A handout photo shows wind turbines in Glenrock, Wyoming. Handout via REUTERS

(Reuters) - With the Trump administration expected to publish an analysis that could undermine the U.S. wind and solar industries, two renewable energy lobbying groups on Tuesday released their own study saying new energy sources pose no threat to the country’s power grid.

Wind and solar advocates have said the government study’s outcome appeared to be pre-determined to favor fossil fuel industries. The new report, commissioned by the American Wind Energy Association and Advanced Energy Economy, says cheap natural gas is behind most of the decline in the numbers of U.S. coal-fired power plants in recent years, not government subsidies that have bolstered the growth of wind and solar power.

It also said there is no evidence to show that wind and solar energy are threatening the reliability of the electric grid.

The groups commissioned the report shortly after Energy Secretary Rick Perry in April ordered a 60-day study of the reliability of the grid and said Obama-era policies offering incentives for the deployment of renewable energy had come at the expense of energy sources like coal and nuclear.

With the 60-day deadline for the DOE study looming this month, AWEA and AEE released their own analysis of the issue performed by economic consulting firm Analysis Group.

The authors of the analysis found that the rapid growth of renewable energy and related policies were “a distant second to market fundamentals in causing financial pressure” on coal plants without long-term contracts. Market forces such as new, more-efficient efficient natural gas plants, low natural gas prices and flat electricity demand are the biggest contributor to coal plants’ inability to compete, the report found.

The analysis also found that greater diversity of technologies made the system more reliable.

“There are lots of different technologies that fill different pieces of the reliability puzzle,” said Susan Tierney, one of the report’s authors. “That led us to believe that there is not a problem on the horizon for reliability.”

The DOE’s grid study is expected to be released later this month.