Tampa Electric's $660 million Polk Power Station upgrade goes live

Tampa Electric lit the fires on a $660 million expansion of its Polk Power Station on Monday and began providing energy to the Tampa Bay area.

The retrofitting project converted four, gas-powered, single-cycle generators at the Mulberry power plant into a combined-cycle system, adding 460 MW to 680 MW.

The utility broke ground on the project April 2014 and planned to have it completed this month with an estimated price of $700 million. The project was designed and managed by Black and Veatch, a Kansas-based engineering, construction and management firm focused on large-scale infrastructure.

With the "four-on-one" project, the gas turbines - similar in function to a turboprop engine on a commuter aircraft - will direct their exhaust heat to a single boiler. The boiler's high-pressure steam turns a secondary generator, increasing the maximum output by two-thirds.

The added capacity is enough to power 100,000 homes, according to the utility. Tampa Electric has about 73,000 customers in Polk County.