Why not ammonia, NH3, as liquid fuel?

Discussion in 'Chemistry' started by Billy T, Feb 26, 2007.

  1. Enmos Staff Member

    Messages:
    43,184
    Oh, my bad..

    Please Register or Log in to view the hidden image!

     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. dixonmassey Valued Senior Member

    Messages:
    2,151
    the Book


    Renewable Energy Cannot Sustain a Consumer Society
    Trainer, Ted
    2007, VIII, 200 p., Hardcover
    ISBN: 978-1-4020-5548-5

    It is widely assumed that our consumer society can move from using fossil fuels to using renewable energy sources while maintaining the high levels of energy use to which we have become accustomed. This book details the reasons why this almost unquestioned assumption is seriously mistaken.

    Chapters on wind, photovoltaic and solar thermal sources argue that these are not able to meet present electricity demands, let alone future demands. Even more impossible will be meeting the demand for liquid fuel. The planet’s capacity to produce biomass is far below what would be required. Chapter 6 explains why it is not likely that there will ever be a hydrogen economy, in view of the difficulties in generating sufficient hydrogen and especially considering the losses and inefficiencies in distributing it. Chapter 9 explains why nuclear energy is not the answer.

    The discussion is then extended beyond energy to deal with the ways in which our consumer society is grossly unsustainable and unjust. Its fundamental twin commitments to affluent living standards and economic growth have inevitably generated a range of alarming and accelerating global problems. These can only be solved by a transition to The Simpler Way, a society based more on simpler, self-sufficient and cooperative ways, within a zero-growth economy. The role renewable energy might play in enabling such a society is outlined.
    Written for:
    Specialists in all energy fields, including renewable energy technology, environmentalists, economists, social theorists, policy specialists, futurologists

    Quote:

    If we take the above capital cost and efficiency figures for PV panels, along with
    Sydney’s 34 degrees south annual average solar incidence of 4.6 kWh/m/d, what
    would be the cost of electricity supplied at a rate equal to a 1000 MW coal-fired
    plant operating at 0.8 capacity? To generate this amount of electricity at 13% efficiency,
    6.154 million kWh of solar energy would have to be collected per day, and if
    solar incidence is 4.6 kWh/m/d this would require 32.1 million square metres of panels.
    At $1,500 per metre the cost would be $(A)48.2 billion, some 13 times the cost
    of the coal-fired plant plus coal.


    Let's be optimistic and assume that in 40 years it will take 20 millions square meters of panels to replace a 1000 MW coal fired plant. There are some 50,000 coal power stations worldwide. OK, let's use 30,000 number. 30,000*20,000,000 m2=600,000 km2. Roughly, it's an area of Texas. Since an estimate is deliberately "optimistic" practically it's gonna take 2 Texas areas to substitute just coal fired powerplants. BTW, Texas is not as good as Australia photovoltaic vise.

    In two words, there is a little chance to power current (not speaking the future) way of life using renewable energy. Don't forget that renewable energy will kill/starve plants and critters albeit in different ways.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Nasor Valued Senior Member

    Messages:
    6,221
    What a load of bullshit. You think the world uses 30 TW of electricity??? Try 2 TW. http://www.indexmundi.com/world/electricity_consumption.html

    As of 2009, we can produce panels that are 22% efficient at a cost of less than $1/W. The average solar flux on the earth's surface is 160 W. Average world electricity production is about 2 TW. To replace all electricity production in the world with solar panels at 22% efficiency would require about 57,000 km^2.

    The price of $1500/meter^2 that your source quoted is looooong outdated. Today it's more like $35/m^2 (for a panel that has 22% efficiency, rather than the 13% efficiency of the panel referred to in your book).

    And of course, the technology continues to advance; it will only get cheaper and more efficient was time goes on.
     
    Last edited: Aug 23, 2009
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. dixonmassey Valued Senior Member

    Messages:
    2,151
    18.58 Trillion KWH (2005 Est.)
    According to https://www.cia.gov/library/publications/the-world-factbook/print/xx.html . World electricity generation increases by 77 percent from 2006 to 2030 in the IEO2009 reference case. http://www.eia.doe.gov/oiaf/ieo/electricity.html. I was wildly guessing 40 years ahead. 30 terrawatt is a fairly good guess.

    Efficient where? In the lab? Practical efficiency of solar panels remains somewhere between 6 and 13%. Well, your numbers are fantastic, as of 2006 it costs something like $7-10 per 1 W for residential solar (all gadgets and wires included). OK, let it be $4/W for Mega commercial projects. Still, 4 fold cost decrease in just 3 years is something out of this world.

    550MW California plant requires 9.5 square miles, let's be optimistic and think that in 40 years 1000 MW plant would require 10 square miles. (30TW/1000MW)*10=300,000 square miles or 750,000 km2.

    Don't forget all the wires and gadgets, it's not just panel. Don't forget about energy input /energy output ratio. It's still unclear (for me) whether solar panels are energy source or energy sinks, all things included.
     
  8. Nasor Valued Senior Member

    Messages:
    6,221
    ...which is equal to 2 TW average consumption for the year. Do you know how to convert from units of power to units of energy?
    Uh...you realize, I hope, that if you increase 2 TW by 77% you get 3.54 TW? Using your own numbers of of 1 GW/10 square miles, that would mean you need about 35k square miles (an order of magnitude less than the figure you calculated).
    At least two companies, Nanosolar and Firstsolar, are manufacturing panels that are 16-22% efficient at a production cost of $1/watt. They currently sell them at about $3 watt, because at that price they're already selling the panels as fast at they can make them, so for the moment they have little incentive to lower the price.
     
    Last edited: Aug 23, 2009
  9. dixonmassey Valued Senior Member

    Messages:
    2,151
    There is no need to converts from units of power to units of energy since all power generation is customarily measured in units of power. As for now, USA alone roughly consumes 7 terawatts of electric energy/year. http://en.wikipedia.org/wiki/World_energy_resources_and_consumption. I don't know how you come up with 2 TW.

    I repeat there is more to solar power than solar panels; wires, circuitry, electronics, installation, maintenance etc. are also included and they cost pretty penny.

    In a statement — seen by Green Inc. on Tuesday — First Solar, which has produced modules for solar installations in several countries in Europe, said it had brought costs down to $1 from $3 over the past four years through economies of scale by increasing its production capacity by 50 times, and by passing on those savings to consumers.

    So, yes, production costs for solar panel dropped thanks to economy of scale , otherwise there is nothing revolutionary. Again, there is more to solar energy than solar panels. However, I would not focus on costs per watt, human monetary systems are artificial and have little to do with environment and energy balances. What is more (much more) important is Energy Input/Energy output ratio. What energy is spent per 1W of solar electric power generation is way more important than how much $ is spent per 1W (and it's better be less than 1, otherwise there is no point).
     
  10. Nasor Valued Senior Member

    Messages:
    6,221
    You quoted a source saying the world consumed 18.58 Trillion KWH (which is a unit of energy) in one year. If you convert 18.58 kwH/year into watts, you get 2 TW.

    I was unable to find such a claim on that wikipedia page.
    Again, I will ask - do you know how to convert units of energy to units of power? Because I got the 2 TW figure from your own source!
     
  11. dixonmassey Valued Senior Member

    Messages:
    2,151
    The energy events of the 1970’s raised the issue of whether economic measures such as price or cost accurately captured all the relevant features of an energy supply process. Economists generally argue that, by definition, the price of a fuel automatically captures all such relevant features. Yet, a strong case can be made that the standard economic approach to measuring the economic usefulness of a fuel yields one type of information and only partially informs us about all relevant aspects of resource quality. Net energy analysis, through the calculation of EROI, informs us about some of those other qualities, such as the potential for a fuel source to yield useful energy to the rest of the economy. Such qualities may or may not be reflected in a fuel’s price. As Peet et al, 1987, stated:

    ...we believe the conventional economic perception of the ‘value’ of primary energy resources is incomplete and potentially misleading, in that it does not adequately take account of the factors which constrain a society’s ability to obtain useful consumer energy from such sources.

    http://www.eoearth.org/article/Net_energy_analysis
     
  12. Nasor Valued Senior Member

    Messages:
    6,221
    The entire electricity generating capacity for the US is only about 1 TW. Actual consumption is far less than that, because we don't run every power plant at 100% output all the time. http://www.eia.doe.gov/cneaf/electricity/epa/epates.html

    Again, you 7 TW (or 30, or whatever the hell you're imagining it to be) figure is absurd.
     
  13. dixonmassey Valued Senior Member

    Messages:
    2,151
    OK, Here is info you could not find on the page.
    The United States Energy Information Administration regularly publishes a report on world consumption for most types of primary energy resources.
    Fuel type Average power in TW[12]
    2006
    Oil 5.74
    Gas 3.61
    Coal 4.27
    Hydroelectric 0.995
    Nuclear 0.929
    Geothermal, wind,
    solar, wood 0.158
    Total 15.8 TW
     
  14. Nasor Valued Senior Member

    Messages:
    6,221
    That's TOTAL energy consumption, including things like fuels burnt to power cars/trains/aircraft/whatever, not electricity consumption, dumbass. The US has less than 1 TW of electrical production capacity.

    You yourself posted a link earlier saying that the world uses 18 trillion kwh/year of electricity, which I agree with, because 18 trillion kwh/year is equal to only 2 TW average consumption over the year. So you are now apparently trying to argue against your own sources. But hey, who needs to know how to convert units, right?

    Edit: Sorry, it's not less than 1 TW, it's about 1.1 TW.
     
    Last edited: Aug 23, 2009
  15. dixonmassey Valued Senior Member

    Messages:
    2,151
    Let's go one more time

    World Total Net Electricity Generation (Billion Kilowatthours), 1980-2006
    http://www.eia.doe.gov/iea/elec.html

    For 2006 total = 18,014.67 billion (Giga) KWhrs or roughly 18TW

    1000 MW power plant produces 1000 MW x 24hours x 365.25 days in an average year, or about 8,760 Giga KWattHours. Let's make it 8 G.

    So, in 40 years (77% increase) it would take roughly 30,000/8 = 3750 1000MW power stations to produce all that electricity. The question is how many square miles of solar panels it would take to generate all that power. Even larger question - what is Energy Input/Energy output for solar, are they any better than coal? Do you know?
     
  16. dixonmassey Valued Senior Member

    Messages:
    2,151

    Can you add? Coal +Hydroelectric+Nuclear, those are used mostly to generate electricity. 4+1+1=?

    Well, according to http://www.eia.doe.gov/iea/elec.html USA generates 4TW/year. It's not 7TW but it's not 1TW either.
     
    Last edited: Aug 23, 2009
  17. Nasor Valued Senior Member

    Messages:
    6,221
    No it doesn't, dumbass. KWhrs is a unit of energy, and TW is a unit of power. To convert watt hours (energy) to watts (power), you divide the number of watt hours by the number of hours over which the energy was produced. The 18,000 billion kWhrs number you quoted was for an entire year of production. There are 8760 hours in a year.

    18,000 billion kWhrs / 8760 hours = 2 billion kW = 2 TW.

    This is why I asked you if you knew how to convert units. Obviously now I have my answer.
     
    Last edited: Aug 23, 2009
  18. Nasor Valued Senior Member

    Messages:
    6,221
    Yes, but they are not used efficiently. If you release 1 joule of heat energy from coal or oil, you get far less than 1 joule of electrical energy out of it, because most of it will end up as waste heat. The number to look at is how much electrical energy comes out of the plant. When people talk about a plant being some number of MW, they mean the output. They aren't talking about the fuel energy that it consumes to make the electricity.
    Yes, I can add, but apparently you can't read.

    From your own source:
    http://www.eia.doe.gov/cneaf/electricity/epa/epat2p2.html
    Generator Nameplate Capacity: 1,087,791 MW.
    Net Summer Capacity: 994,888 MW
    Net Winter Capacity: 1,031,978 MW

    Since I know units aren't really your thing, I'll give you a hint and tell you that 1 million MW = 1 TW.
     
  19. dixonmassey Valued Senior Member

    Messages:
    2,151
    Man, if you want to see a dumbass look in the mirror. What in the hell you are dividing, OK, it's not academic paper so I abbreviated 18,000 billions KWhrs as 18TW, it's just simply obvious that I meant 18TWhrs. Me omitting hrs at the end shall not tempt you to divide energy by hours to get what, what you are getting if you divide energy by the number of hours, genius, just stop and think about it.
     
  20. dixonmassey Valued Senior Member

    Messages:
    2,151
    Again, Capacity in what Units? Obviously MW is units of power. Look, look carefully in a mirror before calling names

    Please Register or Log in to view the hidden image!

     
  21. Nasor Valued Senior Member

    Messages:
    6,221
    This all started because you tried to claim the world would need 30 TW of generating capacity (generating capacity is measured in watts). I said that was bullshit, and that it was more like 2 TW. You then tried to refute me in post # 144 by posting a link to a source saying the world uses 18 TWhours/year and that usage would grow 77%, apparently not knowing that 18 TWhrs/year = 2 TW.

    So no, it's not obvious that by "18 TW" you meant "18 TWhrs," because that's not how you were trying to argue a minute ago. You were treating "18 TWhrs" as "18 TW" when you calculated the area needed for a solar plant. Here is an exact quote from you:
    Obviously you were confused about consumption being in TWhours and the solar pant's capacity being in MW, which is why you divided 30TW by 1000MW.
    When you divide energy by hours, you get power. Which is what generating capacity is measured in.
     
    Last edited: Aug 23, 2009
  22. Trippy ALEA IACTA EST Staff Member

    Messages:
    10,890
    What Nasor did was correct.
    http://www.tpub.com/neets/book1/chapter3/1-9.htm

    A simple dimensional analysis should have been enough to indicate this.

    kW≠kWh
    However
    \(\frac{kWh}{h}\)=kW
     
    Last edited: Aug 23, 2009
  23. dixonmassey Valued Senior Member

    Messages:
    2,151
    It doesn't look either of us got it right all the time. I got it wrong with area of solar panels. However, I don't see mistake in the text you quote. World' electricity production per year (2006) 18TW*hr, yup I missed hr in the end. TW*hr is a unit of energy NOT power.

    Nasor said:

    First, world uses electric energy not electricity. Electric energy is measured in TW*hrs (hrs missing after 30). As for 2006, world uses 18TW*hrs of electric energy. It's projected to grow 77% by 2030, therefore 30TW*hr.
    Therefore, if one divides 30TW*hrs by the number of hours in a year he'll get unit of power (watt). World is using energy not power in watts. Citing the indexmundi Nasor quoted, USA alone consumes 3.892 trillion kWh (2007 est.)
    http://www.indexmundi.com/united_states/electricity_consumption.html.


    18TW*hr/(365*24) = 2GW, it's the average energy world's power station generate in an hour, as far I understand.
     

Share This Page