To the Editor,
As an engineer I have long been disturbed by the claims made by TC Energy in their Overview of the project on their corporate web site.
Prominent bullet item benefits on the page include:
– 1,000 MW clean energy
– zero emissions
– powers 1 million homes
To begin with, MW is not a measure of energy. It is a measure of instantaneous power. From this overview page I assume they mean 1,000 MWh (Mega Watt hour). In other words, it can supply 1,000 MW for an hour. Most people are more familiar with KWh which is how our home hydro is measured. When you see a nuclear power plant rated in MW, the hours are irrelevant because it can keep producing this power continuously. Pumped storage can’t. I don’t see anything about recharge times in the TC’s information, so I can’t even speculate on how long it will take or how often they expect this to happen given expected province wide fluctuations in demand and excess capacity. It would be nice to see how many MWh they expect to deliver each month. I will point out that a graphic in another of one their presentations seems to indicate that they may be able to supply 1,000 MW for 8 hours or a total of 8,000 MWh. TC?
Secondly, it may be low emissions, but it most certainly isn’t zero. Hydrocarbons will be consumed during construction (diesel for excavation, coal for steel, natural gas for concrete, …) and during operation (lubricants, office supplies, transportation, …). These need to be amortized over the expected lifetime of the power plant, just like those used in battery production and electricity production need to be included in the true emissions of electric vehicles.
I expect the last benefit should read “may power 1 million homes for an hour (or 8?) every now and then. fewer during peak demand”. It seems that they came up with the million number by using an old StatsCan estimate of the average household (not exclusively a single-family home) using 722 KWh per month. As an hourly average over the month, this is 1.0444 KW (power not energy). Dividing the 1000 MW by 1.0444 KW yields 958,000 or about 5% less than claimed. Of course, this is an average, but the claim is that TC can take Off Peak energy production and shift it to Peak Demand periods. I know my personal energy consumption is much higher during the day when this Peak Demand happens. I would expect it to be at least 2X. It also doesn’t account for higher electricity consumption in our area since the average includes Condominiums and Apartments in big cities and places where Natural Gas is regularly used for heating. How many homes like ours will it actually power for an hour during peak demand is a good question.
Of just these three claims, I find the first the most egregious since the difference between power and energy is an extremely basic concept. Not to mention the company even has the word Energy in their name! I could speculate on why they made them, but I will leave it as an exercise for the reader. Hopefully, TC can provide some clarity on their claims.
Paul Layman Ph.D., Annan
