St. Francis Power Plant

Plant statistics Unit 1 - 1999 Siemens combined-cycle, gas-based unit Net capacity of 245 MW Operated by Siemens Unit 2 - 2001 Siemens combined-cycle, gas-based unit Net capacity of 256 MW Operated by Siemens In 2002, the St. Francis Power Plant was recognized among the top 20 combined-cycle plants in the country for low emissions and efficient performance. The 501-MW plant ranked 14th most efficient and 13th lowest nationwide for NOx emissions among combined-cycle plants.

AECI’s St. Francis Power Plant won the “Year 2000 Powerplant Award,” given annually by “Power” magazine, for its “innovation in economical power delivery and use of state-of-the-art emissions control and information systems technology to decrease the environmental impact of power generation.”

Dedicated in 1999, St. Francis Unit 1 was singled out as operating one of the first 84.3A gas turbines in the nation with advances such as a 40-degree Fahrenheit increase in firing temperature, dry low-nitrogen oxides combustion when burning either natural gas or fuel oil and single-crystal turbine blading.

In 2001, AECI brought on line the second combined-cycle unit at the St. Francis Power Plant, located in southeast Missouri. Together, the two units can generate 501 megawatts of electricity.

Fuel for the generating units is natural gas supplied to the plant by Texas Eastern Transmission Corp., a wholly owned subsidiary of Duke Energy Corp. Operating at full load, each unit burns roughly 43 million cubic feet of natural gas per day.

Siemens oversaw the construction of both units -- including the design, engineering and construction – and operates the units under a contract with AECI.

Features of the power plant include an advanced combustion turbine which is considered one of the most efficient units of its type on the market, a steam turbine, a heat recovery steam generator, cooling towers, water treatment facilities and an electrical switchyard.

Heat-recovery steam generators capture exhaust from the gas turbines to heat water to create steam to power a steam turbine that turns a generator to produce electricity. These heat-recovery steam generators increase the efficiency of the combined-cycle units to 58 percent, compared with 33 percent efficiency of a simple-cycle unit (which does not capture exhaust for further use).

St. Francis Power Plant, which requires 10 acres, sits on a 49-acre tract.

The environmental impact of operating St. Francis is minimal. Its emissions are among the lowest in the state with nitrogen oxides limits of 4 parts per million and 4.5 parts per million on Unit 1 and Unit 2, respectively.