The Tent Mountain Renewable Energy Complex (TM-REX) in southwest Alberta, Canada, is a planned renewable development that will be located at the site of a historical steelmaking coal mine called Tent Mountain Mine.
TM-REX will include three primary elements- 320MW / 4,800MWh Pumped Hydro Energy Storage (PHES); a 100MW Offsite Green Hydrogen Electrolyser; and a 100MW Offsite Wind Farm.
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The construction of TM-PHES is expected to start as early as 2026 and commercial operations may begin between 2028 and 2030.
The TM-REX is estimated to offset up to 590,000 tonnes of carbon dioxide emissions per year over an 80+ year project life.
History and ownership details
Tent Mountain Mine is located approximately 16km west of the township of Coleman, Alberta. The mine ceased operations in 1983.
Montem Resources, a renewable energy and steelmaking coal development company, acquired the Tent Mountain Mine property in 2016 and started working on the redevelopment of the mine.
In 2019, the company started exploring the feasibility of a PHES at the end of mine life.
Due to the uncertainty in restarting mining operations, Montem expedited the plans to develop the site as renewable energy complex.
The company completed a Pre-Feasibility Study for the PHES element and development studies for the Green Hydrogen Electrolyser element in 2022. According to the company, both the elements have the potential to offer strong returns for shareholders and add value for Alberta.
The pre-feasibility studies (PFS) to develop Tent Mountain Project into a renewable energy complex were completed in 2022.
In March 2022, Montem Resources and Invest Alberta signed a memorandum of understanding (MoU) that outlines a joint commitment to establish the TM-REX.
In February 2023, Montem signed a binding agreement to sell 50% stake of the TM-REX to clean energy solutions company TransAlta. The C$24.7m ($18.47m) deal closed in April 2023.
It included the rights to the land, fixed assets and intellectual property associated with the PHES project, along with the intellectual property of offsite green hydrogen electrolyser and wind farm.
Under the terms of the agreement, the two companies will jointly manage the project, with TransAlta acting as the project developer.
Tent Mountain Pumped Hydro Energy Storage details
The 320MW TM-PHES is planned to be co-located with a wind farm and green hydrogen electrolyser facility.
The facility will leverage existing assets at the mine. This includes two large water reservoirs separated by a 300m of elevation.
The upper reservoir, at an elevation of 1,800m, will be connected to the powerhouse beside the lower reservoir by penstock.
The powerhouse will house 4 x 80 MW fixed speed reversible Francis turbines.
At times of low demand, the turbines can be utilised to reverse pump the water to the upper reservoir, using wind power-generated electricity.
When there is an increase in demand, the water stored in the upper reservoir will be released to turn the turbines and generate power.
The PHES will thus act as a very large battery with a storage capacity of 2,560MWh (potential for up to 4,955MWh) providing electricity for up to 8 hours (potential for up to 15 hours).
The PHES project will create around 200 construction jobs and support 30 full time operational jobs over its life.
It will be connected to the Alberta grid via powerlines to send power at times of need as well as procure power when the turbines are reversed.
Green Hydrogen Electrolyser
The renewable energy generated by PHES facility will be used to power the offsite Green Hydrogen Electrolyser.
The 100MW green hydrogen Electrolyser will split water molecules to create hydrogen and oxygen. The hydrogen gas will be then compressed and stored for export.
According to October 2021 Montem’s investor presentation, the electrolyser is planned to be located at Tent Mountain near the CP rail line, the TC Energy gas pipeline, and the interprovincial highway.
The hydrogen will be used in domestic and industrial sectors.
100MW Wind Farm
The 100MW wind farm, located offsite from Tent Mountain, will provide renewable power to the TM-PHES as well as electrolyser.
Contractors involved
The Pre-Feasibility Studies (PFS) for the pumped hydro energy storage system and green hydrogen electrolyser of the TM-REX were completed by Hatch and GHD.
Engineering company Hatch carried out the Gap Analysis, Hydrological Assessment, Geological and Hydrogeological Assessment, and the Options Study, and determined that there are no geotechnical fatal flaws in developing the TM-PHES.
GHD conducted the business case analysis for the Green Hydrogen Electrolyser element. The scope of work included preliminary engineering design work, including the assessment of land, water, and regulatory requirements for the project.
