ARCADIA, Fla. (AP) -- President Barack Obama made a pitch for renewable energy Tuesday, announcing $3.4 billion in government support for 100 projects aimed at modernizing the nation's power grid.

Touring a field of solar energy panels in west-central Florida, the president urged greater use of several technologies to make America's power transmission system more efficient and better suited to the digital age. The projects include installing "smart" electric meters in homes, automating utility substations, and installing thousands of new digital transformers and grid sensors.

"There's something big happening in America in terms of creating a clean-energy economy," Obama said, although he added there is much more to be done.

He likened the effort to the ambitious development of the national highway system 50 years ago. He said modernization would lead to a "smarter, stronger and more secure electric grid."

Under muggy skies, Obama toured the DeSoto Next Generation Solar Energy Center, which is designed to generate enough energy for about 3,000 residential customers of the utility FPL. It is the nation's largest photovoltaic electricity facility.

Obama said a modern grid could give consumers better control over their electricity usage and costs, and spur development of renewable energy sources such as wind and solar.

The $3.4 billion in grants from the government's January economic stimulus program will be matched by $4.7 billion in private investments. The smallest grant will be $400,000 and the largest $200 million.

"We have a very antiquated (electric grid) system in our country," Carol Browner, assistant to the president for energy and climate change, told reporters. "The current system is outdated, it's dilapidated."

Matt Rogers, the Energy Department official involved in the program, said the 100 projects were selected from 400 proposed. The money will be distributed over the next two months and the work is expected to be done over the next one to three years, he said.

Even as Obama pitched more efficient and renewable energy use, his trip to Arcadia made it clear that old habits and dependencies die hard. He arrived in a motorcade of gas-guzzling SUVs. While waiting for the motorcade to get started, several vans kept their engines running to provide air conditioning for occupants escaping a hot Florida sun.

The U.S. Chamber of Commerce, which has been at odds with Obama over health care, energy and other matters, praised the clean-energy initiative.

Associated Press reporter H. Josef Hebert in Washington contributed to this report.