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Technology Science

Green Energy Now, And On The Tide 577 577

thpr writes "The Electric Power Research Institute and its partners have completed their Offshore Wave Power Feasibility Demonstration Project, which defined potential wave energy projects off the shores of the United States. This is building off of work already done in Scotland (and elsewhere). San Francisco, New York and other areas are considering trial installations of the technology. It is interesting to note (table 1 in the report) that the energy density (kW/m^2) that can be achieved is much higher than wind or solar. In addition, harnessing 24% of available wave energy near the US at 50% efficiency is equal to all of the hydropower currently generated in the US (~7% of total electricity production). On a separate note, in the Office of Energy Efficiency and Renewable Energy's $1.2B 2006 budget the Department of Energy is closing out the Hydropower Technologies Program. Maybe that's why this technology is missing from our National Energy Policy?" Until it reaches maturity, though, U.S. readers can pay for other forms of green energy.
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Green Energy Now, And On The Tide

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  • Wave-Powered Whisky (Score:2, Informative)

    by Geek Yid (798534) on Tuesday February 15, 2005 @01:27AM (#11675143) Homepage
    Interesting how these wave generators wind up at whisky-distilling islands. Orkney has the wonderful Scapa and better known Highland Park, not to mention the Orkney Brewery. Islay, meanwhile, with its seven working distilleries has much of its electricity generated by a 'Limpet' wave generator. (See http://www.fujitaresearch.com/reports/limpet.html for more.) Environmentally friendly power: it's just one more good thing about Scotch Whisky!
  • by Lackaff (247537) on Tuesday February 15, 2005 @01:36AM (#11675188)
    Until it reaches maturity, though, U.S. readers can pay for other forms of green energy.
    Hey, if Timothy says green pricing is on-topic for this discussion, who am I to argue? Green pricing programs are not only available in the US. I helped compile this information about international green pricing programs [energy.gov] a few years ago. Looks as if it hasn't been updated in a while, but non-Yankee Slashdotters might find something useful there.
  • Re:Side effects (Score:5, Informative)

    by wayne (1579) <wayne@schlitt.net> on Tuesday February 15, 2005 @01:47AM (#11675225) Homepage Journal
    "Slows the planet's rotation?" Please cite your source for THAT one, I'd love to see who came up with it.

    Yes, tidal forces DO cause the earth's rotation to slow down.

    The tidal forces created by the earth on the moon have slowed the rotation of the moon down to the point that we only see one side of the moon. That is, the moon rotates about once a month. Similarly, the tidal forces of the moon are slowing the earth's rotation down, and it will eventually reach one about one rotation per month also. Assuming that the sun doesn't become a red giant first. And, speaking of the sun, there is also a tidal force that from the sun that will eventually cause the earth to rotate once per year. I'm not sure who this conflict between the moon's and the sun's tidal forces work out.

    Conservation of angular momentum means that the tidal forces are causing the moon to orbit the earth faster, and thus further away.

    While all these tidal forces are very small and only add up over very long periods of time, they can be measured. In particular, things like variations of the amount of snow on mountains, the amount of water in man-made lakes, the force of huricanes, and variations in the shape of the earth caused by earthquakes all add up to enough to cause the need for leap seconds.

    Leap years keep the seasons from rotating through the calendar. Leap seconds keep the zenith of the sun ("noon") from rotating through the day. I forget the exact value, but there is something like an accumulated 20-30 seconds difference caused by these forces over the last 50 years, and therefore there have been 20-30 leap seconds added since then.

  • A look at solar. (Score:4, Informative)

    by Malluck (413074) on Tuesday February 15, 2005 @01:47AM (#11675226)
    How viable is solar power? I was asking myself this question and here's the numbers I came up with.

    In 2001 the USA used 96275 trillion BTUs of energy [slashdot.org] that year. This comes to 3.22 trillion watts.

    Now there are about 295 million people [census.gov] in the US, so this comes to about 11Kw per person [google.com] at any given time.

    This means each person uses is responsible for 262 Kwh of power [google.com] per day.

    Now lets say that square meter of sunlight provides 1 kw of energy on average and the average area gets 5 good hours of sunlight per day. Looking at this chart [stirlingenergy.com], you can see that this assumption isn't too far off.

    The typical solar panel is about 30% efficient. This means that for every square meter of solar panel would render 1.5 KwH [google.com] every day.

    This means that each man woman and child would need 174 square meters [google.com] of panel to be responsible for all the energy made and used in their name!

    If every person in the united states of America put up solar panels. We would have over 51 billion square meters [google.com] of panel, that's close to 20,000 square miles [google.com]of panel or the equivalent of covering most of over in panels. [enchantedlearning.com]

    Now these numbers account for all energy used both domestic, industrial, and exported. Also these numbers do not account for the added or lost efficiency of converting systems over to pure electrical power as opposed to other energy processes like those used in the internal combustion engine.

    I left the links to my math in just incase I botched anything.
  • Re:Idiocy (Score:3, Informative)

    by Tiger the Lion (808669) on Tuesday February 15, 2005 @01:53AM (#11675240)
    Not 24% of coastline, but 24% of total tidal energy. You can't assume that the waves are equal everywhere along the coastlines.

    And 7% of total energy demand is nothing to scoff at. Imagine if it was actually realised - a lot of greenhouse gases would be saved. All I hope is that the picture is still rosey after an in-depth environmental assessment.

    ------
    Daily energy news and discussion: http://www.thewatt.com/ [thewatt.com]
  • by MikeCapone (693319) <skelterhellNO@SPAMyahoo.com> on Tuesday February 15, 2005 @01:56AM (#11675247) Homepage Journal
    For those who want more, the best links on for intelligent green reading:

    WorldChanging.com [worldchanging.com] -- which also has an article about wave power [worldchanging.com].

    TreeHugger [treehugger.com], which is already linked in the story.

    Dave Pollard [salon.com], which writes very insightfully about lots of things including environmental philosophy.

    Green Car Congress [greencarcongress.com], where you can get the best news about green mobility, cool cars & industrial developments.

    IDFuel [idefuel.com], which is more about design but covers some of the same ground as TreeHugger.com

    FuelCellWorks [fuelcellsworks.com] for all the latest news about fuel cells.

    Grist Magazine [grist.org], for news and a touch of humor, plus lots of interviews.
  • by dasunt (249686) on Tuesday February 15, 2005 @01:57AM (#11675252)

    The main advantages that nuclear has over solar, wind, hydroelectric, geothermal, and tidal:

    • We have the technology now.

    This is a biggie. We know how to build nuclear power plants. Other countries have been doing so for years. Even in the US, nuclear is a proven energy source: IIRC, the US derives 24% of its electricity from nuclear power.

    • The technology can replace full US capacity.

    Look at how much energy the US uses now, and how much the US predicts it will be using. Can solar cells, wind farms, hydroelectric, or tidal replace that? It doesn't seem that wind nor solar can -- it doesn't have the capacity nor the constant power generation. Hydroelectric isn't unlimited either: sooner or later you run out of damnable rivers. Geothermal? It seems location dependent (but I'll admit, I haven't done my homework on this one). Tidal? How much coastline would we need again?

    • Relatively non-disruptive.

    Hydroelectric power creates lakes and turns rivers into streams. It changes aquatic ecosystems. How about tidal? How many shorelines are we going to line with tidal energy power generation? What do you think that will do to the environment? (Wind power is also relatively non-disruptive.)

    • Cost effective.

    Nuclear has been competing with traditional electric generation for decades. We know we can generate nuclear power at a relatively low cost. The same can't be said for many other alternative energy sources.

    Effective at limiting pollution.

    No matter what "green" energy we use, there will be pollution. Check out the byproducts created in the manufacture of solar cells. Yes, nuclear does require some mining, and it requires proper disposal of nuclear waste. Yet, in the end, nuclear is amazingly efficient at eliminating greenhouse gases on a level with other green technologies.

    So, lets sum up - Nuclear is:

    • We have the technology now.
    • The technology can replace full US capacity.
    • Relatively non-disruptive.
    • Cost effective.
    • Effective at limiting pollution.

    Perhaps this is why noted scientists such as James Lovelock also advocate nuclear power.

    The main problem is the public and the greens. They are convinced that nuclear power is unsafe, that radiation will kill us all, and they are playing a NIMBY game with nuclear waste disposal.

    To be honest, nuclear power isn't my first choice for green energy: That would be orbital space platforms harvesting the energy of the sun, or fusion reactors. Perhaps one day, those technologies would be feasible. Right now, they are slightly more of a pipe dream than other green energy. Nuclear exists now, and it works. Conservation goes only so far -- the third world is slowly turning first world, and that will require an enormous consumption of energy.

    We need to be realistic about our energy problem and about what solutions will work. Most alternative energy sources won't work right now. Nuclear will.

  • by MikeCapone (693319) <skelterhellNO@SPAMyahoo.com> on Tuesday February 15, 2005 @01:58AM (#11675256) Homepage Journal
    The problems with nuclear power are pretty well outlined here [tompaine.com], I think. Give it a read, it fills some of the holes left in the the recend Wired article that most here have probably seen.

    Nuclear has many advantages, but we must not turn a blind eye to its shortcomings.
  • by Anonymous Coward on Tuesday February 15, 2005 @02:02AM (#11675273)

    Waves are cool, but don't forget ... OTEC (Ocean Thermal Energy Conversion) [hawaii.gov]

    My father was a primary designer on this, so I had the "real scoop" on what was going on there in real time, it was real exciting stuff back then!

    Mini-OTEC, 1979

    In 1979, the first successful at-sea, closed-cycle OTEC operation in the world was conducted aboard the Mini-OTEC, a converted Navy barge operating in waters off Keahole Point.

    This plant operated for three months, from August-October 1979, and generated approximately 50 kilowatts of gross power with net power ranging from 10-17 kilowatts.

    Its turbine generator produced a gross output of up to 55 kW. About 40 kW were required to pump up 2,700 gallons/min of 42F water from 2200-ft depth through a 24-in diameter polyethylene pipe and an additional 2,700 gallons/min of 79F surface water, leaving a maximum net power output of 15 kW.

    This was a joint effort by the State of Hawaii and a private industrial partner.

    More linkage: NREL's OTEC site [nrel.gov]

    Google [google.com]

  • by MikeCapone (693319) <skelterhellNO@SPAMyahoo.com> on Tuesday February 15, 2005 @02:14AM (#11675320) Homepage Journal
    It's effect of ocean life (and the planet in general) is microscopic, infinitesimal, compared to the effect of the coal plants and other brown and black energy sources.
  • Re:A look at solar. (Score:2, Informative)

    by Anonymous Coward on Tuesday February 15, 2005 @02:16AM (#11675325)
    Just some minor corrections.....BTU is energy, Watts aren't. Watts are power, or Energy / Time. KW-Hr is not power, but in fact a measure of energy. Yeah it gets really confusing and I am an EE.

    1 BTU = .2933 Watt-hr
  • by Eivind (15695) <eivindorama@gmail.com> on Tuesday February 15, 2005 @02:42AM (#11675415) Homepage
    Nuclear is a lot better than oil/coal burning, that much is for sure. Atleast in countrys with enough of a reliable infrastructure that failing safety-mechanisms won't just be disabled to avoid interupting the production. (as in Chernobyl)

    That said, hydroelectric is also *very* well-tested mature technology, wind and solar less so.

    Norway, for example, have produced like 98% of the electricity needed (including the humongous amounts needed for large aluminium-plants) by hydroelectric since a century. That should count as well-tested I think.

    Different areas have different possibilities for different energies. Where there are large amounts of water (i.e. rain) falling in mountains, there'll be large amounts of hydroelectric power to earn with relatively modest negative consequences.

    Some places there's a lot of wind, and some places there's a *lot* of area and a lot of sun. Those places I think we should use it. Basically the only thing stopping us is that currently solar and wind is more expensive than burning fossil fuels. hydroelectric on the other hand is a lot *cheaper* than the alternatives on good locations.

  • by spencerogden (49254) <spencer@spencerogden.com> on Tuesday February 15, 2005 @02:43AM (#11675416) Homepage
    Good article on Wired [wired.com] about a safe way to do Nuclear power. Still need to get rid of the waste, but at least meltdowns wouldn't be a problem.

    We've missed out on a lot by not developong nuclear plants over the last 25 years. As other posters have said, its here now, and its the cleanest we have.
  • by Anonymous Coward on Tuesday February 15, 2005 @02:47AM (#11675421)
    "Check out the byproducts created in the manufacture of solar cells"

    Here's a link

    http://hem.dis.anl.gov/eehem/01/010305.html

    I'm still a big fan of Solar and will be adding a grid-tie system
    to my home.
    It is a technology that is here today that we can take into our own hands and apply without having to wait for big companies to come up something.
    p.s.
    I do have solar hot water if you are thinking about solar for your home this is a great place to start.
  • by Anonymous Coward on Tuesday February 15, 2005 @03:05AM (#11675466)
    Wow, that entire article is a load of shit.

    First, Pebble Bed Reactors aren't "Generation after Next", they're here. Now. Well, not "here" if you live in the US, but "here" if you live in the EU, or (God Forbid) China.

    Second, Nuclear never promises to replace oil. Ever. That web page keeps telling you it is, and it's covering a hidden agenda. But no. Nuclear replaces COAL. Oil is still the best we have for transportation, thanks to energy density. Nuclear Reactors are rather... large. They don't fit that well in cars.

    Third, it talks about how inefficient these are, because they're big, and service many people. Unforunately, it completely ignores the fact that BIG PLANTS ARE MORE EFFICIENT. It's called economy of scale. Rather than many cheap, small, local natural gas plants which that site advocates (Which DOES emit CO2, gosh golly) which are inefficient because they're small and cheap, you can have huge, expensive and few nuclear plants, step up the voltage to a very big number, and transmit the power over very long distances for very little loss, then when it gets to the destination, step it down, and that's where the real losses happen (After the stepping down, not the stepping down itself... the transformers are quite efficient).

    Wait, damnit, I've been trolled, haven't I?
  • by eh2o (471262) on Tuesday February 15, 2005 @03:43AM (#11675552)
    here is the link... http://www.wentworth.nsw.gov.au/solartower/ [nsw.gov.au]
  • by Rakishi (759894) on Tuesday February 15, 2005 @03:53AM (#11675572)
    Are you aware of how many solar panels you'd need? The amount of ecological damage that covering all that land would cause is not trivial. Are you aware of how much pollution the creation of a solar panel creates?
  • by ZorbaTHut (126196) on Tuesday February 15, 2005 @04:00AM (#11675584) Homepage
    Wait a second.

    Article summary: "Nuclear is a bad idea because a lot of nuclear plants are getting old and will need to be replaced. Also, if everyone had solar and wind and personal gas turbines, we wouldn't need nuclear. Oh yeah, and politicians are evil and trying to exploit this for their own benefit."

    (1) Those nuclear plants are getting old anyway, and will need to be replaced anyway. That has nothing to do with what they're going to be replaced with.

    (2) Not everyone does have those, and I rather doubt everyone's going to suddenly buy those. Great idea for new houses, lousy idea for existing ones.

    (3) And there aren't any politicians trying to make a fast buck off green power either? That's practically what a politician's job *is*.

    Where's the section that looks at a realistic breakdown of realistic costs and goals? Where's the section that makes any attempt to compare the two besides "hey! look! NUCLEAR POWER ISN'T PERFECT!"

    -1, flamebait.
  • by tonyr60 (32153) on Tuesday February 15, 2005 @04:11AM (#11675612)
    But not as much radioactive waste as coal fired stations. And it does not dump its waste into the atmosphere, like coal fired stations. And does not kill as many workers in the extraction of the raw material. etc. etc.
  • Sustainable choices (Score:5, Informative)

    by mangu (126918) on Tuesday February 15, 2005 @04:34AM (#11675661)
    Using algal biodiesel, breeder fission(with development on fusion), and wind where suitable, are the only remotely practical eco-friendly choices that are sustainable


    There is one alternative that is fully sustainable and has been working economically for decades. Brazil has been producing ethanol powered cars for 25 years. Every gas station in Brazil sells straight ethanol at a lower price than gasoline. Although the proportion is lower now, in the 1980's about 90% of the cars in Brazil were powered by straight ethanol, and the rest used a 75%/25% mix of gasoline and ethanol. Today several models of cars in Brazil come with "flex power" motors, which can burn any proportion of ethanol/gasoline mix.


    The Brazilian alcohol program is the largest renewable energy program for cars in the world. The only reason why it has been pulled back a little is because the oil prices aren't as high now as in 1980, after you take inflation into account. Also, the whole country has a much better economical situation, with a lower debt, internal oil production is higher and world sugar prices are higher (Brazilian ethanol is made from sugar cane). All these factors have contributed to decrease the proportion of ethanol in the total fuel consumption in Brazil, but ethanol is the first and most viable alternative for renewable transportation fuel in the world.

  • by dbIII (701233) on Tuesday February 15, 2005 @05:03AM (#11675725)
    If every person in the united states of America put up solar panels. We would have over 51 billion square meters of panel, that's close to 20,000 square miles of panel or the equivalent of covering most of over in panels.
    Solar panels are what you do if you want a bit of energy now in a spot that is off the grid - like a pocket calculator or marine navigation beacon. If you want power in industrial quantities you use heat - there are plenty of solar thermal solutions out there - some use steam and existing technology, some use hot oil as the working fluid, and some split ammonia during the day and recombine it at night for a constant output. The big problem is it has to be done on a large scale before it gets cheap - while the current solar approach is to have a dozen silicon panels in a paddock and say you are doing things for the environment. Solar panels don't scale, they are just convenient and require very little planning. It doesn't take huge areas exposed to the sun to get a lot of heat - and industrial amounts of heat can give us industrial amounts of electricity. We are still building coal fired plant designs from the 1960's despite the technology moving on there as well, people are very conservative about large capital projects.
  • by Lisandro (799651) on Tuesday February 15, 2005 @05:05AM (#11675733)
    I kindly disagree. Nuclear power has it's peeves, but nowadays it's a well understood technology; we're well past the days of Chernobyl. Very safe nuclear reactors can be made, and what's more important, are being made. The newer, so called "fast" reactors can actually generate more fuel than they consume! [wikipedia.org] (to an usability limit - it's not a perpetual motion machine).

    I don't have a link handy, but i recall reading the vast majority of the worlds' power was generated by burning coal. I'd much rather have nuclear plants. Then again, i'd much rather have eolic, tidal and solar powerplants, but if we have nuclear now, why can't we use it?
  • by dbIII (701233) on Tuesday February 15, 2005 @05:19AM (#11675765)
    we're well past the days of Chernobyl
    Did the remaining units of Chernobyl get shut down sometime in the last week when I wasn't paying attention to the news?
    Very safe nuclear reactors can be made, and what's more important, are being made
    Yes, a larger pebble bed prototype - which I mentioned I suspect.
    "fast" reactors can actually generate more fuel than they consume!
    Fast breeders have been around for a long time, but rememebr the fuel costs of any nuclear plant are trivial in comparison to the capital costs - that is how they are supposed to eventaully break even.

    The big problem I have is the bullshit ornl paper that was refered too about coal being a nuclear material so nuclear is OK too. We don't need that sort of crap now that nuclear looks like it may finally get somewhere on its own merits. What is a "coal is bad so nuclear is OK" post doing on a tidal power article anyway? The real nuclear power industry engineers I have worked with would never believe any crap like the "coal is nuclear waste" ornl paper which has mostly been circulated by an advertising agency.

  • by Anonymous Coward on Tuesday February 15, 2005 @05:19AM (#11675767)
    Indeed, with both solar and wind power the best solution is simply to add the facility to generate power to buildings (new or existing).

    www.windsave.com gives you an idea of what can be done with wind power.

    Also energy efficiency can reduce energy requirements by 30% in a building for a small expenditure (2% additional spend on new construction).

    Combine something like a windsave turbine or two and an energy efficient house and you have halved the energy requirement. Domestic power consumption in the USA accounts for something like 15% of the CO2 production, or approximately 4% of the world's CO2 production. In theory measures like this, if applied to all domestic housing, could go a long way to meeting Kyoto targets. Obviously it would take time to achieve this across the whole of the USA and the work required would produce some CO2 itself, as would the maintenance industry required. However it could still significantly reduce CO2 production without unduly affecting lifestyle, which is an admirable goal.

    Solar panel production can be polluting, so an alternative is solar heating in which water is heated by the sun. This is mostly a matter of plumbing. In some parts of the USA this could be used to generate hot water needed by a house on sunny but not especially hot days, and run air conditioning if used in conjunction with a heat exchanger. Efficiency is not nearly as high as solar power, but it's not high tech or polluting. Again there is a slight negative in that it also requires more plumbers, but this could be a job stimulus and jobs that could not be outsourced to India.
  • Re:Side effects (Score:3, Informative)

    by StrawberryFrog (67065) on Tuesday February 15, 2005 @05:36AM (#11675808) Homepage Journal
    ..Back under the bridge, troll. "Slows the planet's rotation?" Please cite your source for THAT one,

    http://en.wikipedia.org/wiki/Tidal_locking [wikipedia.org] or a google search on "tidal locking" will do you.

    Don't be so hasty with the troll label, or you'll be labeled a troll yourself. Troll.
  • by Anonymous Coward on Tuesday February 15, 2005 @06:10AM (#11675871)
  • by Goth Biker Babe (311502) on Tuesday February 15, 2005 @06:38AM (#11675938) Homepage Journal
    I work here [saltsmill.org.uk]. The building is limestone/sandstone and has been cleaned so the stonework is a sort of sandy colour. Everything around it is black. In fact most of 'old' West Yorkshire is black. That's because of all of the soot from British industry in the Georgian and Victorian eras and the early Twentieth Century. In fact, all the way up to the point where the clean air act was introduced which prevented the burning of coal which hadn't been treated. That made it expensive and caused the destruction of many fine Victorian cast iron fire places as gas fires were fitted. Coal is not clean.
  • by nathanh (1214) on Tuesday February 15, 2005 @06:43AM (#11675946) Homepage
    Then I want to see the KWH cost of solar when you are done. Average in the US is about $.075 KWH or so.

    Solar power costs are closely tracked on Solar Buzz [solarbuzz.com] and the average industrial cost is 20c/kWh. Those plants are commercial enterprises operating at a sustainable profit.

    New solar power plant designs from Australia (google for Big Dish ANU) have gotten the costs down as low as 12c/kWh, all inclusive. It's still not as cheap as coal but it's definitely competitive.

  • Re:A look at solar. (Score:3, Informative)

    by Renegade Lisp (315687) * on Tuesday February 15, 2005 @07:47AM (#11676132)
    I think these numbers, and this perspective, are very much mistaken.

    R. Buckminster Fuller, in his 1980 book Critical Path, claims that humanity's energy income from the sun (the amount of energy from the sun that reaches the earth every second) is several million times larger than humanity's total energy consumption, world-wide. Granted, you have to find ways to make use of that energy, but the energy is there, and it's nothing but solar energy.

    How does that relate to your numbers? Well, to begin with, we need to ask what 30% efficiency of solar cells refers to. Does it really include all the energy from the sun that hits a given area, and the resulting electrical power that's generated? What about thermal solutions, as another poster pointed out?

    Also, keep in mind that practically all other forms of energy that we know on this planet are ultimately solar energy. Wind, for example: it's flow of the atmosphere because the air is heated differentially by the sun (we're using the atmosphere as a big turbine, as it were). Water power: the water is elevated to higher levels by solar energy, and then we take some of that energy out of it again as it flows downward. Examples abound. So, in fact, there is far more solar energy than you'd think, and certainly far more than we could ever use.

  • by nilenico (688350) on Tuesday February 15, 2005 @08:01AM (#11676163)
    not necessarily flooding.

    In Norway, it's been done by piping up and damming waterfalls.

    Not pretty either, but at least it's not flooding large areas.

  • by The Original Yama (454111) <lists.sridhar@dhana p a l a n . com> on Tuesday February 15, 2005 @08:31AM (#11676225) Homepage
    Nobody is saying that coal is clean, but when you consider the entire life cycle of the fuel, it is safer and cleaner than nuclear eneregy. Nuclear fuel is environmentally damaging to extract (often more so than coal), and the waste needs to be reprocessed and stored securely for thousands of years.

    Today we have technologies which can filter out most of the pollutants which plagued Britain during the Industrial Revolution. I certainly don't like coal, but I'd prefer to use it over being lulled into thinking that nuclear energy is somehow clean.
  • by quad4b (858152) on Tuesday February 15, 2005 @09:11AM (#11676380) Homepage

    There are numerous sources of alternate energy that could replace environmentally harmful sources of energy within decades.

    The problem is not scarcity of alternatives but that the true cost of harmful sources is not factored into the price paid by consumers (nor charged by suppliers). This is the only reason alternative sources are more expensive. True cost would include the cost to undo the damage caused by using it. What is the cost to reverse global warming? What is the cost to reverse damage caused by coal mining (leached acids and heavy metals into the groundwater + acid rain)?

  • by mre5565 (305546) on Tuesday February 15, 2005 @09:12AM (#11676381)
    I saw a documentary about oil and energy efficiency a while ago that stated that solar power would required 1/3 of the world's land in solar panels in order to meet the world's energy needs. Hmm...
    That seems quite high. Let's look at some publically available info.

    http://www.jc-solarhomes.com/solar_energy_facts.ht m [jc-solarhomes.com]

    Assume each square metre can receives 1 KW hr per hr. Assume 20% efficiency for photovoltaics. So 0.2 KW hr per hr per metre.

    http://www.infoplease.com/ipa/A0001729.html [infoplease.com] says a kw hour is 3412 BTUs, so photo voltaics produce 0.2 * 3412 = 682.4 BTU/hr per square metre.

    http://energy.cr.usgs.gov/energy/stats_ctry/Stat1. html [usgs.gov] says the 1998 U.S. energy consumption was about 94 quadrillion BTUs Assumong 8 * 365 hours of decent sunshine in the desert year around. So that's 100 * 10^15 / (8 * 365 ) = 34 * 10^12 BTUs/sunshine hour.

    (34 * 10^12 ) / (682.4 ) = 49 * 10^9 square metres = 49 * 10^9 / 10^6 = 49000 square kilometres = 223 KM by 223 KM or 140 miles by 140 miles.

    If you "want" the entire world to consume energy at per-capita rates like the USA, then assuming the US population is 300M, and the world population is 6B, then 6*10^9/(300*10^6) * 49000 = 980000 square km. The Earth's land surface area is claimed to be 148,300,000 [hypertextbook.com] sq km, so 980000 / 148300000 = .006608 or less than 1% of the Earth's land surface area.

    Mind you, for infrastructure that huge, you have to build roads, support buldings, etc. So even if a factor of 3 off, that's still about 2% of the surface area.

    Also, once demand for photovoltaics reached 1% of the above, I imagine the industry would drive efficiency from 20% to higher levels. So 1/3 of the land surface area is way too high.

    The real problem with photovoltaics is the cost. http://store.yahoo.com/sancor/50w.html [yahoo.com] will sell you a 502mm x 939mm panel for $588, or 588 / (502 * 939) * 1000000 = $1247 per sq metre. Let's be hopeful that in quantity, wholesale lots, we could buy this for $1000 per sq metre. 980000 * 1000 * 1000 * 1000 = $980 trillion. Note that the annual GDP for Earth, according to http://www.cia.gov/cia/publications/factbook/print /xx.html [cia.gov] is $51.48 trillion. That figure is at purchasing power parity. I'll leave it others to speculate whether photovoltaics can be manufactured cheaper in third world countries or not. If you don't think so, then considering that the U.S. economy is about $11 trillion, and that it is blamed for consuming about 1/2 the world's resources, the non purchasing power parity world GDP is probably closer to $22 trillion.

    There needs to be a 10X reduction in the price/energy ratio of photovoltaics. Do that, i.e. reduce the cost of the solar energy to meet the world's needs to an investment of about $100 trillion, amortize it over 30 years, and I'm sure we can find the money and land to do this.

  • by mikael (484) on Tuesday February 15, 2005 @09:13AM (#11676390)
    The reason I believe this is because electronics in peoples homes are growing at a faster rate than "green technology" (like solar power) is improving.
    The amount of solar panels required to power the 3 computers, 4 TV's, 2 PlayStations, DVRs, cordless phones, etc. in my house in cloudy/rainy NY would be crushing.

    It's not your home computer equipment that sucking up all those kilowatts, it's the electrical appliances you take for granted. We once stayed in a rural cottage with a 5 kilowatt trip switch - any time the energy demands exceeded this limit, the main fuse would cut off.

    Our morning would begin with putting the laundry into the washing machine(3 kW/h), switching on the kettle (2kW/h). By lunchtime, the cooker would be on (3kW/h), and the washing machine would now be in spin mode (2kW/h). Not forgetting the television (300 watts), refrigerator (500 watts), and a computer (120 watts), and maybe a couple of light bulbs (100 watts x 2).

    Needless to say, our power supply was tripping out more often than hippies at a summer festival. A short term measure was that we had to switch off all lights and appliances whenever the cooker or washing machine was on. The long term solution was that the trip switch was upgraded to 9 kilowatts.

    For 3 computers, 4 TV's, 2 playstations, DVR, the power demand would be an additional:

    3 x computer . .= 3 x 200 watts = 600
    4 x TV . . . . .= 4 x 80 watts = 320
    2 x playstation = 2 x 80 watts = 160
    2 x DVR. . . . .= 2 x 120 watts = 240
    3 x cordless phones = 3 x 5 watts = 15
    Total = 600 + 320 + 160 + 240 + 15 = 1335 kilowatts

    Sources: Energy Efficiency Guide [consumereducation.org.uk], Energy Whiz [energywhiz.com] and Saving Electricity [michaelbluejay.com]
  • by ylikone (589264) on Tuesday February 15, 2005 @09:26AM (#11676434) Homepage
    I was one of the web developers for these two Canadian green energy sites.

    canwea.ca [canwea.ca]
    skygeneration.ca [skygeneration.ca]

    Both of which are hosted by a green web host, appropriately called thegreenwebhost.ca [thegreenwebhost.ca]
  • by Anonymous Coward on Tuesday February 15, 2005 @09:53AM (#11676585)
    The Bay of Fundy [wikipedia.org] already makes use of tidal power generation. It is in a limited form at the moment but there have been attempts to expand the operation.
  • by Surur (694693) on Tuesday February 15, 2005 @09:58AM (#11676625) Journal
    This is a myth. Funny how old myths refuse to die. Energy Payback Time is in the order of 1-2 years these days, and then will run efficiently for 10-20 years.

    http://www.otherpower.com/otherpower_solar_new.h tm l

    Solar cells are not just "batteries" and have not been for a very long time.

    Surur
  • by AdmiralWeirdbeard (832807) on Tuesday February 15, 2005 @10:13AM (#11676745)
    The real problem with nuclear energy is not the actual energy production and waste management as most people seem to believe. We can make safe reactors, and we can make safe waste-storage systems. The real proplem, from an ecological perspective is the mining of uranium.
    You have the proportions of fissionable Uranium to inert Uranium backwards. Fissionable Uranium is the much less common isotope, and must be concentrated, through gas-diffusion, or other methods to achieve the concentration necessary to be considered "enriched." Mass quantities of ore must be mined in order to accumulate the requisite amount of Uranium, and the tailings are the real environmental problem, as is abandoned mines. Uranium mine tailings are saturated with radon, and heavy metals in such concentrations as to poison entire watersheds for several thousand years. We have this fear mentality about nuclear power stemming from 3-mile island and chernobyl that focuses all of our concern for the safety of nuclear power on activities pertaining to the reactors, at the expense of the totality of the process, beginning with the mining of the ore and ending with the storage of the waste.

    Nuclear reactors can and are made perfectly safe. WAste storage systems can be made perfectly safe. However as long as uranium ore is mined in an unsound manner, the process as a whole will fail to be environmentally sound.
  • by AdmiralWeirdbeard (832807) on Tuesday February 15, 2005 @10:30AM (#11676921)
    I assume you are reffering to the older, high-rpm, turbine farms such as the ones in southern cali. The newer turbines, such as the Horseheaven Hills Wind Farm near Walla Walla, Wa, turn at a sufficiently low rpm that they make almost no noise at all.
    In fact, having spent a good deal of time studying them, i'd have to say that the entire wind farm was eerily silent. But I wasnt sleeping underneath one, of course...
  • by TheSync (5291) on Tuesday February 15, 2005 @10:39AM (#11677003) Journal
    Just FYI...

    Lithuania gets 86% of electricity from nuclear power. France gets 78%. Belgium gets 57%. Sweden gets 52%. Switzerland and Slovakia get 45%. Ukraine gets 44%. Germany gets 29%. Japan gets 28%. The UK gets 23%.

    The US only gets 20% of electricity from nuclear.
  • by AmericanInKiev (453362) on Tuesday February 15, 2005 @11:05AM (#11677220) Homepage
    That Wave energy is more reliable - and reliable means a lot when you're competing with dispatchable power such as coal - which can be operated and amortized on a 95% utilization schedule. If your wind is only 30% available, and down in the summer when you need it most, you will need back-up generators to make it through the year. That's redundancy - as in twice the cost - twice the pollution etc ...

    Backup power can pollute more than baseload power (See single cycle vs. combined cycle) and as a result, unreliable green energy may result in dirtier air - this is no a concern in Denmark, which has the highest percentage of Wind - but the dirtiest power scheme of its peers. (France by contrast is mostly nuclear.)

    AIK
  • by Anonymous Coward on Tuesday February 15, 2005 @11:31AM (#11677492)
    I've been working in the wave energy industry for a decade now and it is becoming more viable. One of the biggest problems, sadly, is regulatory uncertainty over permitting requirements and gamesmanship between various agencies. Thus, many US wave developers need to spend precious resources on compliance with regulation rather than refining the technology. To make matters wosre, many of these prototype projects are extremely benign - a couple of small buoys and a tiny footprint. Of course, larger developments might have more impacts, but you can't get to that stage unless you can get a prototype into the water.

    Most experts believe that right now, wave is where wind power was 15 years ago. Now, wind is fairly pervasive, though admittedly, it does need to begin to wean itself off the production tax credit and other such subsidies. For more information on recent wave developments and barriers to commercialization, visit www.renewablesoffshore.blogspot.com

    Carolyn Elefant www.his.com/israel/loce
  • by Firethorn (177587) * on Tuesday February 15, 2005 @11:31AM (#11677502) Homepage Journal
    Not really, the thing about AC is that it's very easy to adjust it's voltage with a transformer. It's also safer than DC of the same voltage, so unless you really want to run heavy lines, we're better off with AC for the moment.

    Though I do agree with you that doing little things like turning off the TV, lights, playstations, etc will help. Not only in saving electricity directly, but also likely the need for air conditioning.

    Sure, we could power the services/appliances that homes had in the 1950's home with green electricity today(using modern power efficient appliances), but do we really want to go back to that?

    That being said, 24% of our coastline is still a HUGE amount of area, especially when the graphic in the article included Alaska & Hawaii. And that's only to match hydroelectric, 7% of total electricity generation? At 50% efficiency I'll note that increasing efficiency would likely have more effects on the enviroment, which would make the power less 'green'.
  • by Firethorn (177587) * on Tuesday February 15, 2005 @11:51AM (#11677690) Homepage Journal
    Most mines now replace the tailings into the mine once they're done with the mine. So while they do have to do some work to safely store the tailings in the short term, it ends up more or less neutral. Especially in areas where they have multiple shafts, and they put the tailings from the new mine shaft down the old mine shaft. Due to processing, they should be able to stuff a little more into each mine than just the tailings from that mine, given that they are removing material.

    Also, the tailings issue comes up with just about every mine, whether it be lead, iron, copper, or the more rare elements.
  • by The Wannabe King (745989) on Tuesday February 15, 2005 @12:12PM (#11677948)
    Try this. [nrel.gov]


    There are much better ways of storing the energy than using battery banks, especially when you don't have to carry the storage around (think cars). Many places hydro-electric power and solar cells could be run togehther very efficiently. Shut down turbines and save water in the reservoire when there is much sun, restart them at night.

  • by DigitalWallaby (853269) on Tuesday February 15, 2005 @01:58PM (#11679164)
    The problem is that you can't unrefine it. When you take Uranium out of the ground it is usually processed in to the form of yellowcake, which is Uranium Oxide. Yellowcake is insoluble, as is the original ore.

    After it has gone through the reactor, a lot of it is no longer Uranium. There's a lot of radioactive isotopes of elements like Cesium, and Iodine, and some of these elements are, or easily form compounds which are soluble. Also, a lot of these elements are used in life processes, and accumulate up the food chain.

    So just putting the waste back in the ground would be a nightmare. You'd be putting a huge amount of soluble radioactive material into the environment, where it would gradually accumulate in your body. That is pretty dangerous.

    That's not to say there aren't solutions. I remember that the CSIRO a number of years back invented a ceramic called SynRock which basically trapped the radioactive material in a hard non-porous ceramic disc. Stored in a safe place something like that might be an option. And, material science has come a long way since SynRock was invented.

    I even wondered if we could drill a deep well at the edge of a continental plate that was going to be sub-ducted(?) in a few hundred years, and put the waste in there. In the mantle there wouldn't be anything to worry about.

  • Re:Only US? (Score:2, Informative)

    by tim256 (855256) on Wednesday February 16, 2005 @12:45AM (#11686026)

    I'm sorry that your country is unable to build nuclear power plants, as they are very expensive. However, you have some of your facts wrong.

    Aren't we threatening Iran because they are are planning to build on?...

    The US doesn't want Iran to have nuclear materials because they might build bombs with the material.

    Read some history - that isn't why plants haven't been constructed in the USA for years

    The main reason nuclear power plants have not been built is because of mass hysteria from the accident at the poorly designed Three Mile Island plant. PBS did a wonderful one-hour special on this accident. You can see info at their website. Also, the accident at the poorly operated Chernobyl plant didn't help things. Nuclear power plants take much care to operate correctly, but are much more enviromentally friendly than coal, oil, and gas.

    Construction was stopped during the days of Jimmy Carter...

    The last constrution of a nuclear power plant in the US was completed in 1996. See US Dept. of Energy [doe.gov]

    It's funny how wind, waves and solar have to be cheaper than anything to be considered

    Wind, waves, and solar are very expensive. Solar and wind power is more than $80/MWh compared with the average coal cost of $16/MWh (in US); this is not a good deal. A quick search on google for wind and solar costs will show you. Here [earthlink.net] is an example.

    cheap by some unknown force of magic that defies reality...

    I know because of experience in the energy business that nuclear power is usually cheaper than power generated from other fuels, but this article [uic.com.au] has some good facts about that.

    There was a big reason for there being a lot of nuclear power in Europe - it was known as the USSR

    Yes, the USSR has many nuclear reactors (probably poorly maintained), but even without the USSR, there would be plenty more nuclear power plants in Europe than in the US. See this [doe.gov] Dept. of Energy article.

  • by wjwlsn (94460) on Wednesday February 16, 2005 @08:22AM (#11687498) Journal
    I call bullshit on this - otherwise you would never have been clueless enough to made the concrete and steel comment. Exotic, expensive, and very interesting materials are used in areas exposed to radiation. Please ask your science teacher to post here, they may say something useful.

    Believe me, or don't... it doesn't matter. However, you may be interested in the following web pages, which will tell you a little bit more about the materials used in nuclear reactors. By and large, fairly common steels and concretes are used. The "exotic" materials are generally found in fuel (uranium, gadolinium, erbium), control rods (boron carbide, silver, indium, cadmium, hafnium), and detectors (too many to list here).

    Anything else?

  • by Firethorn (177587) * on Wednesday February 16, 2005 @11:09AM (#11688696) Homepage Journal
    Um, I've mentioned the waste any number of times.

    What WILL we do with all that delicious fresh radioactive waste? Pile it up out back?

    Basically, yes. that's the best thing to do with fresh nuclear waste. You leave it on site until the radioactivity levels drop a bit. It's not like arsenic, it'll become less dangerous with time.

    Nuclear Proponent's waste management:
    1. Reduction: Newer plant designs are simpler, safer, and more fuel efficient.
    2. Reuse: There are plant designs that can use current nuclear waste as fuel with minimal #3
    3. Reprocess: Something like only 5% of the potential fuel is used in convential US reactors. After the waste has cooled down a bit, it's possible to reprocess the waste into more fuel. Waiting 40 or so years makes it substantially easier on the equipment.
    4. Disposal: If you follow the first 3 steps, the remaining waste (reduced by a factor of 20-100!)is much more highly radioactive than what is currently being held in pools at power stations. This is actually a good thing, because the average halflife is months-years, not centuries. This means that if you keep 20 years of fuel (1 railcar is the average per year per power station right now, so it'd be 1 railcar's worth per 20 years) onsite, by the time you're looking to bury it in a yucca mountain it's down to something like 1% or less of it's original radioactivity. Also, it degrades much faster, so you only need a shelter that'll last centuries rather than eons.

    Sure the waste needs to be addressed. But we can handle it now. We just need to work through some of the politics, as only for nuclear power is reprocessing, recycling, and reuse BAD.

"If a computer can't directly address all the RAM you can use, it's just a toy." -- anonymous comp.sys.amiga posting, non-sequitir

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