By Stephen Kishewitsch
A pumped storage hydroelectric project being proposed by TC Energy would be the largest of its type in Canada, providing billions of dollars of savings to ratepayers over its operating lifetime as well as being one of the largest greenhouse gas emission reduction projects in the country.
Planned for a location near the base of the Bruce Peninsula between Lake Huron and Georgian Bay, the project would sit within a federal military base and be connected via a dedicated transmission line to the Hydro One Essa TS. The site is part of Canada’s Department of National Defence (DND)’s Meaford Tank Range.
TC Energy lists several anticipated benefits of the project; in particular, reduced electricity costs to ratepayers:
Figure 13. Capacity Price Forecasts and Market Clearing Capacity – Base Case
• Avoided system costs in providing capacity. With an expected three years needed for the environmental assessments and a four-year timeline for construction, the project is expected to start operations in 2028 (2027 at the earliest) which puts it after the current planned shutdown of Pickering in 2024-25 timeframe. A short-term capacity option may be required to bridge the gap until the project is in operation following the Pickering closure. But with the project in the mix, capacity prices are expected to be reduced (figure 13).
Figure 16. Average September 2029 Daily Energy Price Suppression – Base Case
• Reduced energy cost for customers. By filling the upper reservoir using low-cost off-peak and surplus generation, the project could provide up to 8,000 megawatt-hours of supply during peak demand hours, replacing energy that would otherwise come from higher-cost gas-fired peaking plants (fig. 16). Clean power to charge the reservoir would likely come from Ontario’s surplus wind, hydro, solar and nuclear energy, and beyond that potentially from one of the interconnections to Hydro-Quebec’s relatively low-cost hydro power generation.
• Reduced CO2 emissions from the avoided gas-fired power that would otherwise be called on during times of peak demand. In addition, the project’s reversing hydro turbines can respond quickly to changes in demand, providing grid balancing and reserve power services. Such services are currently provided by gas turbines that have to be kept spinning even when not providing power. Between the two forms of savings, detailed modelling by Navigant estimates average CO2 emissions reductions of 490,000 tonnes per year.
• Those reversing hydro turbines will also lead to lower costs for operating reserves and avoided costs for regulation. Considering the flexibility of the generation and the variable speed pumps, the project is assumed to provide 500 MW of the province’s current operating reserve needs and 100 MW of its anticipated regulation needs.
Navigant’s analysis estimates net savings to ratepayers of some $250 million a year, or $12.1 billion over 40 years, under the base case (see Table 1). The base case assumes, among other things, that peak demand will remain relatively flat through the late 2020s before increasing gradually at a 0.5% compound annual growth rate (CAGR) through 2040. But under an analysis of several alternate scenarios (“Booming Economy Case,” “Clean Grid Case,” “Challenging Supply Case” that assumes no additional conservation programs, a slow growth “Low Net Demand Case,” and a “No Market Case”) all show savings.
TC Energy emphasizes that the proposal is at the earliest stages, with project feasibility studies underway. DND is also conducting its own independent studies to determine if the project could coexist within the operational base.
DND has opened public consultation with Indigenous communities and other stakeholders, with a deadline, initially March 31, extended to July 31. A local advocacy group, Save Georgian Bay, has expressed concerns about the project; in particular, about its effect on fish populations and spawning beds.
The DND notice adds that, if TC Energy does go ahead with the project after it has conducted its feasibility studies, it would still be subject to further government review and approvals in consultation with Indigenous groups, the Meaford community, and other interested parties.
Contact has been initiated with municipal stakeholders as well as with 41 Indigenous communities in the area. The Saugeen Ojibway Nation were provided a “Letter of Comfort” giving assurance that the project would not be constructed without their support. Assuming that the project can meet rigorous standards designed to protect the environment, the anticipation is that they will participate as investors and part owners.
Currently, the Canada Energy Regulator lists Ontario Power Generation’s 174 MW Sir Adam Beck Pump Generating Station as Canada’s only operating pumped storage hydro facility. A few others have been proposed:
• The Alberta legislature approved the 75 MW Canyon Creek Pumped Hydro Energy Storage Project near Hinton in late 2018. The project relies on an open-pit coal mine for one of its reservoirs. A July 2019 report set an in-service date in August 2021.
• TransAlta announced recommencement of a pumped hydro project at its existing Brazeau facility, and is targeting 2021 for commencement of construction, according to a July 2019 report.
• Northland Power announced its 400 MW Marmora pumped storage proposal in 2011, using an abandoned open-pit iron mine in Ontario.
The United States has over 30 pumped hydro storage facilities, with a combined capacity of 22 gigawatts.
Project details
• Three 333 MW units providing 1,000 MW of pumping and generation
• Fast start-up in less than 5 minutes to either pump or generate
• Complete ramp range (when online) within 40 seconds
• Ability to start and stop multiple times per hour without restriction and to switch from pumping to generation in minutes
• Two variable speed pumps to provide 100 MW of regulation services
• 72% round-trip efficiency (based on the specific elevation and topography of the project site)