An analysis run in 2011 shows it is better to keep Crist Unit 6 in operation, instead of retiring it in December 2014 and replacing it with new gas-fired combined cycle capacity, said Gulf Power in an updated clean-air plan.
The plan, filed April 2 with the Florida Public Service Commission, noted that Crist is a four-unit (Units 4-7), coal-fired plant. Three other units have already been retired. Units 4 and 5 each have nameplate capacity of 93.75 MW, Unit 6 is at 370 MW and Unit 7 at 578 MW.
All four Crist units have low-NOx burners. Units 4-6 also have selective non-catalytic reduction (SNCR) for NOx control. Unit 7 has selective catalytic reduction (SCR) for NOx. An SCR for Unit 6 is due to be operational in April of this year. All four units are covered by an SO2 scrubber that became operational in December 2009, which gives the plant the option of burning higher sulfur coal.
Under the U.S. Environmental Protection Agency’s new Mercury and Air Toxics Standards (MATS), Gulf Power is looking at additional controls at Crist, including dry sorbent injection and/or a baghouse, changing the fuel sources for certain units, the addition of new generating resources, and/or transmission upgrades.
If any party objects to the revised Gulf plan, claiming gas is cheaper, then the commission would look at that, perhaps in a separate docket.
Gulf Power also owns 50% of each the two coal-fired units at the Daniel plant, with the other 50% of each unit held by Mississippi Power, which is another subsidiary of Southern Co. (NYSE: SO). Each of the units has a nameplate capacity of 548.25 MW.
Both Daniel units have low-NOx burners and a major need for new emissions controls to comply with various clean-air programs. SO2 scrubbers for both units are currently scheduled for completion in late 2015. SCRs for both units are planned to be operational in the 2017-2018 period. Analysis shows that these emissions projects are better than shutting the units and replacing them with gas-fired capacity, Gulf Power said.
There are two coal-fired units at the Smith plant, with Unit 1 having a nameplate capacity of 149.6 MW and Unit 2 at 190.4 MW. Both have various NOx controls, including new SNCRs that became operational in the 2008-2009 period. Scrubber equipment for both units are in Gulf Power’s future plans, but that plan remains very flexible as new emissions rules are added and analyzed. A baghouse for Unit 2 is also in the utility’s very flexible future plans. Gulf Power said it hasn’t done a shutdown analysis for these coal units lately, but will do a new one when it gets closer to the time to make the scrubber/baghouse decisions.
The old, two-unit (49 MW nameplate for each unit) Scholz plant is nearing retirement, so Gulf Power said it won’t add any new controls there and will simply rely on emissions allowances for the time being.