How the biggest US grid operator could add 6.6GW without rebuilding lines

Analysis from Rocky Mountain Institute (RMI) reveals how PJM Interconnection, the biggest grid operator in the US, could enable the integration of 6.6GW of clean energy onto the grid through the use of grid enhancing technologies (GETs), rather than reconductoring or rebuilding power lines.

According to the US-based research institute and consultancy, GETs, which are hardware and software solutions deployed within the transmission system, would help increase the capacity, flexibility and efficiency of the current grid.

The study, GETting Interconnected in PJM, finds that although GETs – including dynamic line ratings (DLRs), advanced power flow controls (PFCs) and topology optimisation (TO) – are becoming more widely studied and deployed in the US and internationally, they are not yet routinely considered in planning paradigms such as grid operators’ interconnection studies.

By freeing up additional transmission capacity for clean energy, 95 GETs projects considered in RMI’s analysis would generate approximately $1 billion in production cost savings per year for PJM, a regional transmission organisation (RTO).

“With growing demand for electricity to power our lives and an influx of clean energy projects under development, the US grid needs to expand, fast,” said Katie Siegner, an electric sector expert at RMI.

“Grid-enhancing technologies can be deployed in a matter of months and offer a multi-faceted solution – they unlock greater efficiency on the grid, keep electricity rates down, and enhance reliability throughout the energy transition.”

Interconnecting 6.6GW of projects by 2027

According to RMI’s study, GETs could facilitate the interconnection of 6.6GW of new wind, solar and storage generation across Illinois, Indiana, Ohio, Pennsylvania and Virginia that otherwise might have required prohibitively high-cost or time-consuming network upgrades.

For comparison, they add that in these five states, just over 2GW was connected to PJM’s grid in 2023.

Additionally, they state, that evaluating and deploying GETs as network upgrades would allow for faster and cheaper integration of large volumes of new generation. Traditional network upgrade costs have increased significantly in recent years — in PJM and elsewhere — as less and less hosting capacity is available on regional grids and more expensive upgrades are required.

RMI states in the study that transmission owners are now commonly identifying reconductoring or rebuilding affected transmission lines as such upgrades to address overloads triggered by interconnecting projects. However, GETs costs range from $272 to $523 million less than these types of network upgrades.

In addition to the cost savings, GETs significantly reduce the time required to connect new generation; reconductoring or rebuilding lines can take up to three years or more, adds RMI, while transmission owners can deploy GETs in months.

RMI adds that their analysis revealed significant savings that would flow to electricity consumers in the PJM region.

Specifically, within their production cost modelling analysis, RMI found that GETs-enabled new generators and reduced congestion would reduce energy production costs by just under $1 billion in 2027, ramping up to over $1 billion in savings per year by 2030.

Driven by lower OPEX of new renewable and storage resources, as well as the broader congestion relief that GETs provide, additional lower-cost generation would thus be enabled on PJM’s grid.

Recommendations

RMI comments in the study that, to further realise the potential of GETs, PJM should institute robust evaluation of the technologies across its interconnection and transmission planning practices and ensure its staff has the requisite training and modelling tools.

Transmission owners, they add, should build their internal capacity on GETs through studies and deployments, developers should propose and support GETs evaluation as network upgrades and state regulators should provide oversight and guidance to spur GETs adoption by their jurisdictional utilities.

Additionally, RMI states that the Federal Energy Regulatory Commission (FERC) should take additional steps to provide a comprehensive national regulatory framework that supports GETs adoption.

Have you read:
Ofgem policy to push ‘zombie projects’ out of grid connection queue
Action plan for Europe’s grids launched

Filings for GETs

According to the WATT (Working for Advanced Transmission Technologies) Coalition, RMI’s findings follow a filing from the PJM Interconnection to FERC on January 17, 2024, emphasising the value of DLR deployments during Winter Storm Elliot:

“The DLR ratings on this line during the storm proved higher than the ambient adjusted ratings PJM would have operated to otherwise. Had PJM not had the higher dynamic line ratings, PJM would have had to take action to re-dispatch the system to maintain reliability. Such action would have been very difficult under the critical operating conditions.”

PJM reaffirmed their support, states WATT, for a requirement for utilities to deploy DLR on all thermally constrained lines that lead to significant congestion and noted the need for application guides to facilitate utility adoption.

PPL Electric Utilities followed with their own filing to FERC on February 9, 2024, reporting that their DLR deployments have operated successfully since deployment – in one case eliminating congestion which was $12 million in summer 2022, and reducing congestion on another line from approximately $66 million to $1.6 million.

According to WATT, PPL Electric Utilities reported that they plan to install DLR on five more lines by the end of June this year.

Commenting in a release, Julia Selker, executive director of the WATT Coalition, said:

“It is very encouraging to see a system operator and utility sharing new information with FERC about the value of Dynamic Line Ratings. These comments show the substantial cost-saving and reliability benefits of DLR.

“The RMI study reminds us that it’s crucial to integrate all Grid Enhancing Technologies into utility practices to achieve the lowest-cost electricity system.

“I look forward to seeing compliance filings this spring in response to FERC’s Order 2023 on generator interconnection, which requires advanced power flow control and topology optimisation to be studied in interconnection processes and left DLR to the operator’s discretion.”

PJM Interconnection coordinates the movement of wholesale electricity in all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.

GETting interconnected was funded by Amazon and based on analysis conducted by Quanta Technologies.