Louisville officially has one fewer coal-fired power plant. Louisville Gas & Electric officials and Mayor Greg Fischer on Monday cut the ribbon on the company’s new Cane Run natural gas power plant.
The plant is on the same site as the coal-fired plant in southwest Louisville. The old Cane Run is still on the property on the same spot its been for the last 61 years. But now, next to it, there’s the much-shinier new Cane Run plant. The $545 million, 640-megawatt plant has been fully operational since June 19.
The plant is the first natural gas combined cycle plant in Kentucky. It uses two natural gas combustion turbines, where natural gas turns a turbine. The turbine is connected to a generator and creates power. But there’s also another system: a heat recovery steam generator. That machine uses the excess heat generated by the combustion turbines to boil water, and generates more electricity.
Those two systems together mean the new Cane Run plant is much more efficient than the average power plant, said John Voyles, LG&E vice president of transmission and generation.
“A normal power plant … normally converts the energy into electricity at about a 30-35 percent efficiency rating,” he said. “This machine in combined cycle takes us over 50 percent. So it’s a very, very phenomenal machine, and very, very efficient and some of the most modern technology that we have.”
The plant will still have emissions—gases including carbon dioxide, carbon monoxide, nitrogen oxide and sulfur dioxide. But it’s much cleaner than a coal-fired power plant. On Monday morning, looking at the stacks, nothing visible was coming out. The company estimates that the new plant will reduce sulfur dioxide emissions by 99 percent and nitrogen oxide emissions by 82 percent.
LG&E had originally sought permission for the new gas plant to comply with upcoming federal regulations, including stricter regulations on mercury and other air toxics. That mercury rule’s fate is uncertain, after the Supreme Court sent it back to a lower court last week. But LG&E has already made most of the equipment improvements it needed to comply with the rule, and Voyles said the company is moving forward. The new Cane Run plant is now functional, and Voyles said Mill Creek should be in compliance by next spring. But he said decisions are still being made about how to operate Mill Creek; without a federal standard, LG&E might not choose to deploy all of the pollution control equipment.
The natural gas plant also won’t produce the material that Cane Run has become known for in recent years: coal ash. Mountains of coal ash rise around the plant—it’s a dry landfill, where the ash will be stored permanently. There’s grass growing over much of the landfill, and company officials say eventually, the whole landfill will be covered. The company’s wet landfill—a large pond filled with ash—will remain, too. It will be capped. Both landfills have been a source of concern for regulators and nearby residents in recent years; LG&E has been fined nearly $150,000 since 2011 by the Air Pollution Control District for repeatedly allowing ash to leave the company’s property and contaminate nearby homes.
Here’s a map of the new plant, courtesy of LG&E: