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Monday, December 13, 2010

The EPA's outrageous lie?


Photo from Wikipedia

Back in September I wrote a rebuttal titled:

Securities Lawyer Mocks Electric Vehicle Enthusiasts--Gets Mocked Back

Here I rebut that author's latest critique of electric cars which he titled Alice in EVland Part II; The Hall Of Mirrors.

Instead of mocking electric car proponents, he questions their integrity:

Mark Twain reportedly said that "Figures don't lie, but liars figure." Truer words were never spoken.

Both stickers [for the Leaf and Volt] were heralded as the dawn of a new age in transportation [which isn't true]. Unfortunately, they were outrageous lies that account for the distance a car can travel on a kilowatt-hour of electricity but ignore the energy needed to make a kilowatt-hour of electricity in the first place. [my emphasis]


What got this securities lawyer's boxers in a bind this time? Well, apparently it was the revelation that the Leaf will use about ten percent more life cycle energy than a Prius. Not to suggest that this is his revelation. He's just parroting other internet blog articles (without attribution) that pointed this out last month when the EPA first released its new mileage sticker for electric cars:



He thinks he has stumbled onto something new and that the EPA sticker is trying to deceive consumers because it does not account for life cycle energy use. Here's an article I wrote on equivalent MPG back in August of 2009.

However, every study I've read on this subject for the last several years has pointed out the fact that electric cars use slightly more life cycle energy (and produce slightly more GHG) than an equivalent hybrid when their electricity comes from non-renewable sources like coal. But, they have also pointed out that electric cars use far less life cycle energy and produce far less GHG than the average car, of which there are over 300 million in this country.

What is life cycle energy? Well, about 60-70 percent of the energy in the coal used to make electricity is lost. Only about 30-40 percent of it gets into the wires as electricity. More energy is lost in the wires, the charger, and the electric motor.

Even though and electric car is three times more efficient than a normal car, in the end, the Leaf will actually use about 10 percent more total energy than the most efficient car ever mass produced, the Prius, but about half the total energy of the average car.

EPA mileage stickers have never used life cycle energy. That would be complicated, and confusing. For example, it takes about 20 percent more oil to make diesel fuel than gasoline. So, using life cycle energy, you would have to reduce that mileage on the Jetta sticker 20 percent, but the diesel Jetta will still go a lot further on a gallon of fuel than the gasoline Jetta, in large part because diesel engines are more efficient.

Is that what consumers are interested in or do they want to compare how efficiently different cars use the energy stored in their tanks or batteries? That is why the EPA came up with MPGe (miles per gallon equivalent).

The sticker also rates GHG emissions out of the tail pipe, of which electric cars have none. Life cycle green house gas emissions are not part of the deal either. If your car gets its electricity from a coal plant, it is in theory increasing GHG emissions more than a Prius. In reality, until there are enough electric cars to be noticed, the power plant will not be throwing any more coal on the fire and if you have solar, or hydro, or wind, or nuclear making your power, your life cycle GHG is going to be lower than a Prius. So again, why try to convey that kind of complexity on a window sticker?

You have to start somewhere and consumers can start with a low emission, highly efficient vehicle. Cleaning up power supplies is happening in parallel.

Not to say that total energy consumed (from coal mine to wheel turning) isn't important. I'm saying it is not the only metric that's important.

A solar panel only captures about 8 percent of the energy that strikes it. Solar energy is far less efficient than coal but who cares if we have to waste 92 percent of the sun that hits it to get solar power? A similar argument holds for nuclear power (and lets face it, solar collectors are essentially fusion powered).

If we can displace coal and natural gas with solar, wind, hydro, geothermal, and nuclear, we will have a carbon and oil free transportation system and it does not matter if that takes more overall energy use. It's an engineering trade off that's well worth it.

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3 comments:

  1. Efficiency does matter during this point in time. Already, leds are over TWICE as efficient as the CFL (Cree). And the electric motor IS three (or more) times as efficient as the gasoline counterpart. Just because it is dragged down by coal doesn't mean it is not worth pursuing (a way to bring back the LiFePO4 battery from China)... Coal will still be phased out eventually.

    Tens of thousands of square miles of solar panel will need to be installed in America just to meet (our current...). Imagine, being able to displace thousands of those square miles to efficiency! (There will still be plenty of jobs). Until fusion "kicks in", we will have to continue to make things as efficient as possible...

    Including the automated mass manufacture of solar PV.

    ReplyDelete
  2. " A solar panel only captures about 8 percent of the energy that strikes it. "

    I think it is wrong to assume such a low figure. Depends how you calculate.

    If you take 24h a day and divide by 12h of sunshine a day, then your panels achieve only 50% overall raw energy capture efficiency in summer, and even lower in the winter, compared to water dam, geothermal, biomass or other sources of energy providing a 24h/7days a week predictable energy supply.

    Of that theoretically 50% incoming energy caught in a summer day, depending on the efficiency of solar PV panels and type, a thin-film convert between 8-15% of it in electricity (Miasole) , a c-Si has between 15% (mine from Bisol) to 19% (SunPower), and concentrator solar PV panels that only work in direct (not diffuse) sunlight achieve 39% conversion of the incoming sun ray energy (Boeing panels). Firofenergy is therefore right to say efficiency is the major goal to be chased right now, which of course is being done by industry manufacturers.

    50% x 8% = 4% of sunray energy converted in electricity

    50% x 19% = 9.5% of sunray energy converted in electricity

    50% x 39% = 19.5% of sunray energy converted in electricity

    http://www.electroiq.com/index/display/photovoltaics-article-display/3714823450/articles/Photovoltaics-World/cpv/multi-junction-cells/2010/11/boeing-readies-terrestrial-cpv-solar-cell-for-mass-production.html?cmpid=$EnlEIQDailyNovember242010
    November 24, 2010 - Boeing readies near-40-percent terrestrial concentrator photovoltaic (CPV) cell for mass production. The company plans to deliver the first of these 39.2% efficiency cells in January. Spectrolab has introduced mass production of a new series of solar cells with increased energy-conversion efficiency each year since 2007. More than 2 million C3MJ cells have been sold to customers around the world.

    http://www.renewableenergyworld.com/rea/news/article/2010/06/highly-efficient-solar-cells-could-result-from-quantum-dot-research?cmpid=SolarNL-Tuesday-June22-2010
    Conventional solar cell efficiency could be increased from the current limit of 30 percent to more than 60 percent, suggests new research on semiconductor nanocrystals, or quantum dots, led by chemist Xiaoyang Zhu at The University of Texas at Austin. He cautions that this is just one scientific step, and that more science and a lot of engineering need to be done before the world sees a 66 percent efficient solar cell.

    ReplyDelete

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