Dive Brief:

The United States added 2,387 MW of solar PV capacity in the second quarter of this year, topping Q1 installations and representing an 8% year-over-year gain, according to GTM Research and the Solar Energy Industries Association ( SEIA ) latest U.S. Solar Market Insight Report.

) latest U.S. Solar Market Insight Report. All three United States solar market segments, commercial, residential and utility-scale, saw quarter-over-quarter growth, according to the report. However, year-over-year residential installations saw a significant drop.

SEIA and GTM say they continue to believe the United States will triple cumulative capacity over the next five years — however, the report concludes that a proposal to impose tariffs on all imported solar panels “would result in a substantial downside revision to our forecast."

Dive Insight:

The outlook for installed solar capacity remains strong, according to the annual report, though it hinges on the outcome of an ongoing trade case.

Earlier this year, bankrupt solar panel manufacturer Suniva requested the International Trade Commission impose tariffs on all imported solar panels and establish a floor price on solar panels. The company is seeking an initial additional tariff of $0.40/watt and a floor price of $0.78/watt.

Solar installers have generally condemned the proposal, arguing that it would erase roughly two-thirds of installations expected to come online in the next five years. SEIA says the petition could cause the solar industry to shed 88,000 jobs in 2018. The potential loss could essentially negate the 51,000 jobs added last year.

The utility-scale segment made up almost 60% of the solar PV capacity installed in the second quarter, and marked the seventh straight quarter in which the United States added more than 1 GW of utility-scale solar. But residential solar is struggling: About 560 MW of residential solar was installed, representing a 17% decline year-over-year. GTM solar analyst Austin Perea blamed the slowdown on national installers scaling back operations in large state markets, prioritizing profitability over growth.

“While California was the first major market to exhibit signs of slow-down in Q1, many major Northeast markets began to feel the impact of national installer pull-back in Q2 despite a stable policy environment and strong market fundamentals," Perea said in a statement.

The report predicts the solar industry will add 12.4 GW of new capacity this year, down slightly from GTM Research’s previous forecast of 12.6 GW.