Duke Energy has put battery and ultra-capacitor system to test at its Rankin Substation in Gaston County, North Carolina, US.
The new hybrid ultracapacitor-battery energy storage system (HESS) will demonstrate various service applications such as load shifting, extended operational life, real-time solar smoothing and extended shelf-life.
Duke Energy technology development manager Thomas Golden said: "This approach will allow our energy storage systems to do a variety of tasks.
"With so many solar installations in North Carolina, we must look for innovative ways to better incorporate renewable energy into our system, and still provide reliable service at a competitive price for our customers."
The substation has a distribution line with a 1.2MW solar installation that is connected almost a mile away. With North Carolina ranking fourth in the country for installed solar power, managing such grid-linked renewable installations has become critical, added Golden.
Energy Storage Association executive director Matt Roberts said: "Energy storage is changing the paradigm on how we generate, distribute and use energy. The demonstration of new technologies will help facilitate wider adoption across the nation."
For this project, Duke has partnered with Aquion Energy for innovative battery technologies and associated engineering services.
Maxwell Technologies has provided fast response ultracapacitors (UCAPs) that can store and effectively and quickly discharge energy.
Win Inertia has offered SHAD solution that integrates enhanced power electronics and patented energy management and control systems.
The new HESS system will make use of the UCAPs to manage solar soothing events in real-time scenarios, especially when the solar power on the grid fluctuates due to cloud cover or other weather circumstances.
UCAPs have been proven in other applications to cut down heat stress on the battery and degradation. The batteries will be used to shift
solar load to a more advantageous time for the utility.
The 100kW / 300kWh battery makes use of novel Aqueous Hybrid Ion chemistry, which includes a saltwater electrolyte and synthetic cotton separator. These materials reduce costs.
Furthermore, the water-based chemistry will offer a non-toxic and non-combustible product that is not only environmentally friendly but is also safe to handle.
Image: The new hybrid ultracapacitor-battery energy storage system will demonstrate various service applications. Photo: courtesy of Duke Energy Corporation.