November 10, 2026

Transmission is the green transition's greatest bottleneck

by Al-Amin Bugaje, Ph.D.

A graphic of a transmission tower with lightning coming from the top and a series of images of solar panels and wind turbines

Key Takeaways

With solar and wind now beating fossil fuels on price, the bottleneck for solar and wind adoption has shifted from generation economics to transmission infrastructure.
As of 2025, over 2,060 gigawatts of clean energy – nearly double the current installed capacity – waits in interconnection queues in the United States.
Interconnection timelines have ballooned from under two years in 2008 to nearly five years today.
Texas saved consumers an estimated US$31.5 billion between 2010 and 2022 by investing in grid infrastructure.

Powering our planet with renewable energy is crucial for stopping climate change, as the electricity sector accounts for more than 23% of global greenhouse gas emissions. Over the past decade, efforts to clean up the sector have focused primarily on lowering the cost of wind and solar power to accelerate their adoption. Today, solar and wind generation cost as much as – or in some instances less than – fossil fuels. As the cost of building renewables continues to fall, the primary bottleneck in the energy transition has shifted from generation to transmission. In other words, we have the power; now we need to move it.

A reality of renewables is that the best places to build wind and solar are rarely near the largest sources of demand. For instance, in the United States, the best onshore wind resources are concentrated in the Great Plains, far from coastal population centers and industrial hubs. Similarly, the highest-quality solar sites sit in the deserts of the Southwest, hundreds of miles away from consumption clusters in major cities.

In the same way that batteries can provide energy storage across time for when the sun isn’t shining or the wind isn’t blowing, well-connected transmission infrastructure can act as storage across space, allowing surplus electricity to shift dynamically from one place to another to meet real-time energy demand.

Unfortunately, the gap between how much energy we can produce and how much we can move continues to widen. As of 2025, U.S.-based transmission operators reported more than 2,060 gigawatts (GW) of proposed generation and storage that are waiting to be connected to the grid. That’s nearly twice the power the country can currently generate just waiting for transmission, with renewables and battery storage making up over 80% of stalled projects.

And the lag time between requesting to be hooked up to the grid and actually starting operations is getting longer, stretching from under two years in 2008 to nearly five years today. Just 19% of projects that requested grid connection between 2000 and 2020 had reached commercial operation by the end of 2025. The vast majority withdrew or were delayed into nonexistence.

This backlog stems from a decade-long failure to align transmission planning with generation deployment. Utility-scale solar and wind facilities can be sited, permitted, and constructed in 2 to 4 years. Conversely, building high-voltage interstate transmission lines requires 10 to 15 years to clear the complicated web of environmental reviews, right-of-way approvals, and local land-use disputes in each state.

This failure manifests as a hidden tax on renewable energy adoption in the form of grid congestion and curtailment.

When transmission is congested, clean energy in one place cannot reach demand in another, and consumers pay more than they should. For instance, CAISO, the grid operator for California, wasted 5.3 million megawatt-hours (MWh) of renewable energy so far this year, primarily because transmission infrastructure was too limited to move peak midday solar power around the state.

As AI data centers demand ever-growing amounts of power, sufficient transmission infrastructure becomes even more important for the climate, since without it, developers may opt instead for polluting on-site natural gas plants. (Although even this fossil-fueled fallback to bypass grid constraints faces hurdles. There is currently a massive global backlog on new gas turbines stretching into the 2030s.)

So, what does sufficient transmission infrastructure look like in the first place?

To start, it would have a high-voltage direct current, or HVDC, backbone. Unlike traditional alternating current (AC) networks, HVDC technology can transport massive volumes of electricity across thousands of miles with significantly lower losses due to heat. Furthermore, HVDC allows precise control over the flow of power, allowing operators to route electricity around congested areas in ways AC systems cannot. Importantly, HVDC lines can connect completely separate regional grids that otherwise cannot share power. Because it acts as an electrical firewall, HVDC lines link these grids safely – allowing them to trade electricity without forcing either region to change how it operates, and without letting a blackout or power surge in one region spill over to crash the other.

China has already demonstrated the benefits of this approach, constructing over 20 ultra-high-voltage direct current (UHVDC) corridors that transfer hundreds of gigawatts from inland solar and wind installations to coastal metropolises.

Solar and wind are undoubtedly how we will power the future, but only if we can get that power where it needs to go.

Meanwhile, Europe is expanding its cross-border connections under the European Network of Transmission System Operators for Electricity (ENTSOE) to solidify a unified continent-wide grid and market. By contrast, the United States remains divided into three distinct grids – the Eastern, Western, and Texas (ERCOT) grids – with negligible high-voltage transfer capacity between them despite clear and significant climate and economic benefits.

Of course, constructing continental-scale HVDC infrastructure in the United States is no small feat. It would require massive capital for converter stations, transformers, and cables, costs that neither utilities nor their customers typically care to bear. Moreover, a transmission line crossing multiple states must navigate each one’s independent regulatory processes, environmental reviews, landowner concerns, and jurisdictional disputes. Indeed, these barriers have stalled or ended major transmission proposals for years.

But getting this right is too important – for people, for the climate, for the future – to just give up.

Overcoming these barriers requires proactive, anticipatory transmission planning policy, rather than reactive, incremental upgrades. Texas's Competitive Renewable Energy Zones (CREZ) provide a compelling blueprint for successful transmission policy. By identifying wind-rich regions in West Texas and pre-authorizing a transmission buildout in 2005, state regulators gave power developers and grid operators much-needed certainty before committing capital investments.

By 2014, nearly 3,600 miles of transmission corridors had been built, unlocking tens of gigawatts of clean energy capacity. Moreover, this effort dramatically lowered regional curtailment rates from 17% to around 1.2% and reduced wholesale electricity costs for consumers to historical lows by 2016, delivering cheap wind power to urban centers like Dallas, Austin, and San Antonio.

As a result, Texas customers saved an estimated US$31.5 billion on wholesale power costs between 2010 and 2022, dwarfing the US$7 billion in initial infrastructure investments. Adopting similar policies across the country could save Americans between US$1.60 and US$1.80 for every dollar invested. Congress is currently legislating the Bipartisan American Affordability and Jobs Act, a landmark permitting reform bill designed to simplify interstate transmission permitting and cut red tape. Yet whether this legislation passes and actually speeds up the process of putting in power lines remains to be seen.

However, even with proactive policies, building physical power lines can take decades to complete. Fortunately, grid-enhancing technologies (GETs) offer an immediate stopgap for our transmission troubles.

GETs are hardware and software tools that can extract additional capacity from existing transmission lines without the need for major construction. Deploying GETs – such as sensors that help to adjust transmission based on the weather, advanced devices for controlling the flow of power, and software that can help reroute power around areas of congestion – can expand the transfer capacity of existing lines by 10% to 30% at a fraction of the cost and timeline of new construction. GETs will not replace the need for building better transmission infrastructure, but they can greatly support the grid while this infrastructure is being built.

Ultimately, we already have everything we need for a cleaner, more resilient electricity sector. The true bottleneck is institutional, requiring political will to reform who pays for the necessary infrastructure, streamline environmental permitting, and establish regional planning mandates towards proactive grid planning. Solar and wind are undoubtedly how we will power the future, but only if we can get that power where it needs to go.

About the Author

Al-Amin Bugaje, Ph.D., is a scientist with a background in electrical engineering and experience in power systems modeling and applied machine learning. His research focuses on developing methods and tools that support the reliable and efficient operation of decarbonized grids. At Project Drawdown, his work focuses on assessing climate solutions in the electricity sector.

About Project Drawdown

Project Drawdown is the world’s leading guide to science-based climate solutions. Our mission is to drive meaningful climate action around the world. A 501(c)(3) nonprofit organization, Project Drawdown is funded by individual and institutional donations.

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