Electrifying our grids: The role of HVDC technology
March 24, 2025
High voltage direct current technology can help us to deliver large amounts of power safely and reliably. Here’s how.
The energy transition is upon us, and it’s demanding significant investments to modernize our electrical grids. This modernization is crucial for integrating new types of generation and energy storage, renewing aging infrastructure, and ensuring the reliability of our electrical supply. It all starts with careful planning to deliver power safely and support the ongoing expansion and development of the grid.
Enter high voltage direct current (HVDC) solutions. HVDC has been used to transmit large amounts of power over long distances. Now, it’s role is growing and evolving. HVDC will be essential not only for these traditional applications, but also for connecting isolated transmission networks and integrating renewable energy sources. In the near future, HVDC grids could revolutionize power transmission between regions, making it more efficient and reliable.
As the energy industry continues to evolve, adapting to changing conditions and needs is a must. By staying ahead of the curve, HVDC can help our grid infrastructure to meet the increasing demand for clean, reliable energy, paving the way for a sustainable future.
The growing interest in HVDC systems is likely here to stay. This is of course fueled by our ambitious goals for decarbonization, clean energy, and modernizing aging infrastructure.
A powerful tool
Most of the electricity that powers our homes and businesses is delivered using alternating current (AC). This type of power, which operates at a frequency of 50 or 60 hertz (Hz), has been the standard for over a century. AC power is relatively economical over short distances and moderate power levels. However, as the distance and power levels increase, AC power becomes more costly and less efficient.
HVDC is different. Unlike AC, HVDC uses a constant voltage and current to transmit power. This is done using electronic devices that control the flow of power and can convert AC power to HVDC and back again. HVDC is more efficient and economical for transmitting power over long distances. It's also better for situations where precise, fast control of power flow is needed to keep the electrical grid stable. Plus, HVDC can be used to restart a power system after a blackout. This process is known as a "black start."
As we modernize and expand our electric grid, HVDC technology is becoming a game-changer. And one that the grid will rely heavily on.
HVDC technology is not just about meeting rising energy demands. It’s about rethinking and revolutionizing the ways we can deliver clean, reliable electricity to our homes and businesses.
Interconnection: Bridging the gaps
HVDC technology allows our grids to connect seamlessly. This helps to enable a stable and reliable supply of energy across vast regions that are hundreds or even thousands of kilometers apart, sometimes even operating at different AC frequencies. This is especially important as renewable energy projects, often located in rural or remote areas with an abundance of energy potential, grow in scale.
Take the SunZia Transmission Project, for example. This project is part of the largest clean energy infrastructure initiative in US history and, once complete, will provide the capacity to deliver 3,000 megawatts (MW) of clean renewable energy generated in New Mexico to communities in Arizona and California. SunZia uses HVDC technology to transport wind power nearly 900 kilometers away, supplying enough clean energy for up to three million homes.
Offshore wind projects and international interconnections also rely on HVDC. The EuroAsia Interconnector, a proposed HVDC link connecting Crete, Cyprus, and Israel, will use submarine cables installed at depths of up to 3000 meters. This project aims to help the European Union (EU) achieve its energy and climate goals and will be one of the first multi-terminal HVDC systems in the world.
And these projects are only the start. We expect to see many more HVDC systems constructed around the world in efforts to integrate more renewable energy into our electrical grids.
As the energy industry continues to evolve, adapting to changing conditions and needs is a must.
Upgrading infrastructure: Building for the future
Our aging energy infrastructure needs upgrades to support the energy transition, meet increasing power demands, and ensure reliable energy delivery. This means not just building new HVDC systems but also upgrading existing ones.
Consider the Intermountain Power Project (IPP), which has delivered energy from Utah to Southern California using HVDC for nearly 40 years. The IPP Renewed project involves replacing the HVDC converter stations to ensure continued reliable delivery of cleaner, hydrogen-sourced energy to California for many more years to come. It also provides increased flexibility to use new renewable wind and solar energy sources.
But we also must make upgrades to improve resiliency. Extreme weather events are becoming more frequent, threatening the reliability of our electricity supply. In Manitoba, over 70% of power came from the Nelson River Bipole I and Bipole II HVDC systems, which are located close to each other and vulnerable to single weather events. To enhance reliability, Manitoba Hydro constructed a third transmission link, Bipole III, using HVDC technology. This new link is physically separated from the existing ones for increased resiliency against extreme weather to ensure a continued, reliable supply of hydroelectric power.
To enhance reliability, Manitoba Hydro constructed a third transmission link, Bipole III, using HVDC technology.
Keeping pace with an evolving industry
The energy transition and modernization of our electrical grids have already sparked an unprecedented demand for HVDC systems. In 2023 alone, five new HVDC projects went online around the world. Plus, over 45 new HVDC contract awards were announced, driven partially by multi-year, multi-project framework agreements.
This boom in HVDC projects has forced owners to rethink their approach. Increased lead times and reduced interest from HVDC suppliers have significantly changed the landscape from what it was less than a decade ago.
Now, instead of relying on a single HVDC supplier for a turnkey solution, owners are opting for a more segmented approach. First, owners select a preferred HVDC supplier to develop the system design and supply the equipment. Then, owners separately hire contractors for site civil works and equipment installation. This new approach means that project owners must manage the risks and coordinate the many interfaces between contracts—tasks that were traditionally handled by the HVDC supplier in a turnkey arrangement.
Delivering decarbonization with HVDC
The growing interest in HVDC systems is likely here to stay. This is of course fueled by our ambitious goals for decarbonization, clean energy, and modernizing aging infrastructure. HVDC technology is not just about meeting rising energy demands. It’s about rethinking and revolutionizing the ways we can deliver clean, reliable electricity to our homes and businesses.
We’re excited to see this kind of innovation in the industry and we’re optimistic for the future. It is our hope to see more and more HVDC projects come online as we continue to modernize our electrical grids and decarbonize our energy infrastructure.