Thursday, October 29, 2009

Beginning Thoughts of Math, Carbon Footprint

In effort to show the value of home energy conservation efforts, I have done math for heat transfer, and fuel costs crunched for my city. Now, I want to join the game of declaring benefits as reduction of carbon footprint. An advantage in this is that low, subsidized, cost of heating fuel is divided out. I accept numbers from a recent issue of National Geographic, March 2009, p 67:

Driving: a gallon of gasoline adds 19.6 lb CO2.
One KWh electric use adds 1.5 lb CO2.
100 cf of natural gas emits 12 lb CO2.

I need to back up a few steps, and understand where I am expected to go, with reduction employing such numbers. Start with the EPA Household Emissions Calculator.
Here is my annual carbon footprint, living alone, working hard as a weatherization contractor:
12,438 pounds CO2 in driving 13,400 miles per year.
2,808 pounds CO2 for 239 therms of natural gas in an efficient furnace heating my modest 1000 sf home and productive workplace.
7,063 pounds of CO2 to generate 7663 KWH of electricity per year.
22,309 pounds CO2 before savings efforts volunteered, about 1000 pounds of CO2, through car maintenance and through steadfast recycling.

Numbers correspond fairly well with the National Geographic conversions. I am near the 20,750 per-person US average. I have begun to share my home, and that will push me below the average. The sharing of my home is in fact the most powerful thing I can do.

Better-educated by this study, I am inspired to save a few thousand pounds of CO2 emissions per year. Here are several ways I could save 1000 pounds: Drive less by 8%, fifty gallons, or 1080 miles. Reduce electricity use by 14%. Reduce my use of natural gas for heating, by a harder-to-do 35%, or 85 therms. There is promise in all of these. Only heating reduction through conservation, what I do for others as a contractor, is painless.

I began this writing exercise upon concluding that large effort in a customer's attic of 720 sf, going from R13 to R40, would save fifty therms, the equivalent of using thirty gallons in driving, and about 600 pounds of CO2 averted. It was a small gain, but beyond painless. It is a more than twenty percent annual return on the customer's investment, forever, and further value in more-comfortable living. The customer will still look for harder ways to reduce footprint. The saving corresponds also to that of diligent use of clothes lines in a wet climate; this with no effort.

No comments: