The DTE Electric subsidiary of DTE Energy (NYSE: DTE) is wrapping up air emissions control projects at several coal units while targeting the retirement in 2016 of the 100-MW Trenton Channel Unit 7A.
DTE Electric on Feb. 1 filed a rate case application at the Michigan Public Service Commission. In that filing is testimony from Franklin D. Warren, the Vice President Fossil Generation for DTE. He noted that the company’s 7,505 MW of fossil steam plant contains coal-fired units that provide 6,720 MW of capacity. The coal plants are:
- Belle River (DTE ownership), 1,034 MW (net), two units
- Monroe, 3,066 MW (net), four units
- River Rouge, 523 MW (net), two units,
- St. Clair, 1,367 MW (net), six units;
- Trenton Channel, 730 MW (net), three units
The Michigan Public Power Agency (MPPA) is joint owner of the Belle River Power Plant and its ownership entitlement is effectively 18.61% (234 MW) of the plant. The MPPA ownership of Belle River is not included in the 1,034 MW Belle River Plant’s capability shown above.
In January 2014, Fossil Generation retired Harbor Beach Unit 1, a 103-MW coal unit and 4 MW of diesel peakers also located at Harbor Beach. In 2015, DTE Electric retired Trenton Channel Unit 8, a coal-fired unit rated at 100 MW. In 2016, Trenton Channel Unit 7A’s 110 MW will be retired. Trenton Channel Unit 9 will also have its capacity rating lowered by 40 MW from 520 MW to 480 MW because supplemental steam will no longer be available when the boilers associated with the operation of Trenton Channel Units 7A and 8 are retired.
Starting in 2020, Fossil Generation is tentatively forecasting the retirements of multiple coal fired facilities and the addition of new combined cycle and simple cycle gas turbine units. No formal approvals have been obtained for these additional unit retirements, nor for procuring/building additional new generation units; therefore, specific details on these options is not available at this time, Warren noted.
With regards to the retirements of Harbor Beach and Trenton Channel Units 7A and 8 the company requested and received Midcontinent ISO permission to retire these units through the MISO Attachment Y process, Warren said.
In anticipation that certain coal-fired generating units will be retired years before others, Fossil Generation created a tiered maintenance and capital expenditure allocation strategy. It now operates its coal fleet with two distinct strategies. The tier 1 long-term coal-fired units were identified as Belle River and Monroe while the remainder of the coal-fired units were classified as tier 2 units. Fundamental in this tiered strategy was establishment of different operating performance metric targets which drive both the O&M and capital expenditure plans for the different tiers.
Heavy spending done on ACI and DSI systems
Required expenditures will continue for the installation of new environmental compliance equipment. Approximately $110 million is being expended at Monroe to complete the installation of the flue gas desulfurization (FGD) and selective catalytic reduction (SCR) emissions control technology. Fossil Generation is also expending $199 million at Belle River, Trenton Channel, St Clair and River Rouge to meet new federal Mercury and Air Toxics Standards (MATS) rules between 2014 and 2017. That expenditure in Activated Carbon Injection (ACI) and Dry Sorbent Injection (DSI) technology to meet MATS compliance was approved by the commission.
Without ACI and DSI expenditures, compliance with environmental regulations would not be possible and these plants would not be allowed to continue to operate. If shut down, over 3,400 MW of capacity provided by these four power plants would be lost from the system along with their black start system restoration abilities in April 2016, Warren wrote.
Fossil Generation is also expending $65 million at Monroe and the other coal plants to meet the new federal coal combustion residuals (CCR) rules. An additional $6.1 million is being spent to complete engineering studies to prepare for 316b regulations (cooling water) and other new environmental regulations.
Warren said that $12.6 million is being spent to install new auxiliary boilers and steam systems at Trenton Channel to support the operation of Unit 9 after the retirement of Units 7A and 8 and their associated boilers. Without these new auxiliary boilers, Trenton Channel Unit 9 cannot continue to operate because it will not be able to heat the plant in the winter and will not have the steam required to startup Unit 9 after an outage.
Warren said that MATS allowed for one-year extensions to the initial April 2015 compliance date. DTE Electric applied for and was granted one-year extensions at its Monroe, Belle River, St. Clair, River Rouge, and Trenton Channel plants by the Michigan Department of Environmental Quality. Therefore, the compliance deadline for those five plants is currently April 16, 2016. Although Monroe physically complied with this regulation in 2015, the EPA supplemented the rule and enacted stringent new reporting requirements. In order to fully comply with these new reporting requirements the company asked for and got an extension at Monroe until April 2016.
At Monroe, the recently-completed FGDs and SCRs will allow Monroe to meet all the limitations of the MATS regulations. While FGDs and SCRs allow coal-fired units to meet the MATS regulations, DTE Electric has successfully tested less costly control technologies to be utilized at the remaining operating coal-fired plants. Performance testing has been completed at Belle River Units 1 & 2, St Clair Units 1 & 2, St Clair Units 3 & 4 and St Clair Unit 6. The remaining units – St Clair Unit 7, Trenton Channel Unit 9 and River Rouge Unit 2 & 3 – will have their performance testing completed in the first quarter of 2016. The testing completed to date has proven that the systems meet the MATS limits for acid gases and mercury. The particulate matter results for Belle River Units 1 & 2 also show compliance with MATS. The particulate matter results for St Clair Units 1 & 2, St Clair Units 3 & 4 and St Clair Unit 6 are pending. Further testing to fully optimize chemical injection rates will be conducted once the systems commence continuous operation.
During the 2014-July 2017 timeframe of this rate case, Fossil Generation is investing a combined $970 million in routine capitalized maintenance and non-routine environmental projects for its Tier 1 and Tier 2 coal units. The six tier 1 coal units (Belle River 1 & 2 and Monroe 1-4) are receiving 47% of this total capital for routine capitalized maintenance while 21% is going towards the tier 1 non-routine environmental requirements. The nine tier 2 coal units (St Clair 1-4, 6 & 7, River Rouge 2 & 3 and Trenton Channel 9) are receiving 15% of the total investments which is directed towards their routine capitalized maintenance while 17% is being directed total towards their non-routine environmental requirements.