Battery storage is now central to a more flexible and reliable energy system. However, scaling from pilot to utility-scale operation requires more than increasing capacity. It depends on learning from real operations, managing data transparently, and ensuring consistency. In 2023, Elli, Volkswagen Group’s charging and energy subsidiary, brought its first pilot battery energy storage system (BESS) online in Baunatal. Supported by Cellect’s full software suite, Baunatal served as the proof-of-concept site for Elli’s BESS operations, providing practical experience in managing grid-connected storage. The pilot project was disconnected at the end of 2025 after completing its operational phase.

The day-to-day operations at the pilot site gave Elli’s teams a chance to test strategies, refine workflows, and build robust data practices under real conditions. This operational foundation directly shaped the approach to their next project.

With the BESS Elli PowerCenter now connected to the grid, Elli is putting this experience into practice on a new scale. The site delivers 20 MW of power and 40 MWh of capacity, marking a significant step forward in both size and operational ambition.

Value at a glance:

· Unified operations: A single software suite connects asset management, control, and trading, reducing manual work and delivering end-to-end visibility.

· Faster scaling, lower risk: Proven workflows and shared data models enable smooth scaling from pilot to utility scale, without reinventing processes for each site.

· Full trading autonomy: Elli's trading team directly controls strategies and market participation, without sacrificing transparency or operational oversight.

The Volkswagen plant in Salzgitter is more than a scaled-up version of Baunatal. Three elements set this project apart:

1. Industrial location and integration

The Elli PowerCenter is located next to Volkswagen’s PowerCo gigafactory in Salzgitter, where PowerCo has begun producing its first Unified Cells “made in Europe.” With PowerCo, Volkswagen Group is designing, developing, and producing battery cells in Europe as part of its strategy to strengthen technological sovereignty in battery manufacturing.

The proximity between battery manufacturing and grid storage creates a direct link between production and energy system integration. Locating the storage system within Volkswagen’s battery ecosystem enables closer collaboration between manufacturing and operations while supporting more streamlined integration with the power system.

2. Use of in-house manufactured batteries

The system operates with lithium-ion cells delivered from PowerCo, creating a closed loop from manufacturing to grid storage. This integration provides transparency for performance monitoring, warranty management, and long-term asset lifecycle planning.

3. Direct market participation and operational autonomy

Elli operates its own trading desk and optimizer, connecting via Cellect Control’s API. This allows for real-time market participation, flexible strategy updates, and reduced reliance on third-party platforms.

Elli’s operational strategy at both Baunatal and Salzgitter is built on the complete Cellect software suite—integrating asset management, control, and data for consistent, reliable operation.

· Cellect Platform: Centralizes asset monitoring, performance analytics, and warranty tracking, meeting PowerCo’s warranty requirements at every level.

· Cellect Data Management: Provides a unified, secure data layer for both sites, supporting real-time access and collaboration for operators, asset managers, and trading teams.

· Cellect Control: Enables direct, API-based integration between Elli’s in-house market optimizer and both BESS sites, ensuring flexibility and transparency in market operations.

This unified asset management approach helps Elli transfer lessons between projects, maintain high operational standards, and scale efficiently across a growing pipeline.

Using Cellect’s full software suite translates into tangible operational advantages that show up in daily workflows and when scaling operations.

One system that connects performance, control, and markets

When asset monitoring, data management, and control live in the same ecosystem, operational decisions no longer rely on reconciling multiple systems.

For Elli, this means:

· asset performance, control actions, and market dispatch are traceable end to end

· operators and trading teams work with the same, consistent data

· issues can be analyzed in context—what happened, why it happened, and how it affected revenues

Instead of stitching together logs and dashboards, teams see the full operational picture in one place.

Faster transition from pilot to utility scale

Because the Elli PowerCenter runs on the same software foundation as the Baunatal pilot, Elli does not start from zero with each new project.

Using the full suite allows Elli to:

· reuse operating procedures, KPIs, and monitoring logic

· apply lessons learned from the pilot site directly at larger scale

· onboard new assets faster with less operational uncertainty

This reduces ramp-up risk and helps maintain consistent operational quality as projects grow in size and complexity.

Trading autonomy without operational blind spots

Cellect Control connects Elli’s in-house optimizer directly to the battery systems via API—while staying integrated with asset monitoring and data management.

The result:

· Elli keeps full control over trading strategies

· no additional hardware or custom integrations are required

· control actions remain visible, auditable, and linked to asset performance data

This combination supports market autonomy without creating blind spots in operations.

Reduced operational overhead as complexity increases

Running asset management, control, and data through one vendor significantly reduces operational friction.

In practice, this means:

· fewer suppliers and SLAs to coordinate

· simpler commissioning and system architecture

· faster root-cause analysis when issues occur

Problems can be identified and resolved within a single environment, instead of escalating across multiple external providers.

Warranty-ready performance data without retroactive effort

With Cellect Data Management integrated into the suite, operational data is structured, secure, and accessible to all relevant stakeholders.

For Elli, this supports:

· transparent performance tracking across sites

· warranty-relevant data availability for PowerCo batteries

· long-term insights into degradation, usage, and lifecycle behavior

The same data foundation supports immediate operational decisions and strategic asset planning.

Standardized operations that stay adaptable

Standardized processes across monitoring, control, and data handling reduce operational risk, especially as systems scale.

At the same time, the suite allows:

· site-specific configurations

· market-specific strategies

· flexible integration with internal tools

This balance helps Elli operate reliably today while staying adaptable for future projects.

Trading autonomy without operational blind spots

Cellect Control connects Elli’s in-house optimizer directly to the battery systems via API—while staying integrated with asset monitoring and data management.

The result:

· Elli keeps full control over trading strategies

· no additional hardware or custom integrations are required

· control actions remain visible, auditable, and linked to asset performance data

This combination supports market autonomy without creating blind spots in operations.

If you’re interested in how an integrated approach to BESS operations can support your projects, get in touch with our team or explore more insights on our blog.