Transmission Permitting Is the Bottleneck to U.S. Electrification

Elisabeth Moyer frames the U.S. power sector as a system entering several stresses at once: electricity demand is rising after decades of near-flat growth; coal is retreating; wind and solar are becoming economically competitive but harder to integrate; and the transmission network cannot be expanded at the pace the emerging system requires.

The immediate experience for most customers remains deceptively normal. Flip a switch and power arrives. There are no routine brownouts or blackouts. But bills are rising, Moyer says, because new demand is arriving faster than new generation can be built. Data centers are part of that increase, alongside expanded manufacturing, heat pumps and electric vehicles. When demand rises and capacity cannot be added quickly enough, operators must run more expensive plants more often. Prices follow.

That is a departure from the recent past. For roughly two decades, Moyer says, U.S. electricity demand was essentially flat even as population and wealth grew. The new trajectory is much steeper. She cites projections of electricity demand increasing by roughly half again by the 2030s, with data centers potentially representing 10% of total U.S. electricity demand within a decade or so. She qualifies that forecast: the AI boom could weaken. But under the projected growth path, the system will have less generation capacity relative to demand than it had before, forcing greater use of older, less efficient plants.

The short-run consequence, in her account, is higher prices. Higher prices can reduce consumption, but the infrastructure response is slow. New plants take time; transmission takes longer; and grid managers are already operating a system made more difficult by variable renewable generation and market arrangements designed around a different mix of power plants.

The question is not simply whether the United States has prospective solar, wind, gas, nuclear or storage resources. It is whether those resources can be built, connected, dispatched and paid for through a physical network designed for lower demand growth and a different generation mix.

Elisabeth Moyer uses energy accounting to establish the scale of the system that climate policy seeks to change. Motion, heat, radiation, chemical bonds, electricity and nuclear processes are different forms of energy, she says, but they are interconvertible and can be measured in common units.

Energy is work: force multiplied by distance. Since force is mass multiplied by acceleration, the joule can be written as:

Power is energy over time: one joule per second is one watt. Moyer makes the scale physical by lifting a half-liter water bottle. Raising roughly half a kilogram one meter against gravity requires about five joules of work; doing it once every second is about five watts.

The useful comparison is not the derivation but the human baseline. A person consuming 2,000 food Calories a day is consuming 2,000 kilocalories—about 2 million physics calories. Converted to joules per second, that is approximately 100 watts of continuous input power. Moyer calls this the human “bio engine.”

A person cannot produce 100 watts of mechanical work indefinitely. Bodies lose energy as heat, require rest, and need more food when performing sustained work. But the number provides a reference point for the far larger flows that support modern life.

An American, Moyer says, uses about 10,000 watts per person on average—roughly 100 times the biological input rate. Her metaphor is 100 mechanical servants working continuously: fuel burned in cars; power plants supplying lights and appliances; motors turning washing machines; and systems providing heating, cooling, industrial production and travel.

Energy use and GDP per capita, she says, are tightly correlated across what she calls normal countries, within roughly a factor of three. The relationship reflects the services people value: lighting, mobility, machines and freedom from hand labor. A society might reduce energy use without returning to subsistence conditions, but it will not reduce it to zero. The practical climate question is how to feed those servants with something other than fossil fuels.

Roughly a third of U.S. primary energy use now passes through the electrical system, Moyer says. Decarbonization requires moving more activity through electricity because electricity can be generated without carbon emissions. If electricity’s share grows from one-third toward the whole economy, the country may need a grid roughly three times as large.

Moyer says about two-thirds of that infrastructure is effectively committed to fossil fuels and would need to change. The scale does not make transformation impossible. It explains why it is slow.

Elisabeth Moyer argues that the United States has already experienced repeated energy transitions. Her research separates residential and commercial buildings, industry, transportation, agriculture and electricity generation rather than treating the national fuel mix as one undifferentiated whole.

The historical visualization shown in her presentation follows the country from biomass toward coal, oil, natural gas and electricity in different uses. It begins with an economy dominated by wood, household heating and agriculture; coal expands with railroads and industry; petroleum enters transportation; natural gas spreads after World War II; and electricity becomes a major conduit for energy use. The current shift appears in the final decades: coal’s retreat from power generation as gas expands and renewables begin to grow.

Moyer’s group defines a sectoral transition mechanically: a primary fuel’s market share falls from 80% to 20% of its peak share in a given sector. The threshold is arbitrary, she says, but it creates a consistent way to compare shifts that otherwise look unlike one another.

The history does not suggest that energy systems change overnight. A transition may remain stalled for decades, then accelerate once the infrastructure needed to move a new fuel is built. The decisive infrastructure is often “midstream”: pipelines, rail links, transmission lines and other systems that connect a resource to its users.

Natural gas could be produced near a well, for example, but it could not become a broad urban fuel until pipelines brought it to consumers. Before that buildout, industries that needed gas sometimes moved to the resource. Moyer points to Ohio’s glass industry, where factories clustered around available natural gas because the fuel could not yet be transported widely.

Once suppliers, customers and delivery infrastructure reinforce one another, transitions become comparatively durable. More infrastructure makes more consumption viable; more consumption makes further infrastructure worthwhile. Moyer says the hard economic question is often what starts that cycle. Once a transition is underway, its pattern is more stable: typically two to four decades, though it may take much longer for the necessary conditions to form.

The electricity sector’s current move away from coal is, in Moyer’s reading, a price-driven transition. Fracking made natural gas cheaper beginning around 2009, providing a more flexible substitute for coal generation. Wind and solar have since declined sharply in cost. She estimates that the coal transition will meet her group’s mathematical definition after roughly 16 or 17 years.

Coal’s apparent durability in U.S. history comes largely from one sector. Outside electricity, Moyer says, coal consumption peaked in the 1920s and then declined. Electricity was different: as power generation expanded from the late 1950s, coal became its dominant fuel. By around 1990, almost no one was heating or cooking with coal, and only a small number of industrial users remained. Coal’s survival was overwhelmingly tied to power generation.

The plant maps shown in the presentation make the shift visible. Coal dominates the 1990 map and remains extensive in 2010. By 2024, many smaller coal plants have disappeared; the remaining facilities are generally large and costly to retire. Moyer says they are also being asked to operate more flexibly than they were designed to operate. In her view, new coal construction is economically implausible regardless of political support for the fuel.

She describes this as the first U.S. case of a fuel being “extirpated”: not merely displaced in a single application, but potentially abandoned because better alternatives are available.

Elisabeth Moyer distinguishes renewable generation’s falling cost from the operational problem of integrating it. Natural gas fits readily into the existing grid because it is dispatchable: operators can run a gas plant when they need power and turn it down when they do not. Wind and solar produce when wind and sunlight are available, not necessarily when system demand is highest.

Moyer says solar panel prices fell by a factor of 100. A technology once associated with heavily subsidized California projects is now cost-comparable and deployed widely. In utility-scale installations, she says, mounting racks, wiring and labor can cost more than the panels themselves.

The cost breakthrough does not eliminate the problem of timing. California supplies her clearest example. The state can generate large quantities of solar power in the middle of the day, when residential demand is relatively low. Demand rises in the morning and evening as people use lights, appliances and other household loads. But the evening peak arrives as solar production falls.

Operators must then ramp other resources quickly. They may need to start gas plants before they are needed, leave them idle during midday solar abundance, and rely on them heavily after sunset. That complicates both physical grid operation and the economics of keeping dispatchable plants available when they may not run for much of the day.

California tried to fill some of the gap with imports, but its transmission connections limited how much outside electricity it could obtain. Moyer says the state then subsidized large battery installations to shift solar output into the evening. In her account, those batteries solved a real operating problem but at substantial cost.

The distinction matters. Batteries shift electricity across time; transmission moves it across location. Moyer’s argument is not that batteries have no role, but that a connected system can use power from elsewhere instead of storing every local surplus for later use. Battery storage, she says, still requires subsidy and remains expensive.

She expects low-cost solar and wind to keep changing the power mix. But their economics do not answer where generation will be built, where demand is located, or what infrastructure connects the two.

Elisabeth Moyer describes electricity as unusually demanding because cheap, large-scale storage remains limited. A grid must produce almost exactly as much electricity as customers consume at each moment. If production and consumption are not balanced, the system fails.

That burden falls on grid operators, who make daily market arrangements and then make additional minute-by-minute adjustments. Moyer describes control rooms staffed by managers whose role was so essential during COVID that some isolated from their families to keep the grid operating. The system also maintains redundant control facilities in case a primary center is incapacitated.

In a market-based system, one symptom of transmission scarcity is a difference in locational marginal pricesThe instantaneous electricity price at a particular location on the grid.. The price map shown in Moyer’s presentation used red for high prices and blue for negative prices, where the system may effectively pay someone to consume surplus electricity.

Those differences, Moyer argues, reveal transportation constraints rather than a simple shortage of generation. Her central visual evidence was a map in which places with surplus electricity could sit close to places facing high prices. A gradient in price meant, in her formulation, that the system lacked a way to move power from source to customer.

The mismatch between renewable resources and transmission is visible in the plant maps she showed. Solar projects in Southern California line up along existing transmission corridors “like beads on a string,” including lines originally built to serve coal plants. Developers cannot generally finance a dedicated line for one solar farm, so projects cluster where they can reach an existing high-capacity route back to Los Angeles.

The Midwest wind map shows the same constraint from the other direction. The strongest wind belt lies farther west than many existing wind farms. Developers build on the eastern edge of the resource area because that is where transmission is available. Yet wind speed matters disproportionately: Moyer says wind output scales with the cube of wind speed, so doubling wind speed can increase potential power by a factor of eight. The best resource locations can therefore be much more productive, but without a line they remain commercially stranded.

Large industrial customers already encounter location- and time-specific electricity prices. Moyer says hourly pricing is coming to Illinois, which will make these differences more visible to customers there. She also expects more demand-side management: customers may be asked to let utilities control when electric vehicles charge or to adjust air-conditioning use during stressed periods.

When asked about demand flexibility and virtual power plants, Moyer said managed charging and controlled demand would have to be part of the response, even though people will dislike surrendering control over their equipment. In her account, the alternative is not unrestricted consumption at the same price; it is greater scarcity and the risk of pricing some customers out of high-demand periods.

Data-center demand intensifies the political difficulty. Moyer says it makes otherwise useful projects harder to defend, because communities already resist new construction and may see new plants, lines or demand-management programs as infrastructure built for someone else’s private expansion.

Elisabeth Moyer identifies transmission—not the availability of renewable resources—as the binding constraint on the next phase of electrification.

She points to SunZia, a newly built high-voltage direct-current line, as an example of what a major renewable connection requires. Moyer says the line can carry three gigawatts, cost $11 billion and required more than a decade of planning. It is, in her account, the first significant U.S. high-voltage DC project built since the late 1970s.

The logic for the project was straightforward. Los Angeles needed power, particularly during the evening decline in solar output. Strong wind resources existed farther east, but a connection gap separated Nevada from New Mexico. A wind farm without a customer and a route to that customer has little value; a transmission line without committed generation, contracts and users lacks a business case.

Those investments must be coordinated while every jurisdiction along the route grants approval. Moyer notes that the route could not simply follow the most direct line; it had to go where construction could be permitted. She says the associated wind development opened in 2026 as the country’s largest wind farm and has changed Southern California’s power market.

The project is an optimistic sign, in her view, because it shows the United States can build long-distance transmission again. It is also a warning. If a single major line takes more than a decade to plan, tripling the grid cannot be assumed to follow automatically from lower renewable costs.

Moyer contrasts that history with China’s centrally planned buildout of hydroelectric generation and high-voltage DC lines running from western resource regions to eastern coastal cities. The United States built several large DC interties in the 1960s and 1970s, including the Pacific Intertie carrying Columbia River power toward Los Angeles, but then largely stopped building major new long-distance projects.

The limiting work is planning, siting, zoning, permitting, contracting and public acceptance of transmission lines crossing landscapes and backyards. Moyer does not dismiss batteries, invention or new generation technologies. She believes solar and wind prices are likely low enough to continue changing the electricity sector even without subsidies, and she expects coal’s economic decline to continue despite attempts to extend its life.

But favorable generation economics do not create an energy system on their own. Decarbonizing the economy requires more electrification. More electrification requires a larger grid. And a larger grid requires the institutional capacity to build physical infrastructure at a pace the United States has not demonstrated for decades.