Up to 40 percent of the region's grid could be suitable for reconductoring - for less than half the time and cost of building new transmission lines.

The lights could soon dim on the Northwest's climate goals unless the grid gets some serious TLC.

The region, like the United States as a whole, needs more electric transmission capacity to reach the best wind and solar resources and meet rising power demand without burning coal or gas. But building new transmission lines can take decades and cost billions. Luckily there are no-brainer ways to squeeze more juice out of the existing grid.

Among the options, reconductoring - swapping out the wires on transmission lines for higher capacity ones - holds particular promise for its relative speed to deployment, capacity potential, and cost. Reconductoring can more than double a line's capacity, costs less than half the price of building a brand-new line, and can take just 18 to 36 months to implement.

In the Northwest, up to 23,000 miles of transmission lines (about 40 percent of the region's grid) could be suitable for reconductoring. To get more wire upgrade projects off the ground, policymakers can improve utility planning processes, fast-track permitting, and introduce performance incentives. With most of the region's grid strung up with wires invented more than 100 years ago, a grid glow-up is long overdue.

Reconductoring can double transmission lines' capacity for less than half the cost of building new lines

Why should people who care about climate change pay attention to wires? Here's a quick primer: In sum, the type of wire - conductor - on a transmission line affects how much power it can carry, how much electricity it wastes, and how much it sags. (Sagging lines can spark wildfires.) Swapping out old wires with the latest and greatest technology is far cheaper, faster, and easier than building whole new transmission lines.

For more than 100 years, transmission owners have strung up the same type of wire. Aluminum conductor steel reinforced (ACSR), as it is known, remains the default conductor for most transmission projects in the United States.

In the Northwest, nearly all investor-owned utilities' transmission lines are outfitted with ACSR. (Bonneville Power Administration [BPA], which owns and operates most of the region's high-voltage transmission system, does not provide detailed data about conductor type. However, the vast majority of its lines use ACSR, according to a BPA representative.)

In the 1970s, the industry introduced a new type of conductor known as aluminum conductor steel supported (ACSS). ACSS conductors nearly double the capacity of their ACSR counterparts, but they come with a big downside: excessive sagging at high temperatures. Sag is a particular concern in wildfire-prone areas like the Northwest. Reconductoring with ACSS conductors can require raising structures or placing more towers closer together to meet minimum clearance standards, which increases project costs.

In the 2000s, newer, more advanced conductors entered the market, which traded out the traditional steel core for a smaller composite of glass, ceramic, or carbon fibers. This new lighter core allowed more aluminum (which conducts electricity) to fit on a wire of equal diameter, making it possible to operate the line at a higher temperature. Higher operating temperatures increase a line's thermal limit - one of three possible limits to transmission lines' capacity.

The most promising and widely deployed composite-core conductor is known as aluminum conductor composite core (ACCC). (ACSS trapezoidal wire [ACSS/TW], a more advanced ACSS model, was also introduced in the 2000s.)

Here's an analogy to explain this that will make sense to anyone born before the 2000s, at least: If ACSR conductors are dial-up internet, ACCC conductors are 5G. ACCC conductors double the capacity of ACSR models. They don't sag at high temperatures, and they're the most efficient conductors on the market, meanin...