Wednesday, October 31, 2012

The Energy Pie

There’s a lot of chat these days about “sustainable” or “green” energy.
And a lot of confusion, too.
 “Green” energy means, here in BC, energy that is made using hydro, wind, or wood. Fossil-fuel energy – the kind that comes out of the ground – is not “green” or “sustainable”. So this is the kind of energy that environmentalists would like us to wean ourselves off of.
So let’s first wrap our heads around the size of the problem, and where the problem is. Here’s a graph, based on numbers from Canada’s government office on energy efficiency (2009 numbers), on energy use per sector here in BC:
[ energy use by sector and type ]

It’s colour coded: red pie pieces are “fossil fuel”, blues are “electricity”, and green is “wood”. It’s divided up by industrial sector: residential ("rez"), commercial / institutional ("comm"), heavy industry ("ind"), transportation ("trans"), and agriculture ("ag").
The idea here is that we want to reduce the size of the red chunks. The biggest red chunk is fossil-fuel-based transportation - moving ourselves and our stuff around - surprise, surprise! This chunk represents 33% of all our energy use here in BC, and it is more than twice as large as the total energy used by the residential sector. The next biggest red piece is the fossil fuel energy used by heavy industry (mining, forestry, cement) – which is 15% of our energy use – less than ½ of the transportation piece! Residential and commercial fossil fuel use (most which is used for water and space heating) is third on the list, and come in at about 7.5 and 5.5%, respectively.
[what surprised me was the huge amount of wood-fired industrial use. BC's energy hungy pulp mills use wood waste and what's leftover from their process to fire their boilers.]
So, moving to a more “sustainable” energy basis means we really need to get our transportation system onto electricity. Yeah, home heating could use some updates, but this is a much smaller problem if we want to reduce our fossil fuel use.
The real problem is, of course, that there is not enough electricity in BC right now to electrify our transportation sector. Basically, we are already using all of it. If we want to move our current transportation, as-is, to electricity, we’d need a futher 123PJ of energy from somewhere (taking into account the fact that electric motors are 3x more efficient than FF motors); this is the equivalent of 4.5 site C dams.
We can shrink the currently blue pieces of the pie (probably by 60%) by making better use of electricity…turning off lights, and especially trading in those baseboard heaters for (more expensive) heat pumps, would free up about 20PJ -  but that would still leave us with 100PJ to find somewhere. Still the equivalent of 3.5 site C dams…
It is really hard to escape the conclusion that we need to rethink our freight and human transportation systems if we want to move to more sustainable energy sources. The current system of commuting in single-occupancy vehicles, electric or not, cannot be part of this future.

Wednesday, October 24, 2012

...and yet again more praise for the Germans...

Interesting article, heaping more praise on the German solar PV experiment. I gotta say, these articles rub me the wrong way. They get my bogosity antennae going, big time.

The reporting is really pretty poor; there is no putting this in context of how much energy the nation uses, or explaining of terms. For example, let's parse this one sentence:

" [their solar PV infrastructure] is the equivalent generation capacity of 20 nuclear power plants."
At first glance, this would appear to mean that Germany is able to generate 20 nuclear plants' worth of electricity using its solar PV grid. Wow! Sure makes it seem like they are right on target to shutting down their entire set of 27 nuclear plants! Yay!

But wait. This isn't what that statement actually means...

What the sentence really means, is that they have built enough infrastructure to generate this much electricity if the sun were shining 24x7, 365 days per year. This is what the words "generation capacity" mean. Do they explain this? Nope.

In fact, on an average day, the amount of energy Germany generates using its solar PV arrays is a mere 5% (!!!) of what it requires. You can look this up on Wikipedia. Sure, there are days here and there where they generate 50% of their needs using PV, but these occasions last a few hours or so, and are followed by days of cloud cover, when they generate basically nothing using their arrays. And this is the basic problem with solar (and wind) power: it is intermittent. Doesn't matter if you blanket the country with the things, you're still not gonna get reliable power.

The cost of putting this much infrastructure in place is borne by the Germans as a whole; the article itself makes clear that the general public is enthusiastically donating cash for this purpose. People pay whatever the article says for their array, and then more in taxes to subsidize the hookups, reduce their electrical bills, etc etc. The sum total cost to the German people is, I'm happy to concede, probably less than building 20 nuclear plants, but I'm pretty sure it's not 20x cheaper. Let's say it's 50% of the cost of 20 nuclear plants.

In other words, they are effectively paying for 10 nuke plants (billions of $) to get 5% of their electrical needs met. Is this a deal, or what?

By the way, Germany has 27 nuclear plants in total (also from Wikipedia - some are shuttered, most are scheduled to be so), which used to provide about 25% of their electrical needs (most of rest comes from coal.) So, to put this in yet another perspective, they have built an entirely new, parallel system of solar PV to take out the nuclear plants, in order to obtain 1/5th of the power that the old system provided.

The mittelstand, so praised in the article, requires reliable power to run their myriad of high-tech factories. And the power can't be too expensive, or the German engineered goods they produce would be too expensive for others to buy. So, back in reality, they are ramping up buying electricity from outside, to make up the shortfall. Germany already imports 2/3 of its energy. Imported energy is overwhelmingly either from nuclear, or coal plants in neighbouring countries, so in effect Germany is exporting their nasty nuclear and GHG-producing power plants to others.

There is nothing inherently wrong with solar power, or wind power, or any of those other renewables, as long as one recognizes their limitations (intermittency). What is wrong, deeply wrong, is assuming that we can just continue with business as usual - same consumption, same prices! - by magically switching over to them as a power source and turning off the nasty coal / nuclear plants.

Well, at least here in BC we have legacy hydro, which is clean, cheap, and reliable. Let's just not waste it on frivolities like electric cars.