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Always-on, always-clean: flip the switch to nuclear

When was the last time that you reached for a light switch and thought about whether or not the lights would come on? Or the last time you woke up in the morning worrying that your plugged-in phone didn’t charge overnight?

For most Canadians—myself included—these thoughts don’t really cross our minds.

We expect that the electricity we need will be there when we want to use it. Thankfully, for decades, a stable and steady supply of power has been there to meet these expectations.

We call this baseload power.

Energy definition time! Baseload power refers to the minimum amount of electricity that’s needed to be supplied to the grid at any given time.

This power is provided by sources that can provide a steady and consistent amount of power to meet this minimum demand.

Sources of baseload can include carbon-spewing sources like natural gas- or coal-fired electricity generation and emissions-free sources like hydroelectric dams and nuclear power.

Across Canada and in Ontario, hydroelectric and nuclear do the heavy lifting when it comes to providing steady, reliable sources of clean baseload.

Check the app for always-on, always-clean nuclear

So, what’s powering our electricity grid right now? When you flip that light switch, how much of the power is coming from carbon-free sources and how much from GHG-heavy natural gas?

Good news: There’s an app for that!

I’m a huge energy nerd (is that a thing?), so I downloaded the Gridwatch app where I can get an hour-by-hour view of how much electricity each sources is contributing to Ontario’s grid.

I’ve never seen a day where nuclear isn’t contributing the biggest share—typically around half of all electricity—powering Ontario’s homes, hospitals and businesses.

Are all power sources reliable?

The reliability of any source of electricity generation is measured by what is known as its capacity factor.

Time for another energy definition! Capacity factor is how much energy a source actually produces out of what it’s capable of producing if it were running at its maximum capacity.

For example, a source of electricity generation that has a maximum capacity of 100 megawatts (MW) but only has an average real output of 40 MW would have a capacity factor of 40%.

In Canada over the last decade, we’ve seen these average capacity factors for each generating source:

  • Nuclear plants: 85%

  • Wind power: 30-35%

  • Solar power: 13-20%

Source like wind and solar are called intermittent—they can’t be available all the time because of external factors like when the sun isn’t shining or the wind isn’t blowing.

So can we even add more solar and wind?

A steady supply of clean baseload power helps other clean sources of electricity generation to provide power to the grid when they’re best able to do so.

Because wind and solar can absolutely play their part! They just need to be backed up by either clean baseload power (like nuclear) or a form of clean energy storage.

Energy storage technologies like huge grid-scale batteries or pumped hydroelectric storage let us shift the use of electricity from when it’s generated to when it’s needed.

And although energy storage has shown promise in helping fix some of the challenges associated with intermittency, the fact remains: clean baseload will be a critical part of the grids that power our lives in a net-zero future.

Last year, my colleagues and I reported on how clean energy storage technologies powered by clean baseload power from nuclear provide grid operators with the flexibility they need to make sure intermittent sources can effectively contribute to the grid and meet peak electricity demand during the day.

CANDU, Canada’s nuclear advantage

We’ve talked about how nuclear power plants can operate for extended periods without interruptions (as demonstrated by their high-capacity factor, above) and our country’s CANDU reactors are a leader in this field.

Made-in-Canada CANDU has unique abilities, like on-power refuelling, that allow for these sources of clean electricity generation to continue for months—even years—without interruption.

Down the road from where I live, the Bruce Power Nuclear Generating Station is living this out each day: in 2020, for example Unit 3 at Bruce Power set an operational record of 404 continuous days online.

Clean and reliable baseload power for more than 400 days. That’s the CANDU advantage.

Nuclear is an always-on and always-clean source of electricity. And the value of this reliability cannot be understated—for our hospitals, businesses and homes who know that the electricity they need will be there for them when required.


Chad Richards is the Director of the Bruce Power Centre for New Nuclear and Net Zero Partnerships.


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