Transmission lines are the lifeblood of America’s electricity system — and we urgently need more, built at a faster rate than we’re completing. We need more to connect new sources of clean energy to transition off polluting fossil fuel plants; more to meet surging demand from new manufacturing facilities and data centers; and more to keep the lights on during extreme weather events.
But building entirely new transmission lines in the United States is difficult. And building the long regional and interregional lines required to move clean electricity from where it is generated to where it is needed — and to share electricity between regions during extreme weather events — are particularly tricky.
Faced with the crunching need to supply more electricity, many utilities are proposing new gas plants to deal with the grid’s pressures. Building them, however, would lock in years of new greenhouse gas pollution precisely when we must be cutting emissions.
But what if we didn’t need to build new transmission lines or new gas plants to meet our near-term needs? Today, the Department of Energy announced a new set of final rules to reform the transmission permitting process, including one that specifically streamlines environmental reviews for projects that use existing transmission rights of way. That includes, significantly, reconductoring.
New research from UC Berkeley, GridLab, and Energy Innovation shows that reconductoring existing transmission lines with advanced conductors — an industry practice that involves replacing old conductors with higher-performance ones — can dramatically increase the grid’s capacity, save customers money, and cut emissions.
Between now and 2035, reconductoring existing transmission lines can add up to four times as much transmission capacity in the U.S., as compared with building new transmission alone. And this quadrupling of added capacity would require just 20%more transmission investment compared to business-as-usual spending. This would yield massive overall customer savings — roughly $85 billion in avoided costs.
Reconductoring involves re-stringing existing towers with new cable, which avoids the need to identify and permit new pathways for these lines or build new structures. The new cables, referred to as advanced conductors, often use a composite core instead of steel, which makes them stronger and lighter, and use more densely packed annealed aluminum, which allows them to carry more current.
(Note: The renderings on the bottom were used in our figure with permission from Idaho National Laboratory.)
Several utilities, including Nevada’s NV Energy, have already used these new conductors extensively, installing 125 miles of advanced conductors across 25 lines, with another 18 projects in the pipeline. The effort has increased capacity along existing transmission corridors, reduced sag for public safety, and allowed rapid load growth.
Reconductoring existing transmission lines with higher-performance wires is one of the fastest and cheapest ways to add capacity to the existing grid. So why aren’t utilities taking widespread advantage of this opportunity to expand the grid and bring more power online?
Well, they face myriad barriers, including planning practices that fail to prioritize long-term benefits, utility business models that incentivize spending capital over saving customers money, and a lack of knowledge of the technology.
But federal and state governments, as well as utility regulators, can overcome these barriers by embracing policy solutions that explicitly work to deploy advanced conductors.
For instance, state utility regulators can investigate the benefits of advanced conductors so utilities can ensure their investments will be green-lit. State legislators can lend their support to approving these lines. Regulators can improve grid planning processes by requiring transmission planning to occur alongside generation planning. FERC can create independent transmission monitors to objectively review investments by monopoly transmission owners. And both states and the federal government can provide additional funding, and can also collaborate with industry on education and training for utilities on how to work with this technology.
If we get it right, reconductoring can move forward in time to unlock the thousands of wind, solar, and battery projects that our grid desperately needs to protect both customers and the climate. Without it, though, we risk failing to expand the electricity system fast enough to meet decarbonization and clean energy goals — and leaving the excess costs of fossil fuel plants to electricity customers who can’t afford it.
Michelle Solomon is a senior policy analyst in the electricity program at Energy Innovation. The opinions represented in this article are solely those of the author and do not reflect the views of Latitude Media or any of its staff.
