The Montana Public Service Commission is reviewing a 2013 integrated resource plan (IRP) from Montana-Dakota Utilities that includes a new simple cycle combustion turbine at Heskett (Heskett 3) and the in-construction air quality control system (AQCS) at the existing Big Stone coal plant.
The Montana commission is taking public comment on the IRP until Dec. 20.
The potential resource options studied included simple-cycle combustion turbines, combined cycle combustion turbines, internal combustion engines, coal-fired generation, wind generation, solar, geothermal, biomass, landfill gas, 50 MW to 100 MW wind purchase power agreement from bids received as part of a 2013 Request for Proposals (2013 RFP), and the addition of a baghouse required to continue operating the existing Lewis & Clark coal plant.
Along with the potential resource options, Midcontinent ISO energy purchases are available to meet energy needs, MDU noted in the September IRP filing.
The results of the integration analysis indicate that Montana-Dakota’s current optimal resource plan includes:
- the commercial operation of the 88-MW Heskett 3 by 2015;
- three additional 36.6 MW internal combustion engine projects (two by 2015 and one in 2017);
- the continued construction of the Big Stone AQCS to be in service by 2015;
- the addition of a baghouse at the Lewis & Clark coal station in 2015;
- contracting for 50 MW to 100 MW of wind generation; and
- adding 200 MW of a gas-fired combined cycle unit in 2020.
Additional options were included in the analysis in order to model the cost effectiveness of adding a baghouse to the Lewis & Clark Station or converting the coal plant to run only on natural gas. To comply with the federal Mercury and Air Toxics Standards (MATS), Lewis & Clark will be required to install a baghouse for particulate control or convert to natural gas-fired generation only.
Lewis & Clark is a 50-MW plant in Sidney, Mont. Lewis & Clark is located within the Bakken oil field development area and is an important generation resource within the Bakken area that serves load and provides voltage support to the region. With the rapid growth of activity in the Bakken area, the Lewis & Clark Station is needed to maintain reliability in the area under both peak system conditions and various transmission outage conditions, the IRP noted.
Otter Tail Power told the Minnesota Public Utilities Commission in an update filed Oct. 11 that it is making progress on the AQCS project at Big Stone. Actual construction commenced on the project on March 18. The 475-MW Big Stone plant is located at Big Stone City in South Dakota, fires sub-bituminous coal and is majority owned by Otter Tail, with minority stakes held by Northwestern Energy and Montana-Dakota.
Montana-Dakota is a unit of MDU Resources Group (NYSE: MDU).