Poland C&I High Voltage ESS Case Study: 2 × 100kWh ESS Battery Storage in Parallel (200kWh System, 2026)

Project Year: 2026

Location: Poland

System Topology: 2 × 100kWh ESS battery cabinets in parallel

Cooling Method: Air-cooled integrated cabinet

Inverter: Deye (external connection)

Application: Commercial & Industrial peak shaving + backup power

In 2026, a commercial facility in Poland deployed a 200kWh high voltage ESS battery storage system to reduce electricity costs, manage peak demand, and ensure backup power during grid instability. The solution consists of two 100kWh ESS battery cabinets connected in parallel, forming a scalable C&I energy storage system.

System Architecture

The project adopts an air-cooled all-in-one ESS cabinet design with external Deye inverter integration. The high voltage DC architecture improves efficiency and reduces current losses compared to low-voltage systems.

Key Features:

• High voltage ESS battery clusters in each cabinet

• Independent BMS with parallel coordination

• External inverter for flexible AC integration

• Intelligent air-cooling system

• Plug-and-play parallel scalability

Why Air-Cooled ESS?

For medium-scale C&I energy storage (100–300kWh), air-cooled ESS battery storage offers a cost-effective and reliable solution.

On-site Advantages:

• Lower maintenance without liquid cooling risks

• Fast installation with integrated cabinet design

• Higher efficiency from high voltage architecture

• Easy future expansion through parallel connection

• Flexible compatibility with existing AC systems

Installation & Commissioning

The two ESS battery cabinets were installed side-by-side, connected in parallel on the DC side, and integrated with the Deye inverter on the AC side. System commissioning included BMS communication setup, DC bus configuration, inverter parameter alignment, peak shaving scheduling, and backup power testing.

The system was commissioned smoothly with minimal integration effort.

Operational Results

After months of operation, the client reported:

• Stable daily peak shaving performance

• Reduced electricity bills

• Seamless transition during grid outages

• Consistent thermal performance

• Reliable cooperation with the Deye inverter

Technical Overview

• Total Capacity: 200kWh (2 × 100kWh)

• Battery Type: LiFePO₄ ESS battery

• System Voltage: High voltage ESS architecture

• Cooling: Intelligent air cooling

• Inverter: Deye (external)

• Application: Peak shaving + Backup power

• Scalability: Parallel expandable

This Poland C&I high voltage ESS project demonstrates a practical and scalable commercial energy storage model, balancing efficiency, CAPEX control, and operational reliability for European commercial and industrial applications.