A significant advancement in the energy transition has been achieved with the successful demonstration of a world-first technology that allows High Voltage Direct Current (HVDC) transmission systems from different manufacturers to connect and operate seamlessly, boosting network reliability.

SSEN Transmission's innovative Aquila Lite project has showcased a software interface enabling HVDC multi-vendor interoperability. This groundbreaking development means that control systems and main circuits from various manufacturers can now work in unison, eliminating the need for expensive AC/DC conversion when transferring power between them.

The project, spearheaded by SSEN Transmission with support from Ofgem’s Network Innovation Allowance (NIA), represents a major step forward in realising the potential of an offshore HVDC grid network. This network is crucial for delivering substantial amounts of renewable energy to meet national clean energy targets and enhance energy security.

Beyond reducing capital investment costs associated with converter stations, the technology also mitigates supply chain risks by lessening reliance on a single supplier. Without interoperability, depending on one manufacturer for the majority of technology in the developing offshore HVDC grid could expose future network operations to potential outages.


The project has led to the development and patenting of a novel multi-terminal, multi-vendor HVDC control approach by The National HVDC Centre, which is owned and operated by SSEN Transmission in collaboration with other transmission operators and the National Energy System Operator.

The Aquila Lite project was initially demonstrated with principal contractors GE Vernova and Mitsubishi at the recent IET ACDC International Conference. Further demonstrations with Hitachi Energy and Siemens Energy are planned before the project's completion.

Nithiananthan Vejayan, Innovation Delivery Project Manager at SSEN Transmission, commented: "We’re delighted to have achieved this historic milestone in our Aquila Lite innovation project, which has demonstrated how different vendor devices can harmoniously connect to a DC network and operate collectively to meet the requirements of Transmission Owners and operators. The achievement of multi-vendor interoperability in HVDC technology signals a new era in sustainable energy innovation and underscores SSEN Transmission’s commitment to driving transformative change in the electricity sector to deliver a network for net zero."

Ben Marshall, HVDC Technology Manager at The National HVDC Centre, added: "The results of our demonstration have instilled industry confidence that interoperability is not just theoretical but practical and can be commercially, legally, and technically managed across the delivery of real projects. By patenting our process, we have removed any barriers to implementing this approach, setting the stage for future deployments with multiple Transmission System Operator projects in the early 2030s."

This technological breakthrough paves the way for a more resilient and cost-effective offshore HVDC grid, crucial for transporting vast amounts of renewable energy generated offshore to where it is needed.