ABB MV Titanium motor projects 2500 MWh annual savings at Stora Enso Varkaus containerboard mill

The energy equation in containerboard manufacturing leaves no room for inefficient legacy systems. At the Varkaus mill in Finland, which produces approximately 420,000 tonnes of containerboard annually, Stora Enso is currently piloting ABB’s MV Titanium technology to address a specific, high-consumption bottleneck: the primary air blower of its fluidized bed boiler.

By replacing a traditional direct-on-line (DOL) motor that relied on damper regulation, the installation marks the first industrial deployment of a medium-voltage motor with built-in speed control. The operational data from the 2026 pilot already confirms a drastic reduction in power draw, projecting an annual energy saving of 2,500 MWh.

Eliminating mechanical inefficiency

In typical boiler operations, primary air blowers rarely need to run at full capacity. At Varkaus, the blower operates predominantly between 40 and 60 percent flow. Under the previous DOL setup, the motor ran at a constant speed, and airflow was restricted mechanically using a damper—a notoriously inefficient method that wastes significant electrical energy.

The MV Titanium unit delivered to Stora Enso is rated at 6.3 kV, 1.25 MW, and 1490 rpm. By integrating the variable speed drive directly into the motor housing, ABB allows the system to adjust its speed electronically to match the exact process demand. The most substantial efficiency gains at Varkaus have been recorded at the 50 percent flow mark, where the blower operates most frequently.

According to the initial performance metrics, the speed-controlled setup will cut the primary air blower's energy consumption from 5,300 MWh to 2,900 MWh per year.

Streamlined infrastructure for heavy industry

Beyond the direct reduction in megawatt-hours, the architectural advantage of the MV Titanium lies in its footprint. Historically, retrofitting large medium-voltage motors with variable speed drives required substantial infrastructure investments. Mills had to construct additional electrical rooms, install separate HVAC systems to manage the heat generated by the drives, and often deploy extra transformers.

The integrated nature of this new ABB motor eliminates these requirements. It functions as a drop-in replacement for existing DOL motors, simplifying the upgrade path for energy-intensive pulp and paper operations. For a facility like Varkaus, which generates its own steam and power through the recovery and fluidized bed boilers, optimizing the parasitic load of auxiliary equipment directly improves the mill's overall net energy balance.

As containerboard producers face tightening margins and strict carbon reduction targets, the ability to retrofit critical heavy-duty applications without expanding the plant's electrical footprint provides a viable template for the wider corrugated packaging sector. Stora Enso will use the ongoing data from this pilot to further fine-tune the boiler's air delivery system, setting a new technical baseline for motor efficiency in paper mill environments.