A Humbling Excersize in Minimization

[trebuchet03]

I had an epiphany today. Currently, I'm running an experiment on a standard refrigerator, trying to keep in the cold and save energy. I'm trying to minimize losses.

My datum for the experiment. My refrigerator consumes 1.32kWh per day.

Experiment aside, lets do a quick benefit analysis (we're not going to even consider the cost at the moment - just all the benefits).

So, 1.32kWh per day translates to:

481.8 kWh per year - $48.18 per year @ 10 cents/kWh (mine is a tiny bit less)
~646 pounds of CO2 annually by 1999 standards (if you can find more recent data, I'd appreciate it)

So, for every .01kWh/day saved you save
3.65kWh per year - $0.37 per year @ 10 cents/kWh
~4.78 pounds of CO2
3.65kWh gets an EV (250wH/mi) ~ .9 miles

For every .5kWh/day cut... you save:
182.5kWh per year - $18.25 per year @ 10 cents/kWh
~239 pounds of CO2
182.5kWh gets an EV (250wH/mi) ~ 46 miles
This type of savings begins to be reasonable

For every 1kWh/day cut... you save
365kWh per year - $36.5 per year @ 10 cents/kWh
~478.15 pounds of CO2
365kWh gets an EV (250wH/mi) ~ 91.25 miles


Now, if I had did this basic calculation beforehand... I may not have gone forward with the experiment without doing some hand calculations. I have a strong feeling that ~40% (.5/1.32) of the energy that goes into a refrigerator does not come from opening the door considering that the door stays closed for most of the refrigerator's life...

Perhaps later, or tomorrow, I'm going to do some hand calculations to see just how much energy is lost when one opens/closes a refrigerator door - 40% very well could be reality... But here's a preliminary result.

Subjectively - I feel very little cold air hit my feet when I open my refrigerator (as compared to pre modification).
Quantitatively - we're seeing little results on the KillaWatt (although, the average goes down slightly every day - I'm resetting tonight)



As this applies to everything else.... Looking at the overall impact when you're trying to minimize a low number is very important. When you're starting off low, and try to minimize... It's difficult - and in some situations, not cost effective or worth the effort. 1 cD point (.01) saved is worth it - but an eighth of a point (0.00125) may not be depending on cost...


Doh! I put this in the wrong category (maybe)... Sorry about that :/