The embodied energy in an apple

To begin in describing the embodied energy of an apple, we will first consider the definition of embodied energy.

Embodied Energy: 
The sum of energy inputs (fuels/power, materials, human resources etc) that was used in the work to make any product, from the point of extraction and refining materials, bringing it to market, and disposal / re-purposing of it. [1]

Now it is safe to say that the apple is a very common occurrence in house holds all over the world and possibly even more so in my home location of Iowa City, Iowa. Often times what goes in to our basic products such as an apple can be over looked. We don't think about how far that apple has traveled and resources utilized to bring the apple to our table. There will obviously be a difference in the embodied energy of an apple in apple season from a local orchard and an apple out of season imported to your area. First we will look at in season apples. We will assume that in season apples means that one can get the apples from a local orchard. We will analize just the energy of travel.

The average gallon of gasoline contains 36.6 kWh/gal. [2]

Lets say it takes a drive of 10 miles round trip to get to the apple orchard and back. We will consider the average mileage of a car to be 20 mpg. With 1/2 a gallon being used to retrieve one apple.In season embodied energy of one apple is 18.3 kWh.

So say they that we are going to be cooking some apples decide it would make more sence to buy these apple in the form of a bushel of apples, roughly 126 apples. These 126 apples will make us around 15 apple pies. This brings the embodied energy of the apple down to around .145 kWh per apple.[3]

 In season embodied energy of one apple is .145 kWh.

Now lets consider if the apple is out of season or needs to be transported. Lets try to keep the calculation in the same terms. So if we transport the apple over land from Chief Seattle apples in Seattle, Washington to Iowa City, Iowa, the distance traveled would be close to 1,500 miles. This means that 750 gallons were used in getting the apples to Iowa City. Lets also say 20 bushels of apples were in the truck or 2520 apples.

This gives us an out of season embodied energy of 10.9 kWh.   

 This bring us to how much energy does an apple give you when you eat it, or the energy out.
The average apple has about 80 calories. When converting that to kWh one apple gives you 9.3* 10^-5
kWh of energy and keep in mind that you still are utilizing energy to eat it. This energy given to the person eating the apple is less than that of even the in season embodied energy of the apple and makes one consider a system of checks and balances. 



[1] http://en.wikipedia.org/wiki/Embodied_energy
[2]http://en.wikipedia.org/wiki/Gasoline
[3]http://www.pepinheights.com/apple-info/weights-measures.php