Yes it used to mean if someone was green they were gullible. With all the hype of green products and Madison Avenue creating ads about the greenest car company, the greenest energy company, etc. I decided it would be good to put some thermodynamic reason to all these claims and expose the messages of these promoters against the backdrop of the gullibility of the average Joe.
Just yesterday CNN had a news headline of a company in Texas that has a super duper way for growing algae to make algae oil as a bio-fuel substitute. I had blogged on algae and their ability to produce lipids (oil) and how the lowly life-form was indeed better than bio-fuel from corn. The promoter from Texas is now making huge claims regarding the productivity of algae in producing oil. http://www.cnn.com/2008/TECH/science/04/01/algae.oil/index.html The claim that his algae can yield 100,000 gallons of bio oil per acre per year kind of blew my mind. I decided to challenge the claim by doing a simple energy balance comparing how much incident sunlight there is available in an acre of desert during a year. http://www.ucsusa.org/clean_energy/renewable_energy_basics/how-solar-energy-works.html Turns out that in Arizona one can expect about six kilowatt hours per day per square meter of incident solar radiation. This is about 2,000 kilowatt hours per year per square meter. There are about 4,000 square meters in an acre so one has Mother Nature providing 8 million kilowatt hours per year of incident radiation per acre of Arizona desert. The Texan’s claim of 100,000 gallons of diesel type oil per year per acre can now be compared. A gallon of diesel has some 130,000 BTUs or some 38 kilowatt hours. Therefore the 100,000 gallons has about 3,800,000 kilowatt hours of energy. The Texan is not claiming perpetual motion but is claiming half of the incident solar radiation is converted in algae oil. Algae also produces protein, carbohydrate, and fiber besides oil (lipids). Lipids are typically one third the mass of the algae. The other two thirds are protein, carbohydrate and fiber. One a unit mass basis protein and carbohydrate have half the energy of lipids so the other two thirds of the algae mass has about the same energy content as the oil. Therefore the Texan is claiming almost 100% conversion of the incident solar radiation into algae on an energy balance basis. I have to say this is bunk! Most photosynthesis is only 0.1% efficient in converting solar radiation into BTUs. I would doubt that this Texan has improved this 1,000 fold and is approaching full conversion of sunlight into algae. On top of this the concentration of carbon in the atmosphere needed to be converted into plant material by photosynthesis would limit the rate at which biomass can grow. Enough said CNN was gain duped by not knowing thermo.
Given the British failure to lower electricity consumption for a day, the rest of the world attempted an hour of lower electricity consumption. http://www.foxnews.com/story/0,2933,343088,00.html This hour was called Earth Hour and some energy savings were affected. The problem is there are 8,760 hours in a year and we can’t save the world by gimmicks of shutting the lights on Sydney’s Opera House for an hour.
Yahoo did have an interesting article to tell the average Joe how to save gasoline while driving on the freeway by slowing down. http://finance.yahoo.com/family-home/article/104752/Slow-Down-a-Lttle-Save-a-Lot-of-Gas Yes Yahoo has finally found the formula that shows the power needed to propel a vehicle through air is proportional to the cube of the velocity. Of course slowing down has an almost exponential effect in saving gas. Why not slow down all the way to zero and walk or take a bicycle. The folks in the holy land are trying to do this by having an inexpensive bicycle leasing program http://www.haaretz.com/hasen/spages/902732.html Paris will have 20,000 rental bicycles available at 1,500 stations by year end. The West is trading cars for bicycles while the Chinese are trading bicycle for cars. Just goes to prove that Newton was correct in stating that for every action there is an equal and opposite reaction.
The word of the day is bellwether or a leading indicator of future trends. The bicycle bell will be a bellwether indicator of whether the bell has tolled on peak energy usage.
bellwether \BEL-weth-uhr\, noun:A leader of a movement or activity; also, a leading indicator of future trends.
Raised to believe they were among their generation's best and brightest, my class can be seen as a bellwether for a generation caught without a compass on the cutting edge of uncharted territory.-- Elizabeth Fishel, Reunion: The Girls We Used to Be, the Women We Became
Before that election, Maine's proud citizens had fancied their state to be a sort of bellwether, a notion embodied in the saying "As Maine goes, so goes the nation."-- Robert Shogan, The Fate of the Union
Bellwether is a compound of bell and wether, "a male sheep, usually castrated"; from the practice of hanging a bell from the neck of the leader of the flock.