Ameren Missouri to shut aging Meramec coal plant by 2022

The Sierra Club on July 7 celebrated the fact that Ameren Missouri recently told the Missouri Public Service Commission that it plans to shut its coal-fired, 839-MW Meramec power plant by 2022.

“Communities in south St. Louis have struggled with unsafe air for decades, and Ameren’s announcement that it will stop burning coal at the Meramec power plant is an important step forward for these communities,” said Sara Edgar, Field Organizer with the Sierra Club Beyond Coal campaign in St. Louis. “We are ready to work with Ameren on a plan to invest in local clean energy, to build a responsible timeline for transition of its workforce at Meramec and to move as expeditiously as possible to stop burning coal in St. Louis.”

Ameren’s clean energy portfolio is currently small, and Kansas City Power & Light (KCP&L), Missouri’s second-largest electric utility after Ameren, overshadows Ameren when it comes to clean energy investments, the Sierra Club said. In January, KCP&L announced it was nearly doubling its investment in wind power. 

The announcement of the phase out of the Meramec coal plant represents the 168th coal plant to retire or be announced for retirement since 2010, the club noted.

Ameren says Meramec is old and not very efficient

The club based its pleasure on July 3 testimony from Kevin DeGraw, Vice President of Power Operations for Union Electric d/b/a Ameren Missouri.

“Meramec is a four unit, coal-fired base load power plant whose first generating unit went online in 1953 and whose last generating unit went online in 1961,” DeGraw wrote in testimony filed at the PSC. “It is by far the Company’s oldest and least efficient base load power plant, and is one of the older coal-fired power plants in the nation. Its low efficiency, relative to the Company’s other coal-fired plants, is because of the technology available at the time it was built as well as the age of the plant. This  is not unlike the efficiency of an older model car versus a much newer car. Meramec has served the Company and its customers very well over the past approximately 61 years, and we believe it can still provide service for a few more years, but, as I discuss below, it is clear that it is nearing  the end of its useful life and that it will have to be retired by 2022.”

Ameren has experienced some equipment failures at Meramec that caused it to have concerns about its ability to operate the plant safely. In 2012, the utility had two failures in high energy pipes that could have resulted in severe injuries to employees working in the area. Since its retirement date was last set for depreciation purposes, the plant has also run much less because the economics in the market have not supported dispatching it nearly as often as was the case historically, DeGraw pointed out. The Meramec plant was originally designed for a 40-year life.

As part of its evaluation of Meramec’s future, Ameren engaged consultant Burns and McDonnell to conduct a comprehensive assessment of key plant components. That effort began in September 2013, and was completed with the delivery of their report in May. Burns and McDonnell determined that the plant could be safely operated through 2022 with certain capital investments and maintenance expense. The level of capital and maintenance expense predicted currently support economic operation until 2022 in Ameren Missouri’s economic modeling. Ameren has a difficult time seeing any scenario where Meramec could operate after 2022 without installing substantial pollution control equipment (likely a flue gas desulfurization unit at a minimum) at a cost of several hundred million dollars. DeGraw said federal greenhouse gas or other rules could force the plant to be shut earlier than 2022.

DeGraw also testified about the status of Ameren’s sale of coal from stockpiles at its Labadie, Sioux and Rush Island plants to refined coal companies, which add chemicals to it to reduce certain pollutants when burned, then sell the refined product back to Ameren for actual use.

DeGraw said the refined coal can cause problems. “The refinement process creates bromic acid as a byproduct in the exhaust gas at the plants. The bromic acid has condensed causing corrosion on the air heater baskets at the plants and related equipment. This corrosion is expected to increase the operations and maintenance costs at the plants. This is an industry-wide problem for power plants utilizing this type of coal refining. Additionally, the refinement chemicals increase slagging rates in the boilers, requiring more frequent boiler cleaning operations.”

But he said that refined coal produces tax-credit-related revenues above these costs, and also reduces plant emissions, so these refined coal projects are worth doing.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.