To generate the power, the plant used a combination of clean synthetic gas, which is produced from Mississippi lignite coal, and natural gas.

Southern Company chairman, president and CEO Thomas Fanning said: "After decades of research and years of hard work at the site, we are thrilled that the Kemper County energy facility, the world's most advanced coal plant, has generated electricity using syngas.

"The technology at the heart of the first-of-its-kind facility provides a way forward for energy companies in the US and around the world to cleanly generate electricity using an affordable and abundant resource."

Mississippi Power said that the production of electricity with synthetic gas needs integration of operation of the plant's gas cleanup system and associated gasifier, which has been operational since the middle of September.

Later, the synthetic gas is sent to one of the plant's combustion turbine electric generators.

As a step towards starting commercial operations, electricity generated at the plant will involve testing on synthetic gas, natural gas or a combination of both.

Mississippi Power chairman, president and CEO Anthony Wilson said: "The generation of electricity using syngas is just the latest example of our company's commitment to deliver on our promise that Kemper will provide Mississippi Power customers with safe, reliable energy for decades to come.

“Achieving this latest milestone means that we are implementing innovative 21st-century technology right here in Mississippi."

The next phase of the project is expected to see generation of electricity with second gasifier and operation of both combustion turbines using all syngas.

Mississippi Power expects the remaining part of the project to be placed in service by 30 November 2016.

Upon completion, the project will be the first large-scale power plant in the US to gasify coal and capture carbon, Bloomberg reported.

The project received a funding of $245m from the US Department of Energy.

Image: Southern Company generates power at $6.9bn Kemper plant for the first time. Photo courtesy of Southern Company.