Maxim Power Corp. (MAXIM) applied Sept. 19 at the Alberta Utilities Commission (AUC) for approval of its M3 project, which is an additional gas-fired facility for the currently coal-fired HR Milner Generating Station.
There is currently a 150-MW coal unit at this site called M1. The Milner site is located about 20 kilometers north of the town of Grande Cache, Alberta. In June 2014, MAXIM received approvals from the AUC to build a 520-MW gas-fired unit called the Milner Expansion Project Amendment or “M2.” This unbuilt M2 project replaces a previously approved, 500-MW coal-fired version of the M2 project. MAXIM plans to build M2 in two phases of two 260-MW combined-cycle gas turbine (CCGT) power plants.
Now, said the Sept. 19 application, MAXIM also wants to build the gas-fired, 86-MW M3 project.
“Environment Canada’s new Federal Greenhouse Gas (GHG) regulations that came into force in September 2012 require stringent performance standards for coal-fired generators,” said the company about the need for the project. “The standards are fixed at 420 tonnes of carbon dioxide per gigawatt hour (CO2/GWh) to be met by new coal-fired generators by July 1, 2015. The regulations also require existing coal burning power plants to be in compliance with the new limits over time. M1 was commissioned in 1972 and the Regulation requires M1 to stop its base load operation on December 31, 2019. Beyond that, M1 is allowed to operate as a Standby Unit, burning coal for an annual capacity factor of 9% until December 31, 2029. Provincial regulations require that M1 have Best Available Technology Economically Achievable (BATEA) solutions installed as of January 1, 2023 for pollutant control.
“MAXIM proposes to enhance the Milner Sites’ current energy output by building the ‘M3 Project’, which is comprised of two gas turbine generator packages, equipped with Heat Recovery Steam Generators (HRSGs). M3 will burn natural gas to generate electrical energy and the exhaust energy from the gas turbines that will be converted to steam in the HRSGs. This steam will be piped into M1 and expanded in the M1 steam turbine, displacing a portion of the coal-sourced steam. This will allow M1 to reduce the amount of coal that it presently burns.
“By using the steam generated by M3 in M1, MAXIM will reduce GHG emissions and increase power output from the Milner Site. With M1 and M3 operating together, the electrical output of the Milner Site will increase by approximately 84 MW (net) for a total of 228 MW (net) capacity. There will be reductions in the total emissions from the Milner Site: carbon dioxide (CO2), nitrogen oxides (NOX), sulfur oxide (SOX) and particulates.
“M3 will be constructed and operated within the existing boundaries of the Milner Site, adjacent to M1. M3 will not change the Milner Site’s physical footprint. No expansion of the Milner Site is required and there are no new restrictions on land use adjacent to the facility.”
M3 will be made up of two GE turbines
MAXIM said the M3 project will consist of two packaged General Electric LM 6000 aero-derivative gas turbine generators (GTG) and auxiliaries operated in simple cycle mode to meet the peak power needs of the Alberta electrical grid. With the installation of a HRSG on the exhaust of each gas turbine, high pressure steam will be generated and subsequently piped into M1 to be expanded in the M1 steam turbine to generate electricity.
M3 will also have the following major systems, MAXIM said:
- Generator step-up transformers (13.8 kV/144 kV)
- Water treatment facilities to produce purified water to meet the NOx control needs, boiler feed water quality, evaporative cooling quality and compressor water wash needs
- Natural gas supply and compression to the M3 site
- Interconnection with the AIES at the adjacent existing 144 kV electrical substation
- Gas turbine and boiler controls to allow standalone operation, or dispatch from M1 or other locations
- Safety systems to ensure safe operation, start-up, shutdown, and emergency management
The gross generating capacity of the M3 will be a nominal 86 MW. Peak generation of steam with duct fire for export into the M1 steam system will be about 207 MW thermal.
The natural gas supply for M3 will be delivered to the Milner Site by an expansion of the supply service on TransCanada Pipelines Ltd.‘s system. TransCanada will carry out its own application process with relevant regulatory bodies for any necessary pipeline expansions.
The current schedule for M3 calls for a construction start, following regulatory approvals, in the second quarter of 2015, with commercial operation in the third quarter of 2016.