Wednesday, September 24, 2008

Which came first the chicken or the egg in being green?

Thank Gluttony It’s Wednesday

Yes today’s G word is one of the seven deadly sins. Gluttony can be loosely defined as eating or drinking more than you need to the point of waste. The word is derived from Latin from the word to swallow or gulp. We in the USA certainly know how to gulp and if I remember right Seven Eleven even named their drink size the Gulp. I don’t want you all to stop eating steak or hamburgers as I love these menu items and can think of nothing better than sitting on Sam’s deck eating one of their burgers and gulping a diet coke. However the consumption of meat protein over the past thirty years has quadrupled on the planet and this is a major contributor to global warming.

The habit of eating meat has moved from the Occident (west) to the Orient (East). The collective mass of all livestock on our planet is now almost twice as much as the collective mass of all humans living on earth. For most of history the collective mass of humans exceeded the collective mass of our livestock. Most of our grains and soy beans are fed to livestock. Cattle in particular are large generators of greenhouse gases in the form of methane. Before all of you giggle because of bathroom talk, you have the wrong end of the cow. The predominant quantity of greenhouse gas emanates from the mouth of a cow. You need to remember that pound for pound methane is twenty one times worse as a greenhouse gas than carbon dioxide.

Why do cows emit methane from their mouths? The reason is that cows belong to the group that are called ruminants or those that chew their cud. The polite word for the act of belching is eructation. Approximately 8% of the fodder fed to a cow winds up as methane that is eructated. This volume of methane is approximately one hundred gallons of gas a day. Before you all rush out to capture gas from the mouth of a cow remember this is not liquid volume but gaseous volume. The amount of energy contained in each cow’s daily eructation is about equal to the energy in a pint of pure ethanol.

Now that we know cows emit a massive amount of greenhouse gas, we need to answer the question whether cows are more efficient at converting feed to meat than other livestock? Sorry cows are not the most efficient at this task, broiler chicken are the most efficient. Chickens require 3.4 pounds of feed for one pound or ready to cook meat, cows require 6.2 pounds of feed. Before we blame cattle for all of our ills, pigs require 8.4 pounds, eggs 3.8 pounds and cheese requires 7.9 pounds. Therefore if you want to lower your greenhouse gas footprint, next time you are on the deck at Sam’s eating lunch order a chicken breast with cheese sandwich instead of a bacon burger. Actually ordering a veggie burger made of soy would save the world all of the conversion losses of growing, transporting, butchering, and refrigerating the food we eat. In fact the United Nations is suggesting that humans adopt an increasing amount of soy in our diets as a method to mitigate global warming. While science is certainly on the side of the UN’s argument, I believe a nice juicy burger is still one of life’s pleasures and I will do my part to save the planet by carpooling. Based on the conversion of feed we also know that the chicken came before the egg.

Wednesday, September 17, 2008

What is the average vehicle mass in grams?

Today we will discuss mass. Grams are a metric unit of measure of mass. The US EPA reported that the fuel efficiency of the average vehicle sold in 2007 was the same as the average of a vehicle sold in 2006 at 20.2 miles per gallon almost ten percent lower than the average for the year 1987. This means we have been going backwards since 1987 in our fleet efficiency thanks to the size and mass of the average vehicle sold in 2007. Therefore we can thank grams for our current energy problems. The interesting data on fleet fuel efficiency can be found at

It is interesting that the average mass of vehicles sold in the USA has increased significantly since 1987 from 3,221 pounds to 4,144 pounds or 1,873,088 grams. The average horsepower of a vehicle has almost doubled since 1987 from 118 to 223 horsepower. The heaviest horse in history had a mass of 3,360 pounds or about the mass of the average vehicle sold in the USA in 1987. This horse named Sampson lived in England in 1846, and had he not been gelded he would have weighed even more. The acceleration of the average vehicle measured in the time taken to get from zero to sixty MPH has decreased from 13.1 seconds to 9.6 seconds in the past twenty years. The fuel economy of the average vehicle has decreased from 22.0 mpg to 20.2 mpg because of the change in mass, horsepower and the proliferation of trucks (SUVs included) from only 28% of vehicles sold in 1987 to 49% of the vehicles to be sold in 2007.

If we all remember a previous Green Machine episode explaining the Newton’s laws of motion we all know that the force that is needed to be applied to an object to yield a set acceleration is directly proportional to the mass ( F=MA ). In accelerating cars from zero to sixty there are some other forces (resistance) to be overcome such as wind resistance and rolling resistance but for the moment will simply deal with old Isaac’s second law. The mass of the vehicles has increased in the past twenty years by 29%. Acceleration increased by 36% so accounting for increased mass and increased acceleration one would have expected the required force from the engine to have increased by 75% which is in line with the added horsepower in the 2007 models. With all this increased mass, faster acceleration and more powerful engines how did we still achieve only an 8% reduction in fuel efficiency? This can be answered by the improved efficiency of the later model engines. Primarily as a result of fuel injection, multi valve engines, and variable valve timing that were not available back in the old days. These improvements all relate to how the fuel is burned in the engineIn the future we will have higher compression engines, direct fuel injection, and of course smaller and lighter vehicles. We can thank the Governator for the proliferation of SUVs as his movie Kindergarten Cop started the Hummer rage. My prediction is that within a decade the average mass of a vehicle will drop to value we had in 1987 and the average fuel efficiency will be close to 30 mpg. Also within a decade we will have long forgotten Arnie.

Saturday, September 13, 2008

How much energy is there in a hurricane?

Thank Gustav It’s Saturday

Yes Gustav is the G word of the day. Why would we thank Gustav for being green when in fact he was the hurricane that hit Louisiana on Labor Day? Well first Gustav is a Swedish name for the “staff of the gods” and maybe the gods were trying to tell us that increasing the ocean temperature helps hurricanes form and intensify. The scale or category of hurricanes is measured from 1 to 5 with 5 being the most powerful. The scale named the Saffir Simpson scale was developed in 1971 by a Structural Engineer named Herbert Saffir and a meteorologist named Bob Simpson. Bob Simpson was the director of the National Hurricane Center and Herb Saffir was interested in designing inexpensive hurricane resistant housing. They could of called their hurricane scale the Herb and Bob scale but then who would have taken them seriously?

The amount of power contained and hence released by a hurricane is proportional to the cube of the velocity of the winds ge nerated by the hurricane. Therefore a category 5 storm with winds of greater than 156 miles per hour has 430 percent of the power of a category 2 storm with winds greater than 96 miles per hour. The residents of the Gulf Coast were indeed fortunate that Hurricane Gustav had lessened in intensity to a Category 2 by the time it hit land. 96 mile per hour winds are still not something to sneeze at. I actually have never tried to sneeze into a powerful wind, perhaps Newton’s laws of motion would cause one to sneeze inward rather than outward.
There are sceptics who believe that the increase in global warming gases in our atmosphere have nothing to do with hurricanes and that all hurricanes just come and go in cycles. There is likely a cycle between periods of fewer hurricanes and periods of increased hurricane activity but the warming of the ocean by a degree or two will have a significant influence on the intensity and severity of each hurricane. The hurricane gains strength when it is over warm water and dissipates its strength by traversing land or cooler waters. All the added carbon dioxide and other greenhouse gases will indeed increase earth's temperature by a degree or more in the next fifty years and folks living in Florida and the gulf coast will have to live with more severe hurricanes. In fact the Saffir Simpson scale may need to expand to a category 6 hurricane but this is purely academic as a category 5 hurricane will damage just about every building in its path.We are fortunate that Gustuv moved across the gulf in pretty rapid fashion with a forward motion of the eye that was between 15 and 18 miles per hour. This more rapid movement prevented Gustav from exceeding a category 2 when it made landfall on the Louisiana coast. Other factors that influence the intensity of the hurricane besides ocean temperature and the speed the eye is traveling is the amount of shear the hurricane experiences in the upper atmosphere by other weather systems. In the case of Gustav there was another weather system that did moderate the hurricane by the presence of counter flowing winds above Gustav. We are indeed fortunate that Gustav only caused $10 billion in damages and there was little loss of life. As Gustav did not reach a category 5 storm his name was not retired and Gustav will live to frighten us again in a future hurricane season. Perhaps the folks who name hurricanes will also use the names herb and Bob in the future.

Wednesday, September 3, 2008

Does gallium stand a chance?

Thank Gallium It’s Wednesday

Today we thank the thirty first element of the periodic table for contributing to our green machine. Gallium is named after Gaul the Latin name for France. Actually France is a leader in high tech but is often remembered for poor quality autos and rude waiters. Gallium is playing a very important role in the greening of lighting. Gallium Arsenide is used in fabricating light emitting diodes (LEDs), a technology that will soon proliferate in lighting homes, offices, streets and the outdoors. LEDs are much more efficient in converting electricity into light than incandescent or even florescent bulbs. LEDs also are also long lived and can glow continuously for 100,000 hours before needing replacement.

We can also thank Gaul for the Smart Car that is beginning to be sold in the USA. Yes Mercedes owns the Smart Car brand, but the cars are manufactured in France. Hopefully the folks from Mercedes have better quality control systems than Renault. Who remembers the Le Car Renault 5 that tried in vain to compete with the Honda Civic in 1980? Well this time I believe the French may actually have a winner in the Smart Car if the quality is can be maintained. One thing about the French, they can make the “Smart Car” as well as the “Not So Smart Car”.

There is some good news on the energy front with gasoline prices dropping since reaching a peak in mid June here in Tiburon. I use mid grade even though Mercedes recommends premium for my 1999 C 280. Actually every car can run on a grade lower than that recommended by the manufacturer, except of course if you use regular there is no grade marketed as sub-regular. On June 19th I filled up at the gas station by the Cove with mid grade costing $4.79 a gallon, on August 23 the very same gasoline cost $4.15 a gallon some sixty four cents less. It must be that Ark readers are paying attention to the Green Machine and driving less. If this is true for you I tip my black beret to you and say merci.

Returning to the periodic table, Gallium is a metal that falls between Aluminum and Indium and is referred to as a “poor metal”. Prior to its use in LEDs, gallium was used to help fabricate fine mirrors, nuclear weapons, and solder. The term “poor metal” does not refer to its economic status but like the other metals such as lead in its column of the periodic table, Gallium is soft and therefore considered poor. There is some hope that Gallium can be alloyed with other elements for dental fillings, hydrogen storage, and even treating cancer and autoimmune diseases.

LEDs will save a significant amount of electricity and is in essence the solid state replacement of a vacuum tube in lighting applications. We can thank Gallium for this improvement in efficiency. I personally like the name Gallium for a race horse or even a high performance car. Just think of it someday we may have the Hyundai Gallium just like we have the Hyundai Tiburon. However, if Renault named a car the “Le Gallium” this would relegate Gallium back to its poor metal status forever.