementing customized control strategies based on each plant's equipment configuration and operational conditions.

Background of Service Launch

With the increasing deployment of renewable energy, securing flexible resources to absorb fluctuations in electricity supply and demand has become critical. Grid-connected battery storage systems are valuable assets not only for price arbitrage in the JEPX market but also for participation in demand-supply balancing markets. In particular, low-voltage battery storage facilities are well-suited for installation on small-scale land and decentralized deployment, offering faster feasibility assessment and project development timelines compared to high-voltage or extra-high-voltage systems.

However, due to their smaller individual capacities, standalone low-voltage facilities often cannot meet the minimum output thresholds required for market participation. Therefore, aggregating multiple sites requires centralized management of available output, measurement data collection, remote control, and monitoring of communication status and outage risks.

Overview of the Low-Voltage Aggregation Service

This service provides an aggregation platform that bundles multiple battery storage systems distributed across low-voltage grids into a 'virtual battery' on the cloud, enabling them to function as a control unit equivalent to high-voltage storage facilities. By integrating control agents installed at each low-voltage site with a cloud-based virtual EMS, the service supports charge/discharge and output control commands for the virtual battery, available output management, and integration with various aggregators’ systems. The design assumes grouping around 25 low-voltage units per cluster, aiming to form aggregation units of 1 MW or more. The system is designed to interface with existing aggregator systems via OpenADR and EMSAPI, supporting participation in JEPX and primary, secondary, and tertiary regulation markets.

Key Features

1. Integration of low-voltage battery clusters into aggregation units of 1 MW or more

Multiple low-voltage battery storage systems are bundled into a virtual battery on the cloud and managed as a unified control unit equivalent to high-voltage storage. By issuing charge/discharge and output control commands from the virtual EMS to the virtual battery, low-voltage resources can be utilized not as individual devices but as aggregation units with measurable output capacity.

2. Fleet management based on available output, SOC, and communication status

The cloud platform monitors each site’s state of charge (SOC), charge/discharge availability, communication status, outage risk, and measurement data, presenting aggregators with a clear, manageable view of available output for market operations.

3. Connection verification with multiple aggregators and manufacturers

Helios is conducting communication and control tests in collaboration with multiple domestic and international aggregators, PCS manufacturers, and battery manufacturers. By verifying integration according to each company’s system and equipment specifications, Helios is building the foundational infrastructure necessary for low-voltage battery aggregation.

4. Proven track record in PV and battery resource control

Helios has provided resource control technologies for battery PCS and PV-PCS systems targeting primary, secondary, and tertiary regulation markets to multiple aggregators. Building on its development and deployment experience at extra-high-voltage, high-voltage, and low-voltage grid-connected sites, Helios is extending these capabilities to low-voltage aggregation.

5. Cloud-based architecture without on-site EMS installation

Instead of installing individual EMS systems at each power plant, Helios deploys control agents on-site and performs integrated control via a cloud-based virtual EMS. This simplifies system architecture when deploying low-voltage battery storage across multiple sites, reducing equipment burden while delivering essential aggregation control functions.

6. JC-STAR★1 certified terminals and in-house developed frequency measurement device

For control terminals at low-voltage battery sites, Helios uses its HELIOS-B4 series, which has already obtained JC-STAR★1 certification. For grid frequency measurement required in primary regulation control, Helios employs its own compact, high-precision frequency measurement device. This device achieves ±0.01Hz measurement accuracy and ultra-low latency communication as fast as 1.7ms via a proprietary protocol, enabling integrated design of measurement and control systems tailored for low-voltage battery aggregation.

7. Manufacturing readiness for low-voltage aggregation deployment

Anticipating large-scale deployment of low-voltage aggregation sites, Helios is strengthening its manufacturing capacity for the HELIOS-B4 series and frequency measurement devices. For developers planning multi-site installations, Helios offers customized delivery plans based on project scale and timeline.

Target Users

Target Users

Expected Needs

Aggregators

Want to bundle clusters of low-voltage battery storage into 1MW+ output units

Battery Storage Developers

Want to deploy multiple low-voltage battery projects using small-scale land

Power Generators

Want to expand revenue opportunities from existing power plants and solar-plus-storage systems

PCS and Battery Manufacturers

Want to connect and verify their equipment for aggregation operations

Power and Energy Companies

Want to build control and data integration platforms for aggregating distributed flexibility resources

Future Outlook

Helios will continue advancing control agents at low-voltage sites, synthetic output control via virtual EMS, and cloud-based EMS integration with aggregator systems, pushing forward the implementation of control and data linkage platforms to manage multiple low-voltage battery storage facilities as aggregation units of 1 MW or more. Additionally, Helios will support aggregators in entering and expanding low-voltage aggregation services, while providing implementation platforms for battery developers, power generators, energy companies, and PCS/battery manufacturers to leverage aggregated low-voltage resources in energy markets.

About Helios Co., Ltd.

Helios Co., Ltd. is a 100% subsidiary of J City Co., Ltd., having taken over its solar power plant monitoring business on April 1, 2026. The company develops and sells the 'HELIOS' series of power plant monitoring systems, provides EMS systems, and designs and sells VPP systems and DER control terminals. It has a proven track record of delivering battery PCS and PV-PCS resource control technologies for primary, secondary, and tertiary regulation markets to multiple aggregators at extra-high-voltage, high-voltage, and low-voltage grid-connected sites. Leveraging its expertise in control devices for solar power plants compliant with output control from general power transmission and distribution companies, Helios also implements coordinated control at sites with co-located batteries and PV systems, tailored to each plant’s equipment configuration and operational