Over the past six years, rooftop solar panel installations have seen explosive growth — as much as 900 percent by one estimate.

That growth has come to a shuddering stop this year, with a projected decline in new installations of 2 percent, according to projections from Bloomberg New Energy Finance.

A number of factors are driving the reversal, from saturation in markets like California to financial woes at several top solar panel makers.

But the decline has also coincided with a concerted and well-funded lobbying campaign by traditional utilities, which have been working in state capitals across the country to reverse incentives for homeowners to install solar panels.

Utilities argue that rules allowing private solar customers to sell excess power back to the grid at the retail price — a practice known as net metering — can be unfair to homeowners who do not want or cannot afford their own solar installations.

Their effort has met with considerable success, dimming the prospects for renewable energy across the United States.

Prodded in part by the utilities’ campaign, nearly every state in the country is engaged in a review of its solar energy policies. Since 2013, Hawaii, Nevada, Arizona, Maine and Indiana have decided to phase out net metering, crippling programs that spurred explosive growth in the rooftop solar market. (Nevada recently reversed its decision.)

Many more states are considering new or higher fees on solar customers.

“We believe it is important to balance the needs of all customers,” Jeffrey Ostermayer of the Edison Electric Institute, the most prominent utility lobbying group, said in a statement.

The same group of investor-owned utilities is now poised to sway solar policy at the federal level. Brian McCormack, a former top executive at the Edison institute, is Energy Secretary Rick Perry’s chief of staff. The Energy Department did not make Mr. McCormack available for an interview.

In April, Mr. Perry ordered an examination of how renewable energy may be hurting conventional sources like coal, oil and natural gas, a study that environmentalists worry could upend federal policies that have fostered the rapid spread of solar and wind power.

Charged with spearheading the study, due this summer, is Mr. McCormack.

“There’s no doubt these utilities are out to kill rooftop solar, and they’re succeeding,” said David Pomerantz, executive director of the Energy and Policy Institute, a renewable energy advocacy group. “They’re now driving the agenda.”