The United States is turning to a faster alternative to building entirely new transmission corridors as electricity demand begins to rise at a pace not seen in decades.
The U.S. Department of Energy announced on September 24 that it intends to provide $1.9 billion for 31 grid modernization projects across 26 states under its SPARK initiative — short for Speed to Power through Accelerated Reconductoring and other Key Advanced Transmission Technology Upgrades.
Combined with $3.35 billion in recipient cost sharing, the projects represent approximately $5.25 billion of planned grid investment.
DOE expects the selected projects to reconductor or rebuild more than 1,500 miles of transmission lines while deploying Grid-Enhancing Technologies, or GETs, across nearly 21,000 miles.
Together, the upgrades are expected to make more than 23 GW of additional electricity-transfer capacity available and improve grid service affecting roughly 100 million Americans.
The significance of the program goes beyond its headline investment.
Much of the additional capacity will come not from constructing entirely new transmission corridors, but from upgrading infrastructure that already exists.
More Power Without Building an Entirely New Grid
One of the central technologies in the program is advanced reconductoring.
Transmission lines are normally limited by the thermal properties of their conductors. As current increases, a line heats up and begins to sag, forcing operators to restrict how much electricity can safely pass through it.
High-performance conductors can carry more power while using existing transmission towers and rights of way.
That can significantly shorten project development timelines.
Building a new interstate transmission corridor may involve years of land acquisition, environmental reviews, permitting and local negotiations. Reconductoring allows utilities to reuse much of their existing infrastructure.
Industry groups supporting advanced transmission technologies argue that high-performance conductors can, in suitable applications, roughly double the capacity of an existing corridor without requiring a new right of way, although actual gains depend heavily on the specific grid configuration.
The SPARK program also goes beyond replacing physical conductors.
A substantial portion of the strategy involves using sensors, software and real-time data to determine how much electricity transmission lines can actually carry.
Transmission Capacity Is Not Always a Fixed Number
Many power grids still operate transmission lines using relatively conservative static limits.
In reality, however, the safe capacity of a power line changes depending on weather conditions such as ambient temperature, wind speed, solar radiation and conductor temperature.
During cooler or windier conditions, for example, a transmission line can dissipate heat more efficiently and may safely carry more electricity.
Dynamic Line Rating technology uses sensors and real-time operating data to continuously calculate those changing limits rather than relying on a single year-round rating.
Other Grid-Enhancing Technologies include power-flow control devices and topology-optimization software that help grid operators redirect electricity toward parts of the network with available capacity.
The Federal Energy Regulatory Commission has also been pushing regional grid operators to more seriously evaluate advanced transmission technologies when determining how large new loads should connect to the grid and what network upgrades are actually necessary.
The underlying issue is increasingly clear: the United States may have enough generating resources in some regions, but insufficient transmission capacity to deliver that electricity where demand is emerging.
AI Is Changing the Electricity-Demand Equation
The urgency behind the investment is closely linked to a sharp change in U.S. electricity demand.
According to the U.S. Energy Information Administration, electricity demand grew by only about 0.1% annually between 2005 and 2019.
Between 2020 and 2025, however, annual growth accelerated to approximately 1.7%, with data centers becoming one of the major drivers.
EIA's latest outlook expects U.S. electricity sales to reach about 4,135 billion kWh in 2026, almost 2% higher than in 2025, before rising again to roughly 4,211 billion kWh in 2027.