- About
- Equipment
- Key Project Features
- How It Works
- Water Management
- Safety
- Regulatory Overview
- Timeline
- Community Engagement
About the Project
The Keephills 1 Repowering Project is expected to include two new combustion turbine generators (CTGs) and two new heat recovery steam generators (HRSGs) that will supply superheated steam to the steam turbine and condenser, creating a combined-cycle facility capable of producing approximately 829 megawatts (MW) of electricity. A similar configuration using a single gas turbine was previously submitted in 2019 and approved by the Alberta Utilities Commission (AUC) in 2020. The project was paused following the approval and is being brought forward due to emerging market opportunities.
The current Keephills 1 Repowering Project application is similar to the 2019 application with the use of two CTGs, replacing the previously proposal of one CTG. It uses the existing Keephills site and much of the current infrastructure, reduces land disturbance and extends the facility’s operating life.
Key equipment
New:
- Two CTGs – anticipated to be Siemens SGT6-5000F or similar, each paired with inlet and exhaust systems
- Two HRSGs – each equipped with:
- Duct burner system to increase steam production
- Three steam pressures to maximize efficiency
- Exhaust stack
- Continuous Emission Monitoring System (CEMS)
- Gas conditioning and metering station – to manage natural gas supply to the units
Expected to be reused:
- Auxiliary boiler – small natural gas-fired boiler to support startup operations
- Steam turbine and condenser from Keephills 1
- Circulating water, makeup water and water treatment systems
- Cooling pond
- Generator step-up transformer
- Existing substation (Keephills 320P) infrastructure for electrical interconnection to the Alberta Interconnected Electric System (AIES)
- The project footprint will remain within the existing fenced area of the Keephills site
Key project features
Capacity
Approximately 829 MW of gross generating capacity.
Reliability
2×1 combined cycle design allows for continued service, even when one generating element trips offline.
Efficiency
Advanced gas turbine and heat recovery technology improves plant efficiency compared with traditional gas fired generation.
Affordability
Reuse of existing infrastructure reduces capital expenditure to lower the cost of energy produced.
Environmental performance
Increased efficiency reduces greenhouse gas emissions compared with current operations.
Economic benefit
Continued employment and economic activity in Parkland County.
How it works
1. Gas turbine generates electricity
Air is filtered and then compressed to over 17 times ambient pressure. Natural gas is then injected and combusted. The combustion gases expand through the turbine to drive the compressor and generator and the hot exhaust flows to the heat recovery steam generator.
2. Heat recovery system captures exhaust energy
Instead of releasing hot exhaust into the atmosphere, the HRSGs capture it to make superheated steam. Three different steam pressures, with three different boiling points, are used to capture as much energy as possible. Duct burners can be used to boost steam output when needed.
3. Steam turbine generates additional electricity
The combined steam flow from both HRSGs drive the steam turbine, generating even more electricity with the same fuel input.
This process is highly efficient as the natural gas energy is first used to power the gas turbine and then waste heat is used to power the steam turbine. This results in much higher fuel efficiency than a gas turbine or gas fired steam generator alone.
Water management at the Sundance and Keephills sites
An environmental assessment will be completed as part of TransAlta’s applications to Alberta Environment and Protected Areas (AEPA) under the Environmental Protection and Enhancement Act (EPEA). The assessment includes detailed air-quality dispersion modelling to predict concentrations of relevant emissions.
The project will also include environmental management and monitoring plans as required under the EPEA Industrial Approval. Water use will remain within existing licensed limits under the Water Act. The Project will not take water from or return water to Wabamun Lake.
The AUC sets standards for power-plant noise. TransAlta has modelled the overall noise from the repowered units to confirm compliance with AUC requirements (Rule 012). The assessment takes into account existing natural and industrial sources in the area, such as existing Sundanceand Keephills operations.
Safety and emergency response
TransAlta follows all AUC Rule 007 requirements for siting, design, operation and public involvement. The detailed Emergency Response Plan (ERP) for the Keephills facility is regularly updated to reflect the changing operations on-site at Keephills, and will be updated to reflect the operation of the Keephills 1 Repowering Project.
It outlines procedures for communication, evacuation and coordination with Parkland County, local fire services and regional emergency responders. The ERP will align with the County’s municipal emergency plan.
Regulatory overview
TransAlta has submitted a Power Plant Application for the Keephills 1 Repowering Project to the Alberta Utilities Commission (“AUC”) under Rule 007 – Applications for Power Plants, Substations, Transmission Lines, Industrial System Designations and Hydro Developments. The application has been filed as Proceeding #30511 and can be accessed through the AUC’s eFiling system.
TransAlta has also filed an application to extend the previously approved Sundance 5 Unit construction permit. The application has been filed with the AUC as Proceeding #30482 and can be accessed through the AUC’s eFiling system.
TransAlta is also confirming the cancellation of our Pinnacle natural gas project, which was approved by the AUC in summer 2023. In March 2024 the Government of Alberta announced planned changes to Alberta’s electricity market. Due to those changes, TransAlta has decided to formally cancel the Pinnacle Project.
Alberta Environment and Protected Areas (EPA)
TransAlta will submit an amendment to the existing Keephills 1 Environmental Protection and Enhancement Act (EPEA) approval to reflect changes in the proposed repowering configuration. The amendment includes rerunning the air-quality, air dispersion and emissions modelling. If the Keephills 1 Repowering Project is approved by the AUC, the EPEA amendment will be submitted post-approval.
TransAlta will also apply to AEPA for the environmental authorizations required under provincial legislation, including the EPEA. Under EPEA, large industrial facilities such as power plants must obtain an Industrial Approval, which evaluates potential effects on air, land and water. This process includes technical assessments such as air-quality dispersion modelling, emissions controls, waste management and environmental monitoring programs. If the Keephills 1 Repowering Project is approved by the AUC, the Industrial Approval will be submitted post-approval.
EPA’s review ensures that environmental effects are minimized, properly managed and monitored throughout construction and operation.
Alberta Utilities Commission (AUC)
The AUC is a quasi-judicial agency that regulates the approval and operation of utility projects in Alberta. It ensures that developments like power plants and transmission lines are safe, reliable and in the public interest through fair and transparent decision-making.
Information regarding the AUC review process and how you can participate can be found in their brochure “Participating in the AUC’s independent review process to consider facility applications” available on the AUC website.
Municipal requirements
Development and building permit applications will also be submitted to Parkland County, as required under municipal regulations.
Project timeline
Community engagement
Thank you for joining us at our Seba Beach and Keephills open houses in November. If you were unable to join us, we’d like to hear from you. Please reach out to us by phone, email, or by visiting our website. We look forward to hearing your feedback and answering your questions.
Contact information
E-mail: stacey_lauder@transalta.com
Telephone: 780-731-5312