This is very innovative and facilitates a true smart grid capable of maximizing renewables. Each unit, storing 15 kilowatt hours of energy, is paired with a transformer and can supplement needs during peak hours in homes.
Pole-mounted energy storage devices
In what it says is a world first, Toronto Hydro is testing pole-mounted energy storage devices that can supplement electricity during peak hours in homes.
In a pilot project, a compact white box, a little bigger than a suitcase, has been mounted about six metres up a hydro pole in the Keele St. and Sheppard Ave. W. area. It’s paired with a 50 kilowatt transformer that typically powers about 12 houses.
“It’s a lithium ion battery just like the one in your cell phone, and it’s equivalent to 2,000 cell phone batteries,” said Gary Thompson, supervisor of engineering at Toronto Hydro.
These units, each storing 15 kilowatt hours of energy, aren’t meant to provide bulk electricity to power houses but to provide support for a grid by making it more efficient, Thompson said.
They are charged during off-peak hours, around 1 a.m. or 2 a.m., and when a transformer begins to see its biggest load during peak hours, the storage unit will supplement some of the energy, he said.
This means that some of Toronto Hydro’s aging assets won’t have to be replaced soon, he said.
Just imagine plugging in a new Tesla car in your house, said Bala Venkatesh, director of Centre of Urban Energy at Ryerson University, which is the lead on this project.
There’s a sudden demand in the electricity of your house when the car is charging. So what this pole-mounted storage unit can do is store energy during off-peak hours. Peaks in energy demands, like when Tesla cars and other electric appliances are plugged in, will be mitigated through that energy storage device, Venkatesh said.
“The biggest benefit is that you can charge those storage units during off-peak hours and use them when electricity is required for a short time,” Venkatesh said.
To support the charging of the Tesla car, one might have to upgrade the electrical wiring of the house, he said. That means, as energy needs increase, transformers will have to be upgraded. But with these pole-mounted storage devices, that upgrade for electrical systems can be avoided.
Thompson said replacing transformers and electrical infrastructure is easier said than done. It involves a lot of planning, resources and engineering designs.
Dumping excess electricity to neighboring states
One of the criticisms government officials faced was dumping excess electricity to neighboring states and provinces.
But if thousands of these storage units are deployed across the province, they can store that excess energy, Venkatesh said.
The cost of these units if mass produced is about $20,000-$30,000 per unit.
Tori Gass, spokesperson for Toronto Hydro, said energy storage is a relatively new technology within the utility sector. Pole-mount energy storage is a new concept that Toronto Hydro has worked with its partners to focus on, deferring asset replacement and costs by relieving the load on an overloaded transformer, she said.
Early results have demonstrated an ability to reduce strain on the local transformer, Gass said.
“We’re going to continue to run the pilot for quite a while longer, but there’s no firm end date,” she said.
If the pilot continues to show positive results, then more of these pole-top systems could be put in across the city, Gass said.
“Toronto Hydro has more than 175,000 hydro poles and each one could be a candidate,” she said. “But there aren’t any definite plans to install any more just yet. We need to wait for the pilot results.”
Venkatesh envisions Ontario having lots of these units.
“We’ve done research on energy storage before,” he said. “We’ve worked on large energy storage unit, which is the size of a 40-foot container from 2009 to 2016. So this storage unit is a product of that evolution.”