Florida Power & Light Company (FPL)—the principal subsidiary of NextEra Energy Inc., and the largest electric utility in the US serving over 12 million people in Florida—is building an approximately 80-mile (129-km) transmission line between the Okeechobee and DeSoto counties. The project also includes enhancements to existing substations and infrastructure in the area, and will serve substations in the Okeechobee, DeSoto, and Highlands counties.
The project involves both new 230 kV line construction and the conversion of existing 69 kV lines. Approximately 75 per cent of the new transmission line will utilize existing rights-of-way (RoW) and easements of a 69 kV line.
The line will extend from the Sweatt substation in Okeechobee County to the Whidden substation in DeSoto County, traversing through the Okeechobee, Glades, Highlands, and DeSoto counties, and Florida Department of Environmental Protection’s Southeast and South Districts, St. Johns River Water Management District, South Florida Water Management District, and Southwest Florida Water Management District.
After a review of various factors and constraints, FPL identified and certified a corridor for the proposed transmission line, which will cover four segments:
- Sweatt–Basinger
- Basinger–Waterway
- Waterway–Dorr Field
- Dorr Field–Whidden
In a related development, transmission facilities for the Mare Branch Solar Energy Center in DeSoto County will connect the approximate 74.5 MW (nameplate, AC) solar energy center in Q1 of 2026, and includes the construction of a new 230 kV substation (Stallion) on the project site, one 230 kV line switch at Whidden for string bus to the Stallion substation (approximately 11 km), a new 230 kV breaker at the Stallion substation, one 230/34.5 kV main step-up transformer (85 MVA) with a 230 kV breaker to connect the PV inverter array, a 34.5 kV bus to connect the PV array to the Stallion substation, and other relays and other protective equipment. On the transmission front, an 11-km string bus will be constructed from the 230 kV Whidden substation to the Stallion substation.
The Need Determination for the Whidden to Sweatt project was approved on May 17, 2022. The project was certified under the state’s Transmission Line Siting Act (TLSA) on September 22, 2022 after public engagement and input in early 2022. The design and permitting process was carried out during 2022-24, followed by construction beginning in early 2024, consisting of RoW clearing, access road construction (where necessary), and line construction and restoration. The project is subject to various environmental regulations and requires coordination with government agencies like the Florida Department of Environmental Protection and the Department of Historic Resources.
FPL’s transmission plan will allow for the reliable delivery of the required capacity and energy to Its retail and wholesale customers. As part of this plan, the proposed Whidden–Sweatt transmission line would improve system reliability for customers and support future growth in the area. The project is expected to be completed and brought into service in mid-2026.