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Thread: Renewable Energy

  1. #1 Renewable Energy 
    sak
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    Invite every one to discuss scope of various sources of renewable energy to deal with World’s energy requirements or as an infrastructure investment opportunity against mad oil and idiotic nuclei.


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    Whats wrong with nuclear energy?


    Eat Dolphin, save the Tuna!!!!
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    Quote Originally Posted by Cat1981(England)
    Whats wrong with nuclear energy?
    Is it renewable?

    --
    I think it's an excellent short term solution, say the next 30 years, for energy production but not as a long term solution.


    One thing many should be told upfront is most of the current renewable solutions, such as wind, and solar will require massive redundancy or serious research into energy storage technology.

    We've also barely scratched the surface to become more efficient and employ comprehensive conservation.
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    I may be wrong about this but i thought we had thousands of years worth if not more should we need it. That as good as renewable isn't it?
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    Nuclear energy is good, but it runs the risk of have a nuclear explosion like at chernobyl. Other sources of renewable energy are wind, solar, geothermal, and algae. All of them work great, it just depends on where you live. Like a sunny place you use solar and a windy place you use wind turbine. The thing that scientists are working on now is to make these things more efficient. Getting more energy out of them than before. Hope that makes sense, if you need any explaining just ask.
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  7. #6  
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    Quote Originally Posted by Lynx_Fox
    One thing many should be told upfront is most of the current renewable solutions, such as wind, and solar will require massive redundancy or serious research into energy storage technology.
    Yup. For real.

    We ARE NOT building a "green" future on battery-buffered power.

    Currently (and perhaps for all time) the best way to store up energy from intermittent sources is to pump water to higher elevation. Then we get continuous/demand generation, indirectly, from hydro turbines running 24/7 off an annually sustainable reservoir. So if you plan to go solar in a big way, also plan a big hydro project to do the consumer-end generation and act as "battery"... that is obviously more trouble than using straight hydro to begin with.

    I want everyone to understand that wherever possible just running ordinary rain-fed hydroelectric, without the extras, is most efficient of all cleanly renewable schemes.

    Intermittent generation can directly supplement the grid. It can't reliably provide the bulk of power though. At most, we have demand generation (thermal and/or hydro) capable of meeting peak demand, then we take those off line as intermittent spins up by chance. As weather fails, we turn the trusty turbines back on. Thermal like natural gas, coal, etc take some time to come on and we get brownouts in the meantime. Hydro only takes a second - roughly the time it takes a column of water to start falling through the turbine. Again, this is "massive redundancy" as Lynx_Fox put it.

    Next best IMO is (continuous) nuclear. I agree with Cat1981 about the practically unlimited fuel. There's a political dimension though, with some rather shameless interests (e.g. Canada, France) aiming to monopolize fuel extraction and processing as well as plant ownership, through twisting of the Non-Proliferation Treaty. This emerging nuclear cartel threatens to bomb a country that is ethically opposed to nuclear weapons, just to keep the fuel market free of competition. So nuclear is a privilege, with strings attached. And the price of nuclear energy will be subject to gross manipulation by OPEC-like entity in any case. Who wants to live in energy client state with a foreign consortium fixing prices and even threatening to cut supply?
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    the problem with nuclear energy is the life span of the powerplant it self (danger of accident increase after 30year) & toxic waste that it produces...it takes thousands of years to lose its harmful properties...

    there isn't realy a solution for the waste atm (that i know about) except meaby burrying it to the ground like they are going to do in my country ->

    http://www.npr.org/templates/story/s...oryId=12374335


    sources of renewable energy in earth atm have the trouble of being hard to collect, store & distribute and they cant be used all around the globe (i won't deny potential of solar power in dry deserts like sahara or tidal power on endless oceans)

    http://en.wikipedia.org/wiki/Tidal_power

    or meaby Geothermal power?

    http://en.wikipedia.org/wiki/Geothermal_power


    other possibilities that come in mind

    i saw a document about harnessing lunar power of the moon not so long ago and it realy blowed my mind, sunlight in the moon is 8x brighter than in earth due the lack of atmosphere and the materials to build solar panels can be found in there allready -> power is then transmitted to earth in microwaves (if i remember correctly) and collected in earth with receiver connected strait to the powergrid.

    if it can be build it would produce more energy that all the current methods combined and more...

    that vision isnt coming to be reality any day soon but the idea is realy neat...


    any opinions anyone?
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  9. #8  
    sak
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    Quote Originally Posted by Cat1981(England)
    Whats wrong with nuclear energy?
    Personally I don’t have problem with nuclear energy. It simply draw lot of security and political stunt. I think we have better technologies.
    Quote Originally Posted by Pong
    I want everyone to understand that wherever possible just running ordinary rain-fed hydroelectric, without the extras, is most efficient of all cleanly renewable schemes.
    How many KM2 area of forest we have to sacrifice to have a reservoir/ catchments area.
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    Quote Originally Posted by sak
    How many KM2 area of forest we have to sacrifice to have a reservoir/ catchments area.
    Depends on the slope of the land & volume wanted. No more than your typical lake, which is really all it is, far as nature's concerned. Often we're raising the level of existing lake. We may or may not add fish ladders - the best sites, fish couldn't pass in the first place.

    Clearing for transmission lines and access roads probably amounts to as much lost forest as the raised water level.
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    Some potentially wonderful news in the July 31 issue of Science, posted over at Hypography:

    An excerpt:

    "In a revolutionary leap that could transform solar power from a marginal, boutique alternative into a mainstream energy source, MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn't shine.

    Until now, solar power has been a daytime-only energy source, because storing extra solar energy for later use is prohibitively expensive and grossly inefficient. With today's announcement, MIT researchers have hit upon a simple, inexpensive, highly efficient process for storing solar energy.

    Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun. "This is the nirvana of what we've been talking about for years," said MIT's Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT and senior author of a paper describing the work in the July 31 issue of Science. "Solar power has always been a limited, far-off solution. Now we can seriously think about solar power as unlimited and soon."
    ".

    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    More (the meat):

    The key component in Nocera and Kanan's new process is a new catalyst that produces oxygen gas from water; another catalyst produces valuable hydrogen gas. The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity -- whether from a photovoltaic cell, a wind turbine or any other source -- runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced.

    Combined with another catalyst, such as platinum, that can produce hydrogen gas from water, the system can duplicate the water splitting reaction that occurs during photosynthesis.



    I wouldn't characterize electrolysis of water as "major discovery" or cobalt as revolutionary "new catalyst". But if the goal is to decentralize generation (why?) I'm optimistic.

    We'll have to see if this is really affordable after accounting for the machinery, precious metals, and inherent waste of using dedicated units for each house.

    Photovoltaic efficiency is about 10%. Then crack water at about 75% (ideally). Then retrieve electricity through fuel cell at, say, 50%. One can see that if the panel roof was "hot enough to cook an egg" we need a lot of roof to cook one egg after sunset.
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    I think the MIT discovery is a bit over-hyped. Anybody who has a home solar installation or other "green" power generating system in an area with net metering policy

    http://en.wikipedia.org/wiki/Net_metering

    does not have a storage problem. They simply sell any excess generation at retail price back to the utility company. Still, there has not been any great boom in solar energy yet, so why would this make such a difference?
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    Quote Originally Posted by Harold14370
    They simply sell any excess generation at retail price back to the utility company. Still, there has not been any great boom in solar energy yet, so why would this make such a difference?
    That works on very small scales but doesn't work for supporting an entire grid because the entire grid can't store the energy either--it usually just means the utilities end up overproducing power because most of our power production can't be adjusted quickly--in other words little net savings.
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    I'd have thought that power fed to the grid from multiples of home solar systems would follow predictable patterns that would be smooth and sustained on average, so that the generating plant would not need to adjust quickly, but could power down, i.e. burn less coal as the generator torque is reduced, to follow the curve.
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    if we could find a material that could drill deep into the earth without melting or being crushed, then we would have acess to all the free lava-powered energy we would ever need. I am aware that we already have geothermal power, however this would take irt to the next level, with much more energy stroed in magma, than say hot rocks, and natural steam like in the preexisting geothermal power we currently have today. I think it is a long way off, but i also think we can achieve it
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  17. #16  
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    Quote Originally Posted by Bunbury
    I'd have thought that power fed to the grid from multiples of home solar systems would follow predictable patterns that would be smooth and sustained on average, so that the generating plant would not need to adjust quickly, but could power down, i.e. burn less coal as the generator torque is reduced, to follow the curve.
    I think you forgot about clouds. They're huge, they move, they're highly unpredictable on an hourly scale. It's pretty typical for an area the size of a city to go though cycles of full sun and shadow dozens of times in a day. Just look at your local weather animations.

    Demand bottoms during the night, which is alright for solar. However demand spikes in the evening, as many businesses are still operating while folks arrive home to switch on lights, nuke dinner, etc.

    As we build more efficient homes and appliances, standby losses and steady loads such as heating will want relatively less, so individual customer demand will become more erratic. This is why old originally uninsulated houses with 60 amp breaker panels, are upgraded to at least 200 amp. Even water heaters in newer homes are often electric-demand heaters AKA "tankless" (homeowner saves a bit) and this is going to focus demand on just those times when people use hot water.
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  18. #17  
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    Quote Originally Posted by Bunbury
    I'd have thought that power fed to the grid from multiples of home solar systems would follow predictable patterns that would be smooth and sustained on average, so that the generating plant would not need to adjust quickly, but could power down, i.e. burn less coal as the generator torque is reduced, to follow the curve.
    This is true, but the problem with having an unreliable source of power is that the reliable sources still have to be sized to supply the entire peak load. So while you may save some fuel cost you will have the same construction and operating costs for the conventional plants, plus the cost of the solar or wind plants.

    In our area of the country, we try to schedule power plant outages for spring and fall, because the peak loads occur during the hot summer days where air conditioning is running, and in the winter heating season. Solar generation would probably be a good thing here in the summer, not so good on a cold winter night.

    The point I was making above was that cheap energy storage may help solar, but wouldn't suddenly make it an economical alternative. It's not economical now, even when storage is not an issue.
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  19. #18 Renewable Energy 
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    I am just learning about renewable energy but wind makes the most sense to me.
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    I think you forgot about clouds.
    Easy to do when you live in Colorado.
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  21. #20  
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    No such thing as non-renewable energy.

    "Resources are not; they become." -- Erich W. Zimmerman, economist, 1933

    "The assumption of fixed, finite natural resources has caused many to make catastrophic predictions of resource exhaustion. Fortunately, where these prophecies have been sufficiently specific to be testable, the passage of time and events has falsified them." -- Thomas R. DeGregori, economist, 1987

    "I do not know of any idea more likely to keep people impoverished than the idea that resources are natural, fixed, and finite. " -- Thomas R. DeGregori, economist, 2002

    Hydrocarbons are renewable.

    "Hydrocarbons can be re-defined as a 'renewable resource, rather than a finite one' (Gurney 1997)" -- Peter R. Odell, economist/geologist, 2004

    "Enormous implications follow from oil and gas being renewable resources." -- Peter R. Odell, economist/geologist, 2004

    Oil is infinite.

    "It is obvious that the total amount of petroleum in the rocks underlying the surface ... is large beyond computation." -- Edward Orton, geologist, 1888
    "The most likely site for error is in the most fundamental of our beliefs." -- Samuel Warren Carey, geologist, 1988
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