Every positive has a downside, even when it comes to clean power.

A study by the Lawrence Livermore National Laboratory highlights a growing backlog of projects applying, and waiting, for connection to the power grid. The backlog, according to the study, is largely attributable to the expanding volume of renewable energy projects, especially wind and solar.

“Queued Up: Characteristics of Power Plants Seeking Transmission Interconnection as of the End of 2022” was published earlier this month. It notes dramatic growth in the amount of new electric capacity in so-called “interconnection queues,” which are the lists of projects seeking connection to the grid. According to the study, the total generation and storage capacity of these projects now exceeds 2,000 gigawatts (GW). Of note, over 95% of this volume is for zero-carbon resources such as solar, wind and battery storage.

As the lab explains, all projects must submit impact studies to system operators before they can connect. These studies enable the providers to assess what sort of equipment installations or upgrades would be required, and the costs involved, to make the connection possible. The lists of these projects or interconnection queues provided the basic data for the study. The lab compiled queue data for Independent System Operators (ISOs), Regional Transmission Organizations and non-ISO utilities, representing over 85% of the total U.S. electricity load.  

The study found that the total capacity active in the queues is growing year-over-year, with more than 10,000 projects representing 1,350 GW of generation and an estimated 680 GW of storage capacity at the end of last year.

At 95% of the total, or 1,250 GW, zero-carbon sources make up almost the entire volume of projects. Solar accounts for the largest share at 947 GW. At 300 GW, wind accounts for most of the rest. About a third of the wind power capacity, or 113 GW, would come from offshore generation. According to the lab, the combined total of zero-carbon generating and storage capacity 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 target.

The study notes that projects in the queues are dispersed across the entire country, but some states such as Texas, New York and California host the largest shares.

Also of note, the study projects that much of the proposed capacity in the queues will ultimately not be built, as only about 21% of projects (and only 14% of capacity) requesting interconnection from 2000–2017 have reached commercial operations.