The explosion killed one man and injured nine others.
Geoffrey Brown, a Wheeling, W.Va., attorney representing former AEP worker Drumand McLaughlin, 53, of Caldwell, said his client suffered "very serious" injuries in the January 8 incident.
"They are mostly to the left shoulder and neck and are permanent and debilitating injuries," Brown said. "Also, he has had a great deal of psychological issues and stress. The explosion itself was massive. Anyone who has lived through something like that can tell you it affects you."
The suit seeks unspecified damages and alleges AEP was aware, or should have been aware, of problems with a compressed hydrogen storage system that exploded during the transfer of the material from a tanker truck to the storage system.
Truck driver Lewis Timmons, 61, of New Martinsville, West Virginia, was killed in the explosion, which also damaged a generation unit at the plant and tore a 160-foot-by-160-foot section of metal siding from the building.
Brown said he also represents the Timmons family in a wrongful death suit against AEP and others that is filed in Moundsville, W.Va., and set to go to trial in August.
The attorney representing the power company, Mathew Casto, of Charleston, W.Va., declined to comment on the pending suits.
In their written response to the suits, the company denies any wrongdoing.
AEP officials did not return a call seeking comment.
In August 2007, AEP paid more than $55,000 in fines to settle federal Occupational Safety and Health Administration OSHA violations relating to the explosion.
The OSHA investigation led to one "willful" and eight "serious" violations, alleging the company demonstrated "intentional disregard or plain indifference to the law" in regard to the hydrogen storage.
Hydrogen is used as a cooling agent at the coal-fired power plant.
OSHA claimed the hydrogen cylinders were stored in an area that was not properly ventilated, which allowed for the accumulation of dangerous quantities of hydrogen.
Also, OSHA claimed AEP used thin-walled copper instead of stainless steel tubing for the system pressure relief devices were wrong and the containers were stored too close to oxygen and acetylene cylinders.
The trucking company Timmons was working for was also cited, with fines totaling $9,100.
The trucking company violations included failure to use non-sparking tools and failure to shut off the truck engine before starting the transfer of the hydrogen.