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High Performance Flywheel Energy Storage Systems: Temporal Power

December 07, 2017  |  Article

With funding it received in 2012 from the IESO’s Conservation Fund, Mississauga-based Temporal Power successfully developed a state-of-the-art flywheel energy storage system that addresses the challenges of an evolving and increasingly intermittent supply mix. Five years later, the company is one the world’s leaders in the energy storage market. 

Read more about the IESO's Conservation Fund.

"This was a significant first step in testing the application of storage technologies here in Ontario,” says Leonard Kula, the IESO’s Vice-President, Planning, Acquisition and Operations, and Chief Operating Officer. “Aside from the immediate benefit this technology is providing—helping to maintain second-by-second balance on the grid—we’re also learning lessons about the potential future value storage can provide."

"Aside from the immediate benefit this technology is providing—helping to maintain second-by-second balance on the grid—we’re also learning lessons about the potential future value storage can provide."

Leonard Kula, Vice-President, Planning, Acquisition and Operations and Chief Operating Officer, IESO

In this interview, Temporal Power’s president and chief executive officer, Eric Murray, talks about the journey from local start-up to global upstart.

Let’s start with the basics. Can you describe what a flywheel energy storage system does?

For electricity grids, flywheels do three things. First, they regulate power coming onto the grid from intermittent generators like wind turbines. Second, our flywheels store power as kinetic energy in giant 4,000-kilogram solid steel flywheels until it’s needed. When that power is needed, the flywheel converts it back into electricity and propels it back onto the grid. Third, high performance flywheels can help integrate power from renewable sources onto micro grids like you might see on an island, or in the far north, where traditional electricity grids don’t exist. 

Flywheels not only convert electricity to kinetic energy which they store until needed, they can also convert kinetic energy back to electricity as the electricity grid requires it. This diagram is a depiction of how flywheels work.

Is it fair to say that flywheel energy storage balances the supply and demand of electricity on the grid?

Yes, that’s accurate.

Can flywheel energy storage be used to help customers in industry and manufacturing shift their electrical loads?

Not exactly, but they can dramatically reduce the cost of operating rapidly fluctuating loads by using flywheels to reduce demand charges, which we see as an important application of the technology. Flywheel energy storage provides a way for customers to re-use energy on systems like mine hoists and dramatically reduce or minimize their peak demand. Our technology can also make electricity grids more efficient, as well as reduce CO2 emissions from base-load power plants and smooth electricity price fluctuations.

Where is this technology being used currently?

We’re in several important markets. Hydro One is testing 10 of our flywheels on a section of its transmission grid in Clear Creek near Tillsonburg, Ontario that is fed by a large wind farm. It’s also being commissioned on a section of the grid near Guelph, Ontario, where we have a partnership with Convergent Energy + Power and Guelph Hydro through the IESO’s Phase 1 energy storage procurement. And, it’s being used in the Caribbean where the local government in Aruba has committed to making the local electricity grid 100 percent renewables-based by 2020.

How is the IESO involved in this project?

Our funding relationship with the IESO came at a critical point -- after we had developed our business case but before we had actually demonstrated the concept or begun to market it. It allowed us to move into the commercialization stage, and it turned out to be a very savvy investment on both sides. It allowed the IESO to study energy storage at a time when more and more renewables were coming online in Ontario. Obviously, for us, it was a springboard that allowed us to access customers in the electricity space.

Learn more about the IESO's energy storage procurements.

How important are partnerships and joint ventures in your business?

They’re absolutely essential. In our very early days, we developed partnerships with MaRS, Ryerson University and Sustainable Development Technology Canada. They helped us craft our business solution as well as our intellectual property strategy. We also had a very collaborative partnership with NRStor Inc., where we delivered the first flywheel system to the IESO in Minto, Ontario, providing regulation services as part of the IESO’s Alternative Technologies for Regulation procurement. There are partners that invest in us, like Enbridge, which has quite a sizable renewable portfolio. And there are others, like NRStor, which are a good complement to our technology. Collaboration is a key part of the engineering and commercialization process of these sophisticated and capital-intensive initiatives.

What’s the most gratifying part of Temporal Power’s journey so far?

I was in Europe recently for a global conference on energy storage. It was interesting to hear people talking about their current projects and how their focus is shifting.  In a relatively short period of time we’ve seen utilities and end-users shift their thinking from lithium ion batteries alone to hybrid strategies that leverage multiple technologies including flywheels. It’s such a huge change in attitude from five years ago when some of the world’s leading companies had their sights set on one technology only -- lithium ion batteries. I think this hybrid approach makes sense. All the work we’ve done to build awareness and position ourselves within this space is definitely paying off; validation by users like the IESO adds an element of credibility and experience we could not achieve alone.

Bottom Photo: 4 MW Flywheel Energy Storage Facility (Minto, Ontario) for grid frequency regulation.  Lids covering 10 underground flywheels at the first flywheel system site in Minto, Ontario. Each flywheel extends approximately 3 metres (10 feet) underground.  Photo provided by Temporal.


Renewable energy accounts for more than 35 percent of Ontario’s installed capacity and generates approximately one-third of the electricity produced in the province.

As more renewable energy is integrated into the grid, energy storage is increasingly seen as a way to bridge the gaps caused by the intermittent nature of wind and solar power sources, while ensuring the grid operates efficiently and reliably. High performance flywheels in particular are gaining attention, not only in Ontario, but also on the global stage.