WASHINGTON - President Barack Obama will announce the largest investment of economic stimulus funds in clean energy during a visit to Florida, an Obama administration official said on Monday.

The announcement will involve the smart grid, which will help bring energy from clean domestic sources to consumers in 49 states and help build a strong and more reliable electricity grid, the official said.

Obama is to travel to Arcadia, Florida, on Tuesday to make the speech and take a tour of the DeSoto Next Generation Solar Energy Center.

Separately, U.S. Vice President Joe Biden plans on Tuesday to visit a closed General Motors plant in Wilmington, Delaware, where he is expected to announce that it will be reopened for the building of plug-in hybrid electric cars.

The California-based venture capital firm Fisker Automotive Inc has reached a deal to buy the former GM assembly plant and plans to use it for the manufacture of the cars, according to a source familiar with the details of Biden's visit.

A White House statement on Biden's visit said he planned a major announcement about the assembly plant's future, but gave no other details. Delaware is Biden's home state.

(Reporting by Patricia Zengerle)

Energy Florida California Joe biden