As demand for electricity grows, Duke Energy is finding new ways to deliver more from the grid customers rely on every day. With grid-enhancing technologies (GETs), the company is increasing transmission capacity, improving reliability for customers and reducing the cost and timeline of traditional upgrades – helping bring new generation online faster.
Enterprise-wide evaluation of GETs
Duke Energy already uses advanced conductors in North Carolina and Florida. Now, its Emerging Technology Office is leading an enterprise-wide evaluation of GETs to identify opportunities to expand grid capacity.
In line with FERC requirements, Duke Energy Florida is evaluating GETs in generator interconnection studies as alternatives to traditional upgrades, with results reported. Duke Energy Carolinas began a similar review in May. Each technology is assessed for feasibility, cost and schedule benefits.
Delivering more from the existing grid
Across its system, Duke Energy is applying GETs to:
- Increase transmission capacity
- Reduce costs and timelines compared with traditional upgrades
- Improve reliability for customers
- Enable faster integration of new generation and large load growth
North Carolina DLR pilot (~$3M)
To further increase grid capacity, Duke Energy received approval from the North Carolina Utilities Commission to deploy four dynamic line rating (DLR) technologies.
This enables Duke Energy Carolinas and Duke Energy Progress to test a mix of software- and sonar-based approaches across all four seasons and on a range of transmission lines statewide.
Doubling capacity within existing right of way
The 40-mile Lee–Milburnie transmission line rebuild in North Carolina will more than double capacity – from 541 to 1,195 MVA – while reducing outage frequency and interruptions for more than 14,000 customers.
The project remains within the existing right of way, avoiding approximately two years of new land acquisition and saving about $25 million. It will improve reliability across eastern North Carolina as 1979-era wooden H-frame structures are replaced with modern steel monopoles and high-temperature, low-sag (HTLS) conductors.
Duke Energy is also negotiating a $57 million U.S. Department of Energy grant that could reduce costs by about 30% versus a comparable greenfield line and enable double-circuit capability to support future needs.
Near-term solutions to support faster connections
GETs also provide a near-term bridge while long-lead equipment – such as high-voltage power transformers – is designed, procured and installed.
For example, Duke Energy has scoped an advanced power flow control device that could defer the need for a large transformer, creating time to implement a permanent solution. The company is also deploying switchable reactors and remedial action schemes to manage constraints and avoid certain line rebuilds.