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Automated control system for multi-megawatt energy storage

Large-scale battery maker taps Siemens for end-to-end solutions and expertise to save huge costs and critical time-to-market.

The challenge was to develop a comprehensive and highly scalable automated control system for multi-megawatt energy storage using minimum engineering time and cost to ensure fastest time-to-market.

As the smart grid quickly evolves into a distribution infrastructure for AC electricity with ever more sensory, interactive and transactional capabilities, a 150-year-old DC technology has re-emerged on the scene. It’s the wet-cell battery, but now with extremely advanced chemistry and designed, engineered and built to deliver multi-megawatt capacities and with plenty of smarts inside.
One of the world’s top suppliers of such energy-storage solutions is a small but growing company founded in 2012 called UniEnergy Technologies (UET). From its headquarters and manufacturing facility near Seattle, it makes and sells the Uni.System™. This is a highly scalable, next-generation energy-storage solution for utility, commercial and industrial, micro grid and other applications housed in standard 20-foot shipping containers.

UniEnergy Technologies (UET) energy-storage solutions

Their modular architecture enables UET’s customers to add as much capacity as they need with plug-and-play simplicity similar to adding data storage to today’s computer systems.
As a buffer between bulk energy generation and sustained energy use, the Uni.System can provide near-instant energy for different durations.

According to UET’s Director of Electrical Engineering David Ridley, the company faced numerous challenges in bringing the Uni.System to life. “We needed to create a control architecture that’s scalable and extensible just like our product,” Ridley explains. “That way, if customers want to add another megawatt of capacity, no problem. Our controls needed to scale easily, so that once we deliver another container and hook it up, we could just increment the counter in our software by one megawatt and the customer is up and running.” Simplicity and reliability were important too, for both customers and UET.
Among the Uni.System’s other design goals were low manufacturing costs and physical modularity. Ridley says that’s why the company chose the 20-foot shipping containers.
“They’re available as pre-built commodities, saving materials sourcing and fabrication costs,” Ridley says. “They’re also stackable and easy to transport via multimodal logistics, weather by truck, rail or ship.”


Ridley and his team considered other major supervisory software suppliers in addition to their evaluation of SIMATIC WinCC Open Architecture (WinCC OA). But they chose WinCC OA for several reasons – one being its complete object oriented implementation and methodology.
“What really stood out about WinCC OA is the truly extensible architecture, even during run-time in most cases,” he says. “It shows just how powerful and flexible a SCADA solution can be when object oriented design principals are utilized throughout the complete software package.”
“With the SCADA software platform WinCC OA, we can forget all the protocols, drivers, and memory management issues that we’d have to code, then compile, test debug, recompile and on and on. This lets us keep a small, efficient team that just focuses on battery logic. That’s our value-add, not all that other effort.”
Another big attraction was the massively scalable and distributed nature of the WinCC OA platform, as evidenced by a number of the flagship deployments. “UET plans to become a major international supplier for the quickly growing utility energy storage market, with immediate plans to scale up production to over 100MW/year. Our demonstration projects are starting out at 0.5-2MW range, but typical renewal integration projects will range from 5-20 MW, and big replacement projects will surpass 50MW. We needed a platform that will scale accordingly.”


Ridley estimates that choosing WinCC OA helped UET cut its time-to-market in half, saving months of development time and conserving precious cash. But the real value that WinCC OA provides shows not in the first project, but in the avoided recurring engineering efforts required for subsequent projects.
“We now have a control system that can be run-time configured for any number of MWs and MWhs. No need to manually create tags, design new screens, add new interfaces, or include more alarms. All of these tasks happen automatically as we programmatically instantiate additional battery objects.”

The second reason that WinCC OA will reduce future engineering costs is the flexibility of the system. The open concept of WinCC OA allows integration of a wide variety of components. From the automation level right up to operation and management level, the system allows finely tuned solutions.
“The openness of WinCC OA gives me the confidence that we’ll be able to incorporate any new interfaces, features, or standards that are required by our customers. WinCC OA provides a future-proof solution that won’t lead us down a technical dead end.”