Wednesday, May 28, 2008

Thank Grass It's Thursday

Green Thursday

This week’s episode of the green machine is brought to you courtesy of your lawn. Lawns are water hogs and also require a substantial amount of energy for their upkeep. Each day one can see numerous pickup trucks with gardeners traversing Tiburon Boulevard near where I live on their way to mow lawns and blow leaves to the other end of someone’s yard. I often have thought a great name for a landscaping company would be “mow and blow”.

The typical lawn is 5,000 square feet and requires mowing some 30 times a year. The amount of gasoline used for fuelling the mowing machines and the pick up trucks to bring and return the gardeners from and to their distant homes must at least equal 2 gallons each time the gardeners visit us to perform their landscaping chores. This means each lawn requires some 60 gallons of gasoline a year to be kept in pristine condition. 60 gallons of gasoline has a carbon dioxide foot print of about 1,300 pounds. There are approximately 3,000 houses on the Tiburon Peninsular so our collective carbon dioxide footprint for having manicured grass lawns is some 2,000 tons per year.

A 5,000 square foot lawn generates about 1,200 lbs a year of grass clippings. Grass clippings have a carbon composition of 40%. Performing all the requisite and tedious math calculations, these grass clippings took in 1,800 pounds of carbon dioxide via their photosynthesis or carbon dioxide and water. This means that the lawn carbon intake exceeds by almost 50% the carbon emissions of the gasoline used by the gardeners performing the maintenance of the lawn. If the lawn clippings are composted and used as fertilizer, owning a lawn is positive with respect to the carbon aspect of the environment even if one utilizes the services of a gardener who lives far away.

The water footprint of a grass lawn is another matter. Given the long dry summers here in Marin County each homeowner’s lawn requires nearly 50,000 gallons a year of irrigation water. There is an alternate to grass lawns. A company named Fieldturf has developed a synthetic lawn using recycled rubber and sand. Each square foot of Fieldturf requires 3 pounds of rubber and 7 pounds of sand. The carbon composition of rubber is approximately 90% therefore each square foot of Fieldturn contains 2.7 pounds of carbon. Therefore, the average 5,000 square foot Fieldturf lawn has over 13,000 pounds of carbon that has been sequestered from used tires. The Fieldturf lawn also requires no mowing but will need the occasional blowing. If all the residents of the Tiburon Peninsular changed our lawns to FieldTurf, we would save 150 million gallons of irrigation water a year, and the traffic on Tiburon Boulevard would also be reduced.

There are some 25 million acres of lawn in the USA. This is just more than a trillion square feet of lawn. If the entire US got onto the Fieldturf bandwagon we could recycle almost 3 trillion pounds of old tires. Only 280 million tires that in total weigh 6 billion pounds are sold in the USA each year. Fieldturf will need to wait 500 years to replace all of our grass lawns, but when this happens Goodyear would really have a good year and Sears would never sell another riding mower. The result of today’s analysis is that the grass is greener on the both sides of the hill

Wednesday, May 21, 2008

Thanks Gates

Green ThursdayTGIW - Thank Gates It's WednesdayToday's blog will deal with computers and their energy use. The personalcomputer is now ubiquitous and can be found in homes and offices throughoutthe world. In 1983, the year after I moved to Bay Area, there were 2million PCs in the entire USA (homes, offices, factories, etc.) by 1990there were 54 million. At the time of the Y2K scare the number had grown to169 million in the USA. Worldwide 271 million personal computers were soldlast year and the estimated number of these devices operating somewhere onplanet earth is now more than a billion. By 2015 there will 2 billionpersonal computers operating on this minor planet of an ordinary star tomisquote Stephen Hawking.

All these computers need electricity though some more than others. Desktopsneed more power than laptops and desktops with cathode ray tube (CRT)displays use the most energy of any type of PC. Liquid Crystal Displays(LCDs) require less power than CRTs. Liquid Crystals were first describedin 1888 this was 13 years after Hook invented the first CRT. It is quiteamazing that the physics behind these displays were first discovered overone hundred twenty years ago.

A new model desktop with a CRT requires about 200 watts of power. The samedesktop with a LCD monitor uses 150 watts of power or some 50 watts less.If one uses the computer 4 hours per day or some 1,500 hours per year simplybuying a LCD monitor saves some 75 kilowatt hours each year. This amount ofelectricity can power an average Tiburon home for 3 days. During the other7,200 hours of the year when the computer is in the idle mode the LCDmonitor will save about 3 watts of power compared with the CRT. This isanother 21 kilowatt hours of annual savings or about another day's worth ofpower usage in the average home. Buying a laptop instead of a desktop andLCD monitor saves 100 watts of power and would save about 150 kilowatt hoursof electricity per year or about 6.5 days worth of the average homes total electricity usage.

In 1997 there were only 100 thousand LCD monitors sold, this year 180,million or 90% of the all the monitors that will be sold in the world arebased on LCD technology. Amazingly 80% of these LCD monitors are now madeon the island of Taiwan and 0% in the USA. This year we will cross thepoint where half of the PCs sold will be laptops. We are indeed fortunatethat more efficient technologies for monitors and computers have beendeveloped. If we assume that half of the next billion PC that will be soldover the next 7 years are laptops, these 500 million computers each saving100 watts of power implies that the peak demand for electricity will be50,000 megawatts less. This means 50 large 1,000 megawatt power plants willnot need to be constructed. The reduced carbon dioxide emissions by nothaving 50 coal fueled power plants operating 1,500 hours per year is aboutequal to twice the carbon content of the entire sugar crop of Brazil of 35million tons of sugar. Conversely the extra 1 billion computers will requirethe construction of 150 large 1,000 megawatt power plants to meet this peakpower demand. The carbon emissions from 150 additional power generationstations, approximately equals the carbon content of the world's entiresugar crop of 150 million tons. This is not so sweet news.,1769,1151,00.html

All these added sales of computers will make Bill Gates a very happy man andthat is why he is the G word of the day.

Thursday, May 15, 2008

Thank GM

TGIW - Thank GM It's ThursdayToday's green energy episode explains the hope and hype of the universe's lightest element. On the surface it seems like a wonderful idea to use hydrogen as a fuel as the only resulting emission is water. Hydrogen has been sold as a carbon free fuel. The problem is that hydrogen is mistaken as a fuel, when it is really only an energy carrier like electricity. It takes other fuels or electricity to produce hydrogen and typically these other fuels or the electricity entail the combustion of some carbon containing fuel. Therefore hydrogen has a carbon footprint. If the electricity to produce the hydrogen is generated in a coal fired station, the resulting hydrogen has a carbon footprint the size of Sasquatch. Approximately half of the electricity in the USA is generated using coal as the fuel. Some may argue that the hydrogen should be produced with hydroelectric, wind, or nuclear generated electricity. However this means that the coal based energy would serve other power demand loads, and had the hydrogen not been manufactured then indeed the coal fired stations could have been shut.

Is there a Cinderella rather than a Bigfoot story in hydrogen manufacture where the carbon footprint indeed fits the tiny glass slipper? Producing the hydrogen by steam natural gas reforming does have a smaller carbon footprint but the conversion of natural gas (methane) to hydrogen yields only 75% of the energy and the steam methane reforming plant has carbon emissions. The methane could have been compressed and used to fuel a vehicle such as the one marketed by Honda that runs on compressed natural gas. As natural gas has more than three times the energy per unit volume than hydrogen, the compressed natural gas vehicle will have three times the range of hydrogen if the engines are equally efficient. The next trick the hydrogen lobby played on us was that fuel cells are much more efficient than internal combustion engines. Yes this is indeed the case but producing and liquefying hydrogen eliminates the efficiency advantage of the fuel cell over the internal combustion engine.

The fuel cell is expensive and presently costs about half a million dollars to equip a single Honda Civic. Additionally, the fuel cell in the Honda Civic needs approximately two and a half ounces of platinum to function. Each year a total of two and a half million ounces of platinum are mined worldwide so if all of the platinum was diverted to fuel cells we could equip about one million cars per year. Over 60 million cars are sold worldwide each year so GM the fool who sells fuel cells will never capture more than a small fraction of the market. Try saying this fast “GM the fool who sells fuel cells on the free floor”.

Others are trying to produce hydrogen from cellulose and organic waste. Their efforts have yielded some technical success but these sources of hydrogen are miniscule compared to the enormity of the amount of transportation fuel the world requires. Steam methane reforming will remain the pre-eminent method to produce hydrogen and hydrogen will be used as a wonderful chemical to upgrade and refine high sulphur oil, synthesize fertilizers, and sadly to hydrogenate oils to produce margarine that clog your arteries.

The word of the day is paean or a joyous song of praise. The hydrogen economy hoax won’t be playing this song instead we will be just paean more taxes to fund more foolish energy policy

paean \PEE-uhn\, noun:1. A joyous song of praise, triumph, or thanksgiving.2. An expression of praise or joy.

Wednesday, May 7, 2008

Thank Greenwashing

TGIW – Thank Greenwashing It’s Thursday

Yes just like whitewashing there is now greenwashing going on in the marketplace. Greenwashing is when a false “green” claim is made to mislead consumers about a company’s products or services. The largest greenwashing we consumers have experienced in the past couple of years is bioethanol.

Mother Nature never intended to have photosynthesis propel hundreds of millions of vehicles traveling trillions of miles per year. Yes Americans drove more than 3 trillion miles in 2006 Photosynthesis is a very slow and inefficient conversion of sunlight into biomass. The new buzzword in bioethanol we now hear each day from politicians mouths is “Cellulosic”. I love the way the President pronounces cellulosic, it is about as funny as when he pronounces nuclear. Now that these cretins on both sides of the house have used the food we have for fuel ,they think we will believe them that the have managed to separate the wheat from the chaff, and suddenly and mysteriously the chaff can be used for producing bioethanol.

Photosynthesis typically coverts 0.1% to 0.4% of the incident solar radiation into biomass. For the USA which is far less sunny than Brazil we average about 6 tons per year of biomass production on each acre of land irrespective of whether the biomass is switchgrass, corn, poplar trees, or wheat. Converting this biomass into ethanol will yield approximately 400 gallons per year per acre. A gallon of ethanol has a heat of combustion of about 23 kilowatt hours. Therefore before accounting for all the energy inputs to plant, cultivate, fertilize, harvest, transport, ferment, and distil the biomass to produce ethanol, our acre of land yields less than 10,000 kilowatt hours per year. Had we erected wind turbines on our land we would yield 100,000 kilowatt hours of dispatchable electricity per acre per year. Had we instead decided to place photovoltaic cells on the acre of land we could dispatch 1,500,000 kilowatt hours of electricity per year.

Now the zinger in the overall energy equation. The government provides cash subsidies to the farmer as well as the ethanol distiller that total over $1 per gallon of ethanol. The acre of land enjoys a subsidy of $500 per year or about 5 cents of each gross kilowatt hour produced. At best, ethanol production is 50% efficient, therefore our wonderful elected officials are subsidizing this food wasting enterprise to the extent of 10 cents per kilowatt hour of net energy produced. Let the farmers enjoy a 10 cent per kilowatt hour subsidy for wind energy and the Great Plains will support vast wind energy farms and the land will still be available for food production.

There is now a word called vog to describe the mixture of valcano gases and fog that is now occurring in Hawaii. The sulfur dioxide containing gases are also killing the protea flower plantations on the island. I am very fond of proteas as they are the national flower of South Africa where i spent my youth. Sulfur Dioxide also results in the combustion of coal and oil.

The word of the day is contrite. The proponents of corn ethanol are contrite sinners for their crimes against nature.

Today's Word Yesterday's Word Previous Words Subscribe for Free Help
contrite \KON-tryt; kuhn-TRYT\, adjective:1. Deeply affected with grief and regret for having done wrong; penitent; as, "a contrite sinner."2. Expressing or arising from contrition; as, "contrite words."