decisions decisions

These are the decisions I agonize over:

I left the house today with my laptop, but found when i took it out that I'd forgotten the power cord. So... do I drive home and get my laptop's power adaptor, thereby lessening the amount of energy I have to use when I turn it on (it won't need to recharge) but using gas in the car, or do I use the battery, thus not using the gas to get home but using more electricity later to juice the battery up again? Does one have a worse impact than the other? 

According to standby.lbl.gov, my laptop, charging, uses about 97W (about 34% more power than normal). It takes maybe 3 hours to charge fully, so that's basically 0.291kWh. The majority of our power in Ontario comes from nuclear sources, followed by hydroelectricity, followed at a distant third by coal and then gas (http://www.ieso.ca). That may be good news for my dilemma, given that driving my car uses gasoline... 

It's about 1km from where I am to my house. The car's a 1999 Civic, very basic model with no power anything (except locks). It's not hot enough for AC, but even when it is I usually drive with the windows down instead (though I'm told the drag this creates offsets the gas you save not using AC. argh). The US Dept. of Energy says that, driving in the city, I get about 22MPG (http://www.fueleconomy.gov/FEG/noframes/14872.shtml), which is around 35km/gallon or, apparently, around 5.7L/100km (does anyone understand this designation? why aren't we using the equivalent km/litre??) according to Auto123.com. So if I drive 100km, I'm using 5.7L of gas. It took a lot of digging, but I finally found a Ministry of Natural Resources page explaining that each L of gas produces about 2.4kg of CO2 (interestingly, it's 2.7kg/L for diesel!). If you'd like to track your fuel consumption, there is in fact a new intiative through the federal government to do so online: http://oee.nrcan.gc.ca/transportation/tools/fuel-calculator/index.cfm?attr=8. 

At any rate, this means 2km (return trip to and from home)  uses 0.114L of gas, and creates something like 0.2736kg of CO2.  whew.

...how do I determine how much CO2 I create by using 0.291kWh of electricity, with all its various sources? I have no idea. I intuitively guessed, wrongly it seems now, that getting the power cord was better than charging the laptop. 

But part of the madness of trying to find reliable info on this stuff is trying to find a source that doesn't have obvious conflicts of interest... Bullfrog Power, for instance, has some sort of CO2 for electricity calculator, but they are far from an unbiased party. On the other hand, the Ontario and Canadian governments have in their best interests reporting slightly skewed results too so it can seem that they're doing a better job than they likely are at cleaning up the environment. I currently have 13 tabs open, not including this one, just trying to find out how much CO2 Ontario electricity generation produces. And I still have no clue. If you've found your way here, perhaps at least some of the links I've found will help you navigate your way through to some sorts of helpful sites. Meantime, I'll keep looking...