top of page
  • Writer's pictureGwendolyn Dane

Transmission Systems: The Key or the Thorn of the Energy Transition?

Written By: Gwendolyn Dane

Edited By: Sofia Tryfonopoulou

Sunlight breaks through a cloud in the mostly blue expanse of California sky, and streams down, hitting a strategically placed photovoltaic cell. Thousands of miles away, a lightbulb in snowy New York flickers and turns on, powered by the electricity generated by a sunbeam across the country.

This isn’t the reality yet. But it could be--if we expand and upgrade existing transmission systems to carry renewable electricity across entire nations. Countries around the world have come to terms with the importance of building our capacity to transport electricity further and faster, in the pursuit of ending our reliance on greenhouse-gas-emitting fossil fuels. China is in the process of building a cutting-edge ultrahigh-voltage power grid connecting the regions which produce its clean energy to major cities on opposite ends of the country, with talk of potentially expanding to Europe (Fairley, 2021). The US has allocated billions of dollars from its recent infrastructure bill with the goal of enhancing transmission infrastructure (Christian, 2021). So why is this normally overlooked (and even boring) sector suddenly at the forefront of the effort to combat climate change? Before diving into the answer, it’s important to understand the nature of renewable energy sources, including their capabilities and limitations.

It may seem counterintuitive to expand our network of power lines when the most glaring approach to reducing our reliance on fossil fuels seems to lie in producing more clean energy. This is the argument made by those who believe that placing solar panels on everyone’s roof, and wind turbines in front yards will solve our problems (Penn et al., 2021). But think about the scenario outlined in the first few sentences of this article: a snowy day in New York won’t produce much power regardless of the number of rooftop solar panels in place, while California can rely on steady supplies of sunlight year-round. And when the sun does set, California may not be able to meet its own power demand, while windy places like Wyoming will be making far more than its market needs. What are the solutions to electricity generation in conditions where renewables like wind and solar aren’t an option? We call this problem ‘intermittency,’ and today we mainly get around it by relying on alternative energy sources like hydropower, or in many cases, natural gas and coal. This is an issue, because the combustion of fossil fuels releases previously sequestered carbon dioxide and methane into the atmosphere, trapping more of the sun’s heat and driving climate change.

Intermittency is a complex problem, but at its very core it comes down to the reality that we don’t currently have the technology to store solar or wind power on a large scale. This is a challenge unique to renewables, as fossil fuels stay concentrated in the form of natural gas, petroleum, or coal until we’re ready to burn them. As a result, we have to use the energy produced by the sun when it's shining or the wind when it's blowing, and we can’t save much for later. This becomes a significant issue when we try to rely solely on these power sources: picture all the energy that goes to waste at noon when the sun is shining at its brightest but demand is low because consumers are congregated in workplaces or schools. Then, imagine the problems that arise when it gets dark in the evening but everyone is at home using individual heat sources, lights, and other appliances (to cook dinner for example). Many of the proposed solutions to intermittency involve innovating ways to store large quantities of renewable power for extended periods. However, even the most advanced utility-scale lithium batteries today can only hold solar energy for about four hours (Office of Energy Efficiency and Renewable Energy, 2019). Upgrading our transmissions system is an alternative that uses only existing technology, but is often overlooked--a case which may be about to change.

Driving down the highway, it’s likely you don’t notice the huge metal towers with wires strung between them. Their steel lattice forms stick out from the natural landscape like so many Eiffel towers—if the Eiffel was shorter, ugly, and less attention-grabbing. But these hydro towers, as they are sometimes known, could be part of the transition away from our global reliance on carbon-emitting fossil fuels. Their job is to carry electricity from the power plants where it is generated across long distances to where it is demanded (EIA, 2021). This allows cities, factories, and other end-users of electricity to sit far away from the greenhouse gases and other harmful pollutants emitted by fossil fuel power plants. It is also what allows consumers in Canada to purchase and use hydropower, even if they don’t live directly next to a hydroelectric dam. However, there are limits to how far these transmission lines can carry power. Transporting electricity over any distance causes some proportion to be lost as heat, but this proportion grows dramatically if the current increases--a risk that can be avoided by increasing voltage (Brown, 2004). Basically, the lower the voltage and the further the distance, the more energy is lost. Infrastructure based on more recent technology is capable of transmitting large amounts of power at very high voltages, and is therefore much more efficient at covering long distances than older lines.

We have come a long way from the 19th century’s low-voltage transmission systems that required electricity to be generated as close as possible to where it was used, but most lines are due for another major upgrade in order to meet the requirements of a fully renewable power sector (Brown, 2004). A report published by American Clean Power and Wood Mackenzie revealed that 70% of our transmission lines are over 25 years old--a clear indicator of just how much will need to be invested in improving the capacity and reach of existing systems (Wood Mackenzie, 2021). The country’s three existing grids are disconnected and old, factors which work in tandem to exacerbate risks posed by more frequent and unpredictable weather extremes. Results of the Net-Zero America project, an in-depth study conducted by Princeton University, also suggest that the United States will need to undergo a massive expansion in its transmission system in order to reach net-zero emissions by 2050, effectively tripling it within the next thirty years (Seltzer, 2020). We need to be able to carry greater quantities of renewable energy further, which will require sending it at higher voltages to minimize losses (The China Electric Power Research Institute, 2018). New transmission lines with this capability must be built, and older ones need to be upgraded to increase their capacity and ability to withstand climate change.

So, what will it take to accomplish this major update? The short answer is time, money, and an overhaul of existing policies. Beyond the billions that must be spent on construction, there are many forces working against those who want to build new transmission lines, especially in the US. Utilities must get permission from each individual state that lines would pass through, a process which involves currying favor with staunch environmentalists and residents who argue against the negative impacts of towers on ecosystems and aesthetics respectively (Eto, 2016). Getting approval can take years, if it happens at all. Lawsuits from competing utilities who don’t want to share the market add an additional economic component which further complicates the process (Cicala, 2021). A partial response to growing calls to streamline this process, the bipartisan infrastructure bill proposed by the Biden administration and recently passed by the House is an attempt to eliminate or ease some of these obstacles. Of the $73 billion allocated directly to transmission infrastructure, $10-12 billion is earmarked for building new infrastructure. Another $2.5 billion is included for the Department of Energy to kickstart construction of new transmission lines, and tax credits will also work to incentivize private-sector expansion. In order to speed up the permitting process, $800 million is dedicated to compensating communities for the local impacts of construction, as long as they agree to reach a decision within a two-year period. Finally, the bill clarifies the authority given to the Federal Energy Regulatory Commission (FERC), allowing it to overrule states when necessary to build transmission facilities (Temple, 2021). All of this is a step in the right direction. But it is not nearly enough, at least according to the same Princeton study referenced earlier. The US is forecasted to need an extra $300 billion in investment over the next decade to sufficiently expand its transmission systems, compared to a business-as-usual scenario (Seltzer, 2020). In addition to financing, some have argued that FERC should be given far more authority to oversee the entire permitting and construction process, given that the Commission already does so for natural gas pipelines (Meyer, 2021). This would allow utilities to build new lines with only FERC’s approval, a much quicker process that allowed natural gas companies to build over a hundred thousand miles of pipelines in the decade leading up to 2019-- a period in which zero miles of ultrahigh-voltage transmission lines were completed (AGA, 2019).

Ultimately, it’s clear that the US infrastructure bill represents progress, but it's not enough on its own. In the coming decades, demand will grow for renewable energy, and this will need to be met somehow--whether it is through many smaller, distributed energy resources, or a single grid spanning nations. The myriad benefits of a larger, more connected network make it a practical solution, but governments must find the funding and political support necessary to expedite the construction of such a system. Other nations like China provide a glimmer of hope for a future where variability is no longer a concern and renewable energy sources can meet demand nationwide, but they also represent an example of the enormous investment and political consensus that will be needed to make such expansion a reality (Fairley, 2021). A major challenge will lie in convincing those in power that the benefits of more reliable power and reduced dependency on fossil fuels outweigh the high upfront costs of such an investment. According to today’s models, it’s evident that prioritizing the shift from fossil fuels to renewable sources is a necessary component of the fight against climate change, and we must be willing to deploy all the tools at our disposal to achieve it. Quite likely, one of these will be building the capacity to send sunbeams around the world.

Works Cited

AGA, Distribution and Transmission: Gas Industry Miles of Pipeline and Main by Type. American Gas Association. (2019). Retrieved November 9, 2021, from

Brown, M. H. (2004). Electricity transmission: A Primer. National Conference of State Legislatures.

Christian, M. (2021, October 7). Infrastructure bill aims to solve piece of US transmission puzzle. Accelerating Progress. Retrieved November 9, 2021, from

Cicala, S. (2021, June 2). Decarbonizing the U.S. economy with a National Grid. Energy Policy Institute at the University of Chicago. Retrieved November 9, 2021, from

Eto, J. H. (2016). (rep.). Building Electric Transmission Lines: A Review of Recent Transmission Projects (pp. 1–28). Berkeley, CA: Ernest Orlando Lawrence Berkeley National Laboratory.

Fairley, P. (2021, July 29). China's ambitious plan to build the world's biggest supergrid. IEEE Spectrum. Retrieved November 9, 2021, from

Meyer, R. (2021, July 28). Unfortunately, I care about power lines now. The Atlantic. Retrieved November 9, 2021, from

Office of Energy Efficiency and Renewable Energy, Solar-Plus-Storage 101 (2019). Washington, DC; US Department of Energy.

Penn, I., Krauss, C., & Kalifa, T. (2021, July 11). More power lines or rooftop solar panels: The fight over energy's future. The New York Times. Retrieved November 9, 2021, from

Seltzer, M. (2020). Big but affordable effort needed for America to reach net-zero emissions by 2050, Princeton Study shows. Princeton University. Retrieved November 9, 2021, from

Temple, J. (2021, August 6). The $1 trillion infrastructure bill is a baby step toward the US grid we need. MIT Technology Review. Retrieved November 9, 2021, from

The China Electric Power Research Institute (Ed.). (2018). General. In UHV Transmission Technology (pp. 3–20). essay, Academic Press

U.S. Energy Information Administration. (2021). Delivery to Consumers. U.S. Energy Information Administration (EIA). Retrieved November 9, 2021, from

Wood Mackenzie. (2021, May 6). (rep.) Renewable energy and infrastructure policy scenario analysis. ACP. Retrieved November 9, 2021, from


bottom of page