National grid installs power flow tech to solve renewables bottlenecks


In a world-first, National Grid Electricity Transmission (NGET) is conducting a large-scale installing of smart modular power flow controllers to free up 1.5GW of network capacity – enough renewable energy to power 1 million homes.

NGET will be installing the SmartValveTM power flow control technology from US-based company, Smart Wires, at Harker in Carlisle, Penwortham in Preston and Saltholme in Stockton-on-Tees near Middlesbrough. These are sites that have experienced bottlenecks of renewable power. The technology will allow greater volumes of renewable power to be efficiently transferred to customers, by routing power through the circuits which have available capacity, maximising the use of the existing network.

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Julian Leslie, head of networks at National Grid Electricity System Operator said: “Managing constraints on the transmission network is an important part of our work operating the electricity system so it’s great to see Smart Wires technology being utilised. Developments such as this, and the steps outlined in our 5-point congestion management plan, will reduce the impact of constraints, allowing us to harness the full potential of renewable generation and lower costs for the end consumer – all helping towards our ambition of being able to operate the system at zero carbon by 2025.”

Power grids require more intelligent and controllable systems as more renewable generation comes onto the network. Changes in weather and power flows can cause circuits to become unequally loaded, meaning some circuits reach maximum capacity while others are still well below their limits. The modular power flow controllers will allow NGET to provide National Grid’s Electricity System Operator with the tools to quickly reduce the congestion that limits renewable generation.

Before and after SmartValve. Credit: Smart Wires

Technical spec

According to Smart Wires, SmartValve is a single-phase, modular-SSSC that injects a leading or lagging voltage in quadrature with the line current. This means it can increase or decrease power flows on a circuit and perform dynamic services. Distinct from legacy SSSCs, SmartValve is transformerless and uses an integrated, fast-acting bypass for protection from system faults. A SmartValve installation is connected in series with a utility facility, operates at line potential and has no connection to ground.

Peter Wells, Smart Wires CEO said: “With these projects, NGET have pioneered a new way to think about planning and operating the grid – leveraging flexible investments to deliver gigawatts of impact in incredibly short timeframes.

“Our vision at Smart Wires is a highly efficient grid that powers a cleaner planet, and we are so proud to stand alongside our NGET partners and celebrate this success.”

Following these initial installations at the three sites, National Grid is looking to extend the capability at Harker and Penwortham in the Autumn, a move that could free up an additional 500MW of capacity.