Big Thunder Goes Carbon Neutral in Operation
Carbon Neutrality Measured September 2005 to September 2006

Reno, Nevada, October 15, 2006   


   This is a challenging thing to put out there to the world. What exactly does it mean to be "carbon neutral"? How can I, living in a nation of 300,000,000 people (about 5% of the world's population) that consumes something like 25% of the world's energy (as well having an equivalent fraction of the world's lawyers. Coincidence? You decide.) actually claim anything like carbon neutrality.

   Ok, let's start with the definitions. The title of this page claims we are "carbon neutral in operation." That means in the operational energy of the house for the twelve-month period of September 15, 2005 to September 15, 2006 we caused no excess carbon dioxide to be emitted to the atmosphere.

    We have two inputs of energy to the house, grid eletricity and propane. This does NOT include transportation energy or the embodied energy in the construction of the house. It also does not include the gasoline I ran through my chain saw cutting wood for the wood stove, but that amounts to less than one gallon of gasoline for the year.

     So, the numbers:


 

 

Big Thunder Consumption

Big Thunder Production

Nominal Value

Net Impact on the atmosphere

Propane

160 gal

 

12.72 lb CO2/gal

+2035 lb CO2/year

Electricity

8807 kWh

10037 kWh

-1.90 lb CO2/kWh

- 2337 lb CO2/year

 

 

 

 

 

Balance

 

 

 

-302 lb CO2/ year

 

 


     What this says is that we consumed 160 gallons of propane which resulted in the emission of 2035 lb of CO2. Over the same period we over-produced 1230 kWh (that's what we produced minus what we consumed, or 10,037-8807) of electricity, which goes back onto the grid. This means Sierra Pacific Power did not have to produce that power and based on their published emission rate of 1.9 lb CO2 per kWh, this means we prevented the emission of 2337 lb of CO2. On balance that means we prevented the emission of 302 lb of CO2 over that year.

    On this basis, I make the claim of carbon neutrality in operation. Comments?
 

 

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