4 transmission technologies to watch

Source: By Gordon Feller, Utility Dive • Posted: Thursday, February 24, 2022


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As Congress, the Department of Energy and Federal Energy Regulatory Commission move to spur new transmission, efforts are underway to improve existing transmission assets and expand where they can go.

For example, transmission developers are increasingly looking to “shared usage of right of way,” negotiating directly with rail lines and governmental stakeholders of highways to use those corridors to bury transmission lines, according to Kevin Ludwig, associate vice president and grid solutions leader at Black & Veatch. There has also been a focus to use inland waterways with submarine cables which are paired with a high-voltage, direct current transmission system to move large amounts of power, Ludwig added.

In terms of existing transmission technology, high-temperature, low-sag conductors are being deployed in niche cases largely when transmission owners are seeking to push more power in a corridor or need their transmission to span a long distance but are constrained by special crossings, Ludwig said. Such conductors have a heat-resisting composite core rather than steel that’s commonly used to structurally support lines, allowing more power to be pushed through the line without it expanding and sagging.

“The barrier to broader migration to high-temperature, low-sag conductors are its cost and the special tools/hardware required for installation,” Ludwig said. But there are new developments in this space that allow composite conductor installation with the same tools/hardware as traditional conductors with the benefits of high-temperature operation. Separately, there are also advances in conductor monitoring technology that allow for real-time rating adjustments rather than a static rating which often is based on worst-case conditions that only exist for a small portion of a year. This technology allows additional energy flow without any investments in new conductors and will be rolled out by utilities as a result of FERC order 881 to improve transmission line ratings.

Elsewhere, Ludwig said pilot projects are underway with high-temperature superconducting power lines involving underground infrastructure cooled by liquid nitrogen, allowing transmission to have nearly zero resistance. In addition, AC transmission lines — typically governed by breakers that only allow operators to turn the lines on or off — are growing more dynamic with controls that can regulate the power flow by adjusting the line’s impedance, much like using a valve to adjust water flow.

Among the companies pioneering new transmission-related technologies that help utilities, four are worth noting:

1. NewGrid

NewGrid’s congestion monitoring/mitigation solutions for the grid uses “operational transmission topology optimization,” said Todd Allmendinger, director of consulting and research at the Cleantech Group. This can avoid congestion and curtailments affecting renewable power plants by rerouting flow around bottlenecks. This is done by opening and closing transmission circuits, much like traffic lights in a big city.

2. Pearl Street Technologies

The company applies methods used in computer chip circuit design and simulation to grid planning, Allmendinger said. “They’ve developed a physical-based grid model which can run simulation and optimization scenarios for long-term planning.

Initially targeting the transmission networks in the U.S. is a smart move by the firm, given its federally regulated nature and therefore the ability to access clean data at a national scale,” he said. With seed funding raised in January, the company plans to increase its portfolio of ISO customers. Allmendinger notes part of their importance to those who own and operate transmission and distribution systems: their longer-term vision is to “become a one-stop shop for planning real-time control for all distribution, transmission, and microgrid networks,” he said.

Pearl automates the creation of base case planning models for customers who’ve grown tired of the traditional ‘hand-made’ approach, which costs more in the way of staff time. Those models have been a boon to customers seeking to reduce costs and realize greater efficiencies for the planning of new investments, including transmission and other projects. But one potential downside of automating base case planning models is the problem that arises whenever low-quality data is used at the start of the process when base cases get shaped.

3. TS Conductor

The California-based company is updating existing steel-based conductor/wire transmission technologies — a segment of the grid that has changed little over more than a century.

According to founder and CEO Jason Huang, the company produces a new kind of electric conductor (used in transmission and distribution networks) which can increase the capacity of existing lines 2.5 times without having to change or retrofit the existing supporting infrastructure (e.g., poles, towers). “This allows grid operators to accept large increases of renewable power generation coming online at minimum additional cost to electricity consumers, Huang said.” This becomes important as much more of these resources come online during the next few years. Thus, one benefit of TS technology is that it opens up a constrained electric grid, at the minimum cost possible, in order to allow renewable generation to make its way to customers, Hervé Touati, TS’s chief strategy officer, said.