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171 Comments
- inactive, on 03/28/2008, -1/+26I think solar's potential is way underrated...
- Ganja420, on 03/28/2008, -0/+20I saw on the history channel... it would take a solar panel farm 2/3 the size of the entire state of nevada to power the average day in the US.
If regular power gets too expensive, then putting a solar panel on your roof would not only pay off it could even be profitable (since you can sell back your surplus power back into the grid) - JoJoMoMo, on 03/28/2008, -0/+16FTA - “My favorite example in comparing energy storage options is on your desktop,” said John O’Donnell. “If you have a laptop computer and a thermos of coffee on your desk, the battery in your laptop and the thermos store about the same amount of energy. One of them costs about $150 and the other one costs maybe $3 to $5. On the wholesale level, storing electric power is at least 100 times more expensive than storing heat.”
- nroose, on 03/28/2008, -1/+14I generally stop reading when someone says "... up to ..." So what if efficiency is "up to 83%"? What is the efficiency "down to"? What is the actual average efficiency? That is all that matters.
- johnnagy, on 03/28/2008, -0/+10of course solar is a viable alternative energy source. we have tons of open acres of nothing but desert in our country. it's the big oil companies and bush/cheney & co. who are keeping us from progressing.
- sustainablogger, on 03/28/2008, -0/+10I know there's a _huge_ solar thermal plant up now outside of Vegas... not sure offhand how much electricity it supplies... anyone know?
- mcbarron, on 03/28/2008, -0/+8ACCIONA ’s 400-acre, 64 MW Nevada Solar One plant utilizes proprietary tracking technology to concentrate the sun’s rays and track the sun’s location during peak demand hours. The plant employs 760 parabolic concentrators with more than 180,000 mirrors that concentrate the sun’s rays onto 18,240 solar receiver tubes located on their focal line.
A mineral oil heat transfer fluid, which heats up to 735°F, flows through the receiver tubes and is used to produce steam and drive a conventional turbine connected to a generator that produces electricity. The plant produces enough energy to power more than 14,000 households annually. - elxkid, on 03/28/2008, -0/+7All energy on earth, except nuclear and geothermal, comesfrom the sun. Oil after all, is nothing more than solar energy converted by plants that then degrades into a black gooey liquid. Same for all the other fossil fuels... so why not just get it directly from the source?
- bulkhater, on 03/28/2008, -0/+5At the very least using solar energy to heat your water would help a lot. That kind of a system is cheaper than electricity generating solar panels.
- taintedzodiac, on 03/28/2008, -0/+4Insulation. We've been doing it in construction worker coffee holders for decades.
- inactive, on 03/28/2008, -2/+6"then putting a solar panel on your roof would not only pay off it could even be profitable"
That's my entire objection to solar power "plants". Wedon't need them. With new breakthroughs in solar power, each home will be able to produce its own energy. This can already be done, except not enough people are doing it so it remains a very expensive project for a single home.
I want to build a solar powered home, it's an extra 60k. So I'm waiting for the price of the technology to go down a bit. What we need are residential developpers to start building entire housing projects that depend on solar power. Then the technology will be mass produced and become cheap. And the people will rejoice. - roystgnr, on 03/28/2008, -0/+3A $150 battery provides around 85 W-hrs = 306 kJ of electricity. A 1 liter thermos holds a kilogram of coffee, and cooling that from 350K to room temperature of 300C releases 1 kg * 4.2 kJ/kg-K * 50K = 210 kJ of heat. But you can't run your laptop on heat, and the most efficiency you can get out of a heat engine with that coffee in that room is (1 - 300/350) = a little better than 14%. Even though your electric coffee pot needed 210kJ to heat up your coffee, you can only get 30kJ of electricity out of it with the most ideal heat engine. You'd better brew ten times more coffee if you want it to replace that battery.
O'Donnell's got a good point in principle, but the numbers on his example seem to be an order of magnitude off. Storing energy as heat only starts to look like a good idea when you use a working fluid much hotter than coffee and a container much larger than a thermos. - regeya, on 03/28/2008, -0/+3Nice to see that solar is finally being taken seriously, as in, forget the old-school photovotalic noise, THIS is the way you're going to produce large amounts of solar-provided power in the future.
Some people seem to have environmental concerns, and so do I. However, there's no way we're going to have a no-impact effect on the environment, as we live within said environment. Consider instead the consequences of continuing to charge ahead, growing the population without either curbing that or improving infrastructure. Consider the cost of continuing to rely on fossil fuels for every single aspect of modern life. And consider the impact of all the "environmentally friendly" approaches we've come with so far, like hydro, and while you're at it ask those Hoover Dam engineers how long they think it'll be before the dam breaks and how many hours it'll be after that before Vegas is a smoldering pit. Also consider that millions rely on hydro in states like Georgia for both power and water; one official said something along the lines of "every time a light is turned on, a faucet is on."
Finally, consider the environmental catastrophe that would occur if we were to go extinct before we cleaned up our mess. There's a good chance it may be too late already, but I don't think that should stop us from trying.
My prediction is that we won't see real improvement, at least not in the United States, until the Baby Boomers are gone. Hey, they may think they've got another 20-30 years, but my prediction is that most of 'em will be gone in 10. They've just been too greedy, and too selfish; I don't think medical science will keep 'em around that long, especially if the healthcare system crashes along with everything else. There's a quarter of the U.S. population gone in less than a quarter century, by my estimation.
Now, if our economy really is tanking, or if there's at least an impression that America isn't as rosy as it used to be, I really don't think we'll see the sustained immigration levels, so I don't fear the "1 billion people by 2100" estimate. I don't think it's realistic. We'll run out of resources before then. Too much of the country relies on crutches like fossil-based fertilizer and rapidly-depleting underground aquifers, amongst other things. Hell, our most productive ag area is in desert country. I wish I was kidding. We're going to have to change a lot if we want to avoid the second Dust Bowl.
So here's my message to the rest of the world as well: Plan for the end of America as the world's breadbasket. And to my countrymen: Plan for the end of prosperity here, because right now, it looks like those days may be here. Start from that point. Figure out if you can sustain your numbers and your consumption levels. Since you can't, figure out where to go from there, without resorting to tactics such as "invade countries with shrinking populations." This means improving your own agriculture, getting it to sustainable levels without resorting to crutches such as artificial fertilizer. It also means reducing the need for power and personal powered transport. And controlling our numbers to sustainable levels, where we can live remotely enough that common illnesses won't threaten to kill millions at a time, we no longer rely on fantastic bumper crops every year on end, and we're less of a threat to other species.
As I said, it may be too late, but let's not assume that and instead assume that, once we have a few "I gotta be me on my own terms" curmudgeons out of the way, we'll start trying to improve things. As a Bible Belt resident I understand why the Catholic church (and the fundies, of course) is so vehemently against birth control, but I was also taught that we were to be stewards of the Earth, and also that Iraq and much of the Middle East and North Africa were paradises, as opposed to the desert regions they are today. If we cannot learn from history, we are doomed to repeat it. - jambox, on 03/28/2008, -0/+3RTFA! The whle point of this is that it CAN generate base load because it uses thermal storage! Putz.
- jambox, on 03/28/2008, -0/+3It wouldn't matter that much if solar panels could be produced cheaply enough, just put one on each roof. Your argument is like saying that guttering is impossible because to catch all the rain, you'd need a gazillion square miles of gutter. Well, yeah you would, but we manage it anyway.
- jurban, on 03/28/2008, -0/+3The next generation of CSP (concentrated solar power) will capture an even higher level of heat. Heliostats will be used to concentrate entire acres of sunlight onto towers. That spot-of-heat will be used to melt salt (sodium is a metal and has a high heat coefficient that can be drawn off all night long to boil water for turbines) or it will be used to turn zinc or aluminum oxide into their un-oxidized form to make hydrogen when dissolved in water. Check out what the Wiessman institute is doing in Israel. CSP is where the energy future lies!!
- jambox, on 03/28/2008, -0/+2Because fossil fuels are billions of years of solar energy all pent up and waiting to be burned today?
- elementop, on 03/28/2008, -0/+2The sooner we get started, the sooner we'll be off fossil fuels, then.
- jambox, on 03/28/2008, -0/+2great - someone who actually seems to know what they're talking about posts a comment - immediately gets dugg down.
- Terr01, on 03/28/2008, -0/+2Hydrogen isn't a power-generation scheme, it's a power-transport scheme.
- jambox, on 03/28/2008, -0/+2Well it's still better than burning coal, which is "up to" 40%, IIRC.
- Gazoo2001, on 03/28/2008, -0/+2roystgnr,
I see what you're saying. I mostly agree with you, except for one point. You state that you need 210 kJ to heat the coffee up, while you'll only get 30 kJ out in electricity from the hot coffee. That may be correct, but in the solar thermal technology, you're not using electricity to heat the working fluid (coffee in this case), you're using the sun's radiant energy. I think that this low-quality energy (light) to low-quality energy storage (heat) is relatively efficient. Yes, you will ultimately have to pay a price in efficiency to get the desired high-quality output of energy in the form of electricity, but you have to pay that at least once anyway. I would definitely agree that you don't want to pay that penalty twice!
Please correct me if I'm misunderstanding something here. - danbillings, on 03/28/2008, -0/+2I'm not ignoring anything. Dealing with radioactive waste is certainly an issue, but it's very solvable, not a dealbreaker as you are implying
- UliKunkel, on 03/28/2008, -1/+3I think it is 1.21 Jigawatts
- inactive, on 03/28/2008, -0/+2***** you.
- 3tcp, on 03/28/2008, -4/+6It can replace it in the growth but it won't replace the present generation from these dirty fossil fuels unless the regulation of the power industry is overhauled. While solar thermal energy would need power plants, solar panels do not. The decentralization of power generation through solar panels and wind turbines that don't have up front costs of hundreds of millions of dollars would hurt the electric companies. They would become little more than managers of the electric grid who make up the difference between supply from off-site, local, renewable sources like turbines or panels with their plants or by buying power form elsewhere.
The answer is not to provide the power companies (who have little interest in switching us over) with massive subsidies to pay for this stuff but to change regulations to provide for a natural market environment where everyone has a reason to use renewable. End stepped pricing, the economy is not very industrial these days and non-residential power consumption is more price-sensitive than it used to be. Making every homeowner invest the time, money and effort to place a few panels on their roofs won't work, there's too many complications. We need shopping malls, warehouses and factories. They're less likely to be obstructed, it will be easier to orient them for maximum effectiveness on a flat roof, the scale of the project will be greater. Firms are more likely to be concerned with the financial benefits of the panels and will be more likely to make sure everything is working properly. - akschnare, on 03/28/2008, -0/+2Why don't you look into passive solar technology instead of active? You'd save a lot of money.
- jambox, on 03/28/2008, -0/+2>> vast magnetic energy coming from the sun and moon.
The moon? WTF? - inactive, on 03/28/2008, -2/+4Why they don't make solar panels on roofs mandatory like insulation and other building codes is beyond me.
Why doesn't the government make a Solar project like they did the MANHATTAN PROJECT - StormTroopr, on 03/28/2008, -0/+2What? 9000?
- bulkhater, on 03/28/2008, -0/+2As long as you ignore that pesky "Dangerous for 10,000 years" waste product problem.
- rodrigo74, on 03/28/2008, -0/+2Yeah, if only we could find some way to transport energy from one place to another..damn..somebody gotta invent the copper wires soon.
- Ogedei, on 03/28/2008, -0/+2So yes it sounds great.
BUT the article interviewed people from the company.
That would be like us buying everything M$ says about Vista being awesome. At then end of the day we can't believe in everything the company says about the product that is it's life blood.
This has all been brought up, but it is an important consideration.
What kind of foot print are we talking? How much water is required? Does it cause warming of surrounding water bodies like nuke plants? What happens if the weather is CRAPPY for weeks and weeks? In order to store your energy you need to produce extra when the sun is out, which is during peak times. Larger foot print. It might work, but I see a lot of issues I would need resolved before I would jump on board whole sale. - LaughingDjinn, on 03/28/2008, -0/+2If I'm not mistaken I don't think were currently using 2/3's of Nevada..... lots of open space, though I think "Gambling and clean renewable energy" will fit on a state license plate.
- Gazoo2001, on 03/28/2008, -0/+2Hmm, interesting. I didn't realize that's what he was maybe talking about. I don't know about the relative power densities of the two technologies. I know PV cells are about 13% efficient; and full-sun insolation is about 1000 W/sq. m, so PV should get you about 130 watts/square meter in full sun. No idea what solar thermal captures though.
- Gazoo2001, on 03/28/2008, -0/+2OK, let's fool around with some numbers.
From 2000 census, number of single-family detached homes in the U.S. is about 70 million. See p.2, Table 1 of this link: http://www.census.gov/prod/2003pubs/c2kbr-32.pdf
Average size of U.S. home: 2330 square feet. http://www.infoplease.com/askeds/us-home-size.html
That works out to 1.63E+11 total sq. ft of roof area, or equivalently, about 5850 square miles of roof space.
Now, a couple of other factors come into play. In the U.S., you want to face your solar modules south for maximum exposure. North exposure is useless, east and west can be used but generally won't be as good as south facing exposure. So let's say half of our home roofs have north-south exposure, so we'll count the south-facing portion as fully usable, and north-facing portion as unusable. The other half of our home roofs have east and west exposures, let's call both east and west facings usable but only at half the effectiveness of southern exposure. This means we should halve our total roof area:
5850 sq. miles x [(0.25 x 1) + (0.25 x 0) + (0.25 x 0.5) + (0.25 x 0.5)] = 5850 sq. miles x 0.5 =
2925 square miles.
The other factor is the slope of the roof. This actually gives you more effective area, since ideally you'd like to tilt the modules to the south at a tilt angle approximately equal to the latitude of the location. A typical roof pitch is 6:12, meaning for every 12" of horizontal run moving out from the roof ridge, the level of the roof drops 6". (*Pauses to scratch head and doodle*) So Pythagoras says I should multiply the roof area by the (square root of 5)/2 to get the new effective area.
2925 sq. miles x (sqrt(5))/2 = 2925 sq. miles x 1.12 = 3270 square miles effective roof area.
Area of Nevada: 110,000 square miles. Two-thirds of that is 73,000 square miles. So, unfortunately residential (single-family detached) roofs are only about 5% of the area we'd need to power the U.S., going by what ganja420 said; but, there may be enough roof space to offset our residential usage, at least in large part. A lot of our electricity isn't just used in the home, of course.
Geez, guess I was long-winded there. I had fun though! Hope somebody finds this interesting! - jambox, on 03/28/2008, -0/+2Decentralisation is a very good point. Why hand money and power to large organisations when we could be self-sufficient? Would be in your interest if there were some sort of crisis or disaster, since no vulnerable long distance power lines to get damaged. I think you can go buy little generators that sit in your gas flue and make electricity from the hot exhaust from your boiler.
- Kenzan, on 03/28/2008, -1/+3This is the way to go, on a large scale, and we need to do it NOW.
~Or are people forgetting that large ice sheets the size of cities are breaking off the poles. - oth1c, on 03/28/2008, -0/+2The reason why solar power isn't the magical answer (at this time) is the price. Solar costs about $20 per kwh, with energies such as nuclear and coal costing in the area of $2.00. What you're proposing is that we add another $60k+ to the building price of a house, with the housing market already in bad condition. Thats not going to happen.
- Terr01, on 03/28/2008, -0/+2I think it has more to do with conversion costs.
More efficient to do:
Radiant light -> Heat (hot salt storage) -> Steam -> Electrical
Than this:
Radiant light -> Heat -> Steam -> Electrica l-> Chemical (battery storage) -> Electrical - taintedzodiac, on 03/28/2008, -0/+2Let's not forget the fact that you have to have people in charge who are willing to make absolutely, positively, 100% sure that the regulations are followed. See Chernobyl. Those plants are going to be operating for decades if not centuries, so make sure that the regime in charge doesn't change with the times.
- Terr01, on 03/28/2008, -0/+2I hear thorium's a pretty good substitute. A lot of US nuclear technology was based around the idea that it'd do double-duty making military material, so certain kinds of reactors were never designed for efficiency as much as helping us ward off The Evil Communists.
- jambox, on 03/28/2008, -0/+2Loony!
- jambox, on 03/28/2008, -0/+2Yes they do. Mineral oil. Other designs I've seen use molten salt. It's actually quite easy to keep a lot of heat in if you put it underground and use low-density insulation. Think thermos-flask.
- Gazoo2001, on 03/28/2008, -0/+2Yeah. I think the big push is to basically just reduce the amount of semiconductor material used. I think that all of the new thin film stuff people are working on isn't even silicon, it's "CIGS" (copper indium gallium selenide). I don't know this, but I would imagine that CIGS is just as expensive as silicon, or more probably more so, on a per-pound basis (or for the chemists out there, per-mole basis), but I think you can use a lot less of it.
- jambox, on 03/28/2008, -0/+1Well it is possible to do it pretty safely, by digging very, very deep holes and filling them with lots of concrete. But that's very expensive, so it's oft3en the case that's it's just shipped from one place to the next and kept hanging around here and there while the politicians and businessmen decide what to do with it.
- rhbama13, on 03/28/2008, -0/+1you know its funny how generally you don't transmit electricity 1000's of miles unless you have to.
- jambox, on 03/28/2008, -0/+1You can't keep banging the Chernobyl drum for ever. It's like saying all cars must be inherently dangerous because old Cadillacs weren't designed very well in the fifties. Designs do improve and they have improved.
- jambox, on 03/28/2008, -0/+1Aren't we starting to run out of Uranium though?
- SilverBlade2k, on 03/28/2008, -0/+1Better run this by Exxon Mobil... *rolls eyes*
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