The new owner of the mothballed Potrero Power Plant on San Francisco’s central waterfront has submitted a plan to build more than 1,800 residential units on the 21-acre property, a number that could jump to nearly 2,700 homes if the group is successful in obtaining an adjacent switchyard owned by PG&E.

The housing-heavy proposal, which proposes significantly more units than previously contemplated, will be subject to environmental review that will take about 18 months to complete.

Enrique Landa, principal with property owner Associate Capital, said the goal is to construct a “a majority residential project” with a mix of parks, office space, and research and development buildings.

It would consist of 19 buildings, ranging in height from 65 feet near the water to a single 300-foot residential tower at the center of the site. About 6.7 acres would be dedicated to open space, and an existing structure, the four-story concrete Unit 3 Control Room Building, would be converted into a boutique hotel with between 120 and 150 rooms.

The 300-foot concrete smokestack, visible from much of the city, would be preserved.

“The overwhelming response has been ‘keep the stack, keep the stack, keep the stack,’” Landa said. “My 6-year-old son and half the neighborhood would have me hung if they heard it was going away.”

The Potrero Power Plant, just south of Pier 70 in Dogpatch, was shut down in 2011 and has since cycled through several owners. Associate Capital, which is backed by Hewlett Packard Enterprise CEO Meg Whitman, bought the property in October, beating out nine other development groups.

Dogpatch and Potrero Hill neighbors made it clear that in addition to preserving the smokestack and providing as much housing as possible, they wanted a neighborhood with more variety of uses and architectural forms than in nearby Mission Bay, where 90-foot zoning restrictions have resulted in a district where the architectural forms are fairly uniform, Landa said.

Instead, the hope is that the power plant property will become an extension of Pier 70, where a dozen historic industrial buildings will be preserved alongside 1 million to 2 million square feet of new office space and 1,100 to 2,150 housing units.

“Our goal is that 15 years from now, when this site is all built out, no one will be able to tell where Pier 70 ends and where the power plant begins,” Landa said. “It will just be one neighborhood.”

Unlike Pier 70, where the range of housing units and footage of commercial space is still in flux, Associate Capital is committed to specific plans for each. The only wild card is whether the development will eventually also include the 4.7-acre Pacific Gas and Electric switchyard that abuts the northwest corner of the property. PG&E has given Associate Capital permission to include the switchyard in the environmental study, but has not determined whether or when it would relinquish the site.

“We wanted to study (the switchyard) for housing — whether that is today, 15 years from now, or 20 years from now,” Landa said. “There are no plans to buy it, but it’s started the conversation, and we think it’s a good opportunity.”

The fossil-fuel-burning Potrero plant, which regularly was near the top of the list of dirtiest power plants in the state, finally closed in 2011 after a decade-long crusade by neighbors and city officials. Since then PG&E has cleaned up 60 percent of the property to a “commercial standard,” which is not as high as residential standard. Just last summer, the three massive fuel tanks — they held 21 million gallons total — were demolished. That will allow PG&E to clean the rest of the property.

San Francisco Supervisor Malia Cohen said she will push for the maximum amount of affordable housing.

“It’s going to be an exercise for the entire community to reimagine what should go there,” Cohen said. “It’ll be like a phoenix rising out of the ashes.”

Retired waterproofing contractor and former neighborhood association leader Keith Goldstein, who has lived and worked on Potrero Hill for three decades, is “cautiously optimistic.” He said he wants to see a variety of uses and heights, and embraces the idea of a small waterfront hotel.

“They have come up with a good vision for the site,” Goldstein said. “I am willing to take a gamble. If some more height can generate more public benefits, then I am all for it.”

The open space — about 1.7 acres of which would be on Port of San Francisco land — would include an extension of the Blue Greenway trail along the waterfront and a South Park-like common area nearer the middle of the site. Youth soccer fields are planned, including one on top of a parking garage. The 100,000 square feet of retail would include a grocery store.

As the environmental study moves along, the developer plans to hold public events on the site, include the La Cocina street food festival Oct. 15.

Landa said the reaction so far to the proposed building heights has been mixed.

“While there are those who would like to see this all at 40 feet, single-family townhomes, there is an equally vociferous group that is saying you are not building enough housing,” he said.

Potrero Boosters President J.R. Eppler said the details around affordable housing and transit need to be worked out.

“The Potrero Boosters favor a project on that site that prioritizes residential development — we don’t want to get ourselves into a deeper hole with respect to the housing shortage that the region is experiencing,” he said. “We need to see details from the developer regarding their affordable housing component and details from the city on how transit will access the site.”

The developer is proposing 0.6 parking spots per residential unit and one space per 1,500 square feet of commercial development. Parking would be mostly consolidated in a centralized parking garage on the west side of the site. The total amount of parking would be 2,622 spaces if the adjacent switchyard is included.

“Even at 0.6 parking spaces per unit, that is more cars than the street grid itself can handle,” Eppler said.

The project will require the approval of the city Planning Department, Board of Supervisors and the San Francisco public utilities and port commissions.

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jdineen@sfchronicle.com

Twitter: @sfjkdineen