CAMP EDWARDS - The Massachusetts National Guard took a giant leap toward generating its future electricity needs through wind this week with about half of its proposed turbines approved by the Federal Aviation Administration without restrictions.

The FAA approved eight of 17 sites at the Upper Cape military base on Thursday, saying they pose no adverse effects to aviation. Height reductions of 177 to 225 feet are being recommended on seven of nine other locations. At least two of those locations would interfere with radar located at Air Station Cape Cod that tracks planes coming and going from the Cape and Islands, according to the FAA reports.

It's still possible those sites could be approved, Jim Peters, a spokesman for the FAA, said Thursday, but the Guard would have to refile its application with the changes and a new study completed.

All 17 turbines had already received the blessing of the U.S. Air Force Space Command, which operates the base's PAVE PAWS radar station.

"We're quite pleased with it," said Brig. Gen. Thomas Sellars, who is overseeing the wind project for the Guard. "We've taken one more step in a long march."

In June, the National Guard filed its application with FAA for 17 wind turbines, each at 400 feet, calling it the most ambitious renewable-energy initiative in the country at a military base. At the time, officials said the turbines would generate enough electricity to power the base.

These would not be the first wind turbines at the Massachusetts Military Reservation. There is a 1.5 megawatt turbine under construction by the Air Force Center for Engineering and the Environment, which would power water treatment facilities and reduce the Air Force's overall electric bill by 30 percent. That turbine is just waiting for one more column before it can be completed, a spokesman said Friday.

Because the base is home to an active airfield and the National Guard uses Blackhawk helicopters to practice moving troops, the plan will undergo further scrutiny by the military, Sellars said. There are also environmental hurdles to overcome, so it could be another 24 to 30 months before any additional wind turbines rise from the 22,000 acres, he said.

"It's not something that's immediate," he said. "We have a vigorous process to go through."

The base will take a close look at the sites where the FAA said the turbines could pose a risk to aviation and make adjustments, Sellars said.

"Now that we have their answer, we can focus in on the ones that have the greatest potential," he said.

The project has been highly touted by state Senate President Therese Murray, D-Plymouth, and U.S. Rep. William Delahunt, D-Mass., as a way to make the military installation less susceptible to future base closings.