Compact Paradox?

So: We're all replacing incandescent lightbulbs with compact fluorescents, thereby saving electricity, thereby reducing carbon emissions, thereby saving the planet, right?

Or are we?

A comment on another blog prompted me to check that truism. The point is made that, during the heating season (which around here runs from about October through April, depending on how tolerant you are to wearing sweaters indoors) we derive some benefit from the waste heat of electrical appliances like light bulbs. If we switch to more efficient bulbs, that heat must be made up by the furnace, which is presumably burning a fossil fuel.

So the question is: which is more efficient in terms of carbon emissions? Burning carbon-rich stuff for heat, or using electrical heat which includes a component generated from non-fossil sources (dams and nukes)?

Let's do some arithmetic:

I have a recent-model natural gas furnace which is advertised to be better than 95% efficient (ie: out of every joule of heat generated in the burner, 0.95 joules winds up warming the house). How much carbon does my furnace emit to deliver, say, 1 megajoule of space heating? First, to get that 1 MJ delivered, we need to burn about 1.05 MJ worth of fuel. Natural gas is mostly methane, the heat of combustion of which is 55.5 MJ/kg, so that 1 MJ of heat-made-good requires 1.05/55.5*1000 = 19 grams of gas. Methane (CH₄) has a molecular weight of 16, only 12 of which is carbon, so the net carbon emission is 14.2 grams.

What about electrical heat?

The biggest loss in thermal-source electrical generation is right at the turbine. The maximum theoretical efficiency of any apparatus that converts heat into work is limited by the temperature difference between the input and the output. Given available materials, this means that the process that turns boiling water into electricity can never be more than about 40% (and that's generous). Knock off a little for transmission losses, and let's say that the overall efficiency -- from burning the fuel to lighting the bulb -- is 35%. That looks pretty bad until you consider that, in a typical power grid not all the electricity comes from fossil sources. Ontario Power Generation (to use the locally relevant example) gets only 27% of its power from fossil fuel plants (mostly coal, though with some contribution from oil or gas).

(Aside: That OPG page is pretty cool. The big number at the right shows the amount of power currently being generated in the system, continuously updated. As I write, Ontario is running on about 11.5 gigawatts. During summer heat waves, it gets up around 25 GW or more. Clicking on the hydro, nuclear and fossil links at the left lets you see how much is being contributed by each source. Really, engineers are fascinated by this sort of thing. That, and my late father worked for OPG's predecessor Ontario Hydro, so I have a familial interest in the old place. I've been in some of those stations, when he would take me out on a job.)

But back to the arithmetic: Anthracite coal yields 27MJ/kg when burned. So generating 1MJ of electricity emits (1/27)/35%*1000 = 106g of carbon. However, only 27% of OPG electricity comes from fossil sources, so we can discount that amount down to 28.6 grams.

Which is still twice as much as just running my furnace. You'd have to be using a crappy old furnace that was only about 50% efficient to be as bad as electric heat. And in the summer of course, there's no question: every watt of heat you don't produce in the house is one watt your air conditioner doesn't have to scavenge up and move outside.

Conclusion: Even when you allow for the space heating contribution of incandescents, compact fluorescent bulbs still win by a good margin.

[Note: to keep it simple (translation: I'm too lazy to do all the research) I've ignored a lot of upstream carbon contributions here, such as: manufacturing light bulbs; building the different kinds of power plants; mining, processing and transporting coal or uranium. Also, the generation mix I used is the cumulative figure for 2007, which does not necessarily reflect what OPG might be running on a typical cold January night.]

Reflection on Earth Day

Before the turn of the century, so-called “future-watchers” often predicted the advent of the “paperless office”, and by extension, the “paperless society”. Nine (or perhaps eight) years into the new millennium, it seems that if anything more people now have more paper than ever before. The proliferation of personal printers and photocopiers is, in many ways, even more astonishing than that of personal computers. Because the production of printed matter is now so cheap and accessible, the material we have is becoming more and more banal and ephemeral. Our forests are being denuded, simply for the purpose of informing potential customers of their next unique opportunity to spend money they don’t have to buy things they don’t need.

Paper pushers defend their right to free speech and conspicuous consumption, saying that all that paper gets recycled anyway. But, looking at my lawn in the spring, I know that there is a lot of it that is simply tossed away. And, the last time I visited my local stationery store (to buy the supplies I needed to feed my own shameful paper habit), I discovered that the cost of recycled paper was actually 10-30% more than standard paper! I steadfastly bought the more expensive recycled pack, and when I got home, I made sure to hug my favourite trees, telling them what I went through on their behalf (they were not very sympathetic).

I do my best to conserve paper, subscribing to paperless billing where possible, re-using the second side of printed paper for drafts, attempting to cancel subscriptions to advertising – I have even put up a no-flyers sign above my mailbox, but apparently, even though there is as much or more paper than ever before, reading comprehension is still sadly lacking for many of the delivery people who still saddle me with their useless notices.

But recently I committed a dreadful transgression, and was taken to task by my own son! I had suggested that maybe it was not strictly necessary for him to extract all the recyclable paper from the large wad of paper and tape that he had retrieved from our recently mounted garage sale signs (technology made it so easy to print all those signs…but I digress). So, here I am, writing my penitential essay. It seemed like such a little thing, but of course everyone knows all the platitudes about how it’s the little things that make a big difference in the long run.

I promise, I won’t ever do it again – and please: Don’t tell the trees!

I Always Knew....

....that lawns were evil. They require vast quantities of fresh water to keep them green in summer, regular applications of insecticides to keep bugs from munching out on them (it's a frackin' monoculture, duh -- pests love a monoculture), and more applications of herbicides to keep Mother Nature from turning it into, well, not a monoculture any more. (You've heard that Nature abhors a vacuum? It's a lie: the universe is pretty much all high-grade vacuum, but biological monocultures don't last long without a lot of effort.) Then there's the mowing, usually with some stinky two-cycle engine that puts out as much smog as a badly-tuned city bus.

And unlike the other grass monocultures we humans go to great trouble to maintain, lawns don't even feed hungry people. Mostly, they feed the status-conciousness of insecure suburbanites, and the bank accounts of the lawncare companies who do the heavy lifting required to keep our homes surrounded by a surface that resembles a billiards table. What the hell use are they? Approximately none.

And now my long-standing contention on the turpitude of turf is confirmed: in Beacon Woods, Florida, you can go to jail for not keeping your lawn green. It seems that retiree Joseph Prudente had the bad luck that his sprinkler system broke and his lawn died. So the local Home-Owners Association invoked a local deed covenant, requiring him to re-sod his property. Which he couldn't afford to do. So they got a court order telling him to do it. Since that didn't magically make him able to afford it, he still didn't. So on Friday he reported to the county jail, apparently to remain there until he sods his lawn. (One hopes that other residents of the county will send the bill for his incarceration to the Beacon Woods Civic Association, as a hint that the justice/penal system has more important issues than brown grass to deal with.)

It has been said that, in America, it is a crime to be poor. In Beacon Woods, FL, it's apparently even a crime to be not quite as solvent as your stuffed-shirt superficial middle-class neighbours. But the real crime here is having a rule like that in the first place. Look, morons: if the grass dies because the sprinkler system broke, then you obviously have completely the wrong conditions to be even trying to grow the stuff. Get a fracking clue, will you? Grow some native Florida vegetation or something.

(For the record: we have been steadily finding other things to fill the yard with besides grass. What lawn remains includes a mix of spring bluebells, feral violets and clover. Much healthier -- and much better-looking, too).