The Alberta Utilities Commission on June 4 approved Maxim Power to switch the fuel from coal to natural gas at a planned 500-MW addition to its existing coal-fired HR Milner power plant.
Maxim Power held a 2011 approval to construct and operate a 500-MW coal-fired facility designated as the HR Milner Expansion Project (M2 for short) in the Grande Cache, Alberta, area. In November 2013, the company applied to switch the planned fuel for M2 to natural gas.
In its amendment application, Maxim proposed to alter the power plant by changing the fuel type from coal to natural gas and increasing the size of the power plant from 500 MW to 520 MW. Maxim cited new federal government greenhouse gas emissions legislation and the low cost of natural gas as drivers for the alteration.
Maxim presently operates a 150-MW coal-fired unit (M1) at the HR Milner Generating Station. The gas-fired facility would be situated adjacent to M1. The physical footprint of the previously approved M2 power plant would remain unchanged.
Maxim stated that it plans to build the M2 power plant in two phases with the construction of two 260-MW combined-cycle gas turbine generators. Each phase would consist of a gas turbine generator, a heat recovery steam generator, a steam turbine generator and ancillary support systems. The gas turbine would be used to drive an electric generator and the exhaust would be passed through a heat recovery boiler which raises steam to drive the steam turbine generator. The gas would be supplied via an expansion of the existing natural gas pipeline that currently supplies M1.
Maxim said it plans to commence construction for the first phase in the third quarter of 2014 and begin operation in the first quarter of 2018. The second phase is anticipated to begin construction in the fourth quarter of 2016 and operation in the first quarter of 2020.
The commission noted that changing the fuel type for M2 would actually lean lower emissions. “The Commission considers that changing the power plant type, from coal-fired to natural gas-fired results in a decrease in air emissions, specifically a reduction in CO2 emissions by 49 per cent.”