Base load and baseload generation

The term baseload gets thrown around frequently but seldom is associated with a base, or minimum, load. It occurs to me the level of knowledge in discussions on electricity supply could benefit from reviewing the level of total electricity that would be met by a mythical generator running throughout at a the year at the minimum system demand. The results are not surprising,but the current level of discourse indicates the results are not intuitive.

I’ve revisited hourly load data I’ve collected over the past year for two provinces and British Columbia (bce … or BC). Each data set measures “load”, or demand, differently, but the particulars are not important for this simple review. For each province’s data set, I’ve queried the minimum annual load along with the average. Upon reflection it’s obvious that the minimum load divided by the average load produced the percentage of annual supply that could come from the steady production of the minimum load.

Differences between years are minimal, but the difference between Alberta and the other 2 provinces is significant. Alberta’s flat load profile means 80% of annual generation could usually be met by consistent supply at the base load level. “Alberta Internal Load”, or AIL, is the statistic used, and it includes behind-the-fence generation which is large due to extensive cogeneration, particularly from oil sands operations. Large industrial loads tend to be far more consistent than, particularly, residential demands. In Ontario and BC the reported loads, which omit behind-the-fence generation, indicate over 2/3rd of supply requirements would be met by output at the base load level.

For reasons I’ll return to in discussing implication of this base load supply level review, I ran some figures estimating how much usable supply would come from increasing the base supply level to 10% above the annual base load level, and with base supply 20% above base load.

Site C'ing: BC's electricity adventure

Site C is a hydroelectric project in British Columbia that may soon to be cancelled.

The commentary surrounding the Site C project has been driven by political posturing, and a recent change in government is therefore likely to end, at least temporarily suspend, the project. The situation is worth commenting on from afar because while it's B.C. today, in another time and other places some different - and many of the same - people will be discussing the merits of big, public, baseload power projects and small, private, sporadic power projects.

"BC Hydro’s Site C Clean Energy Project will be a third dam and hydroelectric generating station on the Peace River in northeast B.C. It will provide 1,100 megawatts (MW) of capacity, and produce about 5,100 gigawatt hours (GWh) of electricity each year..."   BC Hydro

I have 4 questions I wish to address in discussing the future of Site C:

1. Will there be a need for capacity?
2. Will there be a need for energy?
3. What are the costs and benefits of a Power Purchase Agreements (PPAs) with Independent Power Producers (IPPs)?
4. What are the costs and benefits of publicly owned generation assets

While Site C would have a reservoir (9,300 hectares), the main energy store for the system would remain the Williston Reservoir (177,300 hectares) upstream on the same system. It's not surprising the site would generate 5,100 GWh annually as the implied 53% capacity factor[1] is essentially what the B.C. hydroelectric fleet achieves annually. [2]

Many of those claiming Site C won't be necessary comically follow that argument up with a list of alternative generation technologies. To evaluate the alternatives it is first necessary to determine the value Site C may provide.

B.C. currently has adequate supply - it's peak "load" occurred early in 2017, and the province was a net exporter of power during that peak (as it is during most peaks). BC Hydro's resource planning anticipates the ability to meet the peaks to become less certain, and disappear around 2023. The need for additional annual energy is predicted to come later. The difference between the ability to meet peaks and the ability to provide enough energy throughout the year is important.

Graphics from BC Hydro. Links to view source graphics: Capacity and Energy