To unlock the full emissions reduction potential of the US Inflation Reduction Act (IRA), a report from Princeton University’s Zero-Carbon Energy Systems Research and Optimization Laboratory (Zero Lab) finds that ‘the pace of [electricity] transmission expansion must more than double the rate over the last decade’.

Among the goals of the IRA is that the US enjoys 100% clean electricity by 2035 and a zero-emissions economy by 2050. But renewable energy projects that might help meet those goals are stuck waiting in queues – in part because of a weak grid and rigid bureaucratic controls.

If electricity transmission cannot be expanded fast enough, the Zero Lab report finds that ‘power sector emissions and associated pollution could increase significantly as gas and coal-fired power plants produce more to meet growing demand from electric vehicles and other electrification spurred by the US’ new climate change law’.

About 4.24 TWh of electricity was generated at utility-scale electricity generation facilities last year, according to the US Energy Information Administration. About 60% was from fossil fuels, some 18% was from nuclear energy, and the remaining 22% was from renewable energy sources.

Transmission weaknesses 
While that was up from 11% in 2018, industry experts argue that this green energy growth is being held back by transmission weaknesses. More than 70% of the nation’s grid transmission lines and power transformers are over 25 years old, notes the Department of Energy’s (DOE) Office of Electricity.

‘The power grid in the US is ageing, inefficient and unreliable,’ says Dr Gilbert Michaud, Assistant Professor, School of Environmental Sustainability, Loyola University Chicago. ‘Due to the geographic breadth of the US, the transmission of electricity over long distances causes notable energy losses, and the overhead nature of these power lines makes them more susceptible to natural disasters. Cyber and physical attacks on the power grid are also a growing concern,’ he notes.

The continental US grid system is not only old but also highly fragmented. Its three sections – the Eastern, Western, and Electric Reliability Council of Texas (ERCOT) – ‘are almost completely isolated from one another, electrically speaking’, according to a statement by the RMI, a non-profit organisation working on clean energy transition. There is also a separate grid for Alaska.

‘To make matters worse, the high-voltage, long-distance electric transmission lines that form the backbone of each of these grids are largely planned in even greater local isolation,’ according to the Rocky Mountain Institute. There are 12 transmission planning regions, all of which except for ERCOT are under the jurisdiction of the Federal Energy Regulatory Commission (FERC).

Queue grows 
This system is ill-prepared to cope with the large amount of new power generation and energy storage under development, with transmission interconnection queues across the US continuing to rise dramatically. Indeed, more than 2,000 GW of total generation and storage capacity are now seeking connection to the grid, according to a report by the Lawrence Berkeley National Laboratory (Berkeley Lab).

‘The queues indicate particularly strong interest in solar, battery storage and wind energy, which account for 95% of all proposed capacity,’ notes the Berkeley Lab. The combined solar and wind capacity now actively seeking grid interconnection (~1,250 GW) equals the installed capacity of the entire US power plant fleet.

Entering an interconnection queue is only one of many steps in the development process, says the Berkeley Lab – projects must have agreements with landowners and communities, power purchasers, equipment suppliers and financiers, and may face transmission upgrade requirements.

‘More than 2,000 GW of total generation and storage capacity are now seeking connection to the grid.' – Lawrence Berkeley National Laboratory (Berkeley Lab) report

The total capacity in the queue at the end of 2022, more than 2 TW, is greater than current US generating capacity of 1.25 TW, and more than six times larger than the queue in 2014, the report notes. Solar (947 GW) accounts for the largest share of generation capacity in the queue, but substantial wind capacity (about 300 GW) operators have also applied for interconnection.

However, some promising improvements and solutions are underway. According to the Berkeley Lab, several regional grid operators have made substantial reforms to their interconnection processes or are in the process of doing so.

Last November (2022), the DOE announced $13bn in new financing for the expansion and modernisation of the grid. Funding by the IRA, the US Grid Resilience Innovative Partnership (GRIP) programme and the Transmission Facilitation Program ‘together represent the largest single direct federal investment in critical transmission and distribution infrastructure...’. The Biden Administration noted that it is ‘one of the first down payments on an over $20bn investment’ under its Building a Better Grid initiative. This initiative, which was launched in January 2022, has access to more than $20bn in federal financing tools.

Regulatory hurdles 
However, even with such largesse in the pipeline, regulatory hurdles remain that make it difficult to shorten the transmission interconnection queues. ‘The regulatory framework is very complex,’ comments Romany Webb, a researcher at Columbia University’s Sabin Center for Climate Change Law. ‘Interstate projects are hard to get approved,’ he notes.

Sometimes, in addition to federal and state regulations, local-level permits are required, adds Webb. ‘In some state and localities there are environmental review projects that can be time-consuming and costly.’

Michaud comments that while FERC regulates the power sector, ‘it does not have the authority to nudge needed grid upgrades’. Instead, ‘a convoluted network of state and regional regulators have the authority to push forward grid modernisation’.

However, they rarely do so because ‘it would require them to approve unwanted electricity rate increases', he adds. ‘These regulators are powerful and often financially connected to large electric utilities, who oppose mandates for grid investments or anything that would threaten their monopolistic control over the market.’

Michaud continues: ‘While a national directive to modernise the grid might be the most effective strategy, the regional nature of control and regulation in the US make actual upgrades logistically challenging.’

The Brookings Institution, a US research group, has been studying ways to untangle this red tape. Its February (2023) report How to reform federal permitting to accelerate clean energy infrastructure suggests a number of policy options, including that authority for the location of all interstate transmission lines be federalised with FERC.

Interstate transmission lines are critical for decarbonisation of the US, with national benefits but local costs, that are frequently rejected by state authorities. Natural gas pipelines have similar cost-benefit tradeoffs. But they are permitted much faster due to FERC’s existing siting authority over them, according to the report.

FERC also could ensure that interstate transmission lines ‘allocate a fair fraction of their capacity to the states and communities through which they pass, thereby increasing local support for transmission and more equitably distributing its benefits’, suggests the study.

The Brookings report also suggests that the US Congress could support multi-agency coordination by allocating additional funding to the Federal Permitting Improvement Steering Council and by expanding its scope to cover mid-sized as well as large clean energy projects.

The country’s National Governors Association is also studying ways to shorten the queue. In February (2023), the association issued a briefing on Transmission siting and permitting: How governor leadership can advance projects.

The briefing advises that governors:

• Pursue regional compacts and multistate agreements to establish direct, state-to-state planning procedures, negotiate cost-sharing and build capacity to streamline complex interstate project planning.
• Create state siting offices to coordinate intrastate and interstate transmission siting and permitting efforts.
• Employ strategic land-use to steer transmission routes to publicly owned property and/or away from environmentally or culturally sensitive areas.
• Co-locate transmission infrastructure along existing or previously impacted areas such as highway corridors or existing infrastructure rights of way.

Transmission sub-station technology being developed at the US National Renewable Energy Laboratory, at its Flatirons Campus in Colorado – the goal is a transmission network with better connectivity
Photo: US Department of Energy

Existing technology 
The good news is that while the US struggles with these complex regulatory obstacles, technology already exists to address both capacity expansion and ageing infrastructure needs, according to the American Council on Renewable Energy (ACRE).

Transmission lines that use advanced conductors with carbon and/or composite cores, instead of the steel wire cores used for conventional conductors, ‘can carry more capacity while maintaining better performance at higher operating temperatures’, according to the report on Advanced conductors on existing transmission corridors to accelerate low cost decarbonization, issued by the Council in March 2022.

Reconductoring and rebuilding existing transmission pathways using advanced conductors can help accelerate decarbonisation ‘by creating a significant amount of new transmission capacity more quickly and more cost-effectively than new, large-scale transmission’, ACRE concludes.

Advanced conductor deployment can also offset some of the upfront total costs associated with infrastructure replacement through the more efficient transfer of electricity compared to traditional conductors, according to the ACRE report.

The incremental capacity generated by deploying advanced conductors to address just 25% of ageing infrastructure needs could facilitate the interconnection of at least 27 GW of zero-carbon generating capacity annually over the next 10 years, the report suggests. It estimates that this increase in renewable capacity ‘has the potential to reduce cumulative power sector CO₂ emissions by approximately 2.4bn tonnes over the 10-year period – the equivalent of cumulative CO₂ emissions over 10 years from approximately 22 coal-fired power plants’.

During the same period, energy savings from newly created transmission capacity would save American consumers at least $140bn. So, bending regulatory efforts towards installing this new transmission technology makes lot of sense.