Large-scale solar ground PV installations in the U.S. fell 53% year-over-year in the second quarter of 2022, as policy headwinds and trade concerns weighed on development and increased undelivered delays, according to a new report.

This quarter, the industry developed 41 solar projects with a combined capacity of 1,575MW in the U.S., according to research by the American Clean Energy Council (ACP), a trade body, meaning that solar development in the first half of 2022 was down from the first half of 2021. 25%.

Other headwinds affecting progress in renewable energy include commodity prices, pandemic-related delays, supply chain issues and increased operating costs, the ACP said.

Large-scale clean power development in the United States fell 55% year-on-year in the second quarter to 3,188MW.

"We have been sounding the alarm about the policy storm and economic headwinds facing the clean energy industry, and this is a step in the wrong direction," said Heather Zichal, chief executive of ACP.

"Congressional inaction, uncertain long-term tax policy, tariff and trade restrictions, and transmission restrictions have all impacted the demand for clean energy at a time when we need to rapidly scale our development."

The report noted that solar module supply has significantly delayed project schedules after the U.S. Commerce Department decided to investigate claims to circumvent tariffs.

Currently, nearly 21GW of solar projects in the U.S. are delayed. The ACP said much of this was a direct result of "misleading trade actions".

U.S. imports of solar modules fell earlier this year as a Commerce Department investigation that began in March led to the threat of retroactive tariffs. President Biden has since waived tariffs on solar imports from four Southeast Asian countries for two years.

The ACP report states that despite regulatory headwinds, solar remains the leading technology in the U.S. clean energy sector. The United States has 22,765MW of solar power under construction, and 50,938MW of solar power in the late stage of development.

Texas is the No. 1 state for solar development in the United States, with 14,117MW of projects under construction, followed by California (7,679MW) and Indiana (6,325MW).

Growth in clean power purchases was a bright spot, ACP said, with renewable energy PPAs totalling 8,502MW in the second quarter of 2022, up 27% year-on-year.