Solar installations in the U.S. dropped 17% year-over-year (YoY) in the third quarter (Q3) of 2022, with 4.6 GW of cumulative capacity installed during the period, said a report released by Wood Mackenzie and Solar Energy Industries Association (SEIA).

The report attributes the dip in installations to delays in approvals for hundreds of stranded solar equipment shipments that are subject to inspection under U.S. Customs and Border Protection (CBP).

Several projects await execution and construction, while many imported solar modules and cells await compliance clearance under the Uyghur Forced Labor Protection Act (UFLPA).

While commercial solar installations in Q3 totaled 340 MW, community and utility-scale solar installations stood at 212 MW and 2.5 GW, respectively,

The U.S. Solar Market Insight Report 2022 Q4 said that trade barriers and ongoing supply chain constraints would cause a 23% decline in solar installations this year compared to 2021.

Further, the report forecasted that the utility-scale solar market would add 10.3 GW of new capacity in 2022, representing a 40% drop from 2021 volumes.

The U.S. Department of Commerce’s recent decision to apply anti-circumvention tariffs on solar products from Southeast Asia presents a downside risk to future solar deployment, the report said.

It added that the industry will remain supply-constrained through at least the second half of 2023. “Equipment importers are still contending with detainments as they seek to provide the documentation needed for compliance,” it said.

By 2024, Inflation Reduction Act-fueled growth will begin in earnest, with annual solar growth averaging 21% between 2023 and 2027.

“Once supply chain relief arrives, the true impacts of the Inflation Reduction Act will manifest in our outlooks. Beginning in 2024, annual installations of solar will consistently reach 30-40 GWdc,” the report said.

SEIA President and CEO Abigail Ross Hopper said, “America’s clean energy economy is being hindered by its own trade actions. The solar and storage industry is acting decisively to build an ethical supply chain, but unnecessary supply bottlenecks and trade restrictions are preventing manufacturers from getting the equipment they need to invest in U.S. facilities. In the aftermath of the Inflation Reduction Act (IRA), we cannot afford to waste time tinkering with trade laws as the climate threat looms.”

As a result of supply constraints, the utility-scale, commercial, and community solar markets all experienced quarter-over-quarter declines in Q3. The residential solar segment was less directly impacted by existing trade issues and saw 1.57 GW of new installations, marking a 43% increase over Q3 2021.

“Installations this year were significantly depressed due to supply chain constraints,” said Michelle Davis, principal analyst and lead author of the report. “It has proven more difficult and time-consuming to provide the proper evidence to comply with the UFLPA, further delaying equipment delivery to the U.S.”

The total installed capacity of solar in the U.S. stood at 135.7 GW, sufficient to power around 24 million American homes by the end of Q3.