San Franciscans can now search the Web, return e-mails or help their kids with homework at 30 city parks, plazas and recreation centers where free Wi-Fi was rolled out this week, thanks to a partnership between the city and Google.

Supervisor Mark Farrell, Mayor Ed Lee and other city officials will officially unveil the free Internet access Wednesday morning, more than a year after Farrell announced the $600,000 gift from Google that he helped broker.

The money allowed the city to buy and install Wi-Fi equipment and will help cover two years’ worth of maintenance at 32 city parks, from Balboa Park and Crocker Amazon Playground on the city’s south side to the Richmond Recreation Center and Marina Green in the north. Once renovations at Mission Dolores Park and Boeddeker Park are finished, they will be connected, bringing the total to 32.

The parks were chosen carefully, Farrell said: The city wanted to make sure free access is spread across the city evenly, is being offered in highly trafficked places and that the gift helped bridge the “digital divide” that often leaves low-income families with little access. Users will be able to log in by choosing the “#sfwifi” option on their smartphones, tablets or laptops.

“From my perspective, this is just the beginning — Internet access is no longer a luxury; I believe it’s a necessity,” he said. “This is about economic empowerment, and what drives me is that communities that have not had Internet access before will now be able to be online all the time. It’s the beginning of a broader vision of ensuring everybody in San Francisco has Internet access.”

For seven years, city officials have been talking about blanketing the city with free Wi-Fi, but after a deal among Earthlink, Google and City Hall fell apart during former Mayor Gavin Newsom’s administration, installation has been piecemeal. There is free access in parts of City Hall, San Francisco International Airport, along the Market Street corridor and at public housing developments.

Lee said the Internet access project is a great example of what private industry and the public sector can accomplish together.

“Wi-Fi in our city’s parks will help the city move one step closer to a larger vision of connecting our city as a whole and bridging the digital divide,” he said.

Including recreation centers, public plazas and parks will go a long way toward helping low-income kids, said Rodney Chin, executive director of the Buchanan YMCA, which runs after-school and summer programs at Margaret Hayward Park in the Western Addition.

He said many families have been left behind as more schools move to online homework assignments and use e-mail as a way to communicate with parents.

“A lot of kids in the Western Addition don’t have Wi-Fi or Internet access at home,” he said. “This is great — parents can come in and use our computers to interact with teachers. ... It’s a step toward leveling the playing field.”

The access will also help the Recreation and Park Department facilitate its programs, city officials said — previously, many of its clubhouses didn’t have Internet access, even though the public can sign up for recreation programs online.

Marisa Lagos is a San Francisco Chronicle staff writer. E-mail: mlagos@sfchronicle.com Twitter @mlagos