The Canadian Environmental Assessment Agency said Oct. 19 that it must decide whether a federal environmental assessment is required for Saskatchewan Power‘s proposed Chinook Power Station Project, to be located approximately 11 kilometers northwest of Swift Current, Saskatchewan.
To help inform this decision, the agency is seeking comments until Nov. 8 from the public on the project and its potential effects on the environment. As a next step, the agency will post a decision on its website stating whether an environmental assessment is required. If one is required, the public will have three more opportunities to comment on the project.
The proposed Chinook Power Station is a nominal 350-MW combined cycle natural gas-fired facility. The project also includes a new underground water pipeline from the South Hill Reservoir located within the city limits of Swift Current.
To meet the growing demand for power in the province of Saskatchewan, provide replacement power for the retirement and/or refurbishment of conventional coal-fired generating units and allow for the integration of intermittent renewables, there is a need to build a new large-scale power plant in Saskatchewan that can generate electricity by 2019. SaskPower said it is investing approximately C$1 billion annually for at least the next decade to upgrade and modernize the province’s electricity system. This includes finding cleaner sources of power generation in order to comply with existing regulations, which mandate the phase-out of conventional coal-fired generation as well as new emission standards and emerging regulations.
SaskPower has a number of initiatives underway to meet current anticipated supply needs including carbon capture technology, additional natural gas projects, life extensions to existing hydro (non-greenhouse gas (GHG) emitting) facilities, additional wind and hydro projects, utility-scale solar projects, importation of clean hydro power from Manitoba and evaluating the potential for geothermal and biomass. These initiatives, combined with the development of more demand-side management and energy efficiency programs, will ensure SaskPower can continue to provide reliable, sustainable, cost-effective electricity.
SaskPower is targeting a 40% reduction in GHG emissions from 2005 levels by 2030, exceeding the national target of a 30% reduction. SaskPower recently announced plans to double its renewable generation capacity from 25% today to up to 50% by 2030. Included in these plans is an increase in wind capacity (target of 30% capacity by 2030) and solar. In order to integrate these renewable supply options that are intermittent by nature, a back-up generation source is required to match electricity generation with electricity demand. Natural gas generation is an ideal candidate as it can quickly ramp up or down as the renewable generation output fluctuates.
The Chinook project, as proposed, is the most cost-effective solution to meet increasing electricity demand as well as replace existing conventional coal-fired generation within the timelines required. It will also result in an overall reduction of GHG and other air emissions, the utility said.
Project components will include the power generation facility, a switchyard to interconnect to the 230-kV transmission system, an 18 kilometer long potable water pipeline from the City of Swift Current, and a TransGas gas yard. This area is currently a greenfield site with no existing structures.
For an intermediate to baseload combined cycle facility, a combined cycle using G, H, and J class gas turbines would have better efficiency. However, output of a combined cycle facility using these technologies would be higher than the 350 MW required by SaskPower, the utility pointed out. A plant using these larger gas turbine technologies could require derate of the plant to stay under the 350 MW, which in turn decreases the efficiency resulting in a higher heat rate. The 1×1 F-class turbine configuration chosen for the project is best suited to meet the 350 MW output. Since carbon capture technology is not used for combined cycle units, higher efficiency (lower heat rate) means that less carbon dioxide (CO2) is generated for every kilowatt of electricity generated.
Pipeline quality natural gas will be used as the only fuel for the unit. Prior to entering the gas turbine, the natural gas will be heated in accordance to Original Equipment Manufacturer (OEM) guidelines using the intermediate pressure feedwater. Increasing the temperature of the natural gas increases the cycle efficiency. The heated natural gas is then combusted in the gas turbine to drive the turbine to generate electricity. Electricity generated by the gas turbine generator will be stepped up to 230 kV using the generator step up transformer before interconnecting to the SaskPower transmission system.
For this project, an advanced F-class gas turbine has been selected. The gas turbine is to be equipped with Ultra Low NOx (ULN) burners which optimizes the ratio of combustion air to fuel as well as combustion temperature to control NOx emissions from the natural gas combustion process.
The project schedule calls for commissioning and start-up of the facility in the February-October 2019 period.