The 693MW Lowman Energy Center (LEC) is an operating combined-cycle power plant in Leroy, Alabama, US.
The plant was developed by PowerSouth Energy (PowerSouth), a generation and transmission co-operative headquartered in Andalusia, Alabama.
Construction on the project was begun in 2020 and commercial operations commenced in September 2023. The plant can generate enough power to run 300,000 homes per year.
LEC aims to meet the energy demand of PowerSouth’s distribution members in Alabama and Northwest Florida using cleaner and more efficient natural gas technology.
Project location and background
The Lowman Energy Center was proposed to replace the 556MW Charles R Lowman coal-fired power plant, which was retired in October 2020 after running for 50 years.
The Lowman Energy Center uses advanced combustion turbine technology, which can function at an efficiency rating of more than 64%.
The facility features duct-firing capability, which enables a higher steam flow and pressure in the heat recovery steam generator (HRSG) while also providing accommodation for future upgrades. The increased steam flow and pressure enable more power to be produced in the steam turbine – approximately 80MW.
The power island comprises a M501JAC advanced class gas turbine, a steam turbine and a Vogt three-pressure reheat HRSG in a 1×1 multi-shaft configuration. The gas turbine can reduce CO2 emissions by up to 65% when compared to conventional coal-fired power plants.
The plant utilises excess heat to boil water for the steam turbine unit to capture energy. The feature reduces wastage of resources, while also providing an efficient energy system with low greenhouse gas emissions.
The project also features an 85km-long natural gas supply pipeline that is interconnected with two large interstate pipelines.
The existing infrastructure from the shuttered coal-fired power plant was also put to use, including the water treatment system, river intake structure and switchyards, which enabled considerable savings on the capital and construction costs of the project.
LEC received the 360t 501JAC CT from Savannah, Georgia, in May 2022. The turbine was first fired up in February 2023.
The steam turbine was delivered to LEC from Japan in August 2022 and the installation of LEC’s power island commenced in the same year.
M501JAC gas turbine details
The Mitsubishi M501JAC gas turbine is an air-cooled version of the steam-cooled J-Series gas turbine that was introduced in 2009. The upgraded gas turbine provides improved operational flexibility by detaching the gas turbine from the bottoming cycle.
The turbine has a standalone output of 453MW and a combined-cycle output of 664MW with an efficiency rating greater than 64%. The gas turbine provides improved operability with reduced start-up time and reliable long-term performance.
The gas turbine features a rotor with a simple single-shaft two-bearing support and bolt-connected discs. The turbine casings are also horizontally split to facilitate field removal of the blades with the rotor in place.
Contractors involved in the LEC project
Mitsubishi Hitachi Power Systems was awarded the contract to supply the gas turbine for the Lowman Energy Center in September 2019. The scope of the contract also included service and maintenance for the turbine under a long-term service agreement.
Casey Industrial, a subsidiary of construction company MasTec, was awarded the contract for the mechanical construction services of units 1 and 2 of the project in January 2021.
Engineering company Black & Veatch provided the construction services for the project. The company worked with Casey Industrial to provide startup, commissioning, and performance testing of the project.