Energy of Food

How does energy get into your food?

What is the pyramid of energy?

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

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!)

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

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

Table 17-2, p. 556

Make a school lunch

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

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?

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

Some facts about ethanol: World production of ethanol tripled from 2000-2007 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

How does growing crops for ethanol fuel affect the balance of… pros cons energy Net energy gain: 1 unit IN: 1.3-8 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

Food vs. Fuel http://www.env-econ.net/2011/04/daily-demand-and-supply-why-are-corn-prices-rising-so-fast.html

Some sobering facts… http://motherjones.com/environment/2007/10/ethanol-effect-when-alternative-fuels-go-bad http://www.scientificamerican.com/article.cfm?id=ethanol-domestic-fuel-supply-or-environmental-boondoggle http://knowledge.allianz.com/mobility/?1466/ethanol-fuel-biofuels-driving-alcohol

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