The Great Reinvention logo THE GREAT
REINVENTION

The American Solar Spine: A National Backbone to Move Clean Power Where It's Needed

Proposed legislation: The Interregional Clean Energy Transmission Act

American Solar Spine: A Cost-Benefit and Investment Analysis

The United States has a paradox at the heart of its energy transition: it has more cheap clean power than it can use, and no way to move it. The wind that howls across the Great Plains and the sun that blazes over the Southwest are among the lowest-cost sources of electricity ever measured. But the regions richest in sun and wind are often far from the cities and factories that need the power, and the transmission lines connecting them are inadequate, congested, and stuck in permitting limbo. The result is waste on a national scale: clean electricity that gets "curtailed" — generated and then thrown away — because there is nowhere for it to go.

This page proposes the American Solar Spine: a national high-voltage transmission backbone, built largely with high-voltage direct current (HVDC) technology, linking the sun- and wind-rich interior to coastal and Midwestern demand centers. The proposed federal commitment is $25–40 billion per year in direct investment, loan authority, and anchor financing to break the transmission bottleneck that is now the single largest obstacle to a cheaper, cleaner, more reliable grid.

The need is not speculative. The Department of Energy's 2024 National Transmission Planning Study concluded that the country will need to expand its transmission system to roughly 2.1 to 2.6 times the 2020 level by 2050, with interregional transfer capacity growing by a factor of 1.9 to 3.5, to meet demand growth and reliability needs at lowest cost. The same study found that a substantial, nationwide transmission build-out could deliver net system cost savings of $270 billion to $490 billion through 2050. This is not a subsidy program. It is an infrastructure investment that, by the government's own analysis, pays for itself.

The Bottleneck: Why Clean Power Gets Wasted

The economics of the problem are stark. According to S&P Global, every major U.S. grid operator — CAISO, ERCOT, MISO, NYISO, and SPP — set new records for wind curtailment in 2022, and cumulative day-ahead congestion costs across U.S. markets reached $11.6 billion, an 82 percent increase from 2021. Congestion cost is, in effect, the price the grid pays for not being able to move power from where it is cheap to where it is needed.

The bottlenecks are geographically specific. DOE analysis identifies the "seam" between MISO and the Southwest Power Pool as a critical chokepoint for east-west power flow. The regions requiring the largest growth in interregional transfer capacity by 2035 include the boundary between MISO's southern region and SPP (a median increase on the order of 400 percent), New England to New York, and PJM to MISO. The Plains and Southwest can generate vastly more clean power than their local grids can absorb or export — so it gets curtailed, and demand centers burn more expensive (and often dirtier) local generation instead.

The technology to fix this exists and is proven. HVDC lines move large quantities of power over long distances with lower losses than conventional alternating-current lines. Projects like the planned 800-mile Grain Belt Express, designed to carry up to 5,000 MW between SPP and MISO, demonstrate the model. DOE analysts have estimated that deploying just five 3-GW HVDC links — connecting ERCOT to the Southeast, the Southwest to California, and the Plains to the Mid-Atlantic — could relieve roughly 70 percent of projected interregional congestion by 2035.

What Gets Built

The Solar Spine is a deliberately national, interregional system rather than a collection of local upgrades. Its components:

A backbone of long-distance HVDC corridors connecting the four richest renewable resource zones — the Great Plains wind belt, the Southwest solar belt, offshore wind off the Atlantic and Gulf, and Midwestern wind — to the major load centers of the coasts, the Great Lakes, and the South. The MISO board's 2022 approval of a roughly $10.3 billion transmission plan supporting up to 53 GW of renewable generation across 18 projects shows the scale at which regional planning already operates; the Spine federalizes and accelerates the interregional layer that regional plans systematically underbuild.

Converter stations and AC reinforcements to integrate the DC backbone with existing regional AC grids. Converter stations are the most expensive single element of an HVDC project — by some estimates up to 60 percent of fixed cost, per HVDC cost analyses — so siting them efficiently is central to the program.

Grid-enhancing technologies and storage interfaces to maximize the value of every line, including dynamic line rating, advanced power-flow control, and storage at key nodes to firm up variable output.

Cost Breakdown

HVDC transmission costs vary widely with terrain and length. Per-mile costs for recent HVDC projects range from roughly $1.17 million to $8.62 million, per a review of regulatory filings, with converter stations as a major fixed cost. At $25–40 billion per year over a decade-plus, the program funds thousands of miles of new high-capacity backbone plus the converter and integration infrastructure.

Component Role Cost driver
HVDC backbone corridors Long-distance bulk transfer $1.17–8.62M per mile
Converter stations AC/DC interface Up to ~60% of HVDC fixed cost
AC reinforcements Regional integration Varies by region
Storage & grid-enhancing tech Firming and utilization Modular

Critically, much of the federal commitment can take the form of loan guarantees, anchor "capacity contracts," and federal cost-allocation backstops rather than pure grants. DOE's existing Transmission Facilitation Program already uses capacity contracts to de-risk private transmission investment, and the Solar Spine scales that model. The point of federal involvement is not to own the lines but to solve the coordination and cost-allocation problems that paralyze interregional projects.

Benefits

Economic: lower bills and avoided waste. DOE's transmission analyses find that every dollar spent on transmission saves roughly $1.60 to $1.80 in overall system costs, and that a national build-out could save $270–490 billion through 2050. Reducing the $11.6 billion in annual congestion costs and the rising tide of curtailment directly lowers wholesale power prices, which flow through to consumers and to the energy-intensive industries — including AI data centers — driving new demand growth.

Jobs and industrial base. Transmission construction is labor-intensive and geographically distributed: line workers, electricians, ironworkers, and the domestic manufacturing of conductors, transformers, and converter equipment. A sustained national program creates a stable demand signal that justifies building out domestic supply chains for high-voltage equipment, much of which is currently import-dependent.

Reliability and security. A more interconnected grid is a more resilient grid. When extreme weather knocks out generation in one region — as during Winter Storm Uri in Texas — strong interregional ties allow neighboring regions to share power and prevent cascading blackouts. Greater interconnection turns isolated, vulnerable islands into a mutually supporting national network.

Environmental. By unlocking curtailed clean generation and connecting the lowest-cost wind and solar to demand, the Spine displaces higher-emitting marginal generation. The environmental benefit is a direct consequence of the economic one: clean power is cheap power, and the only thing standing between it and the consumer is wire.

Administrative and Implementation Considerations

Transmission's hardest problems are not engineering — they are permitting, siting, and cost allocation. A line that crosses multiple states and grid regions must satisfy many regulators, compensate many landowners, and divide costs among beneficiaries who all prefer someone else pay. These coordination failures, more than money, are why interregional transmission lags renewable growth.

The Solar Spine therefore pairs investment with process reform: a federal coordinating role for interregional lines (building on FERC's transmission authorities and DOE's National Interest Electric Transmission Corridor designations), streamlined-but-rigorous environmental review, fair landowner compensation, and a transparent cost-allocation framework that assigns costs to beneficiaries. Routing along existing rights-of-way — highways, rail, and existing utility corridors — can dramatically reduce siting conflict, an approach studied for buried HVDC.

International Comparisons and Precedent

China operates the world's most extensive ultra-high-voltage DC network, moving enormous quantities of power thousands of kilometers from its resource-rich west to its industrial east — a deliberate national strategy that has made China the global leader in long-distance HVDC deployment. Europe is building interconnectors and offshore-wind grids to knit national systems into a continental market. These are the models: nations that treated long-distance transmission as strategic infrastructure and built it.

The domestic precedent is the interstate highway system and the rural electrification of the 1930s — federally driven networks that no single state or private actor would have built alone, and that unlocked decades of economic growth. Transmission is the interstate highway of the clean-energy economy.

Comparison to the Status Quo and Alternatives

The status quo is regional underinvestment and rising waste. Regional grid operators plan within their own footprints and chronically underbuild the interregional ties that benefit the nation as a whole, because the costs are local and the benefits diffuse. The result is the curtailment and congestion documented above — a slow, expensive failure rather than a dramatic one.

The leading alternative to long-distance transmission is build everything locally: meet demand with local solar, local gas, and especially batteries. Storage is essential and complementary — and ERCOT studies confirm utility-scale storage meaningfully reduces curtailment. But storage shifts power in time, not space; it cannot move Plains wind to the East Coast. And building duplicative local generation everywhere is more expensive than connecting to the cheapest national resources. DOE's own least-cost modeling repeatedly favors substantial transmission expansion. A second alternative is distributed generation and microgrids, valuable for resilience but insufficient for the bulk-power needs of industry and growing electrified demand. The honest conclusion is that the cheapest, most reliable system uses all of these — and transmission is the piece markets and regional planners most systematically underprovide.

Risks, Trade-offs, and Counterarguments

The strongest objection is execution risk: U.S. transmission projects routinely take a decade or more, derailed by litigation, local opposition, and cost-allocation fights. Pouring federal money into a system that cannot build fast may simply inflate costs without delivering lines. This is the central risk, and it is why the proposal emphasizes permitting and cost-allocation reform as much as money. Without process reform, the funding alone will disappoint.

A second objection is landowner and community impact: long-distance lines cross private property and rural communities that bear local costs for national benefits. Eminent domain for transmission is politically fraught and ethically serious. The program must offer genuinely fair compensation, prioritize existing rights-of-way, and give affected communities a real stake — not steamroll them.

A third critique comes from those who argue the future is distributed, not centralized — that rooftop solar, batteries, and microgrids will make big transmission lines a stranded asset. This deserves a fair hearing, but the weight of grid modeling, and the sheer scale of projected demand from electrification and data centers, point toward needing both distributed resources and a strong backbone. Betting the energy transition entirely on distribution is a riskier wager than building the connective tissue the analyses call for.

Finally, there is cost and ratepayer risk: someone pays for these lines, and if benefits are mis-forecast, ratepayers could be left holding the bill. Rigorous, independent benefit-cost analysis and beneficiary-pays cost allocation are essential guardrails. But the baseline case — DOE's finding of $270–490 billion in net savings — suggests the larger risk is building too little, too slowly, and continuing to throw away the cheapest power the country has ever produced.

Conclusion

The United States is generating clean power it cannot use and paying billions to manage the congestion. The wind and sun of the interior are a national asset stranded by a transmission system that was never built to carry them. The American Solar Spine — a $25–40 billion annual commitment to a national HVDC backbone, paired with the permitting and cost-allocation reforms that actually let lines get built — would turn that stranded asset into lower bills, a more reliable grid, and a durable industrial base. The government's own least-cost analysis says a national transmission build-out saves hundreds of billions of dollars. The bottleneck is not the economics. It is the will to build.

Sources

← Back to The Great Reinvention