It's hockey season once again in the Palo Alto foothills, and neighbors of former Sun Microsystems Chairman Scott McNealy know what that means: the ice dome is back.

After taking it down last spring under pressure from the Palo Alto planning department, McNealy recently resurrected the inflatable roof over his backyard tennis court, turning it back into an ice hockey rink just in time for winter. In response to complaints from neighbors, he has added padded fences to screen the facility from view and muffle the sound of slapshots.

Those modifications have earned him a 45-day permit from the city's planning director, granted last month. Whether they mollify residents of the surrounding estates in this forested, typically serene neighborhood on the border of Palo Alto and Portola Valley remains to be seen.

"We told him if it doesn't work, we won't renew the permit," said Curtis Williams, director of planning and community environment for Palo Alto. "If it seems to do the job and eliminate the off-site impacts, then we would renew it for the rest of the winter, and he would take it down in spring. He doesn't need it in spring and summer."

McNealy, who served as Sun Microsystems' chief executive from 1984 to 2006, is a self-described avid hockey player and reportedly built the backyard rink last year so he could play with friends and with his four sons. A call to his office for comment was not returned.

A hockey rink is a fine idea, neighbor Peggy Law said as she looked down at its white roof from her yard Friday afternoon. The problem, she noted, is that it mars an otherwise beautiful landscape.

"The screen is certainly better than not having a screen," Law said. "But from here, it doesn't cover up the whole thing. Even with the screen it just doesn't look like something that should be in an open space district."

At night, she said, it lights up and glows "like a spaceship landing, or a parked blimp."

The facility was evidently in use Friday, as the echoes of missed shots and players' shouts rang out across the valley.

Williams said the city has gotten one complaint about the rink so far this year, from a resident who griped that the fencing didn't fully obscure it from view. The city's code enforcement officers will see that McNealy addresses that deficiency before extending his permit, Williams said.

If the city gets complaints about the noise, he said, they'll look into that, too.

Neighbors' criticism of the facility first surfaced at a Portola Valley Town Council meeting in February. Leslie Lambert, that town's planning manager, said Friday she was surprised to hear from a resident that the rink was back up. She said she will forward any further complaints from Portola Valley neighbors to Palo Alto's code enforcement staff.