1. Energy of Food

2. How does energy get into your food?

3. What is the pyramid of energy?

4. Why is the pyramid important when considering sustainability?
The higher you eat on the food chain or pyramid, the more energy is required to make your food
Journal of American Clinical Nutrition, 2003
Food
Energy in:out
meat
40:1
eggs
39:1
milk
14:1
chicken
4:1
vegetables
2.2:1
corn
0.25:1

5. Here are some facts from John Robbins’ book, Diet for a New American:
1.3 billion people could be fed by the grain and soybeans eaten by U.S. livestock
20 vegetarians can be fed on the land needed to feed 1 meat-eating person
60 million people could be fed by the grain saved if Americans reduced their beef consumption by only 10%
60 million people will starve to death this year
One-half of all water used in the U.S. is for livestock
50 gallons of water are needed to produce 2 pounds of wheat, but 5,000 gallons of water are required to produce 2 pounds of meat (that’s 100X!)

7. What energy goes into a tomato?
Plant a seedeat it
Plant a seedcook iteat it
Farmer plants a seedtakes it to marketyou drivecookeat it
Farmer plants a seedtakes it to distributortomato is packagedtrucked to Wegmansyou drivecookeat it

8. Figure 17.5: Energy used in the production of a loaf of bread.
Fig. 17-5, p. 557

9. Table 17-2, p. 556

10. Make a school lunch

11. What energy goes into a school lunch?
Production (25%)-
Processing (20%)-
Retailing-(17%)-
Consumption (38%)-

12. What did we learn?
Our present system of mass producing, processing, and distributing food is very expensive with respect to the use of land, energy, people, and $$$$$$$$$$.
This is why there aren’t many stores like Wegmans in Africa and Asia and South America, etc.
Is this sustainable?
What can improve this situation?

13. How is corn turned into fuel?
Fermentation
Distillation
Fields of Energy: ethanol

14. Some facts about ethanol:
World production of ethanol tripled from
The U.S. is the top producer; Brazil #2 (together almost 90%)
The U.S. produces 60% of the world’s corn
At present, 40% of our corn is used to make fuel
Most U.S. cars run on 10% ethanol and the gov. is now considering raising that to 15%
A flex-fuel vehicle can run on E85
Estimates tell us it takes 450 bushels of corn to fill one gas tank and
it takes 3-4 gallons of water to make 1 gallon of ethanol
All the corn we grow in the U.S. would replace only 12% of our gas consumption
Ethanol now provides about 3% of our fuel needs
Ethanol production has been heavily subsidized by the government and
In the name of reducing greenhouse gas emissions and reducing America’s dependence on foreign oil, the 2007 Energy Independence and Security Act (EISA) mandates that we need to consume 36 billion gallons of ethanol by 2022

15. How does growing crops for ethanol fuel affect the balance of…
pros
cons
energy
Net energy gain:
1 unit IN: units OUT
GGE = 1.5
Reduced mileage
Less power $
Fuel prices lower Farmers get paid
Food prices up
Car prices up
environment
Cleaner?
When mixed w/gas maybe; not E100
Hurts land: area, chemicals, water
Still carbon based

16. Food vs. Fuel

17. Some sobering facts…

18. How can we maximize utility of biofuels?
Use recycled materials to keep production costs, land use, etc. minimum
Use non-food crops such as switch grass, algae, etc.
More cellulosic ethanol, less starch ethanol
Develop technologies for using second (corn husks, grass) and third generation (algae) feedstocks
Engine innovations to protect against ethanol and maximize power and gas mileage
Overcome the cold temp obstacle
Use biofuels to make electricity instead of power vehicles