The Canadian Environmental Assessment Agency on Feb. 15 went out for comment on a project summary from ATCO Power Canada Ltd. for the 350-MW, gas-fired Great Plains Generating Station, with this public comment period being part of the agency’s decision-making process on whether a federal environmental assessment is required for the project.
Written comments must be submitted by March 7. 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.
ATCO Power has an ownership position in 13 power generation stations in Alberta, British Columbia, Saskatchewan, and Ontario. ATCO Power has entered a bid process initiated by Saskatchewan Power (SaskPower) to design, build and operate a 350-MW, natural gas-fired combined cycle plant that will be called the Great Plains Generating Station. SaskPower is expected to award the project in July 2016, which is planned to start operating by October 2019.
The project will be located approximately 11 kilometers northwest of Swift Current, Saskatchewan, on a 158-acre parcel privately owned by SaskPower. The project will be entirely within the Rural Municipality of Swift Current No. 137 (RM of Swift Current No. 137).
The project will be designed to use state-of-the-art gas turbine, heat recovery steam generator (HRSG), steam turbine, and air cooled condenser technology to achieve high energy efficiency while producing low air emissions, and with minimal water usage for the amount of electricity produced. The project is located near the major utilities required for large power plants: high voltage transmission lines with available capacity, high pressure natural gas pipelines with available capacity, and a raw water supply from the City of Swift Current.
The objectives of the project are:
- To supply electricity to meet future electricity needs in Saskatchewan and support Saskatchewan’s transition to a lower-carbon electrical grid with less contribution from coal-fired power plants.
- To effectively develop the project on land owned and selected by SaskPower for this specific purpose.
- To configure and design the project for maximum efficiency to reduce air emissions and water usage per unit of power produced and to maximize power produced per unit of natural gas consumed.
- To configure and design the project for flexible operation to allow project electricity output to vary and offset changes in the supply of power in the Saskatchewan electrical system from both renewable and non-renewable generation sources that produce electricity intermittently and at variable rates. Saskatchewan has targeted an increase in the supply of intermittent renewable generation over the next 15 years.
The powerhouse buildings will enclose the gas turbine generator (GTG), HRSG, steam turbine generator (STG), water and wastewater treatment systems, auxiliary boiler, and medium- and low-voltage electrical systems. An air cooled condenser structure, which is a large heat exchanger, will condense steam from the outlet of the steam turbine and return condensate to the process system.
The project will have a maximum capacity of 350 MW (net). ATCO Power will purchase approximately 50 tonnes/hour of natural gas from TransGas that will be burned in the GTG. The GTG will be equipped with a low nitrogen oxides (NOX) combustion system that will optimize the mixing and combustion of the natural gas and air to maximize combustion efficiency while reducing the formation of NOX in the exhaust gases. The electricity generated by the GTG will be sent to the transmission system (operated by SaskPower). The waste heat generated by operation of the GTG will be transferred to the HRSG, where it will be used to boil the raw water sourced to the site and generate steam. The produced steam will be sent to the STG to generate additional electricity and increase the overall efficiency of the plant facility. The electricity from the STG will also be sent to the transmission system (operated by SaskPower).
The emissions produced by the GTG from combustion of natural gas will be released to the atmosphere through either the HRSG exhaust (during combined cycle operation) or through the GTG exhaust stack (during single cycle operation). These stacks are anticipated to be between 35 to 50 meters in height (above grade). Specific stack heights will be determined during detailed design.
The raw water supply will be obtained from the City of Swift Current water reservoir in the southwest portion of the city. The incoming raw water from the city will be treated before being sent to the STG, GTG, or the HRSG to remove minerals that could otherwise result in fouling. The plant facility will also be equipped with an air cooled condenser that will be connected to the STG to regulate the temperature of the condensate. Both the raw water treatment system and the steam blowdown system are expected to generate wastewater. The steam blowdown wastewater stream will be removed from the process cycle to avoid a buildup of minerals or dissolved solids within the steam generation system. Wastewater generated from the project will be sent to the City of Swift Current wastewater treatment facility through a buried pipeline.
The project timeline is:
- Notification of award from SaskPower – July 7, 2016
- Site preparation (e.g., clearing, grading) – Q3 2016 to Q1 2017
- Foundation excavation/construction – Q2 2017 to Q3 2018
- Building erection and equipment installation – Q1 2018 to Q2 2019
- Equipment commissioning and testing – Q3 2019
- Start of operation – Sept. 1, 2019 to Oct. 1, 2019
- Decommissioning (after 35 years of project life) – 2054 to 2057
A project contact is: Amit Bhargava, Manager, Environment and Regulatory Approvals, ATCO Power Canada Ltd., Phone: 403.209.6955, Fax: 403.802.7516, Amit.Bhargava@atcopower.com.