The February Energy Update

  • Steve Jones - SSC Editor

    SSC Guru

    Points: 717951

    Comments posted to this topic are about the item The February Energy Update

  • John Chapman

    SSC-Addicted

    Points: 457

    Yes, the gravia lamp looks cool, but let's have a simplistic look at the physics.

    If we assume that the physical dimensions of the lamp allows a 10Kg (22lb) weight to be raised through 1 meter (about 1 yard) then the potential energy available is:

    Pe = mgh (assume gravity of 10 m/s^2)

    = 10 * 10 * 1

    = 100 Joules

    Assuming that even the most efficient light source possible would need to consume at least 1 watt to produce useful light and that the potential energy stored in the weight can be converted to electricity with an efficiency of 100%, then the light would operate for only 100 seconds before needing the weight to be raised again.

    In reality, we can't convert at 100% efficiency and we need lots more than 1 watt to be useful, so even looking into the future, this idea isn't feasible.

    Producing light is comparatively cheap (from an energy usage point of view). The real consumption hogs are heating and cooling.

  • Robert-377973

    SSC Enthusiast

    Points: 172

    What I don't understand is the idea behind biofuels.

    When parts of the world are starving and the price of basic crops such as wheat are increasing (due to shortages?), what do we do? We grow crops to burn.

    Hmm.

  • Steve Jones - SSC Editor

    SSC Guru

    Points: 717951

    I'm not sure about biofuels myself. It's an interesting idea, essentially using solar energy over time to create fuels, but I think it does need to be managed.

    I've heard that the US has more capacity for farming than we use, and either destroy crops to keep prices inflated or don't plant areas. That's a fundamental problem, but it's not easily solved without government managing this somehow. We certainly don't want farmers switching to biofuels and causing shortages.

    The world hunger issues are other problems and I have no idea how to solve them. Some of that is developed countries helping others, some of it is the native governments not allowing help, probably other reasons. That's not one I have any idea how to solve.

  • webrunner

    SSC-Dedicated

    Points: 30149

    You might have seen news about this knee brace. It's not for protection, though that is probably a possibility. This one actually generates power, helping to recharge small electronics. Gives new meaning to the "talk all day" cell phone if you have one of these.

    The knee brace also gives a twist to an old saying. The knee brace version: He walks the walk, so he can talk the talk....:hehe:

    webrunner

    -------------------
    A SQL query walks into a bar and sees two tables. He walks up to them and asks, "Can I join you?"
    Ref.: http://tkyte.blogspot.com/2009/02/sql-joke.html

  • majorbloodnock

    SSCrazy Eights

    Points: 9384

    webrunner (2/28/2008)


    You might have seen news about this knee brace. It's not for protection, though that is probably a possibility. This one actually generates power, helping to recharge small electronics. Gives new meaning to the "talk all day" cell phone if you have one of these.

    The knee brace also gives a twist to an old saying. The knee brace version: He walks the walk, so he can talk the talk....:hehe:

    ....suggesting it might be more appropriate for some people to have a version of the harness that generates power from the gluteus maximus instead. :Whistling:

    Semper in excretia, sumus solum profundum variat

  • Feifarek

    SSC Veteran

    Points: 247

    I agree it is a bad idea to grow corn to make alcohol. But it is possible for biofuel generation to be beneficial: the idea would not be to grow crops specifically for converting them to energy, but to use the waste and by products of existing crops.

    For example rice crops in California's Central Valley have the rice plant (stalks/leaves) burned in the fields, which creates lots of air pollution. If that material could be used as a fuel or converted into liquid fuel we'd be solving two problems.

    There is also the current practice of converting waste cooking oils into biodiesel-- restaurants and food processors are going to have waste oil, the only question is does it get thrown away or used as fuel?

    Brian

  • majorbloodnock

    SSCrazy Eights

    Points: 9384

    Feifarek (2/28/2008)


    I agree it is a bad idea to grow corn to make alcohol.

    I wouldn't go that far, although I'd agree better using grapes...... 😀

    Seriously, though, I agree with the rest of what you're saying. The answer isn't just a matter of finding a different source of energy, but instead a far more complex picture of how we (re)use a whole gamut of finite resources. Far more can be done to reuse and/or recycle waste and byproducts, and far more can be done to reduce our energy requirement in the first place. IMHO, both those are rather more important than finding an alternative substance to burn as engine fuel.

    Semper in excretia, sumus solum profundum variat

  • Robert-377973

    SSC Enthusiast

    Points: 172

    Agree that using waste is a good idea - if it's going to be burnt then makes use of the process.

    However, is there really enough waste to act as a replacement for oil? Gotta think not, so perhaps just a small part of the jigsaw.

    How much carbon does it take to create a solar panel and how long before the benefits, in terms of carbon reduction, are achieved? A question I have wonder, but yet to research properly.

    Someone once told me that creating a new car has a larger carbon foot print than the fuel it will burn its lifetime. Wonder how true that one is?

    Sorry for the rambling/moaning/whatever you want to call it! I'm just feeling a little green today - as he sits in an air conditioned office with lots of lights on and a PC chucking out heat!!!

    Perhaps we should all just go and live in a cave!!

  • GSquared

    SSC Guru

    Points: 260824

    Feifarek (2/28/2008)


    I agree it is a bad idea to grow corn to make alcohol. But it is possible for biofuel generation to be beneficial: the idea would not be to grow crops specifically for converting them to energy, but to use the waste and by products of existing crops.

    For example rice crops in California's Central Valley have the rice plant (stalks/leaves) burned in the fields, which creates lots of air pollution. If that material could be used as a fuel or converted into liquid fuel we'd be solving two problems.

    There is also the current practice of converting waste cooking oils into biodiesel-- restaurants and food processors are going to have waste oil, the only question is does it get thrown away or used as fuel?

    Brian

    First, burning the rice plant puts exactly 0 net gain air pollution into the atmosphere. Why? Because the rice plant is made of materials that were synthesized out of atmospheric CO2 in the first place. Rice takes CO2 out of the air, uses sunlight, nitrogen and water to turn it into various proteins, carbohydrates, etc. In other words, the whole rice plant is just air, water and sunlight. Burning it adds nothing to the atmosphere that didn't come out of the atmosphere in the first place.

    Second, bio-fuel production requires more fuel than is produced by it. Modern farming techniques require about a 10:1 ratio of energy input versus energy output. (Note, that's a vast improvement over prior centuries, but still entropic.) That means you have to burn approximately 10 gallons of bio-fuel to produce 1 gallon of bio-fuel. Or 10 gallons of petroleum diesel to produce 1 gallon of bio-diesel. So long as the ratio is entropic instead of negentropic, that will still apply. All in all, bio-fuel actually produces more pollution than petroleum fuels.

    Third, there just aren't enough McDonald's, etc., in the world to produce enough waste grease to power even a small city of cars. (Add in some teenage faces, and you might get closer, but even that isn't enough.:) )

    All of this has been in recent headlines and scientific articles. Well ... except the part about teenage faces. I think that comes from Mad Magazine.

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  • Steve Jones - SSC Editor

    SSC Guru

    Points: 717951

    Biofuels as diesel probably isn't a long term solution. Though I'm not sure what the impacts have been in Brazil, which has a large scale program there.

    I'm not sure I agree about the burning of rice crops. The burning might put back different stuff into the atmosphere (than CO2) than was there. Could be an issue, but as the major says, perhaps we should rethink things. Maybe the burning could produce electricity to power local vehicles on the farm. Or produce heat or do something else.

    It's a question of rethinking the way we do things and trying to be more efficient. Not use less energy, but properly reuse it where we can.

  • Kelly Schlueter

    SSC Journeyman

    Points: 88

    Calling the Gravia a gravity powered lamp is misleading. It is actually human powered since a human has to inject the potential energy by lifting the weights back to the top of the lamp. Gravity is just used as a temporary energy storage mechanism.

    Looking at it from that perspective why not use some of the already existing approaches to allow a human to easily generate power for a lamp similar to the design for OLPC or the various emergency radios and battery free flashlights.

    Since the US is having a growing problem with people being overweight, perhaps lamps could be sold with exercise equipment that produces electricity that is stored by the lamp to produce light when desired.

  • Matt Miller (4)

    SSC Guru

    Points: 124208

    Steve Jones - Editor (2/28/2008)


    It's a question of rethinking the way we do things and trying to be more efficient. Not use less energy, but properly reuse it where we can.

    The problem with "energy efficiency" initiatives is that they've consistently had the opposite effect from what they were intended to have. Meaning - by making the energy footprint smaller for something, in pretty much every case that has encourage higher use of said item which more that overtakes the energy savings resulting from the higher efficiency.

    Worded another way - we are now using more gas today than in the seventies precisely BECAUSE our cars are more fuel-efficient. We use more electricity because our appliances get to be more energyStar-compliant.

    It's a problem that has been frustrating a lot of energy conservation specialists. How to create savings without them compounding the problem.

    ----------------------------------------------------------------------------------
    Your lack of planning does not constitute an emergency on my part...unless you're my manager...or a director and above...or a really loud-spoken end-user..All right - what was my emergency again?

  • Miles Neale

    SSChampion

    Points: 13147

    Have you read this?

    http://www.nrgenergy.com/pdf/factsheet_stp.pdf

    It could be the wave of the future.

    Not all gray hairs are Dinosaurs!

  • Steve Jones - SSC Editor

    SSC Guru

    Points: 717951

    I like seeing the proposals for new nuclear plants. The newer designs (I hope ) will get better and pay dividends.

    Matt, not sure I agree with your analysis. Part of our problem is increasing efficiency, but also footprints. This is sometimes unintended consequences, sometimes it's a new technology that takes more energy to produce than the old way.

    I'm not sure we use more gas today because cars are more efficient. In many ways they aren't. Lots of people drive large cars/trucks in the US because has has been cheap and they like the space. We also have more people, and we're more spread out. There are plenty of people that can afford air travel (uses lots and lots of oil) and they take more vacations because we're more prosperous. We have more computers and more electrical gadgets.

    On balance I think that's a good thing, but we need to try to change the way we produce energy, IMHO, not our lives so much.

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