Saturday, February 25, 2023

Four Saskatchewan SMRs isn't enough.

I hope to persuade you that Small Modular Reactors (SMRs) should form a key part of Saskatchewan's power future, and that the four we're talking about building (from 2034 through 2042) are both too little and too late, given our current power generation mix and expected growth.

Saskatchewan should build more than four SMRs, and we should start building them as soon as reasonably possible. 

Background & Assumptions 

A few of my old posts may be worth reading (see index of energy posts) but this post builds significantly on my Path to 2030 post in methodology and what I've learned since August. 

For a deep dive on the BWRX-300 in Saskatchewan and how we can to be evaluating this SMR in particular, see this post

I've held these key assumptions through the analysis below:

  • There is no (or very limited) capacity for new large-scale hydro. This has been frequently repeated by SaskPower and is intuitively true for a very flat province.  
  • Generating assets have approximate lifespans of 20 years (batteries*), 25 years (wind, solar, sawmill waste*), 30 years (coal, natural gas, flare gas*, waste heat*, bio-refinery*), 60 years (nuclear), 100 years (hydro), before major refurb, replacement, or decommissioning is required. Lifespans marked with a * are an educated guess (and the sources are small enough not to impact the analysis), the rest are based on surveys of industry expectations. 

My usual caveat applies: I'm not an expert in this space, but I am highly interested and motivated to learn more. More assumptions are noted in the spreadsheet linked at the bottom of this post. 

The Path to 2050 2055

I've combed through SaskPower's system map and asset list, planning and construction projects list, news releases and more to try and build a basic-but-comprehensive model of our provincial power grid. 

The basic model has just a few parameters:

  • Power plant type (natural gas, coal, wind, etc.) 
  • Power generation capacity (in MW)
  • Expected asset life (in years, and specific dates)

Aggregating this information into one chart, we can visualize SaskPower's planned power mix to 2055. 

Why 2055, and not 2050? It shows the end of life of a large amount of mid-2020s wind and solar assets with expected 25-year lifespans.

Emphasizing my comment above about this being a "basic" model, here are some comments on the above image: 

  • Coal drops off by 2030 per federal regulations. (I don't think SaskPower has shared if it will be a gradual ramp-down or an abrupt stop, so I've modelled it as the latter)
  • Four SMRs are built, commissioned in 2034, 2037, 2040, and 2042. This timeline is based on the 2021 inter-provincial SMR Feasibility Study (but the province has made no firm commitment; the decision on the first SMR is scheduled for 2029. See this post). 
  • It is uncertain if new federal clean electricity regulations will mandate the phase-out of natural gas for electricity by 2035. This model assumes a fast phase-out is unlikely, so I've shown gas capacity tapering off as plants hit end-of-life (30 years). 
  • Of course, most power assets can be refurbished, rebuilt, or replaced-in-kind instead of being taken out of service, but that is not shown. 

Declining Dispatchable ("Base load") Power Poses Risk, Uncertainty 

The most concerning outcome of this model is the uncertainty about where we'll get secure, dispatchable, "base load" electricity in the future. This is power that can be called upon when needed: boilers lit, dam water spilled, atoms split, batteries discharged, etc. 

Intermittent power (like electricity from wind or solar) depends on favourable weather conditions and may not be available when we need it (or: too much may be available when we don't need it). 

On the following chart I've added two lines: 

  • The red line is my forecasted/estimated peak load: the maximum instantaneous power demand in the province. I've taken our historical peak load (3910 MW, set December 2021) and increased it by 0.5% per year. This is an extremely conservative assumption (as we'll see later) given the push to "electrify everything" to reduce emissions, and given Saskatchewan's growth plan which seeks to increase our population to 1.4M by 2030. More people, more industry, more power. 

  • The black line is the total dispatchable power capacity. I've both over-estimated dispatchability by assuming 100% of hydro can be called upon (typically it runs <50% capacity factor, see for historical utilization), and under-estimated dispatchability by assuming imports are not dispatchable. Because this is a simple model, let's say these two assumptions cancel each other out.

The area of concern on this chart is where dispatchable power drops below the conservatively-estimated peak load. This means on a dark, cold, winter night when we need electricity the most, our hospitals, care homes, industries, and homes will be depending on imports and weather-dependent energy instead of "firm" dispatchable power.  

It's fair to object to my suggestion imported power is not dispatchable or reliable. It might come from firm sources... but it might not. 

Consider the new 650 MW interconnect to the Southwest Power Pool (SPP), due to be completed in 2027. SPP is a huge grid: over 85 GW of generating capacity (compared to our 5.5 GW). However, one third of that capacity is wind, and the wind may not be blowing when we need it. 

We cannot absolve ourselves of responsibility for our own energy security. Electricity is critical to homes, businesses, farms, industries, emergency services, and life in general. Like healthcare, we cannot outsource this critical service to other jurisdictions. 

The Impacts of Increasing Intermittency

The final version of this chart condenses different generation types into three categories: dispatchable power, variable (intermittent) power, and imported power. 

Note: Most imported power from SPP would likely be from variable sources, so the % Variable estimate is likely low. 

The dark gray line highlights a growing percentage of provincial electricity will come from intermittent sources. This means:

  • Power prices will increase due to redundancy required by intermittent power sources, including:
    • Dispatchable backups like natural gas for when it is calm/dark. (I don't think batteries are a credible grid-scale solution to get us through 7 days of calm and dark - see this post.)
    • Tons of extra transmission lines to remote generating sites.
    • Lots of empty transmission line capacity waiting for favourable weather. 
  • Our grid will generally be less stable (easy to manage) with increased supply-side variability in addition to existing demand-wide variability. 
  • Dispatchable assets will wear out faster as they ramp up and down harder to match variable generation, requiring more maintenance and/or early replacements. 
  • Prolonged or indefinite lifespan extensions of natural gas generation, which could be costly due to escalating carbon prices and/or possible 2035 federal regulations requiring we discontinue using gas for electricity or retrofit plants with expensive carbon capture equipment

Books that should be required reading for any electricity policymaker and/or wannabe energy pundit are: 

To close this section, I want to re-emphasize that the further we peer into the future, the hazier it gets. 

This model is not the definitive plan, merely a simple extrapolation projects and lifespans we know about today, waiting for questions to be answered and more projects to be proposed to fill in the blanks. 

So, let's try to fill in some of the blanks! 

A Nuclear Future for Saskatchewan

Let's imagine a future where we prioritize and value these qualities for electricity:

  • Reliability 
  • Affordability 
  • Carbon-free

Reliability should be the top priority for any grid. If electricity is not reliable, it is therefore unaffordable: for unreliable electricity generation the grid operator must provision expensive redundancies and raise rates to cover those costs. Or they make reliability the responsibility of consumers, in effect forcing people to procure backup generators, solar panels, batteries, etc. to keep their service reliable. Nuclear power plants in North America run at ~95% capacity factor: that's reliability.

Affordability is tightly coupled to reliability. A predictable, boring grid is an affordable grid. Despite the high capital (e.g. construction) costs of nuclear, operating costs are low and extremely predictable. Thanks to the long asset life of nuclear plants (60+ years), we can "mortgage" construction costs over the life of the asset. Nuclear fuel prices do not fluctuate like the price of fossil fuels, and the fact the fuel is so energy-dense means that only a little bit of fuel is required. (See also: my post on SMR costs)

Carbon-free is the icing on the cake. Nuclear energy has the smallest land footprint per unit of electricity delivered, and uses an extraordinarily small quantity of raw materials, rare minerals, and fuel to unlock a tremendous amount of atomic energy, all to boil water, make steam, spin a turbine, and generate power without emitting carbon. (What about the waste? see the last few sections of my BWRX-300 post)

Nuclear energy is clean energy. Image source: Glex

Using my simple model, I've calculated that Saskatchewan would need to build not four, but eleven small modular reactors between 2034 and 2049 to bring our dispatchable power back above our  (conservatively) forecasted peak load:

The only other change I made to this model was to delete 1,500 MW of wind/solar power from being brought online in 2035, since it would no longer be required. Think about it: why would we generate zero-carbon electricity from gigantic, energy-dilute farms harvesting sporadic energy from the weather when we could simply manufacture electrons in a dozen tiny factories? 

We should be concerned about what happens in 2030 when coal is phased out, and dispatchable power capacity drops below a conservatively-estimated peak load. Yes, coal is bad for emissions - but at least it's available on demand. Unless new dispatchable projects are announced to fill that gap, we will have to depend on a mix of intermittent renewables and expensive imports (see this post - imports are 2-3x more expensive than generating electricity at home) to meet demand during our most challenging conditions. 

It would be ideal (and optimistic) to pull SMR commissioning forward from 2034 to 2030, so that some nuclear can offset the last of the coal.