Transmission week: why we need more big power lines

Transmission week: why we need more big power lines


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Hello, Volties, and welcome to Transmission Week here at Volts! It’s been delayed almost as many times as Infrastructure Week, but it’s finally here. All week, we’re going to be digging into the US energy transmission system.

For those of you new to the subject, “transmission system” refers to the big, high-voltage power lines that carry electricity over long distances, usually perched along tall metal towers. To use a road analogy, transmission lines are like the interstate system, whereas lower-voltage “distribution systems” are like the nests of highways and streets that serve local populations.

I’ve always been fascinated by distribution systems, but I’ve never really taken a deep dive into the transmission side of things. Until now!

Sunset on electrical transmission towers near Lancaster, California (Photo: Getty Images)

And now that I have, I understand better than ever why I put it off for so long.

It’s complicated, y’all. There are lots and lots of acronyms, agencies, and obscure policies involved. It’s not the sexiest stuff.

But it’s important. Transmission is one of the key tools to help decarbonize the country and also one of the biggest, most dangerous bottlenecks standing in the way. We (probably) can’t decarbonize at the scale and speed we need without more of it, but laws, rules, and systems designed for a different century and a different electricity system are slowing it to a snail’s pace.

The entire transmission process badly needs attention and reform. And there are signs it may finally be getting some. There’s bipartisan political support for it, along with support from big unions like the International Brotherhood of Electrical Workers.

“I'm excited about transmission,” says Fatima Ahmad, senior counsel for the House Select Committee on the Climate Crisis. “I see jobs benefits, I see bipartisan interest, I see more and more climate policy advocates taking the time to get educated about these issues — all those things make me excited. This is just such a clear next step.”

So here’s what we’re going to do. Today, I’m going to try to convince you that transmission matters: we need more of it, we’re not building it, our decarbonization goals are at risk, but we’re at a moment when real reform is possible.

In the next post, we’ll get into the weeds. Getting a transmission line built requires planning, financing, permitting, and siting, and right now every single step of that process is dysfunctional and constipated. In each case, we’ll look at what Biden can do (through the agencies) and what Congress can do to expedite the process. Expect acronyms.

In the post after that, we’ll look at a related issue: not how to build new transmission lines, but how to improve the existing transmission system with “grid-enhancing technologies.” (Get excited about topology optimization algorithms!)

And finally, we’ll review what we’ve learned and contemplate the political landscape ahead.

It’s gonna be so much fun!


Why we need more transmission

I wrote about the need for more transmission here and here for Vox, if you want to really dig in, but here’s a quick review of the top reasons.

We need more transmission to decarbonize

A group of researchers at Princeton recently did some comprehensive modeling of US decarbonization scenarios. Of the scenarios that achieved net-zero, the one with the least new transmission — the RE- scenario, which includes lots of nuclear power and natural gas with carbon capture and sequestration — doubles US transmission capacity by 2050. In the more renewables-heavy scenario, E+, transmission triples.

Modeling from Dr. Christopher Clack at Vibrant Clean Energy has produced similar results, as have many other studies.

(Graphic: VCE)
(Graphic: VCE)

If the US wants to decarbonize at all, it’s going to have to build the sh*t out of some new transmission.

We need a national energy grid anyway

Despite my road analogy above, the US transmission system is different from its interstate system in one important way: we have a true national interstate network. No matter where you are in the system, you can drive to anywhere else in the system.

The US does not have a true national energy network. Instead, functionally speaking, it has three transmission grids: the Eastern Interconnection, the Western Interconnection, and ERCOT (a Texas grid, basically). Though there are a few small ties between them, very little energy is exchanged. They mostly operate in isolation.

(As you can see from all the labels below, the Eastern Interconnection is divided up among several functional transmission regions, but they are all connected to a common physical grid.)

NERC grid map

This is goofy. Linking them together with high-voltage direct current (HVDC) lines — i.e., creating a true national energy network — would allow them to share, exporting energy when they have oversupply or importing it when supply is stretched. Early morning solar in Arizona could go to New York at the peak of its afternoon demand. Evening wind power in North Dakota could go to California when everyone is turning on their big screen TVs.

Generally, with grids, the bigger and more interconnected they are, the more efficient, reliable, and cost-effective they are. To wit: a 2016 study by scientists at NOAA found that a national HVDC network would save US consumers $47 billion annually. The Interconnections Seam Study by the National Renewable Energy Laboratory (NREL) — a study the Trump administration tried to squash — found that every $1 invested in a national HVDC grid would return $2.50 in economic, environmental, and social benefits.

A national grid (with the appropriate cybersecurity and resilience measures) would allow the US to make the best possible use of its domestic clean-energy resources. It’s a no-brainer.

(By the by, China is in the midst of plowing $26 billion into a national network of ultra-high voltage lines — UHVDC — to carry renewable energy across the country.)


We need to connect remote renewables to population centers

The areas in the US where sunlight and wind are most intense (the desert Southwest and the Midwest corridor, respectively) are distant from the metropolitan areas (mostly along the coasts) where there is most demand.

To make use of that remote renewable energy, we need transmission lines much longer than most that were built in the age of fossil fuel electricity, when plants could be built close by. Those long HVDC lines will require sophisticated new technologies and unfamiliar planning processes. Right now, we’re stuck in a chicken-and-egg problem: renewable energy developers are hesitant to build, not knowing whether they’ll be forced to pay for expensive new lines; transmission developers are hesitant to build, not knowing whether there will be generators to fill their lines.

Someone (spoiler: the federal government) needs to come in and break up the logjam to get things moving. There’s a huge pool of clean, domestic American energy waiting to be tapped.

We need to prepare for clean electrification

Among today’s US energy wonks, it is now fairly widely agreed that the fastest, cheapest, and possibly only route to large-scale, near-term decarbonization is through clean electrification. That means, first and foremost, transitioning to a net-zero-carbon electricity grid. But it also means shifting most transportation and heating/cooling off of liquid fossil fuels and onto electricity.

Large-scale electrification will dramatically increase demand for electricity — close to 40% by 2050, by some estimates.

(Graphic: NREL)
(Graphic: NREL)

It will also change the location and timing of energy demand, in ways that will change where and when the grid is stressed.

A plan to decarbonize the US must involve looking forward, anticipating those changes, and planning the transmission system around them.

We need to relieve grid congestion

Even transmission wires of modest length can help relieve congestion in regional grids and make them more efficient and cost-effective.

Currently, congestion is a major problem, and it’s creating a nightmare for new renewable energy projects in some regions. A recent report from Americans for a Clean Energy Grid (ACEG) found that, “at the end of 2019, 734 gigawatts of proposed generation — 90 percent of which are new wind, solar, and storage projects — were waiting in interconnection queues nationwide.” Not all that proposed generation would be built, even in the best of circumstances, but it’s still an enormous backlog of projects waiting to connect.

Here’s a map of grid congestion in the territory covered by the Midcontinent Independent System Operator (MISO). The areas in orange and red are already overloaded (as of 2018).

(Graphic: Sustainable FERC Project/MISO)

A recent analysis by the Natural Resources Defense Council’s Sustainable FERC Projectwell-covered by Kari Lydersen for Midwest Energy News — found that “245 clean energy projects that had reached advanced stages of development were withdrawn between January 2016 and July 2020,” mainly due to grid congestion and the resulting high costs of grid upgrades. That’s an enormous amount of clean energy — and work on the part of renewable energy developers — down the drain.

The graph below shows the amount of different kinds of energy waiting in interconnection queues from 2014 to 2019 — as you can see, both solar and wind are spiking. We’ve got more and more clean energy just waiting around to start sending electrons.

(Graph: ACEG)
(Graph: ACEG)

Unclogging those queues requires, among other things, building more transmission.

Remember that study by the NOAA scientists? It also found that a national energy grid would allow the integration of 523 gigawatts of new wind and 371 gigawatts of new solar. (US total electrical capacity is around 1,200 gigawatts, so those are not small amounts.)

So: new transmission would help integrate renewable energy, reduce greenhouse gas emissions, reduce electricity costs, and relieve congestion. It’s national infrastructure that creates jobs and repays upfront investment many times over. We can’t hit our national decarbonization goals without it.

It is good. We should build more of it.


State and local resistance is constipating the national energy grid

I’ll go into this in more detail in the next post, but the root of the problem for transmission in the US is local resistance.

For natural gas, the federal government can step in, permit a pipeline, and seize land via eminent domain. It does not have that authority when it comes to transmission lines (except in some special cases). In the US, transmission siting is controlled by states. The process is a bureaucratic marathon subject to parochial objections and ridden with veto points at every stage.

That’s why, even as the consensus around the need for new national transmission has been strengthening for decades, the US has continued … not building much. We have been under-investing in transmission for decades. Check out how electricity demand outran transmission expansion from 1988 to 2009:

From a presentation by Karl Stahlkopf of EPRI, University of Wisconsin October 20, 2000.
From a presentation by Karl Stahlkopf of EPRI, University of Wisconsin, October 20, 2010.

Texas broke the mold by building a bunch of transmission to connect renewables through its Competitive Renewable Energy Zones (CREZ) program in the 2010s, but the rest of the country hasn’t followed suit. Some shorter local lines are getting built, some lines that are underwater (and thus free of local landowners), but in terms of long-distance, high-voltage lines, there’s been basically bupkis.

(In his book Superpower, journalist Russell Gold tells the story of Houston entrepreneur Michael Skelly and his company Clean Line Energy Partners, which had grand plans to build a national network of HVDC transmission lines — plans that were largely frustrated.)

And so, overall, the US transmission system is as janky and outdated as the rest of its infrastructure.

There are some positive signs, though. Biden is choosing smart people to lead the agencies that will have a hand in transmission, there’s broad public and political appetite for Green New Deal-style infrastructure spending, and advocates have begun a coordinated push to get the issue some attention — see, for example, the Macro Grid Initiative, a co-production of the American Council on Renewable Energy (ACORE) and ACEG. In its recent comprehensive report, the House Select Committee on the Climate Crisis included a whole detailed section on “moving toward a national Supergrid.”

The top recommendation in all the reports I’ve read is simply that transmission be made a national priority. The president needs to affirm via executive order — and preferably Congress by legislation — that federal agencies will cooperate to develop and implement a comprehensive plan for a national transmission grid.

That’s the big picture. On our next episode of Volts, we’ll dig into the specifics of what Congress can do, and what Biden can do without Congress, to get the process of building a national energy grid unconstipated.

Mabel is already bored. (Photo: Jennifer Roberts)
Mabel is already bored. (Photo: Jennifer Roberts)
Volts is a podcast about leaving fossil fuels behind. I've been reporting on and explaining clean-energy topics for almost 20 years, and I love talking to politicians, analysts, innovators, and activists about the latest progress in the world's most important fight. (Volts is entirely subscriber-supported. Sign up!)