Monday Study – Transmission Queue Clog Getting Worse

Queued Up: Characteristics of Power Plants Seeking Transmission Interconnection

Joseph Rand, Rose Strauss, Will Gorman, Joachim Seel, Julie Mulvaney Kemp, Seongeun Jeong, Dana Robson, Ryan Wiser, April 2023 (Lawrence Berkeley National Laboratory)

High-Level Findings

Developer interest in solar, storage, and wind is strong

 Over 10,000 projects representing 1,350 gigawatts (GW) of generator capacity and 680 GW of storage actively seeking interconnection  Most (~1260 GW) proposed generation is zero-carbon  Hybrids comprise a large share of proposed projects

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Completion rates are generally low; wait times are increasing

 Only ~21% of projects (14% of capacity) from 2000-2017 reached commercial operations by the end of 2022  Completion rates are even lower for wind (20%) and solar (14%)  The average time projects spent in queues before being built has increased markedly. The typical project built in 2022 took 5 years from the interconnection request to commercial operations1, compared to 3 years in 2015 and <2 years in 2008.

Proposed capacity is widely distributed across the U.S.

 Substantial proposed solar capacity exists in most regions of the U.S.; 947 GW of solar active in queues  Wind capacity is highest in NYISO, the non-ISO West, PJM, and SPP, with increasing share of offshore projects  Storage is primarily in the West and CAISO, but also strong in ERCOT, MISO, and PJM; much in hybrid configurations  Only 82 GW of gas capacity active in the queues, less than 10% of active solar capacity

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Typical Interconnection Study Process and Timeline

• A project developer initiates a new interconnection request (IR) and thereby enters the queue • A series of interconnection studies establish what new transmission equipment or upgrades may be needed and assigns the costs of that equipment • The studies culminate in an interconnection agreement (IA): a contract between the ISO or utility and the generation owner that stipulates operational terms and cost responsibilities • Most proposed projects are withdrawn, which may occur at any point in the process • After executing an IA, some projects are built and reach commercial operation

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There has been a substantial increase in annual interconnection requests (both in terms of number and capacity) since 2013; over 700 GW added in 2022 alone

Over 2,000 GW (2 TW) of generation & storage capacity active in queues; Especially strong developer interest in solar (~947 GW) and storage (~680 GW), including hybrid

62% (1,262 GW) of total capacity in queues has proposed online date by end of 2025; 13% (257 GW) already has an executed interconnection agreement (IA)

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Interest in hybrid plants has increased over time: Hybrids comprise 52% of active storage capacity (358 GW), 48% of solar (457 GW), and 8% of wind (24 GW)

Only 21% of all projects proposed from 2000-20171 had reached commercial operations by the end of 2022 – 72% had withdrawn from queues

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After falling from a 2012 peak, the typical duration from interconnection request (IR) to interconnection agreement (IA) increased sharply since 2015, reaching 35 months in 2022

Typical duration from IA to commercial operations date (COD) has increased modestly since 2007, except in CAISO where recently built solar projects took 4-6 years after securing an IA

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Conclusions

As of the end of 2022, there were over 10,200 projects seeking grid interconnection across the U.S., representing over 1,350 GW of generation and an estimated 680 GW of storage.

• Solar (947 GW) accounts for >70% of all active generator capacity in the queues, though substantial wind (300 GW) and gas (82 GW) capacity is also in development. 113 GW of offshore wind is currently active in the queues.

• Considerable standalone (325 GW) and hybrid (~358 GW1) storage capacity has also requested interconnection.

• The combined capacity of solar and wind now active in the queues (~1,250 GW) approximately equals the total installed U.S. power plant fleet capacity, and is greater than the estimated 1,100 GW needed to approach a zero-carbon electricity target2.

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• Capacity in queues is widespread across U.S. but some states dominate: Texas has 13% of proposed solar, storage, and gas, and 7% of proposed wind; New York has 23% of all proposed wind (mostly offshore); California has 14% of proposed storage.

• Hybrids now comprise a large – and increasing – share of proposed projects, particularly in CAISO and the West. 457 GW of solar hybrids (primarily solar+battery) and 24 GW of wind hybrids are in the queues.

• The majority (62%) of capacity in the queues is proposed to come online before 2025, and some (13%) already has an executed interconnection agreement (IA).

• The time projects spend in queues before reaching COD is increasing. For the regions with available data3, the median duration from IR to COD has doubled from 20 MW.

• Ultimately, much of this proposed capacity will not be built. Historically only ~21% of projects (and only 14% of capacity) requesting interconnection from 2000-2017 have reached commercial operations. As well, late-stage withdrawals may be on the rise…

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