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Post by nautonnier on Oct 27, 2008 17:46:18 GMT
I guess if we're making wishes, the real thing to make a change is to simply change our consumption habits. This whole deal of having to have the latest & the best is suicidal on a planet barely able to support the race in sheer numbers alone. i work with computers - most people use their computers as glorified typewriters with minimal graphics capabilities. Yet they race to replace them every couple or three years? Why? Because of the Wintel game where software bulges enough to make your hardware slow so you go buy new hardware, which then has a new version of software come out... and so on. Car makers get away with making cars with built in obsolescence because we're convinced the latest design is somehow better. just imagine if you didn't have to buy the exact model of the exact part for your car? If one alternator, one battery etc. fit all cars of the same approximate size? If we could change that one facet of our world, the energy problem, the pollution problem & even the GW issue would be put off for generations - & we could all live better lives. Unless you happen to make those special to type parts. Much of the 'profit' from cars comes from the post sale support. Plus of course some things _have_ actually improved. A diesel car that does better than 600 miles per tank and accelerates to 60 in 8 seconds was infeasible only a few years ago.
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Post by nautonnier on Oct 27, 2008 17:50:06 GMT
The energy is just not there. Spending billions more won't make it so. Sorry, except for satellites, small niches here and there and your friend "out west*", yes solar works wonders, but the idea that either solar and/or wind will ever put a significant dent in our fossil fuel use is just fantasy. OK, here's the math. <<<<<<<<snip>>>>>>>> Yep, those pesky facts always seem to get in the way of a good fantasy I couldn't have said it better myself. As I said before - just hope it doesn't get cloudy or everyone freezes.
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Post by ron on Oct 27, 2008 17:58:00 GMT
It is clear that solar is not the complete answer to all of our ills. Unfortunately snarky (though good natured ) snippet replies don't do much to further the discussion, otherwise we'd have solved the problems by now.
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Post by Acolyte on Oct 27, 2008 19:18:51 GMT
Unless you happen to make those special to type parts. Much of the 'profit' from cars comes from the post sale support. Plus of course some things _have_ actually improved. A diesel car that does better than 600 miles per tank and accelerates to 60 in 8 seconds was infeasible only a few years ago. Oh we know about the parts industry - the RACV did a few 'build a car from parts' examples years back - cost of it ran to 3.5x buying a new car. Actual improvements in the technology should be the only reason for new models - how many come out where the changes are purely cosmetic or with an engine change from 1800cc ro 2000cc? But that diesel improvement is one of the few & in Oz it caused the government to artificially hike the price of diesel to match that of petrol - incidentally driving up the cot of everything that needs transport to market. Diesel now sells for more than petrol here.
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Post by Belushi TD on Oct 27, 2008 20:28:57 GMT
I beleive its been touched on, but just to make it clear...
The reason the US has a boatload of nuclear waste sitting around is because after the three mile island incident (more on that later) laws were passed forbiding the reprocessing of fuel. The US has something like 1,000 tons of spent fuel rods waiting to be reprocessed. Instead, we're trying to bury them in Nevada.
As far as the costs for permitting - 95% to 99%+ of the legal fees and time relating to permitting nuclear power plants as well as other large power plants and refineries are due to the environmental lobby.
And as far as three mile island goes... The people who were WORKING at TMI when it had its accident received LESS radiation than you get from flying from NY to LA or from living in Denver as opposed to a sea level city for one year.
In other words , the scoreboard -
Ted Kenney's Car - 1 Three Mile Island - 0
Belushi TD
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qam1
New Member
Posts: 21
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Post by qam1 on Oct 28, 2008 4:18:28 GMT
OK, here's the math. According to eosweb.larc.nasa.gov/sse/ the average insolation at the top of the atmosphere for Mesa Arizona averaged year-round is approximately 8.3 kiloWatthours/square meter/day (kWh/m 2/day). I am going to use 4 kWh/m2/day as my basis, allowing for 52% atmospheric loss)1 square mile converts to 2,590,000 square meters. 10 square miles = 25,900,000 square meters. 25,900,000 square meters * 4 kWh/m 2/day = 100 million kWh/day = 100 megawatts 100 megawatts / 24hours per day = about 4 megawatts 10,000 square miles / 10 square miles = 1,000 four megawatt areas. (That's right: My 100 miles-per-side square (10,000 square miles) of desert receives the same amount of energy as 1,000 4 megawatt nuclear power plants. (The largest nuke in the country is about 1.3 megawatts, but let's not let a pesky fact get in the way.)) If efficiency of the conversion process is 50%, you have the equivalent of 1,000 2 megawatt nukes. So, let's compare that with Palo Verde (also in Arizona) Nuclear plant: www.eia.doe.gov/cneaf/nuclear/page/at_a_glance/reactors/palo_verde.htmlPalo Verde is just a hair under 4 megawatts capacity total for all three nukes on site. (Palo Verde generation, 2007: 26,782 million kWh, or just over 3 megawatts average for the year, 79 percent of it's 4 megawatt capacity.) It sits on just a hair over 4,000 acres. 4,000 acres = Just over 6 square miles. Hey!!! That's 1.2 megawatts worth of solar collection (at 50% efficiency)! Maybe they should put in solar collection panels and just shut down the 3 nukes!!! (or Gee, I dunno, add them to the site, or build a solar collector next door) Maybe you don't get the math the way I did it. Let's go back and convert them to the same basis as the webpage you and I both quoted: 1 square mile converts to 2,590,000 square meters. 10 square miles = 25,900,000 square meters. 25,900,000 square meters * 4 kWh/m 2/day = 100 million kWh/day 100 million kWh/day * 365 days = 36,500 Million kWh per year 36,500 million kWh Divided by 8760 hours = 4.16 megawatts for each 10 square mile area. The sun is HOT. Then again, maybe I've made a mistake in my math. There are several things wrong with your math The biggest is flaw is the largest nuke reactors are not 1.3 megawatts but 1,300 megawatts, So all your calculations are off by factor of 1000x Thus Palo Verde is not 4 megawatts but Four Thousand Megawatts!!! 1 Megawatt is one typical windmill, 1000 Megawatts or One Gigawatt is your typical nuclear reactor So your dream array would take up an immense amount of land and only be about as powerful as 1 nuclear plant. There's more Solar cells are also not 50% efficient, the best are 25% and that's only in the cold of outer space (ironically, solar cells lose efficiency as temperature rises). On Earth solar is more like 10-20% efficient. But even if we could get those 25%ers to work on the ground you are still off by a factor of 2000x Also your land calcs are not applicable, yes Palo Verde is on 4,000 acres but that just how much land they have, it doesn't mean the whole 4,000 acres are being used (and needed) for nuclear power, it just means how much land they brought. For instance Brown's Ferry in Alabama www.eia.doe.gov/cneaf/nuclear/page/at_a_glance/reactors/brownsferry.html also has 3 reactors and almost puts out as much power as Palo Verde, yet it only takes up 850 acres. Mostly likely the land is just to keep distance between them and their neighbors and for room to put more reactors if they are ever allowed. So sorry but no matter how you slice it, nuclear is by far the best deal and solar is pretty much a dud. Solar is not some new technology, solar cells were 1st invented way back in 1884 en.wikipedia.org/wiki/Charles_Fritts and even as far back as 1903 they were talking about solar towers en.wikipedia.org/wiki/Solar_updraft_tower and Wind so old it's mentioned in the Bible. If solar or wind were any kind of realistic alternatives, you wouldn't need the government to fund these schemes, the private sector would have already done it and done it a whole lot better by now. They see the same numbers you & I do, that they haven't speaks volumes. Take away the subsidies and solar and wind immediately go bankrupt.
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Post by ron on Oct 28, 2008 5:40:16 GMT
You're correct, I neglected to multiply kiloWatt hours by 1,000 to give megaWatts, so indeed my numbers should have been 4,000 megaWatts, not 4 megaWatts. (Notice please, that I made the same exact mistake when I calculated Palo Verde to be 3 to 4 megawatts instead of 3,000 to 4,000 megaWatts.
So let me revise both of those:
1 square mile converts to 2,590,000 square meters. 10 square miles = 25,900,000 square meters. 25,900,000 square meters * 4 kWh/m2/day = 100 million kWh/day = 100,000 megawatts 100,000 megawatts / 24hours per day = about 4,000 megawatts
and
(Palo Verde generation, 2007: 26,782 million kWh, or just over 3,000 megawatts average for the year, 79 percent of it's 4,000 megawatt capacity.)
In a nutshell, using the SAME MATH:
For Palo verde, it's generation was 26,782 million kWh in 2007. 26,782 / 8760 = 3.057 * 1,000 = 3,089 megawatts;
For the 10 square mile solar array it's 100 million kWh per day *365 days = 36,500 million kWh, so 36,500 / 8760 = 4.166 * 1,000 = 4,166 megawatts. Then multiply by the efficiency percentage to get your rated output.
Thanks for the catch.
As for efficiency, who is talking solar cells? IIRC, affordable PV cells are about 9 to 14% efficient. I'm talking about heat collection and concentration. Currently Stirling engines are about 30% efficient; other technologies are on the horizon to nearly double that. Curent steam conversion processes are about 40% efficient (such as the ones inside nukes), with some suggestion that could be increased to 60% as well. There is a no-moving-parts hydrogen based heat engine in development somewhere that is also purported to be in the 60% efficiency range.
Face it man, there's a lot of energy in the sunshine.
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Post by nautonnier on Oct 28, 2008 11:20:13 GMT
Face it man, there's a lot of energy in the sunshine. You are correct - but - and this gets old - that's why we have clouds. The sea surface heats up water evaporates into the air and the sea cools, plants transpire hundreds of litres an hour of water each to cool down and to bring nutrients to the leaves. The hot humid air that results rises adiabatic cooling forces water to condense out and presto there you have clouds and big sunless shadows. Even here in Florida - the sunshine state - I have solar heating panels on my south facing roof, but there are sometimes weeks when they provide little or no heating. There is no guarantee of cloud-free days continuing even in AZ and NV. You cannot expect factories to stop, people to break out candles and all those people with trains and electric cars to stop travel just because its cloudy for a week or so over your solar array. Added to which as I pointed out half in jest earlier - if Svensmark is right we can expect MORE cloudiness in this minimum - which if its a Maunder type could last for a LONG time.
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Post by jimcripwell on Oct 28, 2008 12:48:12 GMT
ron writes "Face it man, there's a lot of energy in the sunshine." Correct. There is a lot of energy in wind and waves as well. The trouble is we want energy to work when it is convenient to us, not when Mother Nature decides to let us have it. Any form of unreliable, intermittent energy, needs to be stored before it is of any real practical use. Storage is the problem. Solve that, and we will be in business.
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Post by ron on Oct 28, 2008 17:11:18 GMT
Well, I'm not sure it's been solved on such a huge scale, but my vision breaks things up into many smaller projects so that we can figure out what works best.
There are some storage technologies and strategies that would allow storage of heat for relatively long periods of time... Liquid sodium comes to mind as it can absorb and radiate heat pretty easily and tons of it. Some solar approaches actually transmit the heat to the storage facility first, then draw the heat from that no matter what time of day or weather it is.
I must admit I'm not intimately familiar with the weather over Arizona and New Mexico; certainly people (and committees) smarter than I can figure out how to distribute some of these arrays to weather diverse areas to reduce the risk of all the arrays being under weather at once. Plus we won't be dismantling all of our traditional forms of power generation nor our nukes. Further I've said before that perhaps nukes are a part of the mix. Perhaps they can be generating (some of) the baseline requirements 24/7 and the solar be taking the daytime peak requirements.
We MUST NOT put all of our eggs in one basket (again).
IM(NS)HO
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wylie
Level 3 Rank
Posts: 129
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Post by wylie on Oct 28, 2008 17:43:38 GMT
Heat Storage,
We don't REALLY have to solve the heat storage problem for solar energy with some fancy new technology. Our world currently stores heat VERY EFFECTIVELY in water. Anyone with a greenhouse or anyone who has lived through a Houston (or Singapore) night knows that water /humidity in the air (especially when it is prevented from convecting/blowing away), can store lots of heat for a long time. Just think of the effectiveness of heat pumps using the heat stored in water underground, or the Swedish town-sized solar energy plants.
Solar Thermal technology uses various low boiling point liquids (e.g. hydrocarbons) to drive turbines or Rankin Cycles to generate power. The beauty of this approach is that you can use water held in tubes with clear tops and black bottoms to both store the heat and transfer it to the liquids being used to drive the engines. Solar thermal can be a lot more efficient than solar photovoltaic AND the storage of the energy is inherent. Of course solar concentrators are necessary and sunny areas (e.g. Los Angeles) are highly favoured, and power does drop off during the night as the water cools BUT it can generate power for the whole 24 hours (albeit at lower levels in the middle of the night and early morning --> when actual power demand is at its lowest anyway). In fact, the load matching to air conditioning is about perfect. It is MUCH better than a nuclear power plant. Unfortunately, the problem is that the energy density is much lower than a nuclear plant (and lower even than coal). You can't have everything from one source of energy!!
We need ALL the energy sources that we can get our hands on. Peak Oil will put a massive premium on ANY other energy source. Bring them all on!!!
Ian
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Post by Acolyte on Oct 28, 2008 19:57:51 GMT
I agree about more energy sources. There's no reason apart from greed & the politics of scarcity for us to have only one or two choices as to source. The large monlithic sources can be used where massive amounts of power are needed for industry, while smaller needs can be met or at least contributed to by localised sources or non-diurnal ones. Designing energy efficient homes & shops for example would allow them to run on far less current than currently. ( sorry) Storage of light-, heat- or wind-dependent power would help even out the supply & use of solar heating & power on rooftops could reduce the footprint of families. We could also improve things by designing water use in the home & using it efficiently - waste water from manufacuring processes could be used for its heat content - there seems to be many ways we could be more effective in our use of energy & having many ways to source it would relieve the burden on any one industry. Tidal, hydro, wave & geothermal sources aren't subject to so much fluctuation & have the possibility of providing large amounts of power from multiple points. Research needs to be stimulated in the areas that are non-traditional - mostly its been small scale because anything large attracts the interest of the vested-interest groups who have billions to spend to ensure hegemony in the power field. We've been conditioned to think power sources are large or monlithic constructions to provide for millions from a single source but there's not really a need to continue to think in a way that lines the pockets of the filthy rich.
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wylie
Level 3 Rank
Posts: 129
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Post by wylie on Oct 29, 2008 20:12:29 GMT
Peak Oil Link: For all those interested in some of the facts associated with Peak Oil and some discussion of the REAL implications (we don't talk about them enough, presumably because they are so "negative"), check out the following very lucid discussion: www.postpeakliving.com/peak-oil-primer The bottom line is that the amount of energy that we get from a given resource always follows a "bell" curve (or something close), i.e. up and then down. All wells, all fields, all producing countries and then ultimately the whole world must follow this kind of function. Unfortunately, our economic system assumes cheap and every increasing amounts of energy in total (and per person!). Some of major assumptions that we have made over the years, e.g. suburban living, personal cars, air travel, importation of food from half-way across the world, increasing "standard of living", are major contributors to the drop in the availability of inexpensive oil and will probably become very rare once the peak has take hold. Many of the assumptions that people have made about "new energy sources" taking over from oil and natural gas in the short term are probably not realistic (too much transition time and energy required and many of those sources are intermittent and do not provide liquid fuels). The sheer number of vehicles on the road (more than a billion) and the average turn-over time to buy a new one (15-17 years) means that a transition to another form of energy will be slow (decades). We do not have decades before oil becomes much less available and the price sky-rockets. So please start preparing for a world with a lot less energy. e.g. take up gardening and canning. They are very relaxing activities and you can be much more secure about the healthiness of your food (not to mention saving a lot of money). Get used to walking and biking. They are great activities and even though they take more time, they are very healthful. Given the expected collapse in many industries (may already be happening) as the price of energy increases dramatically, the rate of unemployment will rise and the amount of time available to you may increase as well (not entirely a bad thing). If we plan for a future with less energy available and do it in a proactive way (see some suggestions above), we will be better off no matter what happens to the future but especially better off if the energy crisis really does come soon. I.e. prepare for the worst but hope for better. Good luck to us all, we will need it. Ian
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Post by nautonnier on Oct 29, 2008 20:40:49 GMT
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Post by ron on Oct 29, 2008 21:00:53 GMT
It won't be draconian if we start the conversion process (whatever it is) NOW. If the transition is 15 years or even 25 years, if we begin to reduce our demand and increase efficiencies commensurate with either the increase in global growth and/or reduction in production capacities the resultant shortages will be managable without resorting to an agrarian economy.
Re: liquid fuel; we can turn our country into a hydrogen economy by using {solar|wind|tidal|whatever} energy to hydrolize water; turning heat and or electricity into a transportable (if not liquid) fuel. Or part of our economy.
Again solar may be best for this as the efficiency of hydrolizing water may be best in a high temperature process rather than a straight electrical process.
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