Storing variable power has never been easier
Storing energy has never been easier or cheaper. Everything from batteries and heated ceramic blocks to giant hydro power reservoirs and compressed air are now being used to hold energy until it is needed. Combined with smart systems that can reduce energy demand in peak periods and draw from these storage solutions almost instantaneously, these storage methods are revolutionizing how we keep the lights on in our homes and factories humming, and are a key way for Ontario to move to a 100% renewable electricity system instead of expanding use of polluting fossil gas.
Here is a quick overview of some major energy solutions.
Batteries
Batteries are the fastest growing form of energy storage, and are particularly useful for solar and wind energy. Prices for lithium-ion batteries have plunged by 90% since 2010, “one of the fastest cost declines of any energy technology ever” according to the International Energy Agency (IEA).
Today, even cheaper lithium iron phosphate batteries that do not require nickel or cobalt and that have lower flammability and longer lifetimes, are replacing lithium-ion batteries for energy storage projects, accounting for 80% of storage batteries installed in 2023.
Meanwhile, progress on commercializing new battery chemistries is rapidly accelerating and the IEA projects that battery costs will fall by a further 40% by 2030. Iron flow (including iron-air) batteries are starting to be adopted by utilities looking for longer-term storage solutions.
Both Texas and California have now installed massive amounts of battery storage and rely on large battery banks to keep the lights on when generating stations are not operational or power demand surges. Ontario recently took a major step toward expanding battery storage, but lags far behind many leading jurisdictions when it comes to producing solar and wind energy to charge these new battery facilities.
EVs: Battery packs on wheels
There is also growing potential to use electric vehicles as not just transportation, but as power storage devices. With bi-directional charging systems, EVs can send power from their batteries back to the electricity system when electricity demand is high. Given that most EVs are idle 95% of the time, there is significant potential to use their batteries to support the broader electricity system and not just draw from it. And EV owners can earn revenue that helps offset the currently higher upfront cost of purchasing an EV.
By 2030, EV battery storage capacity in Ontario could outstrip the capacity of the province’s polluting gas plants.
And EV batteries can be converted to stationary storage batteries at the end of their useful vehicle life. Generally, at the point that EV batteries need replacing (which is proving to be a longer period than most people will own their EV), they will still have around 80% capacity, which is plenty to store power from solar and wind installations.
Concept for Marmora, ON pumped storage facility, which will use an old open pit mine in eastern Ontario to store energy.
Water is stored energy
Water has been used to generate power in this province for over a century. But the most overlooked part of waterpower systems is how they can be used to store energy. By holding back water and filling reservoirs, hydro power facilities are storing energy. That water can be released and used to make electricity when it is needed. So if solar and wind are strong, water can be held back and then released when these sources are less available (e.g. at night or on calm days). It is a simple way to make variable wind and solar power a steady source of power.
Ontario is located next door to one of the world’s biggest producers of waterpower – Quebec. Quebec increasingly sees its massive waterpower system as “a giant battery” that can support other forms of renewable energy. Ontario should take advantage of this low-cost storage solution made possible by existing and easily expandable transmission system connections with our neighbour.
Pumped storage, where water is pumped up into a higher-elevation reservoir when the overall provincial system has a surplus of power and then released to produce energy when demand is higher, is another way to use water to store power. The Sir Adam Beck Generating Station at Niagara Falls includes a 174 megawatt pumped storage facility using a 300 hectare reservoir above the falls.
Heat (or cold)
Storing energy as heat is another way we can make better use of renewable energy. There are a number of ways to convert electricity to heat, from simply using it to heat water or something like ceramic bricks to “phase change” storage (e.g., molten salt) and thermochemical storage, which relies on chemical reactions.
Quebec is currently offering its residents a $22,000 incentive to install a heat pump paired with a ceramic brick storage system to its residents. This super efficient system allows a homeowner to store energy when electricity costs are low and release it during peak periods to heat their home or water. Thanks to the heat pump, heating the bricks is done very efficiently using a fraction of the energy that would be required with a standard electric heating element.
Compressed air
Compressed air storage can take a few different forms. Air can be pumped at high pressure into an underground cavern or even into giant “balloons” that are compressed by the weight of water in lakes or reservoirs. Air is released to turn a turbine to produce electricity when needed.
Canada’s Hydrostar has been a leader in the field of compressed air storage solutions and has developed a pilot project in Ontario. It is now embarking on much larger projects in Australia and California.
Similarly, Bedrock Energy is working to turn two caverns near Lake Huron formerly used for natural gas storage into a compressed air facility that could generate enough power to supply London, Hamilton and Waterloo.
Flywheels
Flywheels are giant wheels that are wound tight during periods of energy surplus and then released to generate electricity in high demand periods. They are generally used for short duration supply to balance the electricity system or deal with a sudden shortage. A flywheel project in Minto, ON is used for grid balancing.