Why You Should Care About Transmission

Contributed by RNW Staff

If you’ve never thought much about transmission lines, you’re not alone, but a lack of transmission capacity is quickly becoming one of the biggest barriers to a reliable, affordable, and clean energy future.

In this first blog, we break down why transmission matters: how it affects your energy bills, impacts reliability, and holds the key to unlocking clean energy across the Northwest and beyond. Next up, we’ll look at what’s standing in the way, and the solutions and state-level actions that could move the grid in the right direction.

What Is Transmission?

You don’t have to be an engineer or energy professional to care about transmission – your power, bills, safety, and climate future are all on the line (pun intended).

Transmission is often confused with distribution, but here’s a simple way to think about it: transmission lines are the high-voltage interstate highways of electricity, moving power from where it’s generated to substations. Distribution lines are the local roads that carry that power from the substations to homes and businesses.

Transmission is easy to take for granted until something goes wrong. But as electricity demand surges, the cracks in our current transmission system are becoming harder to ignore.

So How’d We Get Here?

Much of the Pacific Northwest’s transmission system was built decades ago, primarily by the Bonneville Power Administration (BPA), to power wartime industries like airplane manufacturing aluminum smelting. BPA still serves a large share of the region’s electricity needs today and owns and operates approximately 75% of our region’s transmission. For years after the huge aluminum smelters left the region, we’ve largely coasted on the hydroelectric power and transmission capacity built in the mid to late 1900s. 

Since we largely didn’t need to make new transmission investments in our region for some time, the focus on new transmission faded into the background. While infrastructure modernization investments were more likely to go toward roads, bridges, and broadband, our transmission lines were largely left behind. And because electricity demand stayed relatively flat, the lack of upgrades and investment in new transmission didn’t ring any alarm bells.

Today, electricity demand is climbing fast, driven by electrification, data centers, AI, and onshoring of manufacturing. That demand surge is exposing a hard truth: our grid simply isn’t ready to accommodate the needs of this new era. We’ve upgraded our cars, our phones, and our thermostats, but we’re still relying on a transmission system built for rotary phones and VCRs. Advances in transmission infrastructure and technology have the ability to greatly increase the capacity of the transmission system, but these investments take time. Time we may not have. 

Now, the bill for decades of underinvestment is coming due.

When Weather Strikes, Transmission Makes the Difference

As our grid ages and demand increases, it's increasingly outmatched by the weather. As intense storms become more frequent, the limitations of our transmission system become clear.

In January 2024, a brutal cold snap hit the Pacific Northwest. As temperatures plunged, households cranked up their heat, sending demand, and energy costs, soaring. Spiking to over $1,000 per megawatt-hour, energy costs in Oregon and Washington were more than 18 times the typical rate, in part because of transmission limits to how much energy we could bring in from the south.  

Meanwhile in Montana, NorthWestern Energy had to import energy from out of state to supply more than half of customers’ demand during the cold snap. The event cost utilities upwards of $14 million… costs which are then passed onto customers’ bills. 

And it’s not just a winter problem. With wildfire threats and hotter temperatures in the summer, plus increasing energy use from data centers and electrified homes, grid operators are facing mounting pressure year-round. Cascadia Daily News reported that because of worsening drought conditions and prevailing wildfire threat this summer, Puget Sound Energy may resort to public-safety power shutoffs (PSPS) to limit risk of potential sparking. Other regional utilities have also implemented PSPS protocols that may be called upon under certain fire-prone conditions. These PSPS events can impact both transmission and distribution systems. 

The challenge is that a PSPS doesn’t just affect the line(s) it’s targeting. In areas where there are only a few major transmission corridors, shutting down one line can ripple across the system, leaving entire regions with fewer options–or even none–to move power where it’s needed. More transmission lines creates built-in redundancy: when one pathway is constrained or shut off for safety, power can reroute through other lines, keeping the lights on and critical services running. But the catch is, those new lines need to be built first.

On top of adding more lines, a modern transmission system makes the existing grid more reliable resilient. Innovations like advanced conductoring can boost the capacity of current lines without building entirely new corridors, while also reducing “thermal sag” – the drooping that occurs when older lines overheat and lose efficiency in high temperatures. With stronger materials and better designs, newer lines can carry more power with less loss, and stay safely aloft even during summer heat waves.

Together, new transmission lines and modern upgrades will help keep energy flowing more reliably, no matter the season.

Your Bills Are Rising Because the Grid Is Stuck

Looking ahead, the Northwest’s electricity demand is projected to double over the next 20 years, which is a level of growth not seen since the region’s aluminum industry boom in the 1980s. Without major transmission upgrades, we risk higher prices due to decreased resource availability, more frequent reliability issues, and missed opportunities to deliver energy where and when it’s needed most. A diverse energy resource portfolio is the most cost effective way to meet rising demand. However, without the needed transmission infrastructure investment, we will not be able to access the same level of cheap, plentiful clean energy from outside our region that we would with additional investment. 

What does that mean for you? Higher energy bills. When there isn’t enough transmission to move electricity from where it's generated to where and when it's needed, low-cost sources (like wind and solar) get bottled up. Utilities are left relying on more expensive options, like firing up older, less efficient gas plants, and overbuilding generation in the region because there isn’t enough transmission to bring in power during peak demands.  

Take Montana for example. With world class wind-resources, it could be an energy powerhouse for the West. But a lack of transmission lines means that energy can’t travel where it’s needed. As a result, Montanans and their neighbors alike are paying more than they should for electricity, not to mention missing out on cleaner power in the process. 

Here’s the good news: investments in transmission pay off. According to a recent report from Clean Energy Grid, every $1 spent on transmission returns up to $4.70 in customer benefits through lower energy costs in addition to improved reliability, economic development, and better access to clean energy.

If we want an energy system that’s affordable and reliable, transmission has to be part of the conversation. So why hasn’t more been built? In the next post, we’ll dig into the barriers, from planning and permitting to paying the bill, and how states can step up and lead the way.