Optimizing Our Transmission System
The U.S. DOE will help fund 31 grid-improvement projects across 26 states. These projects are focused on enhancing the existing transmission system, flowing more power with the help of new technologies.
That matters a great deal because the U.S. needs a lot more transmission capacity and today it takes forever to build new lines - in some cases well over 15 years.
Building new transmission generally involves condemning private property through eminent domain, pitting the collective good against the rights of individual landowners. That makes permitting hard. Only about 1500 miles of high-voltage transmission lines was built over the three year period from 2022 to 2024.
So, the DOE will spend $1.9 bn – and catalyze an additional $3.35 bn in recipient cost-share funding in order to make over 23,000 MW (23 GW) of additional capacity available. Project developers will rebuild or reconductor over 1,500 miles of transmission lines. Grant recipients will also deploy Grid-Enhancing Technologies (GETs), non-wires technologies such as Dynamic Line Ratings, Topology Flow Optimization, and Advanced Power Flow Controls across nearly 21,000 miles.
Reconductoring is the process of stringing more efficient wires on existing lines, with new advanced wires employing smaller composite-based core that allows for higher temperatures and the packing of more conductive aluminum in the same equivalent diameter. They can carry up to 2X the power.
Next up, dynamic line ratings. Transmission lines are assigned static ratings for the hottest and stillest hours of the year. The more power you move through the wires, the more resistance you get, with associated heat.
But colder temps chill lines and wind is even more critical, efficient at wicking away transmission line heat. DLRs – using a combination of sensors and software, create situational awareness w/r/t the actual conditions. On the coldest, windiest days, one can move over twice the juice through the same wires.
Topology Flow Optimization is like Waze for the grid, by opening some breakers and closing others to create detours and redirect electron traffic onto different transmission paths. Lower cost power can get to load pockets that would have previously been inaccessible.
Finally, Advanced Power Flow Controls adjust the characteristics of transmission lines so that power moves differently through the transmission system. One can inject reactive power into the system, for example, to shift more power from one overloaded line to another that still has ample capacity.
The DOE grants are meant to stimulate something that should have happened a long time ago: the deployment of technologies and processes that will allow us to utilize our existing system more efficiently. We still have to build new lines, but this is a step closer to being smarter, and adapting the infrastructure we already have.