Wednesday, May 18, 2011

Cars and energy, part 2

I want to do some thinking about electrification of the transportation grid. After doing a bit of wiki-research it appears that electric motors are far more efficient than gas engines. So instead of using 75 GJ to drive your average 20,000 clicks, it'll only take 25 GJ. This sounds quite promising, especially here in BC where virtually all of our electricity is CO2-emission free. So what are we waiting for?

But wait! According what I've read, BC Hydro is already a net power importer (note: we make money on this though, since we can sell our excess - when we've got it - high, to folks sweating down in California, and buy what we need on the cheap from Alberta or Washington, so it's all good, right?). So...how much extra electricity are we talkin' here? I mean, if we switch over all our cars and trucks and everything?

Well, Google to the rescue again, there's this great website from NRC that gives an in-depth breakdown of Canada's energy use. Very instructive. If you spend some time in the numbers, you'll find that BC uses 156 PJ (that'd be peta Joules, or 10e15 Joules) of energy, per year, on average (all figures 2008). This is for home heating, watching the playoffs on TV, cooling the beer, etc. A further 125 PJ is used in what NRC calls passenger road transportation, which I read to be driving ourselves around. Finally, we find that 120 PJ get used on freight shipping - shipping stuff we want to ourselves. Now, I think we can safely assume that these latter two categories currently run mostly on gasoline and/or diesel. So electrification of the transportation sector would mean we need to find an extra (125+120)/3 = 82 PJ of electrical energy from somewhere - that is, if we just keep things going exactly the way they are.

Hm. Sounds like a lot. But are we talking a few windfarms here? Or will the new site "C" dam be enough?

...so, once more back to the computer...(how did we live before Google?)...and find that site C is supposed to give us 5100 GWh annually = 18.4PJ. Yikes. Nowhere near enough! We'd need, like, four and a half site C dams to keep driving like we currently do. Uh oh.

{artists impression of site C, care of BCHydro}

Well, not to worry, there's always wind, right? I must admit that I'm not a big fan ... er, supporter... (but that's for another post), but let's crunch the numbers. A big windmill (like they have on Grouse - anyone ever see that sucker running, by the way?) typically outputs a tiny, dinky 0.02 PJ in a year (and here I'm being generous with a 40% capacity factor, which is high - the rest of the time, the wind isn't the right speed to drive the thing). So...that would mean...4100 windmills. Oookaaay.

Anyone driven through southern Alberta recently? Well, it's been turning into a big wind farm. About 600 windmills are there right now. Still just a tiny fraction of what's needed to keep BC rollin'. Just for reference, there are a 16 windmills in the foreground here (those brown specks are the cows):

{windmills somewhere near Pincher Creek, AB}

Multiply this view by, oh, 250. Clearly, what we're talking about here is massive industrialization of the landscape. And I do mean massive. But heck, we can farm underneath 'em, so no worries eh?

And, just because I happen not to be afraid of newkular power, I can let you know that one typical power station generates about double what site C can give, so we'd need only two nuclear plants. Yup. That's the reason they build these things. Plants are typically sited together, like at Bruce (which has 8 plants and is waay bigger than we'd need), see below.

{Bruce, with 8 plants. Thank you, Wikipedia.}

Now, I'm by no means recommending that we pony up for some nuclear plants so we can continue with happy motordom...but I think the picture is pretty clear. We have a huge problem on our hands if we want to electrify our transportation grid, while assuming everyone can just trade up to a Chevy Volt.

{Chevy Volt, with cute power plug. Photo wikipedia}

Now maybe you see why I get so wild when people get all happy about electric cars. Or when the gubmint spends my tax dollars on infrastructure like giant freeways which only serve to further entrench existing motordom. It ain't helping.

2 comments:

  1. Your numbers are looking at converting 100% of all vehicles on the road. If you ignore the freight, and accept that even 50% of all passenger vehicles is a huge number, you essentially have to quarter all your numbers. Then one site c dam is pretty much enough.

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  2. Yeah, you're right. But keep in mind that these numbers are 2008, and that we're committed to a growth economy...at 3%/year growth in GDP is essentially driven by 3%/year growth in energy use, and this means doubling in 25 years. That's what site C is currently planned for, not for letting everyone drive electric...There are also natgas liquification plants being planned in Kitimat (natgas exports from NE BC) which will require immense amounts of electricity (site-C-sized). I guess my point is to try to get people to see the size of the problem and the scale of the industrialization that we appear to be blindly committing ourselves to. It doesn't have to be like this...

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