Can Technology Solve Our Transmission Problems?
Maybe, but we’ll need a little policy and alignment of incentives to make it work.
This week’s blog is co-authored with Emilia Chojkiewicz and Amol Phadke
The United States needs to up its transmission game. Last fall the US DOE issued a study indicating that a high electrification and renewables generation future needs at least a doubling of the regional transmission capacity we currently have – by 2035. But we aren’t building nearly fast enough to get there. We’ve been expanding transmission capacity at a rate of one percent per year in the last decade. The DOE study suggests we need something closer to 7 percent per year.
Meanwhile, by the start of 2023, developers had submitted applications to connect nearly 2,600 gigawatts of total generation and storage capacity to the grid, and those applications will sit in queues for years as transmission operators study what transmission upgrades, if any, are needed to accommodate new projects. There have been some heroic efforts on the part of FERC and transmission planners to help projects get out of these queues more quickly, but without much needed transmission upgrades, even if they get processed quickly, the huge majority of these projects will exit the queue through the failure door, rather than by getting built.
A technology solution?
It may seem that building new transmission capacity and clearing the interconnection queue isn’t so much a technology problem as it is a societal one. EI blogger Lucas Davis called this “Transmission Impossible,” and his paper with Catie Hausman and Nancy Rose talks about challenges stemming from fragmented utilities, cost allocation, and siting and permitting. But in Mission Impossible, Tom Cruise saves the day with exploding gum, metal-eating foam and voice changers. Can’t we invent fun technologies and gadgets to resolve our transmission woes?
It turns out that some of these technologies do exist – though they’re not exactly Hollywood movie stuff. They’re often put in a broad category of ideas called grid enhancing technologies, or GETs. Some GETs involve changes to how the grid is operated, like dynamic line ratings, power flow controllers, and switching lines in and out. However there’s one idea that involves upgrading transmission to permanently increase its capacity. It begins with the humble transmission wire, (a.k.a., a conductor).
For obvious reasons, we want our transmission wires to be low in resistance. Copper would be a natural material to use if that was all we cared about. But it turns out that copper can’t support its own weight very well. Instead, the technology of choice over the last century has been aluminum – lightweight, strong, with relatively low resistance – with a steel core for added strength. See the figure on the left below to get an idea of what this looks like.
But there’s a newer transmission technology that replaces that steel core with a composite, such as carbon fiber; see the figure on the right above. Composite cores are lighter and stronger, and that allows the conductor to use a different kind of aluminum with lower resistance. The real game changer with these advanced conductors is that they don’t sag as they get hot. That means they can handle more current flow – two times or more – than other technologies.
The opportunity
In the US, these advanced conductors have mainly been used in niche applications, like river crossings with long spans between towers. But in other parts of the world, most notably Belgium and the Netherlands, utilities have started taking their existing transmission rights of way, scrapping the old conductors, and replacing them en masse with these advanced conductors. This process takes a matter of months, can often be done with a maintenance permit, and once the substations they’re connected to are upgraded, it doubles the capacity of the line. Although advanced conductors cost more than conventional ones, increasing capacity in this way costs less than half as much as building a new line, because the advanced conductors avoid the need to get access to new land (right of way, or ROW) and build new towers. See the figure below.
Last December we and our co-authors published an EI working paper that asked the question: What if the US followed the lead of these other countries, and used advanced conductors in more than just niche applications? Could it make sense to reconductor much more than we are now?
The answer is a full-throated yes. Our results, which used a modified version of NREL’s ReEDS capacity expansion model, indicate that advanced reconductoring could save the US $85 billion on generation and transmission combined by 2035. Importantly, we found that reconductoring enables more spending on transmission (since it can be deployed faster than new rights of way), and access to lower cost generation (for example, by making cheap midwestern wind more accessible).
There must be a catch, right?
You may be wondering: if it makes so much sense, why aren’t we doing it already? Last month our colleagues at GridLab and Energy Innovation published a policy report that investigates this question.
Many of the barriers they identified echo Lucas’s barriers to conventional transmission expansion: Planning, permitting, institutions and incentives. But the scale of these problems is much more manageable than in the case of conventional transmission expansion. For example, a key planning barrier to advanced conductors is not having a workforce familiar with the technology. But as workforce development issues go, this one’s pretty easy to deal with. Advanced conductor manufacturers have outreach teams to train crews. Another example, related to permitting, is that environmental review can get triggered when companies want to reconductor, but that issue got resolved in a recent update to the National Environmental Policy Act.
The GridLab-Energy Innovation policy report also talked about policy solutions. Again, compared to conventional transmission capacity expansion, advanced reconductoring policy solutions tend to be much more tractable and concrete. For example, the Feds could develop investment tax credits to cover advanced reconductoring projects, and they could channel more IRA and Bipartisan Infrastructure Law funding toward the technology. State regulators like those in Montana can ensure that the full suite of benefits – including avoided costs of new transmission – are considered when advanced reconductoring is proposed by transmission builders.
In fact, one of the policy recommendations in the report has already been adopted by Biden et al, suggesting that advanced reconductoring policy can get developed at light speed. The report proposes setting a national target for increased transmission capacity by 2030. Just a few weeks after the report was released, the White House announced a target to upgrade 100,000 miles of transmission lines in the US in the next five years, citing advanced conductors as one of the key ways to achieve that upgrade.
Transmission and generation tradeoffs
Our results show that assumptions about transmission – including how quickly it can be built and whether or not reconductoring will play a role – have important implications for what generation is best in a least-cost scenario. As we mentioned above, we found that by investing more into transmission (enabled by advanced reconductoring), a cheaper generation portfolio is possible.
However, transmission and generation planning processes make it difficult to take advantage of these kinds of synergies between transmission and generation siting decisions. Transmission plans are often based on anticipated generation needs, rather than the other way around. This made sense in the days when generation build costs dominated the cost of new transmission, and when there was flexibility in where to put coal and gas plants. It’s no longer the right way to think with extremely low cost wind and solar.
Planning really ought to trade off the cost to build new transmission capacity with the cost to build new generation capacity. This is starting to happen in California. For example, the CAISO’s Draft 2023-24 Transmission Plan highlights a process for coordination between the CPUC, CAISO and CEC on transmission and resource planning. This works as a starting point.
However our results indicate there are benefits to re-stringing massive swaths of the US transmission system. That won’t happen if we follow the current “piecemeal” planning process (FERC’s word, not ours). This suggests that planners need to consider a scenario with large-scale reconductoring, along with what generation resources make the most sense in that case, rather than in a case with incremental buildout of individual transmission projects.
There are reasons for hope that more large-scale reconductoring could start happening soon. One is the White House announcement we mentioned above. There are also a number of active bills (e.g. here, and here) in California that aim to grease the skids for advanced reconductoring. And DOE’s GRIP program just received a slate of proposals to support transmission projects, and at least one of them included a request to support 400 miles of advanced reconductoring in California (full disclosure: we are participants in that proposal).
Fixing the interconnection queue?
It may be that we can leverage the rapid deployment and low cost of advanced reconductoring to directly address the interconnection queue. If transmission owners that serve substations and regions with a large number of projects in the queue upgrade their lines and substations now, they could recover the cost of reconductoring and substation upgrades with a flat fee ($/kW) charged to any project developers that connect there. Something similar has been happening in Sweden (brush up on your Swedish or turn on Google Translate for that link!) for years. In this case, network companies can opt for grid upgrades that are more expensive than the present need, get loans to pay for it, and pay off those loans from payments made by users in proportion to subsequent utilization.
Reconductoring And, not Or
Advanced reconductoring isn’t a silver bullet. Though we are bullish on it, it’s important to note that our results showed that the US needs to keep building new transmission as well. There are also a number of unknowns about advanced reconductoring in the US that need more study, like stability of power flow on longer lines, managing contingencies, and when, and for how long, lines can be taken out of service to do the work (incredibly, a crew of line workers in Texas did a reconductoring project with live wires). There is room for researchers like us to work on these questions, but we’d like to see transmission planners and owners take them up as well.
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Suggested citation: Duncan, Callaway. “Can Technology Solve Our Transmission Problems?” Energy Institute Blog, May 6, 2024, https://energyathaas.wordpress.com/2024/05/06/can-technology-solve-our-transmission-problems/
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Duncan Callaway View All
Duncan Callaway is a Professor of Energy and Resources at UC Berkeley with an affiliate appointment in Electrical Engineering and Computer Science, and a Faculty Scientist at Lawrence Berkeley National Laboratory. He is also a Faculty Affiliate at the Energy Institute at Haas. Before Berkeley he was a research scientist at the University of Michigan. He also spent time working on building energy efficiency, at Davis Energy Group, and designing solar PV systems, at PowerLight Corporation. He teaches classes on electric power systems and data science for energy. His research group focuses on emerging energy technologies by quantifying their impacts on power system operations and developing control, optimization, and data analysis tools to facilitate their integration into power systems.
Energy Institute Blog 
Some new bill touting a plan for a Western Regional Grid seems to appear in Sacramento on a biannual basis. Some believe it would be environmentally-friendly, the idea being “when it’s sunny in California, we can sell clean electricity to Nevada!”, or “We can make our grid more resilient during hot summer months by importing clean electricity from Arizona!”. Yet it has always been voted down, for at least two good reasons:
1. When it’s sunny/hot in California it’s usually sunny/hot in Arizona, Nevada, and Oregon, too. Those states don’t want or need our extra electricity – so we ending up selling it to them at “negative prices”, a renew-phemism for “paying them to take it off our hands.” And if you don’t think California prices are already high enough, you have too much money (if a problem, you can always sell it to me at negative prices).
2. There is no reliable way to identify the provenance of electricity on a multi-state grid. Though a popular assumption is that we’ll only import clean electricity, the SCOTUS decision in Hughes v. Talen Energy Mktg., LLC (2016) determined requiring environmental attributes in electricity constitutes discriminatory pricing, and was thus a violation of the Commerce Clause. Wholesale electricity on a common grid, decided justices, must be sold at auction for fair market value. Though holding a separate auction for clean electricity would solve the problem, it would require building another trillion-dollar grid to carry it.
Thus in the age of climate change awareness, the belief it’s possible to join the grids of multiple states, while meeting environmental goals unique to each, is pure fantasy. Berkshire Hathaway’s PacifiCorp subsidiary will be dumping dirty coal-fired energy from Wyoming onto the grid – and if it’s cheaper than our solar (or even our gas-fired electricity) we’ll be obligated to buy it.
Yet progress on regionalization continues apace. In 2023, eleven U.S. states and two Canadian provinces signed papers for a West-Wide Governance Pathway Initiative to set the wheels in motion.
https://www.westernenergyboard.org/wwgpi/
Though the Initiative reportedly enjoys wide support in both California’s Public Utilities and Energy commissions, it would be an environmental disaster.
California accounts for out of state GHG emissions separately from the CAISO market transactions. The system has its problems with emission leakage, but it works relatively well. This blog has posted several studies on that leakage. A CARB presentation explains how this works: https://www.caiso.com/InitiativeDocuments/CARBPresentation-ElectricitySectorGreenhouseGasAccounting-EDAMWorkingGroup%203-Feb152022.pdf
Great work! A new thing to learn. I’ll look for more details on advanced reconductoring for transmission planning. Transmission seems to be a universal issue, not just in the state. Thanks.
Unfortunately, the real incentive working against this solution is utility shareholders’ profit motive. The current regulatory system provides a 10% or more guaranteed return on each dollar of capital investment for shareholders. A solution that reduces the need for capital investment also reduces shareholders’ long term profits. And the utility labor unions, who are exceedingly influential (see a recent quote from California’s IBEW lobbyist about their success in Sammy Roth’s LA Times column this week) see less work and less income. Why cut off the gravy train?
While I believe the “profit motive” dynamic is worth noting, I don’t think that it in any way dooms the Garcia and Padilla reconductoring bills that Duncan provided links to. He also testified in support of the Garcia bill in the Assembly U&E Committee last month, where the bill passed unanimously — and the same is true for the Padilla bill in the Senate Energy Committee.
Both of these bills will be on the Suspense Files in their respective appropriations committees. I’m strongly inclined to think they both will be passed in appropriations and then each will make it to the other house for consideration. Yes, IBEW is powerful, but the only opposition listed to the Garcia bill was from the CS&SA (and none was listed for the Padilla bill). Stanger things have happened, but I don’t envision IBEW or the IOUs opposing these bills in their second-house hearings given that they’ve not expressed any opposition so far. There could be amendments that change that, but I just don’t see the so-called “gravy train” derailing these bills. As Duncan acknowledges, there are “a number of unknowns” that could throw a wrench in the reconductoring process, but the potential for very positive outcomes looms large.
I hope so! Those are good bills.
I do read a lot of positive reactions on reconductoring, so I am optimistic. There was an interesting comment from SDGE saying something like “we would like to do reconductoring but the PUC does not let us do it”. So, maybe this will happen.
I’m unfamiliar with the legislation. What is the Legislature gong to require? The biggest problem I see is that the focus of this reconductoring is on transmission which is regulated by FERC, not the CPUC, so I’m not sure what leverage state law will have.
FERC, CEC and DOE are all pushing for reconductoring.
This is the Padilla bill – https://www.billtrack50.com/billdetail/1694599/
Thanks for the link.
Requiring a “plan” is the utilities’ way of diverting any real enforcement away from their current MO. The transmission corridor law passed two decades ago and the distribution planning rulemaking a decade ago have had very little impact on T&D planning to date.
As a member of the IBEW I would like to tell you running new lines is hard work far from home, but someone has to do it. Large industrial and utility work is all done with UNION labor with the skills to get the job done right. I personally agree with rooftop solar, mostly done Non-Union, is a good idea to keep more power available to industrial companies that hire us UNION people. The IBEW stance against rooftop solar is only because it is not “their work” in California since a separate classification was made to rooftop solar contractors rather than using Electrical Contractors and the national Electrical Contractors Assocation could allow IBEW member to do the work in. Utilities also hire only IBEW members, and those utility scale projects create hundreds of jobs. I have rooftop solar, and it is great under NEM2.0. NEM 3.0 is destroying the demand for Rooftop solar since it will take a lifetime to get enough payback from the investment and most people stay in their homes in California for only 7 years before moving up or moving on to other states.
Reconductoring is indeed a huge leap forward for our industry. After all, ACSR technology is a century old — about time somebody builds a better mousetrap. Think about the thermal power plants with 20% fuel conversion efficiency that ACSR was built to serve!
I do wonder about how this affects reliability planning. Currently a single 500 kV circuit may carry 1,500 MW of power. With upgraded conductors, that becomes 3,000 MW or more. If that circuit were to fail suddenly, either a parallel path needs to cover that contingency, or else generators and batteries at the destination need to cover that contingency.
If we are reconductoring the parallel pathways at the same time, maybe that works. If we are installing storage and shaping technology sucd as batteries, load shedding (think smart EV charging and ice storage air conditioners, not blackouts), maybe that works. I hope so.
Jim Lazar, Olympia
Getting these transmission lines looks like an expensive proposition. Especially when one uses exotic cabling and other impedance reducing technologies. the ratepayer is really going to be paying a lot for this.
Too bad there isn’t a technology that supplies energy at the site where the energy is needed, that would obviate the need for new transmission lines. Something that doesn’t cost the ratepayer anything, something that is available today, right now, off the shelf.
Oh, wait, that technology, with all the features just described, particularly the “doesn’t cost the ratepayer anything” is already available. It’s called “rooftop solar”
Some lame research and a spreadsheet can show that rooftop solar can supply 80% of California’s energy needs. Yup, we need “garage storage”, too.
This technology is being made unavailable by the CPUC because it has ignored the public, receiving input only from the utilities
… blah … blah … blah! You already know all of this. It has been proven (proof) that rooftop solar provides retail energy. A corollary to this proof is that rooftop solar increases reliability and reduces stresses. But the likes of the people that write articles like this one refuse to believe it.
Of course you don’t believe it because your livelihood depends on the utilities. The utilities’ business model is perpetual construction. You know this, too. Look, at some point the resources, which are finite, will be depleted. In other words, the year-over-year growth is physically impossible.
Please, I’m a technical person; I totally understand what’s written here; it’s cool stuff, but it is pure and simple antisocial avarice.
OSD
Thank you, Surfer Dude. I had both off grid solar and lead acid batteries and grid tied Tesla Solar Roof and both worked equally well to power my home. Off grid required batteries that had to be replaced every 6 years, but it was still cheaper per kilo watt hour than the charges PG&E charges. If the utilities offered a 2 for 1 storage but allowed rooftop solar to produce double the annual usage, then the rooftop solar would still thrive and the utilities would have enough generated power to supply neighborhoods during daylight hour and still make a profit. If lithium batteries ever come down in price to the same equal value of lead acid batteries, utilities would only be back up power for homes leaving the energy for EV charging, government and industry and fancy transmission lines would not be needed. Keep telling it Surfer Dude. 1.3 million Californians with rooftop solar are with you.
Thanks for the post, Duncan.
I’d love to read about the role that advanced conductors can play in the distribution grid. I’ve noticed that some of the vendors now have solutions for the smaller voltage (CTC Global for example).
TIA.
1: We ‘always’ design for PEAK demand/ use, and the utilization is well below that ‘most’ of the time. [the ‘. ‘ indicates an ‘assumption’ on my part]. Why not have ‘congestion pricing’ [variation on ToU].
2: it ‘seems’ to me that last-mile issues are dealt with and frequent public transportation were enhanced we might have a more sustainable solution. Short of ‘less usage’