Climate change has provided an impetus to use renewable sources for energy needs. In Ontario, wind, solar and water are the three feasible sources of renewable energy, however, these energy sources are intermittent and cannot be relied on to provide for the energy needs of the province. The growing emphasis on shifting to renewable energy sources coupled with urbanization of the GTA requires that Mississauga’s current energy infrastructure undergo drastic and innovative changes to support the increased demand, and fluctuation in said demand of energy. On-grid storage of electrical energy is an innovative solution to facilitate a sustainable, reliable, and efficient energy system.
BACKGROUND
Intermittent energy sources are limited in that they are not continuously available for generation of electricity. On-grid energy storage involves storing surpluses of energy: accessed when there is a need for energy, but the energy source is unavailable to generate power. Pursuant to the city of Mississauga’s long-term goal to be a net zero carbon city, on-grid energy storage will enable increased use of renewable energy sources and reduce dependence on fossil fuels. Furthermore, storage of surplus energy generated during low demand (off-peak) periods will reduce the cost of energy consumption to the average home and allow the energy infrastructure to support greater energy demand. As the demand for energy can change very rapidly, energy storage solutions allow for the grid to quickly adapt as they are able to easily switch between feeding energy into the grid and storing energy from the grid.
In terms of energy storage systems, I would like to propose an investment into flywheel energy storage systems in Mississauga serving the Ontario grid.
FLYWHEELS
Energy storage systems include, flywheels, compressed air, batteries, thermal, and hydroelectric dams (currently implemented in Niagara Peninsula Energy). Given Mississauga’s existing infrastructure and future demand of energy, flywheels are the most appropriate energy storage system. Advantages of flywheels include extended lifespan, large storage capacity, and relatively inexpensive implementation. Flywheels are durable and resilient, with materials lasting over 20 years; flywheels have a power density which is 5-10 times greater than that of battery storage systems (their main competition in grid energy storage). In a rapidly urbanizing city with high value for land, new infrastructure must be compact and as efficient of a use of space as possible. Many of the options for energy storage systems are not feasible for the city of Mississauga due to a lack of already existing infrastructure (mines/dams), the creation of would be unfeasible. Compared to alternative energy storage systems, flywheels demonstrate the greatest compatibility with Mississauga’s existing energy infrastructure which translates to efficient implementation which requires minimal resources and maximizes the return on investing in restructuring the energy infrastructure.
Mechanism
The flywheel energy storage system consists of two major components, a disk (wheel) which is attached to a motor generator. The underlying concept that the flywheel depends on Newton’s First Law, an object in motion shall remain in motion unless acted upon by another force. Surplus energy is stored by being fed into a motor generator which puts the disk into motion converting electrical energy into kinetic energy: the disk spins continuously in a low friction environment. When energy is required, the motor generator converts the kinetic energy into electrical energy and consequently the disk slows down. Through this mechanism, the motor generator acts as a motor (converting electrical energy to kinetic energy) and a generator (converting kinetic to electrical energy). The disk’s large mass means that a large amount of energy is required to spin it but its momentum can be used to store large amounts of energy.
Implementation
By investing in flywheels, Mississauga will be a leader in development of sustainable, efficient and reliable energy systems. Flywheel energy storage is a feasible and practical solution which is already being implemented globally as a core component of a new age of renewable energy reliance. In 2010, the city of Stephentown (NY, USA) invested $43 million in the first commercial deployment of flywheel grid energy storage and implemented 200 flywheels which stabilized the New York electrical grid. The project generated 28 jobs in the area and was the first commercial deployment of flywheel grid energy storage. In Aruba, flywheels were introduced as part of the greater goal to become a 100% renewable energy dependent island by the year 2020. The capacity of flywheels to act as a short-term energy store and reinject power when needed was crucial to maintain the efficacy of energy production and mitigate any impact on customers by the switch to renewable energy sources.
When introducing flywheels into the grid, it is imperative that they are able to store very large amounts of energy since GTA energy demand is higher than ever and only increasing due to rapid urbanization. As a result, it is most efficient to increase the capacity and efficacy of each flywheel. To do this I’d like to propose a 4000 kg solid steel flywheel, similar to those currently in use in Aruba in the Caribbean (manufactured by Temporal Power, a global leader in energy storage systems). The massiveness of this flywheel means that it would take significantly more energy to start spinning, however it would also be able to store more energy and have greater momentum, making them more cost efficient than having many smaller flywheels. This flywheel would be placed inside of a vacuum sealed container, maximizing the efficacy as the flywheel would not lose its kinetic energy due to air drag and be able to store more energy for longer periods of time. Finally, in order to reduce friction at the flywheels connection to the motor-generator, it would be attached using magnetic bearings. Whereas traditional flywheels are attached to a motor-generator, using magnetic bearings the flywheel is able to hover, drastically reducing friction and necessary maintenance. This would allow the flywheel to be spun easier (increasing momentum) and the flywheel would not lose as much energy from friction with the motor generator. In addition they would implement the design of the Siemens flywheel, wherein the flywheel is under a vacuum while the motor-generator is under atmospheric pressure. The separation of the flywheel from the motor-generator is a new innovation that allows them to work separately; the motor does not have to rotate with the flywheel, meaning for less maintenance and a longer life.
A comprehensive planning and implementation process will ensure that potential risks are identified and mitigated, and potential opportunities are identified and capitalized on. Given the size, maintenance requirements and storage capacity, the flywheel design will be adapted to support the needs and resource availability unique to the area it is supplying. Adapted designs will be rigorously tested through pilot projects as part of smaller grids in Ontario to assess effectiveness, efficacy and anticipate potential risks. Pilot projects will allow for testing in a relatively controlled environment where the flywheels are in close proximity to the source of the energy they are storing, allowing for accurate comparison of the surplus energy generated versus the energy actually stored. Potential pilot project sites include northern regions of Ontario that are close to large renewable energy generation plants (i.e. solar farms, wind farms) and exhibit reduced energy demands, for example, Tillsonburg Ontario.
Additionally, town-hall meetings will be conducted and surveys will be distributed in locations of pilot projects and Mississauga to gauge consumers’ attitudes and receptiveness towards the shift in energy source, and to address any concerns and questions they may have. An extensive planning process coupled with gradual implementation will maximize the sustainability of the change and ensure that the city benefits from restructuring of the energy infrastructure.
In conclusion, on-grid energy storage is the solution to maintaining sustainable and efficient growth. Through allowing for sustainable energy, its suitability to the needs of GTA infrastructure and with new innovations allowing them to become a system of the 21st century, flywheels are paving the way for the future of energy infrastructure. Continuous innovation and adaption will position Mississauga as a leader in renewable energy as need for more efficient energy production and storage increases. Flywheel technology will not only greatly benefit the citizens of Mississauga, but can prove to benefit the world in leading the future of sustainability.
References:
Flywheels (2018). Retrieved January 2, 2018, from https://www.sciencedirect.com/topics/engineering/flywheel-energy-storage
Flywheels. (n.d.). Retrieved January 2, 2018, from https://www.ieso.ca/en/Powering-Tomorrow/2017/High-Performance-Flywheel-Energy-Storage-Systems-Temporal-Power
High Performance Flywheel Energy Storage Systems: Temporal Power. (2017, December 7). Retrieved January 2, 2018, from https://ieso.ca/en/Powering-Tomorrow/2017/High-Performance-Flywheel-Energy-Storage-Systems-Temporal-Power
Ontario’s Supply Mix. (n.d.). Retrieved from January 2, 2018, https://www.ieso.ca/en/Learn/Ontario-Electricity-Grid/Supply-Mix-and-Generation
Stephentown Spindle. (n.d.). Retrieved January 2, 2018, from https://www.energy.gov/sites/prod/files/2015/08/f26/DOE-LPO_Project-Posters_STOR-TRSM_Stephentown-Spindle.pdf
Amiryar, M., & Pullen, K. (2017). A Review of Flywheel Energy Storage System Technologies and Their Applications. Applied Sciences,7(3), 0-21.
Schrein, K. (n.d.). Smart Grids and Energy Storage: Flywheel Energy-Storage. Retrieved January 2, 2018, from https://www.siemens.com/global/en/company/innovation.html