A Florida developer unveiled plans today to build the nation’s first solar-powered city. The ambitious plan announced on Thursday is for a 19,500-home city with energy-efficient buildings that will be “the first city on earth powered by zero-emission solar energy.”

The new city, “Babcock Ranch” would be built on 17,000 acres in Charlotte and Lee counties, with more than half of the land set aside for nature preserves, agriculture and other open space.  It will include one of the world’s largest photovoltaic power plant, a 75-megawatt solar photovoltaic array, which will be operated by Florida Power & Light to supply electricity to the development’s 6 million square feet of residential, industrial and retail buildings. These will all be certified green and surrounded by thousands of acres of open space.

Developer Syd Kitson is betting heavily that he is going to attract investors, businesses and 45,000 residents to his $2 billion ranch community, which he plans to start building next year. He is promising 19,500 homes, 20,000 permanent jobs, open spaces and plenty of carbon-free megawatts.

“Solar is just the first step,” Kitson told reporters in a Washington news conference today. “Babcock Ranch will be a true living laboratory of the new-energy economy … where innovative companies can design, build and use the renewable and efficient technologies that customers across the country and around the globe will need.”

Three years ago, Florida agreed to buy 73,000 surrounding acres from Kitson’s company, Kitson & Partners, and preserve the land for hunting, camping, hiking and other recreation. The land deal still ranks as the largest of its kind in state history, conservationists say.

“The best thing you can say about Babcock Ranch is ‘diversity,’” said Charles Lee, Audubon of Florida’s advocacy director. “It represents virtually every inland freshwater and upland habitat you have in the state.”

Charles Pattison, president of the conservation group 1,000 Friends of Florida, also applauded the Babcock Ranch plan. Kitson bought the land in 2005 from a family that had used it for timber and ranching since the early 20th century.

“The initial fear was the property would be purchased and then parceled out,” he said. “Hopefully, this deal will be a forerunner of things to come.”

Kitson’s concept is that FPL’s 75-megawatt solar generator will produce more power for the state’s electric grid while the sun shines than the city will use in 24 hours. That means Babcock Ranch will have to rely on conventional power sources for the evening, but its net effect will mean it is a solar-only city.

Gov. Charlie Crist (R) has been forced to scale back a plan to buy land in the Everglades Agricultural Area from U.S. Sugar Corp. The South Florida Water Management District wants to convert the farms to reservoirs and stormwater-treatment marshes for the long-range restoration of the Everglades.

Facing growing costs and shrinking tax revenue, the Florida Legislature is now threatening to cut funding this year for the state’s Forever Florida program, which uses fees from real estate transactions to conserve ecologically important land.

Kitson, who is planning to raise outside capital as the project progresses, said he is attempting to persuade several companies to set up shop in Babcock Ranch. He is targeting solar panel manufacturers, lithium-ion battery makers and other clean-energy companies.

Florida Power & Light aims to break ground on the more than $350 million solar PV project as soon as this year, pending regulatory approval. The 75-megawatt generator would be the largest of its kind in the world and supply surplus electricity to the grid, noted Eric Silagy, FP&’s chief development officer.

The utility plans to raise electricity costs to pay for the project, he noted. The typical residential customer would see his power bill go up by about 20 cents a month.

“We’re looking forward to breaking ground on this project as soon as possible, getting the legislative and regulatory support to move it forward, bringing more jobs to southwest Florida and showcasing the cleantech corridor,” Silagy added.

Construction crews plan to break ground on Babcock Ranch’s infrastructure next year and begin building homes and offices in 2011, Kitson said. The entire city would be certified by the nonprofit Florida Green Building Coalition.

Homes and offices would be able to tap into a high-capacity digital pipeline and use “smart grid” meters to adjust their energy use. A study conducted by the economic research firm Fishkind & Associates Inc. for Kitson projects that Babcock Ranch would generate 20,000 permanent jobs in technology, retail, education, construction and other sectors over 20 years.

Past promises of economically and environmentally sustainable development, however, have earned other Florida developers ample skepticism from conservationists.

Even before the economic crisis, water was beginning to govern growth in Florida. Six million South Florida residents get their water from the Biscayne Aquifer that underlies Everglades National Park and parts of four counties in southeast Florida. Drawing down the aquifer too much could divert water from the southern Everglades and invite saltwater intrusion, warn state regulators, who have rejected several permits on such grounds.

As sustainable design projects throughout the country begin seeing stimulus money, this is a great example of how forward thinking developers can go in implementing new green-build technologies.